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Schwaderer AL, Rajadhyaksha E, Canas J, Saxena V, Hains DS. Intercalated cell function, kidney innate immunity, and urinary tract infections. Pflugers Arch 2024; 476:565-578. [PMID: 38227050 DOI: 10.1007/s00424-024-02905-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/17/2024]
Abstract
Intercalated cells (ICs) in the kidney collecting duct have a versatile role in acid-base and electrolyte regulation along with the host immune defense. Located in the terminal kidney tubule segment, ICs are among the first kidney cells to encounter bacteria when bacteria ascend from the bladder into the kidney. ICs have developed several mechanisms to combat bacterial infections of the kidneys. For example, ICs produce antimicrobial peptides (AMPs), which have direct bactericidal activity, and in many cases are upregulated in response to infections. Some AMP genes with IC-specific kidney expression are multiallelic, and having more copies of the gene confers increased resistance to bacterial infections of the kidney and urinary tract. Similarly, studies in human children demonstrate that those with history of UTIs are more likely to have single-nucleotide polymorphisms in IC-expressed AMP genes that impair the AMP's bactericidal activity. In murine models, depleted or impaired ICs result in decreased clearance of bacterial load following transurethral challenge with uropathogenic E. coli. A 2021 study demonstrated that ICs even act as phagocytes and acidify bacteria within phagolysosomes. Several immune signaling pathways have been identified in ICs which may represent future therapeutic targets in managing kidney infections or inflammation. This review's objective is to highlight IC structure and function with an emphasis on current knowledge of IC's diverse innate immune capabilities.
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Affiliation(s)
- Andrew L Schwaderer
- Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Drive, STE 230, Indianapolis, IN, 46202, USA.
| | - Evan Rajadhyaksha
- Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Drive, STE 230, Indianapolis, IN, 46202, USA
| | - Jorge Canas
- Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Drive, STE 230, Indianapolis, IN, 46202, USA
| | - Vijay Saxena
- Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Drive, STE 230, Indianapolis, IN, 46202, USA
| | - David S Hains
- Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Drive, STE 230, Indianapolis, IN, 46202, USA
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Kang MJ, Ioannou S, Lougheide Q, Dittmar M, Hsu Y, Pastor-Soler NM. The study of intercalated cells using ex vivo techniques: primary cell culture, cell lines, kidney slices, and organoids. Am J Physiol Cell Physiol 2024; 326:C229-C251. [PMID: 37899748 DOI: 10.1152/ajpcell.00479.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 10/31/2023]
Abstract
This review summarizes methods to study kidney intercalated cell (IC) function ex vivo. While important for acid-base homeostasis, IC dysfunction is often not recognized clinically until it becomes severe. The advantage of using ex vivo techniques is that they allow for the differential evaluation of IC function in controlled environments. Although in vitro kidney tubular perfusion is a classical ex vivo technique to study IC, here we concentrate on primary cell cultures, immortalized cell lines, and ex vivo kidney slices. Ex vivo techniques are useful in evaluating IC signaling pathways that allow rapid responses to extracellular changes in pH, CO2, and bicarbonate (HCO3-). However, these methods for IC work can also be challenging, as cell lines that recapitulate IC do not proliferate easily in culture. Moreover, a "pure" IC population in culture does not necessarily replicate its collecting duct (CD) environment, where ICs are surrounded by the more abundant principal cells (PCs). It is reassuring that many findings obtained in ex vivo IC systems signaling have been largely confirmed in vivo. Some of these newly identified signaling pathways reveal that ICs are important for regulating NaCl reabsorption, thus suggesting new frontiers to target antihypertensive treatments. Moreover, recent single-cell characterization studies of kidney epithelial cells revealed a dual developmental origin of IC, as well as the presence of novel CD cell types with certain IC characteristics. These exciting findings present new opportunities for the study of IC ex vivo and will likely rediscover the importance of available tools in this field.NEW & NOTEWORTHY The study of kidney intercalated cells has been limited by current cell culture and kidney tissue isolation techniques. This review is to be used as a reference to select ex vivo techniques to study intercalated cells. We focused on the use of cell lines and kidney slices as potential useful models to study membrane transport proteins. We also review how novel collecting duct organoids may help better elucidate the role of these intriguing cells.
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Affiliation(s)
- Min Ju Kang
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
| | - Silvia Ioannou
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
| | - Quinn Lougheide
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
| | - Michael Dittmar
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
| | - Young Hsu
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
| | - Nuria M Pastor-Soler
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of USC, Los Angeles, California, United States
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3
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Hwang ES, Song SB. Impaired Autophagic Flux in Glucose-Deprived Cells: An Outcome of Lysosomal Acidification Failure Exacerbated by Mitophagy Dysfunction. Mol Cells 2023; 46:655-663. [PMID: 37867391 PMCID: PMC10654461 DOI: 10.14348/molcells.2023.0121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 10/24/2023] Open
Abstract
Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.
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Affiliation(s)
- Eun Seong Hwang
- Department of Life Science, University of Seoul, Seoul 02504, Korea
| | - Seon Beom Song
- Department of Life Science, University of Seoul, Seoul 02504, Korea
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4
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Soleimani M. Not all kidney cysts are created equal: a distinct renal cystogenic mechanism in tuberous sclerosis complex (TSC). Front Physiol 2023; 14:1289388. [PMID: 38028758 PMCID: PMC10663234 DOI: 10.3389/fphys.2023.1289388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
Tuberous Sclerosis Complex (TSC) is an autosomal dominant genetic disease caused by mutations in either TSC1 or TSC2 genes. Approximately, two million individuals suffer from this disorder worldwide. TSC1 and TSC2 code for the proteins harmartin and tuberin, respectively, which form a complex that regulates the mechanistic target of rapamycin complex 1 (mTORC1) and prevents uncontrollable cell growth. In the kidney, TSC presents with the enlargement of benign tumors (angiomyolipomas) and cysts whose presence eventually causes kidney failure. The factors promoting cyst formation and tumor growth in TSC are poorly understood. Recent studies on kidney cysts in various mouse models of TSC, including mice with principal cell- or pericyte-specific inactivation of TSC1 or TSC2, have identified a unique cystogenic mechanism. These studies demonstrate the development of numerous cortical cysts that are predominantly comprised of hyperproliferating A-intercalated (A-IC) cells that express both TSC1 and TSC2. An analogous cellular phenotype in cystic epithelium is observed in both humans with TSC and in TSC2+/- mice, confirming a similar kidney cystogenesis mechanism in TSC. This cellular phenotype profoundly contrasts with kidney cysts found in Autosomal Dominant Polycystic Kidney Disease (ADPKD), which do not show any notable evidence of A-IC cells participating in the cyst lining or expansion. RNA sequencing (RNA-Seq) and confirmatory expression studies demonstrate robust expression of Forkhead Box I1 (FOXI1) transcription factor and its downstream targets, including apical H+-ATPase and cytoplasmic carbonic anhydrase 2 (CAII), in the cyst epithelia of Tsc1 (or Tsc2) knockout (KO) mice, but not in Polycystic Kidney Disease (Pkd1) mutant mice. Deletion of FOXI1, which is vital to H+-ATPase expression and intercalated (IC) cell viability, completely inhibited mTORC1 activation and abrogated the cyst burden in the kidneys of Tsc1 KO mice. These results unequivocally demonstrate the critical role that FOXI1 and A-IC cells, along with H+-ATPase, play in TSC kidney cystogenesis. This review article will discuss the latest research into the causes of kidney cystogenesis in TSC with a focus on possible therapeutic options for this devastating disease.
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Affiliation(s)
- Manoocher Soleimani
- Department of Medicine, New Mexico Veterans Health Care Center, Albuquerque, NM, United States
- Department of Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
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Chelangarimiyandoab F, Mungara P, Batta M, Cordat E. Urinary Tract Infections: Renal Intercalated Cells Protect against Pathogens. J Am Soc Nephrol 2023; 34:1605-1614. [PMID: 37401780 PMCID: PMC10561816 DOI: 10.1681/asn.0000000000000187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/22/2023] [Indexed: 07/05/2023] Open
Abstract
Urinary tract infections affect more than 1 in 2 women during their lifetime. Among these, more than 10% of patients carry antibiotic-resistant bacterial strains, highlighting the urgent need to identify alternative treatments. While innate defense mechanisms are well-characterized in the lower urinary tract, it is becoming evident that the collecting duct (CD), the first renal segment encountered by invading uropathogenic bacteria, also contributes to bacterial clearance. However, the role of this segment is beginning to be understood. This review summarizes the current knowledge on CD intercalated cells in urinary tract bacterial clearance. Understanding the innate protective role of the uroepithelium and of the CD offers new opportunities for alternative therapeutic strategies.
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Affiliation(s)
- Forough Chelangarimiyandoab
- Department of Physiology and Membrane Protein Disease Research Group, Faculty of Medicine & Dentistry, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada
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Du Y, Shang Y, Qian Y, Guo Y, Chen S, Lin X, Cao W, Tang X, Zhou A, Huang S, Zhang A, Jia Z, Zhang Y. Plk1 promotes renal tubulointerstitial fibrosis by targeting autophagy/lysosome axis. Cell Death Dis 2023; 14:571. [PMID: 37640723 PMCID: PMC10462727 DOI: 10.1038/s41419-023-06093-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/07/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023]
Abstract
The prevalence of chronic kidney disease (CKD) has been increasing over the past decades. However, no effective therapies are available for delaying or curing CKD. Progressive fibrosis is the major pathological feature of CKD, which leads to end-stage renal disease (ESRD). The present study showed that Polo-like kinase 1 (Plk1) was upregulated in the kidneys of CKD patients and mice subjected to unilateral ureteral obstruction (UUO) with location in proximal tubules and tubulointerstitial fibroblasts. Pharmacological inhibition, genetic silencing or knockout of Plk1 attenuated obstructive nephropathy due to suppressed fibroblast activation mediated by reduced autophagic flux. We found Plk1 plays a critical role in maintaining intralysosomal pH by regulating ATP6V1A phosphorylation, and inhibition of Plk1 impaired lysosomal function leading to blockade of autophagic flux. In addition, Plk1 also prevented partial epithelial-mesenchymal transition (pEMT) of tubular epithelial cells via autophagy pathway. In conclusion, this study demonstrated that Plk1 plays a pathogenic role in renal tubulointerstitial fibrosis by regulating autophagy/lysosome axis. Thus, targeting Plk1 could be a promising strategy for CKD treatment.
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Affiliation(s)
- Yang Du
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China
| | - Yaqiong Shang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
| | - Yun Qian
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
| | - Yan Guo
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China
| | - Shuang Chen
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China
| | - Xiuli Lin
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
| | - Weidong Cao
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China
| | - Xiaomei Tang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
| | - Anning Zhou
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
| | - Songming Huang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China.
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China.
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China.
| | - Zhanjun Jia
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China.
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China.
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China.
| | - Yue Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Guangzhou Road #72, Gulou District, 210008, Nanjing, China.
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Hanzhong Road #140, Gulou District, 210029, Nanjing, China.
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Gulou District, Guangzhou Road #72, 210008, Nanjing, China.
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Lo CH, Zeng J. Defective lysosomal acidification: a new prognostic marker and therapeutic target for neurodegenerative diseases. Transl Neurodegener 2023; 12:29. [PMID: 37287072 DOI: 10.1186/s40035-023-00362-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/12/2023] [Indexed: 06/09/2023] Open
Abstract
Lysosomal acidification dysfunction has been implicated as a key driving factor in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Multiple genetic factors have been linked to lysosomal de-acidification through impairing the vacuolar-type ATPase and ion channels on the organelle membrane. Similar lysosomal abnormalities are also present in sporadic forms of neurodegeneration, although the underlying pathogenic mechanisms are unclear and remain to be investigated. Importantly, recent studies have revealed early occurrence of lysosomal acidification impairment before the onset of neurodegeneration and late-stage pathology. However, there is a lack of methods for organelle pH monitoring in vivo and a dearth of lysosome-acidifying therapeutic agents. Here, we summarize and present evidence for the notion of defective lysosomal acidification as an early indicator of neurodegeneration and urge the critical need for technological advancement in developing tools for lysosomal pH monitoring and detection both in vivo and for clinical applications. We further discuss current preclinical pharmacological agents that modulate lysosomal acidification, including small molecules and nanomedicine, and their potential clinical translation into lysosome-targeting therapies. Both timely detection of lysosomal dysfunction and development of therapeutics that restore lysosomal function represent paradigm shifts in targeting neurodegenerative diseases.
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Affiliation(s)
- Chih Hung Lo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
| | - Jialiu Zeng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
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Wang X, Li Y, Xiao Y, Huang X, Wu X, Zhao Z, Yang M, Kong L, Shi D, Chen X, Ouyang Y, Chen X, Lin C, Li J, Song L, Lin Y, Guan J. The phospholipid flippase ATP9A enhances macropinocytosis to promote nutrient starvation tolerance in hepatocellular carcinoma. J Pathol 2023; 260:17-31. [PMID: 36715683 DOI: 10.1002/path.6059] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
Macropinocytosis is an effective strategy to mitigate nutrient starvation. It can fuel cancer cell growth in nutrient-limited conditions. However, whether and how macropinocytosis contributes to the rapid proliferation of hepatocellular carcinoma cells, which frequently experience an inadequate nutrient supply, remains unclear. Here, we demonstrated that nutrient starvation strongly induced macropinocytosis in some hepatocellular carcinoma cells. It allowed the cells to acquire extracellular nutrients and supported their energy supply to maintain rapid proliferation. Furthermore, we found that the phospholipid flippase ATP9A was critical for regulating macropinocytosis in hepatocellular carcinoma cells and that high ATP9A levels predicted a poor outcome for patients with hepatocellular carcinoma. ATP9A interacted with ATP6V1A and facilitated its transport to the plasma membrane, which promoted plasma membrane cholesterol accumulation and drove RAC1-dependent macropinocytosis. Macropinocytosis inhibitors significantly suppressed the energy supply and proliferation of hepatocellular carcinoma cells characterised by high ATP9A expression under nutrient-limited conditions. These results have revealed a novel mechanism that overcomes nutrient starvation in hepatocellular carcinoma cells and have identified the key regulator of macropinocytosis in hepatocellular carcinoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Xiaoqing Wang
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China
| | - Yue Li
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Yunyun Xiao
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Xinjian Huang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Xianqiu Wu
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, PR China.,Clinical Experimental Center, Jiangmen Key Laboratory of Clinical Biobanks and Translational Research, Jiangmen Central Hospital, Jiangmen, PR China
| | - Zhen Zhao
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, PR China.,School of Medicine, South China University of Technology, Guangzhou, PR China
| | - Muwen Yang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Lingzhi Kong
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Dongni Shi
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Xin Chen
- Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences; Guangzhou Institute of Oncology, Tumor Hospital, Guangzhou Medical University, Guangzhou, PR China
| | - Ying Ouyang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Xiangfu Chen
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Chuyong Lin
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Jun Li
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, PR China
| | - Libing Song
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, PR China
| | - Ye Lin
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, PR China
| | - Jian Guan
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China.,Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, PR China
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9
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Maxson ME, Abbas YM, Wu JZ, Plumb JD, Grinstein S, Rubinstein JL. Detection and quantification of the vacuolar H+ATPase using the Legionella effector protein SidK. J Biophys Biochem Cytol 2022; 221:212963. [PMID: 35024770 PMCID: PMC8763849 DOI: 10.1083/jcb.202107174] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 12/14/2021] [Accepted: 12/21/2021] [Indexed: 12/11/2022] Open
Abstract
Acidification of secretory and endocytic organelles is required for proper receptor recycling, membrane traffic, protein degradation, and solute transport. Proton-pumping vacuolar H+ ATPases (V-ATPases) are responsible for this luminal acidification, which increases progressively as secretory and endocytic vesicles mature. An increasing density of V-ATPase complexes is thought to account for the gradual decrease in pH, but available reagents have not been sufficiently sensitive or specific to test this hypothesis. We introduce a new probe to localize and quantify V-ATPases. The probe is derived from SidK, a Legionella pneumophila effector protein that binds to the V-ATPase A subunit. We generated plasmids encoding fluorescent chimeras of SidK1-278, and labeled recombinant SidK1-278 with Alexa Fluor 568 to visualize and quantify V-ATPases with high specificity in live and fixed cells, respectively. We show that V-ATPases are acquired progressively during phagosome maturation, that they distribute in discrete membrane subdomains, and that their density in lysosomes depends on their subcellular localization.
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Affiliation(s)
- Michelle E Maxson
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Yazan M Abbas
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Jing Ze Wu
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Jonathan D Plumb
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Sergio Grinstein
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - John L Rubinstein
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
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10
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Chen F, Kang R, Liu J, Tang D. The V-ATPases in cancer and cell death. Cancer Gene Ther 2022; 29:1529-1541. [PMID: 35504950 PMCID: PMC9063253 DOI: 10.1038/s41417-022-00477-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 02/04/2023]
Abstract
Transmembrane ATPases are membrane-bound enzyme complexes and ion transporters that can be divided into F-, V-, and A-ATPases according to their structure. The V-ATPases, also known as H+-ATPases, are large multi-subunit protein complexes composed of a peripheral domain (V1) responsible for the hydrolysis of ATP and a membrane-integrated domain (V0) that transports protons across plasma membrane or organelle membrane. V-ATPases play a fundamental role in maintaining pH homeostasis through lysosomal acidification and are involved in modulating various physiological and pathological processes, such as macropinocytosis, autophagy, cell invasion, and cell death (e.g., apoptosis, anoikis, alkaliptosis, ferroptosis, and lysosome-dependent cell death). In addition to participating in embryonic development, V-ATPase pathways, when dysfunctional, are implicated in human diseases, such as neurodegenerative diseases, osteopetrosis, distal renal tubular acidosis, and cancer. In this review, we summarize the structure and regulation of isoforms of V-ATPase subunits and discuss their context-dependent roles in cancer biology and cell death. Updated knowledge about V-ATPases may enable us to design new anticancer drugs or strategies.
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Affiliation(s)
- Fangquan Chen
- grid.417009.b0000 0004 1758 4591DAMP Laboratory, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120 China
| | - Rui Kang
- grid.267313.20000 0000 9482 7121Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Jiao Liu
- grid.417009.b0000 0004 1758 4591DAMP Laboratory, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120 China
| | - Daolin Tang
- grid.267313.20000 0000 9482 7121Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
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11
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Manzato MC, de Santi F, da Silva AAS, Beltrame FL, Cerri PS, Sasso‐Cerri E. Cimetidine-induced androgenic failure causes cell death and changes in actin, EGF and V-ATPase immunoexpression in rat submandibular glands. J Anat 2021; 239:136-150. [PMID: 33713423 PMCID: PMC8197950 DOI: 10.1111/joa.13408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 01/18/2023] Open
Abstract
Submandibular gland (SMG) is responsive to androgens via androgen receptor (AR). We verified whether cimetidine induces androgenic dysfunction in SMG, and evaluated the structural integrity, cell death and immunoexpression of actin, EGF and V-ATPase in androgen-deficient SMG. Male rats received cimetidine (CMTG) and control animals (CG) received saline. Granular convoluted tubules (GCTs) diameter and number of acinar cell nuclei were evaluated. TUNEL and immunofluorescence reactions for detection of AR, testosterone, actin, EGF and V-ATPase were quantitatively analysed. In CG, testosterone immunolabelling was detected in acinar and ductal cells cytoplasm. AR-immunolabelled nuclei were observed in acinar cells whereas ductal cells showed AR-immunostained cytoplasm, indicating a non-genomic AR action. In CMTG, the weak testosterone and AR immunoexpression confirmed cimetidine-induced androgenic failure. A high cell death index was correlated with decreased number of acinar cells, GCTs diameter and EGF immunoexpression under androgenic dysfunction. Actin immunofluorescence decreased in the SMG cells, but an increased and diffuse cytoplasmic V-ATPase immunolabelling was observed in striated ducts, suggesting a disruption in the actin-dependent V-ATPase recycling due to androgenic failure. Our findings reinforce the androgenic role in the maintenance of SMG histophysiology, and point to a potential clinical use of cimetidine against androgen-dependent glandular tumour cells.
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Affiliation(s)
- Mariane Castro Manzato
- Department of Morphology, Genetics, Orthodontics and Pediatric DentistrySchool of DentistrySão Paulo State University (Unesp)AraraquaraBrazil
| | - Fabiane de Santi
- Department of Morphology and GeneticsFederal University of São PauloSão PauloBrazil
| | - André Acácio Souza da Silva
- Department of Morphology, Genetics, Orthodontics and Pediatric DentistrySchool of DentistrySão Paulo State University (Unesp)AraraquaraBrazil
| | - Flávia L. Beltrame
- Department of Morphology and GeneticsFederal University of São PauloSão PauloBrazil
| | - Paulo S. Cerri
- Department of Morphology, Genetics, Orthodontics and Pediatric DentistrySchool of DentistrySão Paulo State University (Unesp)AraraquaraBrazil
| | - Estela Sasso‐Cerri
- Department of Morphology, Genetics, Orthodontics and Pediatric DentistrySchool of DentistrySão Paulo State University (Unesp)AraraquaraBrazil
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12
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Eaton AF, Merkulova M, Brown D. The H +-ATPase (V-ATPase): from proton pump to signaling complex in health and disease. Am J Physiol Cell Physiol 2020; 320:C392-C414. [PMID: 33326313 PMCID: PMC8294626 DOI: 10.1152/ajpcell.00442.2020] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A primary function of the H+-ATPase (or V-ATPase) is to create an electrochemical proton gradient across eukaryotic cell membranes, which energizes fundamental cellular processes. Its activity allows for the acidification of intracellular vesicles and organelles, which is necessary for many essential cell biological events to occur. In addition, many specialized cell types in various organ systems such as the kidney, bone, male reproductive tract, inner ear, olfactory mucosa, and more, use plasma membrane V-ATPases to perform specific activities that depend on extracellular acidification. It is, however, increasingly apparent that V-ATPases are central players in many normal and pathophysiological processes that directly influence human health in many different and sometimes unexpected ways. These include cancer, neurodegenerative diseases, diabetes, and sensory perception, as well as energy and nutrient-sensing functions within cells. This review first covers the well-established role of the V-ATPase as a transmembrane proton pump in the plasma membrane and intracellular vesicles and outlines factors contributing to its physiological regulation in different cell types. This is followed by a discussion of the more recently emerging unconventional roles for the V-ATPase, such as its role as a protein interaction hub involved in cell signaling, and the (patho)physiological implications of these interactions. Finally, the central importance of endosomal acidification and V-ATPase activity on viral infection will be discussed in the context of the current COVID-19 pandemic.
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Affiliation(s)
- Amity F Eaton
- Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Maria Merkulova
- Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Dennis Brown
- Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
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13
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Zaidman NA, Tomilin VN, Hassanzadeh Khayyat N, Damarla M, Tidmore J, Capen DE, Brown D, Pochynyuk OM, Pluznick JL. Adhesion-GPCR Gpr116 (ADGRF5) expression inhibits renal acid secretion. Proc Natl Acad Sci U S A 2020; 117:26470-26481. [PMID: 33004624 PMCID: PMC7584995 DOI: 10.1073/pnas.2007620117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The diversity and near universal expression of G protein-coupled receptors (GPCR) reflects their involvement in most physiological processes. The GPCR superfamily is the largest in the human genome, and GPCRs are common pharmaceutical targets. Therefore, uncovering the function of understudied GPCRs provides a wealth of untapped therapeutic potential. We previously identified an adhesion-class GPCR, Gpr116, as one of the most abundant GPCRs in the kidney. Here, we show that Gpr116 is highly expressed in specialized acid-secreting A-intercalated cells (A-ICs) in the kidney using both imaging and functional studies, and we demonstrate in situ receptor activation using a synthetic agonist peptide unique to Gpr116. Kidney-specific knockout (KO) of Gpr116 caused a significant reduction in urine pH (i.e., acidification) accompanied by an increase in blood pH and a decrease in pCO2 compared to WT littermates. Additionally, immunogold electron microscopy shows a greater accumulation of V-ATPase proton pumps at the apical surface of A-ICs in KO mice compared to controls. Furthermore, pretreatment of split-open collecting ducts with the synthetic agonist peptide significantly inhibits proton flux in ICs. These data suggest a tonic inhibitory role for Gpr116 in the regulation of V-ATPase trafficking and urinary acidification. Thus, the absence of Gpr116 results in a primary excretion of acid in KO mouse urine, leading to mild metabolic alkalosis ("renal tubular alkalosis"). In conclusion, we have uncovered a significant role for Gpr116 in kidney physiology, which may further inform studies in other organ systems that express this GPCR, such as the lung, testes, and small intestine.
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Affiliation(s)
- Nathan A Zaidman
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Viktor N Tomilin
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Naghmeh Hassanzadeh Khayyat
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Mahendra Damarla
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Josephine Tidmore
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Diane E Capen
- Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114
| | - Dennis Brown
- Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114
| | - Oleh M Pochynyuk
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Jennifer L Pluznick
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205;
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14
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Nakamura M, Satoh N, Tsukada H, Mizuno T, Fujii W, Suzuki A, Horita S, Nangaku M, Suzuki M. Stimulatory effect of insulin on H+-ATPase in the proximal tubule via the Akt/mTORC2 pathway. Physiol Int 2020; 107:376-389. [PMID: 32990653 DOI: 10.1556/2060.2020.00030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 06/12/2020] [Indexed: 11/19/2022]
Abstract
Purpose Acid-base transport in renal proximal tubules (PTs) is mainly sodium-dependent and conducted in coordination by the apical Na+/H+ exchanger (NHE3), vacuolar H+-adenosine triphosphatase (V-ATPase), and the basolateral Na+/HCO3- cotransporter. V-ATPase on PTs is well-known to play an important role in proton excretion. Recently we reported a stimulatory effect of insulin on these transporters. However, it is unclear whether insulin is involved in acid-base balance in PTs. Thus, we assessed the role of insulin in acid-base balance in PTs. Methods V-ATPase activity was evaluated using freshly isolated PTs obtained from mice, and specific inhibitors were then used to assess the signaling pathways involved in the observed effects. Results V-ATPase activity in PTs was markedly enhanced by insulin, and its activation was completely inhibited by bafilomycin (a V-ATPase-specific inhibitor), Akt inhibitor VIII, and PP242 (an mTORC1/2 inhibitor), but not by rapamycin (an mTORC1 inhibitor). V-ATPase activity was stimulated by 1 nm insulin by approximately 20% above baseline, which was completely suppressed by Akt1/2 inhibitor VIII. PP242 completely suppressed the insulin-mediated V-ATPase stimulation in mouse PTs, whereas rapamycin failed to influence the effect of insulin. Insulin-induced Akt phosphorylation in the mouse renal cortex was completely suppressed by Akt1/2 inhibitor VIII and PP242, but not by rapamycin. Conclusion Our results indicate that stimulation of V-ATPase activity by insulin in PTs is mediated via the Akt2/mTORC2 pathway. These results reveal the mechanism underlying the complex signaling in PT acid-base balance, providing treatment targets for renal disease.
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Affiliation(s)
- M Nakamura
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - N Satoh
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - H Tsukada
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - T Mizuno
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - W Fujii
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - A Suzuki
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan.,2Department of Nephrology, Japan Community Health care Organization (JCHO), Tokyo Yamate Medical Center, Tokyo, Japan
| | - S Horita
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - M Nangaku
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - M Suzuki
- 3Health Service Center, Tokyo Gakugei University, Tokyo, Japan
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15
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Aslam M, Ladilov Y. Targeting the sAC-Dependent cAMP Pool to Prevent SARS-Cov-2 Infection. Cells 2020; 9:cells9091962. [PMID: 32854430 PMCID: PMC7563949 DOI: 10.3390/cells9091962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
An outbreak of the novel coronavirus (CoV) SARS-CoV-2, the causative agent of COVID-19 respiratory disease, infected millions of people since the end of 2019, led to high-level morbidity and mortality and caused worldwide social and economic disruption. There are currently no antiviral drugs available with proven efficacy or vaccines for its prevention. An understanding of the underlying cellular mechanisms involved in virus replication is essential for repurposing the existing drugs and/or the discovery of new ones. Endocytosis is the important mechanism of entry of CoVs into host cells. Endosomal maturation followed by the fusion with lysosomes are crucial events in endocytosis. Late endosomes and lysosomes are characterized by their acidic pH, which is generated by a proton transporter V-ATPase and required for virus entry via endocytic pathway. The cytoplasmic cAMP pool produced by soluble adenylyl cyclase (sAC) promotes V-ATPase recruitment to endosomes/lysosomes and thus their acidification. In this review, we discuss targeting the sAC-specific cAMP pool as a potential strategy to impair the endocytic entry of the SARS-CoV-2 into the host cell. Furthermore, we consider the potential impact of sAC inhibition on CoV-induced disease via modulation of autophagy and apoptosis.
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Affiliation(s)
- Muhammad Aslam
- Experimental Cardiology, Department of Internal Medicine, Justus Liebig University, 35392 Giessen, Germany;
- DZHK (German Centre for Cardiovascular Research), Department of Cardiology, Kerckhoff Clinic GmbH partner site Rhein-Main, 61231 Bad Nauheim, Germany
| | - Yury Ladilov
- Independent Researcher, 42929 Wermelskirchen, Germany
- Correspondence:
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16
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Li Y, Hu D, Qi J, Cui S, Chen W. Lysosomal Reacidification Ameliorates Vinyl Carbamate-Induced Toxicity and Disruption on Lysosomal pH. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:8951-8961. [PMID: 32806125 DOI: 10.1021/acs.jafc.0c00534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ethyl carbamate (EC) is a carcinogen toxicant, commonly found in fermented foods and beverages. The carcinogenic and toxic possibility of EC is thought to be related to its metabolite vinyl carbamate (VC). However, we found interesting mechanisms underlying VC-induced toxicity in this study, which were greatly different from EC. We first conducted a simple synthesis procedure for VC and found that VC possessed higher toxicity but failed to regulate levels of reactive oxygen species, glutathione, and autophagy. Notably, VC treatment resulted in upregulation of lysosomal pH, which was responsible for its cytotoxicity. Cyclic adenosine monophosphate (cAMP) pretreatment could enhance restoration of lysosomal acidity and ameliorate VC-induced damage. Inhibition of protein kinase A and cystic fibrosis transmembrane conductance regulator can block cAMP-induced cytoprotection. Together, our results provided the evidence for novel mechanisms of toxicity and possible protection method under VC exposure, which might give new perspectives on the study of EC-induced toxicity.
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Affiliation(s)
- Yuting Li
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou 310058, China
| | - Dongwen Hu
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou 310058, China
| | - Jifeng Qi
- Institute of Drug Discovery and Design, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Sunliang Cui
- Institute of Drug Discovery and Design, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wei Chen
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
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17
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Collins MP, Forgac M. Regulation and function of V-ATPases in physiology and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183341. [PMID: 32422136 DOI: 10.1016/j.bbamem.2020.183341] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/30/2020] [Accepted: 05/03/2020] [Indexed: 02/07/2023]
Abstract
The vacuolar H+-ATPases (V-ATPases) are essential, ATP-dependent proton pumps present in a variety of eukaryotic cellular membranes. Intracellularly, V-ATPase-dependent acidification functions in such processes as membrane traffic, protein degradation, autophagy and the coupled transport of small molecules. V-ATPases at the plasma membrane of certain specialized cells function in such processes as bone resorption, sperm maturation and urinary acidification. V-ATPases also function in disease processes such as pathogen entry and cancer cell invasiveness, while defects in V-ATPase genes are associated with disorders such as osteopetrosis, renal tubular acidosis and neurodegenerative diseases. This review highlights recent advances in our understanding of V-ATPase structure, mechanism, function and regulation, with an emphasis on the signaling pathways controlling V-ATPase assembly in mammalian cells. The role of V-ATPases in cancer and other human pathologies, and the prospects for therapeutic intervention, are also discussed.
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Affiliation(s)
- Michael P Collins
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America
| | - Michael Forgac
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America; Dept. of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States of America.
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18
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Rao R, Bhalla V, Pastor-Soler NM. Intercalated Cells of the Kidney Collecting Duct in Kidney Physiology. Semin Nephrol 2020; 39:353-367. [PMID: 31300091 DOI: 10.1016/j.semnephrol.2019.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The epithelium of the kidney collecting duct (CD) is composed mainly of two different types of cells with distinct and complementary functions. CD principal cells traditionally have been considered to have a major role in Na+ and water regulation, while intercalated cells (ICs) were thought to largely modulate acid-base homeostasis. In recent years, our understanding of IC function has improved significantly owing to new research findings. Thus, we now have a new model for CD transport that integrates mechanisms of salt and water reabsorption, K+ homeostasis, and acid-base status between principal cells and ICs. There are three main types of ICs (type A, type B, and non-A, non-B), which first appear in the late distal convoluted tubule or in the connecting segment in a species-dependent manner. ICs can be detected in CD from cortex to the initial part of the inner medulla, although some transport proteins that are key components of ICs also are present in medullary CD, cells considered inner medullary. Of the three types of ICs, each has a distinct morphology and expresses different complements of membrane transport proteins that translate into very different functions in homeostasis and contributions to CD luminal pro-urine composition. This review includes recent discoveries in IC intracellular and paracrine signaling that contributes to acid-base regulation as well as Na+, Cl-, K+, and Ca2+ homeostasis. Thus, these new findings highlight the potential role of ICs as targets for potential hypertension treatments.
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Affiliation(s)
- Renee Rao
- University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, CA
| | - Núria M Pastor-Soler
- University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA.
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19
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Maity C, Ghosh D, Guha S. Assays for Intracellular Cyclic Adenosine Monophosphate (cAMP) and Lysosomal Acidification. Methods Mol Biol 2020; 1996:161-178. [PMID: 31127555 DOI: 10.1007/978-1-4939-9488-5_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyclic adenosine monophosphate (3',5'-cAMP) is a multifunctional second messenger which controls extremely diverse and physiologically important biochemical pathways. Among its myriad roles, 3',5'-cAMP functions as an intracellular regulator of lysosomal pH, which is essential for the activity of acidic lysosomal enzymes. Defects in lysosomal acidification are attributed to many diseases like macular degeneration, Parkinson's, Alzheimer's, and cystic fibrosis. Strategic re-acidification of defective lysosomes by pharmacological increase of intracellular cAMP offers exciting therapeutic potential in these diseases. Modular assays for accurate assessment of intracellular cAMP and lysosomal pH are a critical component of this research. We describe label-free targeted metabolomics for quantitating intracellular cAMP and integrated assays for measuring lysosomal pH. These hybrid assays offer fast, unbiased information on intracellular cAMP concentrations and lysosomal pH that can be applied to many cell types and putative drug screening strategies.
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Affiliation(s)
- Chiranjit Maity
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Dipankar Ghosh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Sonia Guha
- Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA.
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20
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Cui X, Feng R, Wang J, Du C, Pi X, Chen D, Li J, Li H, Zhang J, Zhang J, Mu H, Zhang F, Liu M, Hu Y. Heat shock factor 4 regulates lysosome activity by modulating the αB-crystallin-ATP6V1A-mTOR complex in ocular lens. Biochim Biophys Acta Gen Subj 2019; 1864:129496. [PMID: 31786107 DOI: 10.1016/j.bbagen.2019.129496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 10/28/2019] [Accepted: 11/13/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUND Germline mutations in heat shock factor 4 (HSF4) cause congenital cataracts. Previously, we have shown that HSF4 is involved in regulating lysosomal pH in mouse lens epithelial cell in vitro. However, the underlying mechanism remains unclear. METHODS HSF4-deficient mouse lens epithelial cell lines and zebrafish were used in this study. Immunoblotting and quantitative RT-PCR were used for expression analysis. The protein-protein interactions were tested with GST-pull downs. The lysosomes were fractioned by ultracentrifugation. RESULTS HSF4 deficiency or knock down of αB-crystallin elevates lysosomal pH and increases the ubiquitination and degradation of ATP6V1A by the proteasome. αB-crystallin localizes partially in the lysosome and interacts solely with the ATP6V1A protein of the V1 complex of V-ATPase. Furthermore, αB-crystallin can co-precipitate with mTORC1 and ATP6V1A in GST pull down assays. Inhibition of mTORC1 by rapamycin or siRNA can lead to dissociation of αB-crystallin from the ATP6V1A and mTORC1complex, shortening the half-life of ATP6V1A and increasing the lysosomal pH. Mutation of ATP6V1A/S441A (the predicted mTOR phosphorylation site) reduces its association with αB-crystallin. In the zebrafish model, HSF4 deficiency reduces αB-crystallin expression and elevates the lysosomal pH in lens tissues. CONCLUSION HSF4 regulates lysosomal acidification by controlling the association of αB-crystallin with ATP6V1A and mTOR and regulating ATP6V1A protein stabilization. GENERAL SIGNIFICANCE This study uncovers a novel function of αB-crystallin, demonstrating that αB-crystallin can regulate lysosomal ATP6V1A protein stabilization by complexing to ATP6V1A and mTOR. This highlights a novel mechanism by which HSF4 regulates the proteolytic process of organelles during lens development.
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Affiliation(s)
- Xiukun Cui
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Ruiping Feng
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Jungai Wang
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Chunxiao Du
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Xiahui Pi
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Danling Chen
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Jing Li
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Hui Li
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Jun Zhang
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Jing Zhang
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China
| | - Hongmei Mu
- Kaifeng Key Lab of Myopia and Cataract, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China
| | - Fengyan Zhang
- Department of Ophthalmology, the First Affiliate Hospital of Zhengzhou University, China
| | - Mugen Liu
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yanzhong Hu
- Joint National Laboratory for Antibody Drug Engineering, Henan International Union Lab of Antibody Medicine, Henan University School of Medicine, Kaifeng, China; Department of Ophthalmology, the First Affiliate Hospital of Zhengzhou University, China; Kaifeng Key Lab of Myopia and Cataract, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China.
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21
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Jewell JL, Fu V, Hong AW, Yu FX, Meng D, Melick CH, Wang H, Lam WLM, Yuan HX, Taylor SS, Guan KL. GPCR signaling inhibits mTORC1 via PKA phosphorylation of Raptor. eLife 2019; 8:43038. [PMID: 31112131 PMCID: PMC6529218 DOI: 10.7554/elife.43038] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 04/30/2019] [Indexed: 01/14/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) regulates cell growth, metabolism, and autophagy. Extensive research has focused on pathways that activate mTORC1 like growth factors and amino acids; however, much less is known about signaling cues that directly inhibit mTORC1 activity. Here, we report that G-protein coupled receptors (GPCRs) paired to Gαs proteins increase cyclic adenosine 3’5’ monophosphate (cAMP) to activate protein kinase A (PKA) and inhibit mTORC1. Mechanistically, PKA phosphorylates the mTORC1 component Raptor on Ser 791, leading to decreased mTORC1 activity. Consistently, in cells where Raptor Ser 791 is mutated to Ala, mTORC1 activity is partially rescued even after PKA activation. Gαs-coupled GPCRs stimulation leads to inhibition of mTORC1 in multiple cell lines and mouse tissues. Our results uncover a signaling pathway that directly inhibits mTORC1, and suggest that GPCRs paired to Gαs proteins may be potential therapeutic targets for human diseases with hyperactivated mTORC1.
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Affiliation(s)
- Jenna L Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States.,Harold C Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, United States.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Vivian Fu
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Moores Cancer Center, University of California San Diego, La Jolla, United States
| | - Audrey W Hong
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Moores Cancer Center, University of California San Diego, La Jolla, United States
| | - Fa-Xing Yu
- Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Delong Meng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States.,Harold C Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, United States.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Chase H Melick
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States.,Harold C Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, United States.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Huanyu Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States.,Harold C Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, United States.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Wai-Ling Macrina Lam
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Moores Cancer Center, University of California San Diego, La Jolla, United States
| | - Hai-Xin Yuan
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Moores Cancer Center, University of California San Diego, La Jolla, United States
| | - Susan S Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, United States
| | - Kun-Liang Guan
- Department of Pharmacology, University of California, San Diego, La Jolla, United States.,Moores Cancer Center, University of California San Diego, La Jolla, United States
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22
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Lesch M, Luckner M, Meyer M, Weege F, Gravenstein I, Raftery M, Sieben C, Martin-Sancho L, Imai-Matsushima A, Welke RW, Frise R, Barclay W, Schönrich G, Herrmann A, Meyer TF, Karlas A. RNAi-based small molecule repositioning reveals clinically approved urea-based kinase inhibitors as broadly active antivirals. PLoS Pathog 2019; 15:e1007601. [PMID: 30883607 PMCID: PMC6422253 DOI: 10.1371/journal.ppat.1007601] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/29/2019] [Indexed: 12/13/2022] Open
Abstract
Influenza viruses (IVs) tend to rapidly develop resistance to virus-directed vaccines and common antivirals targeting pathogen determinants, but novel host-directed approaches might preclude resistance development. To identify the most promising cellular targets for a host-directed approach against influenza, we performed a comparative small interfering RNA (siRNA) loss-of-function screen of IV replication in A549 cells. Analysis of four different IV strains including a highly pathogenic avian H5N1 strain, an influenza B virus (IBV) and two human influenza A viruses (IAVs) revealed 133 genes required by all four IV strains. According to gene enrichment analyses, these strain-independent host genes were particularly enriched for nucleocytoplasmic trafficking. In addition, 360 strain-specific genes were identified with distinct patterns of usage for IAVs versus IBV and human versus avian IVs. The strain-independent host genes served to define 43 experimental and otherwise clinically approved drugs, targeting reportedly fourteen of the encoded host factors. Amongst the approved drugs, the urea-based kinase inhibitors (UBKIs) regorafenib and sorafenib exhibited a superior therapeutic window of high IV antiviral activity and low cytotoxicity. Both UBKIs appeared to block a cell signaling pathway involved in IV replication after internalization, yet prior to vRNP uncoating. Interestingly, both compounds were active also against unrelated viruses including cowpox virus (CPXV), hantavirus (HTV), herpes simplex virus 1 (HSV1) and vesicular stomatitis virus (VSV) and showed antiviral efficacy in human primary respiratory cells. An in vitro resistance development analysis for regorafenib failed to detect IV resistance development against this drug. Taken together, the otherwise clinically approved UBKIs regorafenib and sorafenib possess high and broad-spectrum antiviral activity along with substantial robustness against resistance development and thus constitute attractive host-directed drug candidates against a range of viral infections including influenza. Conventional medications against influenza infections, including vaccination and antiviral drug therapy, are targeted against viral determinants–an approach collectively referred to as pathogen-directed. However, influenza viruses mutate fast and quickly develop resistance to these pathogen-directed treatments. An alternative, yet not well established, is to block host cellular molecules required by the virus to successfully multiply. Such a host-directed approach is anticipated to be more robust against the development of drug resistance. This notion is founded on the different modes of action of the two principal approaches: Virus-directed therapeutics target the virus itself. Thus, just a single mutation could abrogate sensitivity to a virus-directed therapeutic. In contrast, it is unlikely that viruses can easily circumvent a pharmacological blockage of a cellular factor by means of just a few mutations. Instead, the virus needs to either exploit an immediate parallel cellular pathway or adjust its replication cycle to a different cellular factor–the latter being a process likely to require multiple mutations, if possible at all. To identify the most promising targets for a host-directed therapy, we performed a small interfering RNA (siRNA) screen with four different influenza virus strains using a lung epithelial cell line. Subsequently, we tested a series of drugs, specific for the products of the genes that are required for replication of all four influenza virus strains tested. Regorafenib and sorafenib, two chemically related urea-based kinase inhibitors already clinically approved for cancer treatment, turned out to be effective inhibitors of all influenza viruses and displayed low cytotoxicity. These drugs blocked viral replication at an early stage of the life cycle not only in cell lines but also in human primary respiratory cells. Moreover, these drugs exhibited high efficacy even against unrelated viruses. In addition, no development of resistance was observed against regorafenib, which was used in an in vitro assay representatively of urea-based kinase inhibitors. Our results suggest that regorafenib and sorafenib are promising drug candidates for a host-directed therapy of influenza and other viral infections.
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Affiliation(s)
- Markus Lesch
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Steinbeis Innovation Center for Systems Biomedicine, Falkensee, Germany
| | - Madlen Luckner
- Group of Molecular Biophysics, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Michael Meyer
- Steinbeis Innovation Center for Systems Biomedicine, Falkensee, Germany
| | - Friderike Weege
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | | | - Martin Raftery
- Institute of Virology, Charité University Medicine, Berlin, Germany
| | - Christian Sieben
- Group of Molecular Biophysics, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Laura Martin-Sancho
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Aki Imai-Matsushima
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Robert-William Welke
- Group of Molecular Biophysics, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Rebecca Frise
- Section of Virology, Department of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
| | - Wendy Barclay
- Section of Virology, Department of Medicine, Imperial College London, St Mary's Campus, London, United Kingdom
| | | | - Andreas Herrmann
- Group of Molecular Biophysics, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thomas F. Meyer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Steinbeis Innovation Center for Systems Biomedicine, Falkensee, Germany
- * E-mail: (TFM); (AK)
| | - Alexander Karlas
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Steinbeis Innovation Center for Systems Biomedicine, Falkensee, Germany
- * E-mail: (TFM); (AK)
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23
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Hayek SR, Rane HS, Parra KJ. Reciprocal Regulation of V-ATPase and Glycolytic Pathway Elements in Health and Disease. Front Physiol 2019; 10:127. [PMID: 30828305 PMCID: PMC6384264 DOI: 10.3389/fphys.2019.00127] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/31/2019] [Indexed: 12/24/2022] Open
Abstract
The ability of cells to adapt to fluctuations in glucose availability is crucial for their survival and involves the vacuolar proton-translocating ATPase (V-ATPase), a proton pump found in all eukaryotes. V-ATPase hydrolyzes ATP via its V1 domain and uses the energy released to transport protons across membranes via its Vo domain. This activity is critical for pH homeostasis and generation of a membrane potential that drives cellular metabolism. A number of stimuli have been reported to alter V-ATPase assembly in yeast and higher eukaryotes. Glucose flux is one of the strongest and best-characterized regulators of V-ATPase; this review highlights current models explaining how glycolysis and V-ATPase are coordinated in both the Saccharomyces cerevisiae model fungus and in mammalian systems. Glucose-dependent assembly and trafficking of V-ATPase, V-ATPase-dependent modulations in glycolysis, and the recent discovery that glucose signaling through V-ATPase acts as a molecular switch to dictate anabolic versus catabolic metabolism are discussed. Notably, metabolic plasticity and altered glycolytic flux are critical drivers of numerous human pathologies, and the expression and activity of V-ATPase is often altered in disease states or can be pharmacologically manipulated as treatment. This overview will specifically discuss connections between V-ATPase and glycolysis in cancer.
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Affiliation(s)
- Summer R Hayek
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Hallie S Rane
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
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24
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AMP-Activated Protein Kinase (AMPK)-Dependent Regulation of Renal Transport. Int J Mol Sci 2018; 19:ijms19113481. [PMID: 30404151 PMCID: PMC6274953 DOI: 10.3390/ijms19113481] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/26/2018] [Accepted: 10/30/2018] [Indexed: 02/06/2023] Open
Abstract
AMP-activated kinase (AMPK) is a serine/threonine kinase that is expressed in most cells and activated by a high cellular AMP/ATP ratio (indicating energy deficiency) or by Ca2+. In general, AMPK turns on energy-generating pathways (e.g., glucose uptake, glycolysis, fatty acid oxidation) and stops energy-consuming processes (e.g., lipogenesis, glycogenesis), thereby helping cells survive low energy states. The functional element of the kidney, the nephron, consists of the glomerulus, where the primary urine is filtered, and the proximal tubule, Henle's loop, the distal tubule, and the collecting duct. In the tubular system of the kidney, the composition of primary urine is modified by the reabsorption and secretion of ions and molecules to yield final excreted urine. The underlying membrane transport processes are mainly energy-consuming (active transport) and in some cases passive. Since active transport accounts for a large part of the cell's ATP demands, it is an important target for AMPK. Here, we review the AMPK-dependent regulation of membrane transport along nephron segments and discuss physiological and pathophysiological implications.
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25
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Harrison MA, Muench SP. The Vacuolar ATPase - A Nano-scale Motor That Drives Cell Biology. Subcell Biochem 2018; 87:409-459. [PMID: 29464568 DOI: 10.1007/978-981-10-7757-9_14] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The vacuolar H+-ATPase (V-ATPase) is a ~1 MDa membrane protein complex that couples the hydrolysis of cytosolic ATP to the transmembrane movement of protons. In essentially all eukaryotic cells, this acid pumping function plays critical roles in the acidification of endosomal/lysosomal compartments and hence in transport, recycling and degradative pathways. It is also important in acid extrusion across the plasma membrane of some cells, contributing to homeostatic control of cytoplasmic pH and maintenance of appropriate extracellular acidity. The complex, assembled from up to 30 individual polypeptides, operates as a molecular motor with rotary mechanics. Historically, structural inferences about the eukaryotic V-ATPase and its subunits have been made by comparison to the structures of bacterial homologues. However, more recently, we have developed a much better understanding of the complete structure of the eukaryotic complex, in particular through advances in cryo-electron microscopy. This chapter explores these recent developments, and examines what they now reveal about the catalytic mechanism of this essential proton pump and how its activity might be regulated in response to cellular signals.
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Affiliation(s)
- Michael A Harrison
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK.
| | - Steven P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
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26
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Whitton B, Okamoto H, Packham G, Crabb SJ. Vacuolar ATPase as a potential therapeutic target and mediator of treatment resistance in cancer. Cancer Med 2018; 7:3800-3811. [PMID: 29926527 PMCID: PMC6089187 DOI: 10.1002/cam4.1594] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 01/10/2023] Open
Abstract
Vacuolar ATPase (V-ATPase) is an ATP-dependent H+ -transporter that pumps protons across intracellular and plasma membranes. It consists of a large multi-subunit protein complex and influences a wide range of cellular processes. This review focuses on emerging evidence for the roles for V-ATPase in cancer. This includes how V-ATPase dysregulation contributes to cancer growth, metastasis, invasion and proliferation, and the potential link between V-ATPase and the development of drug resistance.
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Affiliation(s)
- Bradleigh Whitton
- Southampton Cancer Research UK CentreUniversity of SouthamptonSouthamptonUK
- Biological SciencesFaculty of Natural and Environmental SciencesUniversity of SouthamptonSouthamptonUK
| | - Haruko Okamoto
- Biological SciencesFaculty of Natural and Environmental SciencesUniversity of SouthamptonSouthamptonUK
| | - Graham Packham
- Southampton Cancer Research UK CentreUniversity of SouthamptonSouthamptonUK
| | - Simon J. Crabb
- Southampton Cancer Research UK CentreUniversity of SouthamptonSouthamptonUK
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27
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Zulauf KE, Sullivan JT, Braunstein M. The SecA2 pathway of Mycobacterium tuberculosis exports effectors that work in concert to arrest phagosome and autophagosome maturation. PLoS Pathog 2018; 14:e1007011. [PMID: 29709019 PMCID: PMC5945054 DOI: 10.1371/journal.ppat.1007011] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/10/2018] [Accepted: 04/06/2018] [Indexed: 11/30/2022] Open
Abstract
To subvert host defenses, Mycobacterium tuberculosis (Mtb) avoids being delivered to degradative phagolysosomes in macrophages by arresting the normal host process of phagosome maturation. Phagosome maturation arrest by Mtb involves multiple effectors and much remains unknown about this important aspect of Mtb pathogenesis. The SecA2 dependent protein export system is required for phagosome maturation arrest and consequently growth of Mtb in macrophages. To better understand the role of the SecA2 pathway in phagosome maturation arrest, we identified two effectors exported by SecA2 that contribute to this process: the phosphatase SapM and the kinase PknG. Then, utilizing the secA2 mutant of Mtb as a platform to study effector functions, we identified specific steps in phagosome maturation inhibited by SapM and/or PknG. By identifying a histidine residue that is essential for SapM phosphatase activity, we confirmed for the first time that the phosphatase activity of SapM is required for its effects on phagosome maturation in macrophages. We further demonstrated that SecA2 export of SapM and PknG contributes to the ability of Mtb to replicate in macrophages. Finally, we extended our understanding of the SecA2 pathway, SapM, and PknG by revealing that their contribution goes beyond preventing Mtb delivery to mature phagolysosomes and includes inhibiting Mtb delivery to autophagolysosomes. Together, our results revealed SapM and PknG to be two effectors exported by the SecA2 pathway of Mtb with distinct as well as cumulative effects on phagosome and autophagosome maturation. Our results further reveal that Mtb must have additional mechanisms of limiting acidification of the phagosome, beyond inhibiting recruitment of the V-ATPase proton pump to the phagosome, and they indicate differences between effects of Mtb on phagosome and autophagosome maturation. Mycobacterium tuberculosis (Mtb) is the infectious agent of the disease tuberculosis. Inside the host, Mtb replicates primarily within the phagosome of macrophages. To replicate within macrophages, Mtb modifies the phagosome by inhibiting the normal host process of phagosomes maturing into acidified degradative phagolysosomes. In order to arrest this process of phagosome maturation, Mtb exports multiple effectors to the host-pathogen interface. Here we found that the specialized SecA2 protein export pathway of Mtb exports two such effectors: SapM and PknG. We discovered that SapM and PknG play non-redundant functions in phagosome maturation arrest by Mtb. We further demonstrated that SecA2 export of both SapM and PknG contributes to the ability of Mtb to replicate in macrophages. We also identified a role for the SecA2 pathway, SapM and PknG in arresting the host process of autophagosome maturation. Our research highlights how two effectors, SapM and PknG, work in concert but also have distinct roles in phagosome and autophagosome maturation arrest by Mtb.
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Affiliation(s)
- Katelyn E. Zulauf
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jonathan Tabb Sullivan
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Miriam Braunstein
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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28
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McGuire CM, Forgac M. Glucose starvation increases V-ATPase assembly and activity in mammalian cells through AMP kinase and phosphatidylinositide 3-kinase/Akt signaling. J Biol Chem 2018. [PMID: 29540478 DOI: 10.1074/jbc.ra117.001327] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The vacuolar H+-ATPase (V-ATPase) is an ATP-driven proton pump involved in many cellular processes. An important mechanism by which V-ATPase activity is controlled is the reversible assembly of its two domains, namely the peripheral V1 domain and the integral V0 domain. Although reversible assembly is conserved across all eukaryotic organisms, the signaling pathways controlling it have not been fully characterized. Here, we identify glucose starvation as a novel regulator of V-ATPase assembly in mammalian cells. During acute glucose starvation, the V-ATPase undergoes a rapid and reversible increase in assembly and activity as measured by lysosomal acidification. Because the V-ATPase has recently been implicated in the activation of AMP kinase (AMPK), a critical cellular energy sensor that is also activated upon glucose starvation, we compared the time course of AMPK activation and V-ATPase assembly upon glucose starvation. We observe that AMPK activation precedes increased V-ATPase activity. Moreover, the starvation-induced increase in V-ATPase activity and assembly are prevented by the AMPK inhibitor dorsomorphin. These results suggest that increased assembly and activity of the V-ATPase upon glucose starvation are dependent upon AMPK. We also find that the PI3K/Akt pathway, which has previously been implicated in controlling V-ATPase assembly in mammalian cells, also plays a role in the starvation-induced increase in V-ATPase assembly and activity. These studies thus identify a novel stimulus of V-ATPase assembly and a novel signaling pathway involved in regulating this process. The possible function of starvation-induced increase in lysosomal V-ATPase activity is discussed.
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Affiliation(s)
- Christina M McGuire
- From the Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine and the Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
| | - Michael Forgac
- From the Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine and the Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
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29
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Bourgeois S, Bounoure L, Mouro-Chanteloup I, Colin Y, Brown D, Wagner CA. The ammonia transporter RhCG modulates urinary acidification by interacting with the vacuolar proton-ATPases in renal intercalated cells. Kidney Int 2018; 93:390-402. [PMID: 29054531 PMCID: PMC6166241 DOI: 10.1016/j.kint.2017.07.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 07/08/2017] [Accepted: 07/27/2017] [Indexed: 12/19/2022]
Abstract
Ammonium, stemming from renal ammoniagenesis, is a major urinary proton buffer and is excreted along the collecting duct. This process depends on the concomitant secretion of ammonia by the ammonia channel RhCG and of protons by the vacuolar-type proton-ATPase pump. Thus, urinary ammonium content and urinary acidification are tightly linked. However, mice lacking Rhcg excrete more alkaline urine despite lower urinary ammonium, suggesting an unexpected role of Rhcg in urinary acidification. RhCG and the B1 and B2 proton-ATPase subunits could be co-immunoprecipitated from kidney. In ex vivo microperfused cortical collecting ducts (CCD) proton-ATPase activity was drastically reduced in the absence of Rhcg. Conversely, overexpression of RhCG in HEK293 cells resulted in higher proton secretion rates and increased B1 proton-ATPase mRNA expression. However, in kidneys from Rhcg-/- mice the expression of only B1 and B2 subunits was altered. Immunolocalization of proton-ATPase subunits together with immuno-gold detection of the A proton-ATPase subunit showed similar localization and density of staining in kidneys from Rhcg+/+ and Rhcg-/-mice. In order to test for a reciprocal effect of intercalated cell proton-ATPases on Rhcg activity, we assessed Rhcg and proton-ATPase activities in microperfused CCD from Atp6v1b1-/- mice and showed reduced proton-ATPase activity without altering Rhcg activity. Thus, RhCG and proton-ATPase are located within the same cellular protein complex. RhCG may modulate proton-ATPase function and urinary acidification, whereas proton-ATPase activity does not affect RhCG function. This mechanism may help to coordinate ammonia and proton secretion beyond physicochemical driving forces.
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Affiliation(s)
- Soline Bourgeois
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Lisa Bounoure
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | - Yves Colin
- UMR_S1134, INSERM, Université Paris Diderot, INTS, Labex GR-Ex, Paris, France
| | - Dennis Brown
- Center for Systems Biology, Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
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30
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Deprez MA, Eskes E, Wilms T, Ludovico P, Winderickx J. pH homeostasis links the nutrient sensing PKA/TORC1/Sch9 ménage-à-trois to stress tolerance and longevity. MICROBIAL CELL 2018; 5:119-136. [PMID: 29487859 PMCID: PMC5826700 DOI: 10.15698/mic2018.03.618] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The plasma membrane H+-ATPase Pma1 and the vacuolar V-ATPase act in close harmony to tightly control pH homeostasis, which is essential for a vast number of physiological processes. As these main two regulators of pH are responsive to the nutritional status of the cell, it seems evident that pH homeostasis acts in conjunction with nutrient-induced signalling pathways. Indeed, both PKA and the TORC1-Sch9 axis influence the proton pumping activity of the V-ATPase and possibly also of Pma1. In addition, it recently became clear that the proton acts as a second messenger to signal glucose availability via the V-ATPase to PKA and TORC1-Sch9. Given the prominent role of nutrient signalling in longevity, it is not surprising that pH homeostasis has been linked to ageing and longevity as well. A first indication is provided by acetic acid, whose uptake by the cell induces toxicity and affects longevity. Secondly, vacuolar acidity has been linked to autophagic processes, including mitophagy. In agreement with this, a decline in vacuolar acidity was shown to induce mitochondrial dysfunction and shorten lifespan. In addition, the asymmetric inheritance of Pma1 has been associated with replicative ageing and this again links to repercussions on vacuolar pH. Taken together, accumulating evidence indicates that pH homeostasis plays a prominent role in the determination of ageing and longevity, thereby providing new perspectives and avenues to explore the underlying molecular mechanisms.
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Affiliation(s)
| | - Elja Eskes
- Functional Biology, KU Leuven, Leuven, Belgium
| | | | - Paula Ludovico
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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31
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Battistone MA, Nair AV, Barton CR, Liberman RN, Peralta MA, Capen DE, Brown D, Breton S. Extracellular Adenosine Stimulates Vacuolar ATPase-Dependent Proton Secretion in Medullary Intercalated Cells. J Am Soc Nephrol 2017; 29:545-556. [PMID: 29222395 DOI: 10.1681/asn.2017060643] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 10/18/2017] [Indexed: 12/29/2022] Open
Abstract
Acidosis is an important complication of AKI and CKD. Renal intercalated cells (ICs) express the proton pumping vacuolar H+-ATPase (V-ATPase) and are extensively involved in acid-base homeostasis. H+ secretion in type A intercalated cells (A-ICs) is regulated by apical vesicle recycling and stimulated by cAMP. In other cell types, cAMP is increased by extracellular agonists, including adenosine, through purinergic receptors. Adenosine is a Food and Drug Administration-approved drug, but very little is known about the effect of adenosine on IC function. Therefore, we investigated the role of adenosine in the regulation of V-ATPase in ICs. Intravenous treatment of mice with adenosine or agonists of ADORA2A and ADORA2B purinergic P1 receptors induced V-ATPase apical membrane accumulation in medullary A-ICs but not in cortical A-ICs or other IC subtypes. Both receptors are located in A-IC apical membranes, and adenosine injection increased urine adenosine concentration and decreased urine pH. Cell fractionation showed that adenosine or an ADORA2A or ADORA2B agonist induced V-ATPase translocation from vesicles to the plasma membrane and increased protein kinase A (PKA)-dependent protein phosphorylation in purified medullary ICs that were isolated from mice. Either ADORA2A or ADORA2B antagonists or the PKA inhibitor mPKI blocked these effects. Finally, a fluorescence pH assay showed that adenosine activates V-ATPase in isolated medullary ICs. Our study shows that medullary A-ICs respond to luminal adenosine through ADORA2A and ADORA2B receptors in a cAMP/PKA pathway-dependent mechanism to induce V-ATPase-dependent H+ secretion.
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Affiliation(s)
- Maria A Battistone
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Anil V Nair
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Claire R Barton
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rachel N Liberman
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maria A Peralta
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Diane E Capen
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Dennis Brown
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sylvie Breton
- Program in Membrane Biology, Center for Systems Biology, Nephrology Division, and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Role of AMP-activated protein kinase in kidney tubular transport, metabolism, and disease. Curr Opin Nephrol Hypertens 2017; 26:375-383. [DOI: 10.1097/mnh.0000000000000349] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Abstract
The vacuolar ATPases (V-ATPases) are a family of proton pumps that couple ATP hydrolysis to proton transport into intracellular compartments and across the plasma membrane. They function in a wide array of normal cellular processes, including membrane traffic, protein processing and degradation, and the coupled transport of small molecules, as well as such physiological processes as urinary acidification and bone resorption. The V-ATPases have also been implicated in a number of disease processes, including viral infection, renal disease, and bone resorption defects. This review is focused on the growing evidence for the important role of V-ATPases in cancer. This includes functions in cellular signaling (particularly Wnt, Notch, and mTOR signaling), cancer cell survival in the highly acidic environment of tumors, aiding the development of drug resistance, as well as crucial roles in tumor cell invasion, migration, and metastasis. Of greatest excitement is evidence that at least some tumors express isoforms of V-ATPase subunits whose disruption is not lethal, leading to the possibility of developing anti-cancer therapeutics that selectively target V-ATPases that function in cancer cells.
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Affiliation(s)
- Laura Stransky
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, and Program in Cellular and Molecular Physiology, Program in Biochemistry, and Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
| | - Kristina Cotter
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, and Program in Cellular and Molecular Physiology, Program in Biochemistry, and Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
| | - Michael Forgac
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, and Program in Cellular and Molecular Physiology, Program in Biochemistry, and Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
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Al-Bataineh MM, Li H, Ohmi K, Gong F, Marciszyn AL, Naveed S, Zhu X, Neumann D, Wu Q, Cheng L, Fenton RA, Pastor-Soler NM, Hallows KR. Activation of the metabolic sensor AMP-activated protein kinase inhibits aquaporin-2 function in kidney principal cells. Am J Physiol Renal Physiol 2016; 311:F890-F900. [PMID: 27534994 PMCID: PMC5130465 DOI: 10.1152/ajprenal.00308.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/15/2016] [Indexed: 11/22/2022] Open
Abstract
Aquaporin-2 (AQP2) is essential to maintain body water homeostasis. AQP2 traffics from intracellular vesicles to the apical membrane of kidney collecting duct principal cells in response to vasopressin [arginine vasopressin (AVP)], a hormone released with low intravascular volume, which causes decreased kidney perfusion. Decreased kidney perfusion activates AMP-activated kinase (AMPK), a metabolic sensor that inhibits the activity of several transport proteins. We hypothesized that AMPK activation also inhibits AQP2 function. These putative AMPK effects could protect interstitial ionic gradients required for urinary concentration during metabolic stress when low intravascular volume induces AVP release. Here we found that short-term AMPK activation by treatment with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR; 75 min) in kidney tissue prevented baseline AQP2 apical accumulation in principal cells, but did not prevent AQP2 apical accumulation in response to the AVP analog desmopressin (dDAVP). Prolonged AMPK activation prevented AQP2 cell membrane accumulation in response to forskolin in mouse collecting duct mpkCCDc14 cells. Moreover, AMPK inhibition accelerated hypotonic lysis of Xenopus oocytes expressing AQP2. We performed phosphorylation assays to elucidate the mechanism by which AMPK regulates AQP2. Although AMPK weakly phosphorylated immunoprecipitated AQP2 in vitro, no direct AMPK phosphorylation of the AQP2 COOH-terminus was detected by mass spectrometry. AMPK promoted Ser-261 phosphorylation and antagonized dDAVP-dependent phosphorylation of other AQP2 COOH-terminal sites in cells. Our findings suggest an increasing, time-dependent antagonism of AMPK on AQP2 regulation with AICAR-dependent inhibition of cAMP-dependent apical accumulation and AVP-dependent phosphorylation of AQP2. This inhibition likely occurs via a mechanism that does not involve direct AQP2 phosphorylation by AMPK.
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Affiliation(s)
- Mohammad M Al-Bataineh
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Hui Li
- Department of Medicine, University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Kazuhiro Ohmi
- Department of Medicine, University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Fan Gong
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Allison L Marciszyn
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sajid Naveed
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Xiaoqing Zhu
- Department of Molecular Genetics, School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands; and
| | - Dietbert Neumann
- Department of Molecular Genetics, School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands; and
| | - Qi Wu
- Department of Biomedicine, InterPrET Center, Aarhus University, Aarhus, Denmark
| | - Lei Cheng
- Department of Biomedicine, InterPrET Center, Aarhus University, Aarhus, Denmark
| | - Robert A Fenton
- Department of Biomedicine, InterPrET Center, Aarhus University, Aarhus, Denmark
| | - Núria M Pastor-Soler
- Department of Medicine, University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of University of Southern California, Los Angeles, California;
| | - Kenneth R Hallows
- Department of Medicine, University of Southern California/University Kidney Research Organization, Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of University of Southern California, Los Angeles, California
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35
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Spies J, Waizenegger A, Barton O, Sürder M, Wright WD, Heyer WD, Löbrich M. Nek1 Regulates Rad54 to Orchestrate Homologous Recombination and Replication Fork Stability. Mol Cell 2016; 62:903-917. [PMID: 27264870 DOI: 10.1016/j.molcel.2016.04.032] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/23/2016] [Accepted: 04/26/2016] [Indexed: 11/17/2022]
Abstract
Never-in-mitosis A-related kinase 1 (Nek1) has established roles in apoptosis and cell cycle regulation. We show that human Nek1 regulates homologous recombination (HR) by phosphorylating Rad54 at Ser572 in late G2 phase. Nek1 deficiency as well as expression of unphosphorylatable Rad54 (Rad54-S572A) cause unresolved Rad51 foci and confer a defect in HR. Phospho-mimic Rad54 (Rad54-S572E), in contrast, promotes HR and rescues the HR defect associated with Nek1 loss. Although expression of phospho-mimic Rad54 is beneficial for HR, it causes Rad51 removal from chromatin and degradation of stalled replication forks in S phase. Thus, G2-specific phosphorylation of Rad54 by Nek1 promotes Rad51 chromatin removal during HR in G2 phase, and its absence in S phase is required for replication fork stability. In summary, Nek1 regulates Rad51 removal to orchestrate HR and replication fork stability.
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Affiliation(s)
- Julian Spies
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Anja Waizenegger
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Olivia Barton
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Michael Sürder
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - William D Wright
- Section of Microbiology, University of California, Davis, Davis, CA 95616-8665, USA
| | - Wolf-Dietrich Heyer
- Section of Microbiology, University of California, Davis, Davis, CA 95616-8665, USA
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
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Cotter K, Stransky L, McGuire C, Forgac M. Recent Insights into the Structure, Regulation, and Function of the V-ATPases. Trends Biochem Sci 2016; 40:611-622. [PMID: 26410601 DOI: 10.1016/j.tibs.2015.08.005] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
The vacuolar (H(+))-ATPases (V-ATPases) are ATP-dependent proton pumps that acidify intracellular compartments and are also present at the plasma membrane. They function in such processes as membrane traffic, protein degradation, virus and toxin entry, bone resorption, pH homeostasis, and tumor cell invasion. V-ATPases are large multisubunit complexes, composed of an ATP-hydrolytic domain (V1) and a proton translocation domain (V0), and operate by a rotary mechanism. This review focuses on recent insights into their structure and mechanism, the mechanisms that regulate V-ATPase activity (particularly regulated assembly and trafficking), and the role of V-ATPases in processes such as cell signaling and cancer. These developments have highlighted the potential of V-ATPases as a therapeutic target in a variety of human diseases.
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Affiliation(s)
- Kristina Cotter
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Laura Stransky
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Christina McGuire
- Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Michael Forgac
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
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37
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Hu DG, Sun CH, Sun MH, Hao YJ. MdSOS2L1 phosphorylates MdVHA-B1 to modulate malate accumulation in response to salinity in apple. PLANT CELL REPORTS 2016; 35:705-18. [PMID: 26687966 DOI: 10.1007/s00299-015-1914-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 10/26/2015] [Accepted: 11/26/2015] [Indexed: 05/22/2023]
Abstract
Salt-induced phosphorylation of MdVHA-B1 protein was mediated by MdSOS2L1 protein kinase, and thereby increasing malate content in apple. Salinity is an important environmental factor that influences malate accumulation in apple. However, the molecular mechanism by which salinity regulates this process is poorly understood. In this work, we found that MdSOS2L1, a novel AtSOS2-LIKE protein kinase, interacts with V-ATPase subunit MdVHA-B1. Furthermore, MdSOS2L1 directly phosphorylates MdVHA-B1 at Ser(396) site to modulate malate accumulation in response to salt stress. Meanwhile, a series of transgenic analyses in apple calli showed that the MdSOS2L1-MdVHAB1 pathway was involved in the regulation of malate accumulation. Finally, a viral vector-based transformation approach demonstrated that the MdSOS2L1-MdVHAB1 pathway also modulated malate accumulation in apple fruits with or without salt stress. Collectively, our findings provide a new insight into the mechanism by which MdSOS2L1 phosphorylates MdVHA-B1 to modulate malate accumulation in response to salinity in apple.
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Affiliation(s)
- Da-Gang Hu
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-an, 271018, Shandong, China
| | - Cui-Hui Sun
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-an, 271018, Shandong, China
| | - Mei-Hong Sun
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-an, 271018, Shandong, China
| | - Yu-Jin Hao
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-an, 271018, Shandong, China.
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38
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Al-Bataineh MM, Alzamora R, Ohmi K, Ho PY, Marciszyn AL, Gong F, Li H, Hallows KR, Pastor-Soler NM. Aurora kinase A activates the vacuolar H+-ATPase (V-ATPase) in kidney carcinoma cells. Am J Physiol Renal Physiol 2016; 310:F1216-28. [PMID: 26911844 DOI: 10.1152/ajprenal.00061.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 02/19/2016] [Indexed: 11/22/2022] Open
Abstract
Extracellular proton-secreting transport systems that contribute to extracellular pH include the vacuolar H(+)-ATPase (V-ATPase). This pump, which mediates ATP-driven transport of H(+) across membranes, is involved in metastasis. We previously showed (Alzamora R, Thali RF, Gong F, Smolak C, Li H, Baty CJ, Bertrand CA, Auchli Y, Brunisholz RA, Neumann D, Hallows KR, Pastor-Soler NM. J Biol Chem 285: 24676-24685, 2010) that V-ATPase A subunit phosphorylation at Ser-175 is important for PKA-induced V-ATPase activity at the membrane of kidney intercalated cells. However, Ser-175 is also located within a larger phosphorylation consensus sequence for Aurora kinases, which are known to phosphorylate proteins that contribute to the pathogenesis of metastatic carcinomas. We thus hypothesized that Aurora kinase A (AURKA), overexpressed in aggressive carcinomas, regulates the V-ATPase in human kidney carcinoma cells (Caki-2) via Ser-175 phosphorylation. We found that AURKA is abnormally expressed in Caki-2 cells, where it binds the V-ATPase A subunit in an AURKA phosphorylation-dependent manner. Treatment with the AURKA activator anacardic acid increased V-ATPase expression and activity at the plasma membrane of Caki-2 cells. In addition, AURKA phosphorylates the V-ATPase A subunit at Ser-175 in vitro and in Caki-2 cells. Immunolabeling revealed that anacardic acid induced marked membrane accumulation of the V-ATPase A subunit in transfected Caki-2 cells. However, anacardic acid failed to induce membrane accumulation of a phosphorylation-deficient Ser-175-to-Ala (S175A) A subunit mutant. Finally, S175A-expressing cells had decreased migration in a wound-healing assay compared with cells expressing wild-type or a phospho-mimetic Ser-175-to-Asp (S175D) mutant A subunit. We conclude that AURKA activates the V-ATPase in kidney carcinoma cells via phosphorylation of Ser-175 in the V-ATPase A subunit. This regulation contributes to kidney carcinoma V-ATPase-mediated extracellular acidification and cell migration.
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Affiliation(s)
- Mohammad M Al-Bataineh
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Rodrigo Alzamora
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Kazuhiro Ohmi
- Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California
| | - Pei-Yin Ho
- Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California
| | - Allison L Marciszyn
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Fan Gong
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Hui Li
- Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California
| | - Kenneth R Hallows
- Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California
| | - Núria M Pastor-Soler
- Department of Medicine, USC/UKRO Kidney Research Center, Division of Nephrology and Hypertension, Keck School of Medicine of USC, Los Angeles, California
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Daryadel A, Bourgeois S, Figueiredo MFL, Gomes Moreira A, Kampik NB, Oberli L, Mohebbi N, Lu X, Meima ME, Danser AHJ, Wagner CA. Colocalization of the (Pro)renin Receptor/Atp6ap2 with H+-ATPases in Mouse Kidney but Prorenin Does Not Acutely Regulate Intercalated Cell H+-ATPase Activity. PLoS One 2016; 11:e0147831. [PMID: 26824839 PMCID: PMC4732657 DOI: 10.1371/journal.pone.0147831] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 01/08/2016] [Indexed: 12/11/2022] Open
Abstract
The (Pro)renin receptor (P)RR/Atp6ap2 is a cell surface protein capable of binding and non-proteolytically activate prorenin. Additionally, (P)RR is associated with H+-ATPases and alternative functions in H+-ATPase regulation as well as in Wnt signalling have been reported. Kidneys express very high levels of H+-ATPases which are involved in multiple functions such as endocytosis, membrane protein recycling as well as urinary acidification, bicarbonate reabsorption, and salt absorption. Here, we wanted to localize the (P)RR/Atp6ap2 along the murine nephron, exmaine whether the (P)RR/Atp6ap2 is coregulated with other H+-ATPase subunits, and whether acute stimulation of the (P)RR/Atp6ap2 with prorenin regulates H+-ATPase activity in intercalated cells in freshly isolated collecting ducts. We localized (P)PR/Atp6ap2 along the murine nephron by qPCR and immunohistochemistry. (P)RR/Atp6ap2 mRNA was detected in all nephron segments with highest levels in the collecting system coinciding with H+-ATPases. Further experiments demonstrated expression at the brush border membrane of proximal tubules and in all types of intercalated cells colocalizing with H+-ATPases. In mice treated with NH4Cl, NaHCO3, KHCO3, NaCl, or the mineralocorticoid DOCA for 7 days, (P)RR/Atp6ap2 and H+-ATPase subunits were regulated but not co-regulated at protein and mRNA levels. Immunolocalization in kidneys from control, NH4Cl or NaHCO3 treated mice demonstrated always colocalization of PRR/Atp6ap2 with H+-ATPase subunits at the brush border membrane of proximal tubules, the apical pole of type A intercalated cells, and at basolateral and/or apical membranes of non-type A intercalated cells. Microperfusion of isolated cortical collecting ducts and luminal application of prorenin did not acutely stimulate H+-ATPase activity. However, incubation of isolated collecting ducts with prorenin non-significantly increased ERK1/2 phosphorylation. Our results suggest that the PRR/Atp6ap2 may form a complex with H+-ATPases in proximal tubule and intercalated cells but that prorenin has no acute effect on H+-ATPase activity in intercalated cells.
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MESH Headings
- Ammonium Chloride/pharmacology
- Animals
- Anion Transport Proteins/genetics
- Anion Transport Proteins/metabolism
- Aquaporin 2/genetics
- Aquaporin 2/metabolism
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Dogs
- Gene Expression Regulation
- Kidney Cortex/cytology
- Kidney Cortex/drug effects
- Kidney Cortex/metabolism
- Kidney Medulla/cytology
- Kidney Medulla/drug effects
- Kidney Medulla/metabolism
- Kidney Tubules, Collecting/cytology
- Kidney Tubules, Collecting/drug effects
- Kidney Tubules, Collecting/metabolism
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/drug effects
- Kidney Tubules, Proximal/metabolism
- Madin Darby Canine Kidney Cells
- Male
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred C57BL
- Proton-Translocating ATPases/genetics
- Proton-Translocating ATPases/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Renin/pharmacology
- Renin-Angiotensin System/drug effects
- Signal Transduction
- Sodium Bicarbonate/pharmacology
- Sodium Chloride/pharmacology
- Sodium-Phosphate Cotransporter Proteins, Type IIa/genetics
- Sodium-Phosphate Cotransporter Proteins, Type IIa/metabolism
- Solute Carrier Family 12, Member 1/genetics
- Solute Carrier Family 12, Member 1/metabolism
- Solute Carrier Family 12, Member 3/genetics
- Solute Carrier Family 12, Member 3/metabolism
- Sulfate Transporters
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Affiliation(s)
- Arezoo Daryadel
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Soline Bourgeois
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | | | - Nicole B. Kampik
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Lisa Oberli
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Nilufar Mohebbi
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- Divison of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Xifeng Lu
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marcel E. Meima
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - A. H. Jan Danser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Carsten A. Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- * E-mail:
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40
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Abstract
The H(+) concentration in human blood is kept within very narrow limits, ~40 nmol/L, despite the fact that dietary metabolism generates acid and base loads that are added to the systemic circulation throughout the life of mammals. One of the primary functions of the kidney is to maintain the constancy of systemic acid-base chemistry. The kidney has evolved the capacity to regulate blood acidity by performing three key functions: (i) reabsorb HCO3(-) that is filtered through the glomeruli to prevent its excretion in the urine; (ii) generate a sufficient quantity of new HCO3(-) to compensate for the loss of HCO3(-) resulting from dietary metabolic H(+) loads and loss of HCO3(-) in the urea cycle; and (iii) excrete HCO3(-) (or metabolizable organic anions) following a systemic base load. The ability of the kidney to perform these functions requires that various cell types throughout the nephron respond to changes in acid-base chemistry by modulating specific ion transport and/or metabolic processes in a coordinated fashion such that the urine and renal vein chemistry is altered appropriately. The purpose of the article is to provide the interested reader with a broad review of a field that began historically ~60 years ago with whole animal studies, and has evolved to where we are currently addressing questions related to kidney acid-base regulation at the single protein structure/function level.
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Affiliation(s)
- Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine, Los Angeles, CA; Brain Research Institute, UCLA, Los Angeles, CA
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41
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Sun X, Stephens L, DuBose TD, Petrovic S. Adaptation by the collecting duct to an exogenous acid load is blunted by deletion of the proton-sensing receptor GPR4. Am J Physiol Renal Physiol 2015; 309:F120-36. [DOI: 10.1152/ajprenal.00507.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 05/05/2015] [Indexed: 12/14/2022] Open
Abstract
We previously reported that the deletion of the pH sensor GPR4 causes a non-gap metabolic acidosis and defective net acid excretion (NAE) in the GPR4 knockout mouse (GPR4−/−) (Sun X, Yang LV, Tiegs BC, Arend LJ, McGraw DW, Penn RB, and Petrovic S. J Am Soc Nephrol 21: 1745–1755, 2010). Since the major regulatory site of NAE in the kidney is the collecting duct (CD), we examined acid-base transport proteins in intercalated cells (ICs) of the CD and found comparable mRNA expression of kidney anion exchanger 1 (kAE1), pendrin, and the a4 subunit of H+-ATPase in GPR4−/− vs. +/+. However, NH4Cl loading elicited adaptive doubling of AE1 mRNA in GPR4+/+, but a 50% less pronounced response in GPR4−/−. In GPR4+/+, NH4Cl loading evoked a cellular response characterized by an increase in AE1-labeled and a decrease in pendrin-labeled ICs similar to what was reported in rabbits and rats. This response did not occur in GPR4−/−. Microperfusion experiments demonstrated that the activity of the basolateral Cl−/HCO3− exchanger, kAE1, in CDs isolated from GPR4−/− failed to increase with NH4Cl loading, in contrast to the increase observed in GPR4+/+. Therefore, the deficiency of GPR4 blunted, but did not eliminate the adaptive response to an acid load, suggesting a compensatory response from other pH/CO2/bicarbonate sensors. Indeed, the expression of the calcium-sensing receptor (CaSR) was nearly doubled in GPR4−/− kidneys, in the absence of apparent disturbances of Ca2+ homeostasis. In summary, the expression and activity of the key transport proteins in GPR4−/− mice are consistent with spontaneous metabolic acidosis, but the adaptive response to a superimposed exogenous acid load is blunted and might be partially compensated for by CaSR.
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Affiliation(s)
- Xuming Sun
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Lisa Stephens
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Thomas D. DuBose
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Snezana Petrovic
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
- Claude D. Pepper Older Americans Independence Center, Wake Forest School of Medicine, Winston-Salem, North Carolina
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina; and
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42
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Triplett JC, Swomley A, Kirk J, Lewis K, Orr M, Rodriguez K, Cai J, Klein JB, Buffenstein R, Butterfield DA. Metabolic clues to salubrious longevity in the brain of the longest-lived rodent: the naked mole-rat. J Neurochem 2015; 134:538-50. [PMID: 25940666 DOI: 10.1111/jnc.13149] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/13/2015] [Accepted: 04/23/2015] [Indexed: 12/16/2022]
Abstract
Naked mole-rats (NMRs) are the oldest-living rodent species. Living underground in a thermally stable ecological niche, NMRs have evolved certain exceptional traits, resulting in sustained health spans, negligible cognitive decline, and a pronounced resistance to age-related disease. Uncovering insights into mechanisms underlying these extraordinary traits involved in successful aging may conceivably provide crucial clues to extend the human life span and health span. One of the most fundamental processes inside the cell is the production of ATP, which is an essential fuel in driving all other energy-requiring cellular activities. Not surprisingly, a prominent hallmark in age-related diseases, such as neurodegeneration and cancer, is the impairment and dysregulation of metabolic pathways. Using a two-dimensional polyacrylamide gel electrophoresis proteomics approach, alterations in expression and phosphorylation levels of metabolic proteins in the brains of NMRs, aged 2-24 years, were evaluated in an age-dependent manner. We identified 13 proteins with altered levels and/or phosphorylation states that play key roles in various metabolic pathways including glycolysis, β-oxidation, the malate-aspartate shuttle, the Tricarboxylic Acid Cycle (TCA) cycle, the electron transport chain, NADPH production, as well as the production of glutamate. New insights into potential pathways involved in metabolic aspects of successful aging have been obtained by the identification of key proteins through which the NMR brain responds and adapts to the aging process and how the NMR brain adapted to resist age-related degeneration. This study examines the changes in the proteome and phosphoproteome in the brain of the naked mole-rat aged 2-24 years. We identified 13 proteins (labeled in red) with altered expression and/or phosphorylation levels that are conceivably associated with sustained metabolic functions in the oldest NMRs that may promote a sustained health span and life span.
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Affiliation(s)
- Judy C Triplett
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Aaron Swomley
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Jessime Kirk
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Katilyn Lewis
- Sam and Ann Barsop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas, USA.,Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Miranda Orr
- Sam and Ann Barsop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas, USA.,Department of Physiology, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Karl Rodriguez
- Sam and Ann Barsop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas, USA.,Department of Physiology, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Jian Cai
- Department of Nephrology and Proteomics Center, University of Louisville, Louisville, Kentucky, USA
| | - Jon B Klein
- Department of Nephrology and Proteomics Center, University of Louisville, Louisville, Kentucky, USA
| | - Rochelle Buffenstein
- Sam and Ann Barsop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas, USA.,Department of Physiology, University of Texas Health Science Center, San Antonio, Texas, USA
| | - D Allan Butterfield
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
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Mauvezin C, Nagy P, Juhász G, Neufeld TP. Autophagosome-lysosome fusion is independent of V-ATPase-mediated acidification. Nat Commun 2015; 6:7007. [PMID: 25959678 PMCID: PMC4428688 DOI: 10.1038/ncomms8007] [Citation(s) in RCA: 281] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/23/2015] [Indexed: 12/20/2022] Open
Abstract
The ATP-dependent proton pump V-ATPase ensures low intralysosomal pH, which is essential for lysosomal hydrolase activity. Based on studies with the V-ATPase inhibitor BafilomycinA1, lysosomal acidification is also thought to be required for fusion with incoming vesicles from the autophagic and endocytic pathways. Here we show that loss of V-ATPase subunits in the Drosophila fat body causes an accumulation of non-functional lysosomes, leading to a block in autophagic flux. However, V-ATPase-deficient lysosomes remain competent to fuse with autophagosomes and endosomes, resulting in a time-dependent formation of giant autolysosomes. In contrast, BafilomycinA1 prevents autophagosome–lysosome fusion in these cells, and this defect is phenocopied by depletion of the Ca2+ pump SERCA, a secondary target of this drug. Moreover, activation of SERCA promotes fusion in a BafilomycinA1-sensitive manner. Collectively, our results indicate that lysosomal acidification is not a prerequisite for fusion, and that BafilomycinA1 inhibits fusion independent of its effect on lysosomal pH. BafilomycinA1 is an autophagy inhibitor, presumably owing to its blocking effect on the lysosomal proton pump V-ATPase. Here the authors show that V-ATPase-deficient lysosomes can still fuse with autophagosomes, showing that lysosomal acidification and fusion are two separable, independent events.
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Affiliation(s)
- Caroline Mauvezin
- Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA
| | - Péter Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pazmany s. 1/C. 6.520, Budapest H-1117, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pazmany s. 1/C. 6.520, Budapest H-1117, Hungary
| | - Thomas P Neufeld
- Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA
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Triplett JC, Zhang Z, Sultana R, Cai J, Klein JB, Büeler H, Butterfield DA. Quantitative expression proteomics and phosphoproteomics profile of brain from PINK1 knockout mice: insights into mechanisms of familial Parkinson's disease. J Neurochem 2015; 133:750-65. [PMID: 25626353 DOI: 10.1111/jnc.13039] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/08/2014] [Accepted: 01/12/2015] [Indexed: 12/27/2022]
Abstract
Parkinson's disease (PD) is an age-related, neurodegenerative motor disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta and presence of α-synuclein-containing protein aggregates. Mutations in the mitochondrial Ser/Thr kinase PTEN-induced kinase 1 (PINK1) are associated with an autosomal recessive familial form of early-onset PD. Recent studies have suggested that PINK1 plays important neuroprotective roles against mitochondrial dysfunction by phosphorylating and recruiting Parkin, a cytosolic E3 ubiquitin ligase, to facilitate elimination of damaged mitochondria via autophagy-lysosomal pathways. Loss of PINK1 in cells and animals leads to various mitochondrial impairments and oxidative stress, culminating in dopaminergic neuronal death in humans. Using a 2-D polyacrylamide gel electrophoresis proteomics approach, the differences in expressed brain proteome and phosphoproteome between 6-month-old PINK1-deficient mice and wild-type mice were identified. The observed changes in the brain proteome and phosphoproteome of mice lacking PINK1 suggest that defects in signaling networks, energy metabolism, cellular proteostasis, and neuronal structure and plasticity are involved in the pathogenesis of familial PD. Mutations in PINK1 are associated with an early-onset form of Parkinson's disease (PD). This study examines changes in the proteome and phosphoproteome of the PINK1 knockout mouse brain. Alterations were noted in several key proteins associated with: increased oxidative stress, aberrant cellular signaling, altered neuronal structure, decreased synaptic plasticity, reduced neurotransmission, diminished proteostasis networks, and altered metabolism. 14-3-3ε, 14-3-3 protein epsilon; 3-PGDH, phosphoglycerate dehydrogenase; ALDOA, aldolase A; APT1, acyl-protein thioesterase 1; CaM, calmodulin; CBR3, carbonyl reductase [NADPH] 3; ENO2, gamma-enolase; HPRT, hypoxanthine-guanine phosphoribosyltransferase; HSP70, heat-shock-related 70 kDa protein 2; IDHc, cytoplasmic isocitrate dehydrogenase [NADP+]; MAPK1, mitogen-activated protein kinase 1; MEK1, MAP kinase kinase 1; MDHc, cytoplasmic malate dehydrogenase; NFM, neurofilament medium polypeptide; NSF, N-ethylmaleimide-sensitive fusion protein; PHB, prohibitin; PINK1, PTEN-induced putative kinase 1; PPIaseA, peptidyl-prolyl cis-trans isomerase A; PSA2, proteasome subunit alpha type-2; TK, transketolase; VDAC-2, voltage-dependent anion-selective channel protein 2.
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Affiliation(s)
- Judy C Triplett
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
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45
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Lucena MN, Pinto MR, Garçon DP, McNamara JC, Leone FA. A kinetic characterization of the gill V(H+)-ATPase in juvenile and adult Macrobrachium amazonicum, a diadromous palaemonid shrimp. Comp Biochem Physiol B Biochem Mol Biol 2015; 181:15-25. [DOI: 10.1016/j.cbpb.2014.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/05/2014] [Accepted: 11/07/2014] [Indexed: 10/24/2022]
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Roy A, Al-bataineh MM, Pastor-Soler NM. Collecting duct intercalated cell function and regulation. Clin J Am Soc Nephrol 2015; 10:305-24. [PMID: 25632105 DOI: 10.2215/cjn.08880914] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Intercalated cells are kidney tubule epithelial cells with important roles in the regulation of acid-base homeostasis. However, in recent years the understanding of the function of the intercalated cell has become greatly enhanced and has shaped a new model for how the distal segments of the kidney tubule integrate salt and water reabsorption, potassium homeostasis, and acid-base status. These cells appear in the late distal convoluted tubule or in the connecting segment, depending on the species. They are most abundant in the collecting duct, where they can be detected all the way from the cortex to the initial part of the inner medulla. Intercalated cells are interspersed among the more numerous segment-specific principal cells. There are three types of intercalated cells, each having distinct structures and expressing different ensembles of transport proteins that translate into very different functions in the processing of the urine. This review includes recent findings on how intercalated cells regulate their intracellular milieu and contribute to acid-base regulation and sodium, chloride, and potassium homeostasis, thus highlighting their potential role as targets for the treatment of hypertension. Their novel regulation by paracrine signals in the collecting duct is also discussed. Finally, this article addresses their role as part of the innate immune system of the kidney tubule.
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Affiliation(s)
- Ankita Roy
- Renal-Electrolyte Division, Department of Medicine; and
| | | | - Núria M Pastor-Soler
- Renal-Electrolyte Division, Department of Medicine; and Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania A.R. and M.M.A. contributed equally to this work.
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Gidon A, Al-Bataineh MM, Jean-Alphonse FG, Stevenson H, Watanabe T, Louet C, Khatri A, Calero G, Pastor-Soler NM, Gardella TJ, Vilardaga JP. Endosomal GPCR signaling turned off by negative feedback actions of PKA and v-ATPase. Nat Chem Biol 2014; 10:707-9. [PMID: 25064832 PMCID: PMC4138287 DOI: 10.1038/nchembio.1589] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/13/2014] [Indexed: 12/13/2022]
Abstract
The PTH receptor is to our knowledge one of the first G protein-coupled receptor (GPCR) found to sustain cAMP signaling after internalization of the ligand-receptor complex in endosomes. This unexpected model is adding a new dimension on how we think about GPCR signaling, but its mechanism is incompletely understood. We report here that endosomal acidification mediated by the PKA action on the v-ATPase provides a negative feedback mechanism by which endosomal receptor signaling is turned off.
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Affiliation(s)
- Alexandre Gidon
- Laboratory for GPCR Biology, Department of Pharmacology & Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Mohammad M. Al-Bataineh
- Renal-Electrolyte Division, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Frederic G. Jean-Alphonse
- Laboratory for GPCR Biology, Department of Pharmacology & Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Hilary Stevenson
- Department of Structural Biology Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Tomoyuki Watanabe
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 0114, USA
| | - Claire Louet
- Laboratory for GPCR Biology, Department of Pharmacology & Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Ashok Khatri
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 0114, USA
| | - Guillermo Calero
- Department of Structural Biology Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Núria M. Pastor-Soler
- Renal-Electrolyte Division, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Thomas J. Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 0114, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology & Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
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Tresguerres M. sAC from aquatic organisms as a model to study the evolution of acid/base sensing. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2629-35. [PMID: 24971688 DOI: 10.1016/j.bbadis.2014.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 06/17/2014] [Indexed: 12/26/2022]
Abstract
Soluble adenylyl cyclase (sAC) is poised to play multiple physiological roles as an acid/base (A/B) sensor in aquatic organisms. Many of these roles are probably similar to those in mammals; a striking example is the evolutionary conservation of a mechanism involving sAC, carbonic anhydrase and vacuolar H⁺-ATPase that acts as a sensor system and regulator of extracellular A/B in shark gills and mammalian epididymis and kidney. Additionally, the aquatic environment presents unique A/B and physiological challenges; therefore, sACs from aquatic organisms have likely evolved distinct kinetic properties as well as distinct physiological roles. sACs from aquatic organisms offer an excellent opportunity for studying the evolution of A/B sensing at both the molecular and whole organism levels. Moreover, this information could help understand and predict organismal responses to environmental stress based on mechanistic models.This article is part of a Special Issue entitled "The Role of Soluble Adenylyl Cyclase in Health and Disease," guest edited by J. Buck and L. R. Levin.
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Affiliation(s)
- Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
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49
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Al-bataineh MM, Gong F, Marciszyn AL, Myerburg MM, Pastor-Soler NM. Regulation of proximal tubule vacuolar H(+)-ATPase by PKA and AMP-activated protein kinase. Am J Physiol Renal Physiol 2014; 306:F981-95. [PMID: 24553431 PMCID: PMC4010682 DOI: 10.1152/ajprenal.00362.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 02/13/2014] [Indexed: 11/22/2022] Open
Abstract
The vacuolar H(+)-ATPase (V-ATPase) mediates ATP-driven H(+) transport across membranes. This pump is present at the apical membrane of kidney proximal tubule cells and intercalated cells. Defects in the V-ATPase and in proximal tubule function can cause renal tubular acidosis. We examined the role of protein kinase A (PKA) and AMP-activated protein kinase (AMPK) in the regulation of the V-ATPase in the proximal tubule as these two kinases coregulate the V-ATPase in the collecting duct. As the proximal tubule V-ATPases have different subunit compositions from other nephron segments, we postulated that V-ATPase regulation in the proximal tubule could differ from other kidney tubule segments. Immunofluorescence labeling of rat ex vivo kidney slices revealed that the V-ATPase was present in the proximal tubule both at the apical pole, colocalizing with the brush-border marker wheat germ agglutinin, and in the cytosol when slices were incubated in buffer alone. When slices were incubated with a cAMP analog and a phosphodiesterase inhibitor, the V-ATPase accumulated at the apical pole of S3 segment cells. These PKA activators also increased V-ATPase apical membrane expression as well as the rate of V-ATPase-dependent extracellular acidification in S3 cell monolayers relative to untreated cells. However, the AMPK activator AICAR decreased PKA-induced V-ATPase apical accumulation in proximal tubules of kidney slices and decreased V-ATPase activity in S3 cell monolayers. Our results suggest that in proximal tubule the V-ATPase subcellular localization and activity are acutely coregulated via PKA downstream of hormonal signals and via AMPK downstream of metabolic stress.
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Affiliation(s)
- Mohammad M Al-bataineh
- Renal-Electrolyte Div., Dept. of Medicine, Scaife Hall A915, 3550 Terrace St., Pittsburgh, PA 15263.
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50
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Coffey EE, Beckel JM, Laties AM, Mitchell CH. Lysosomal alkalization and dysfunction in human fibroblasts with the Alzheimer's disease-linked presenilin 1 A246E mutation can be reversed with cAMP. Neuroscience 2014; 263:111-24. [PMID: 24418614 PMCID: PMC4028113 DOI: 10.1016/j.neuroscience.2014.01.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 12/30/2013] [Accepted: 01/02/2014] [Indexed: 12/27/2022]
Abstract
Mutation in presenilin 1 (PS1) is one of the leading causes of familial Alzheimer's disease (fAD). PS1 mutation exacerbates the autophagic and lysosomal pathology in AD patients, leading to accumulation of partially degraded material in bloated lysosomes and autophagosomes - a pathology that bears some resemblance to other diseases characterized by elevated lysosomal pH, like age-related macular degeneration. In this study, we examined the effect of the PS1-fAD mutation A246E on lysosomal pH and lysosomal function, and asked whether restoration of lysosomal pH could reverse some of these changes. Lysosomal pH was elevated by 0.2-0.3 pH units in human fibroblasts with the PS1-fAD mutation. The lysosomal alkalization in PS1-fAD fibroblasts was supported by a reduction in the pH-dependent cleavage of cathepsin D and by a reduction in binding of boron-dipyrromethene (BODIPY) FL-pepstatin A to the cathepsin D active site. PS1-fAD cells had increased LC3B-II/-I ratios and p62 levels, consistent with impaired lysosomal degradation and analogous to changes induced by lysosomal alkalinization with chloroquine. PS1-fAD fibroblasts had increased expression of ATP6V1B2, ATG5, BECN1 TFEB mRNA, and of ATP6V1B2, ATG5 and beclin at the protein level, consistent with chronic impairment of autophagic and lysosomal functions in the mutant cells. Critically, cyclic adenosine monophosphate (cAMP) treatment reacidified lysosomal pH in mutant PS1-fAD; cAMP also increased the availability of active cathepsin D and lowered the LC3B-II/-I ratio. These results confirm a small elevation in the lysosomal pH of human PS1-fAD fibroblasts, demonstrate that this lysosomal alkalization is associated with chronic changes in autophagy and degradation, and suggest that treatment to reacidify the lysosomes with cAMP can reverse these changes.
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Affiliation(s)
- E E Coffey
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - J M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - A M Laties
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - C H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, United States; Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, United States.
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