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Gober IG, Russell AL, Shick TJ, Vagni VA, Carlson JC, Kochanek PM, Wagner AK. Exploratory assessment of the effect of systemic administration of soluble glycoprotein 130 on cognitive performance and chemokine levels in a mouse model of experimental traumatic brain injury. J Neuroinflammation 2024; 21:149. [PMID: 38840141 PMCID: PMC11155101 DOI: 10.1186/s12974-024-03129-0] [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: 02/28/2024] [Accepted: 05/12/2024] [Indexed: 06/07/2024] Open
Abstract
Uncontrolled neuroinflammation mediates traumatic brain injury (TBI) pathology and impairs recovery. Interleukin-6 (IL-6), a pleiotropic inflammatory regulator, is associated with poor clinical TBI outcomes. IL-6 operates via classical-signaling through membrane-bound IL-6 receptor (IL-6R) and trans-signaling through soluble IL-6 receptor (s)IL-6R. IL-6 trans-signaling specifically contributes to neuropathology, making it a potential precision therapeutic TBI target. Soluble glycoprotein 130 (sgp130) prevents IL-6 trans-signaling, sparing classical signaling, thus is a possible treatment. Mice received either controlled cortical impact (CCI) (6.0 ± 0.2 m/s; 2 mm; 50-60ms) or sham procedures. Vehicle (VEH) or sgp130-Fc was subcutaneously administered to sham (VEH or 1 µg) and CCI (VEH, 0.25 µg or 1 µg) mice on days 1, 4, 7, 10 and 13 post-surgery to assess effects on cognition [Morris Water Maze (MWM)] and ipsilateral hemisphere IL-6 related biomarkers (day 21 post-surgery). CCI + sgp130-Fc groups (0.25 µg and 1 µg) were combined for analysis given similar behavior/biomarker outcomes. CCI + VEH mice had longer latencies and path lengths to the platform and increased peripheral zone time versus Sham + VEH and Sham + sgp130-Fc mice, suggesting injury-induced impairments in learning and anxiety. CCI + sgp130-Fc mice had shorter platform latencies and path lengths and had decreased peripheral zone time, indicating a therapeutic benefit of sgp130-Fc after injury on learning and anxiety. Interestingly, Sham + sgp130-Fc mice had shorter platform latencies, path lengths and peripheral zone times than Sham + VEH mice, suggesting a beneficial effect of sgp130-Fc, independent of injury. CCI + VEH mice had increased brain IL-6 and decreased sgp130 levels versus Sham + VEH and Sham + sgp130-Fc mice. There was no treatment effect on IL-6, sIL6-R or sgp130 in Sham + VEH versus Sham + sgp130-Fc mice. There was also no treatment effect on IL-6 in CCI + VEH versus CCI + sgp130-Fc mice. However, CCI + sgp130-Fc mice had increased sIL-6R and sgp130 versus CCI + VEH mice, demonstrating sgp130-Fc treatment effects on brain biomarkers. Inflammatory chemokines (MIP-1β, IP-10, MIG) were increased in CCI + VEH mice versus Sham + VEH and Sham + sgp130-Fc mice. However, CCI + sgp130-Fc mice had decreased chemokine levels versus CCI + VEH mice. IL-6 positively correlated, while sgp130 negatively correlated, with chemokine levels. Overall, we found that systemic sgp130-Fc treatment after CCI improved learning, decreased anxiety and reduced CCI-induced brain chemokines. Future studies will explore sex-specific dosing and treatment mechanisms for sgp130-Fc therapy.
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Affiliation(s)
- Ian G Gober
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, 3471 Fifth Avenue, Suite 910, Pittsburgh, PA, 15213, USA
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA
| | - Ashley L Russell
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, 3471 Fifth Avenue, Suite 910, Pittsburgh, PA, 15213, USA
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA
| | - Tyler J Shick
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, 3471 Fifth Avenue, Suite 910, Pittsburgh, PA, 15213, USA
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA
| | - Vincent A Vagni
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jenna C Carlson
- Department of Biostatistics, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Amy K Wagner
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, 3471 Fifth Avenue, Suite 910, Pittsburgh, PA, 15213, USA.
- Safar Center for Resuscitation Research, John G. Rangos Research Center, Pittsburgh, PA, USA.
- Center for Neuroscience, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Neuroscience, School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA.
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Zhang C, Gordon MD, Joseph KM, Diaz‐Hernandez ME, Drissi H, Illien‐Jünger S. Differential efficacy of two small molecule PHLPP inhibitors to promote nucleus Pulposus cell health. JOR Spine 2024; 7:e1306. [PMID: 38222816 PMCID: PMC10782076 DOI: 10.1002/jsp2.1306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/31/2023] [Accepted: 11/04/2023] [Indexed: 01/16/2024] Open
Abstract
Background Intervertebral disc (IVD) degeneration is associated with chronic back pain. We previously demonstrated that the phosphatase pleckstrin homology domain and leucine-rich repeat protein phosphatase (PHLPP) 1 was positively correlated with IVD degeneration and its deficiency decelerated IVD degeneration in both mouse IVDs and human nucleus pulposus (NP) cells. Small molecule PHLPP inhibitors may offer a translatable method to alleviate IVD degeneration. In this study, we tested the effectiveness of the two PHLPP inhibitors NSC117079 and NSC45586 in promoting a healthy NP phenotype. Methods Tail IVDs of 5-month-old wildtype mice were collected and treated with NSC117079 or NSC45586 under low serum conditions ex vivo. Hematoxylin & eosin staining was performed to examine IVD structure and NP cell morphology. The expression of KRT19 was analyzed through immunohistochemistry. Cell apoptosis was assessed by TUNEL assay. Human NP cells were obtained from patients with IVD degeneration. The gene expression of KRT19, ACAN, SOX9, and MMP13 was analyzed via real time qPCR, and AKT phosphorylation and the protein expression of FOXO1 was analyzed via immunoblot. Results In a mouse IVD organ culture model, NSC45586, but not NSC117079, preserved vacuolated notochordal cell morphology and KRT19 expression while suppressing cell apoptosis, counteracting the degenerative changes induced by serum deprivation, especially in males. Likewise, in degenerated human NP cells, NSC45586 increased cell viability and the expression of KRT19, ACAN, and SOX9 and reducing the expression of MMP13, while NSC117079 treatment only increased KRT19 expression. Mechanistically, NSC45586 treatment increased FOXO1 protein expression in NP cells, and inhibiting FOXO1 offset NSC45586-induced regenerative potential, especially in males. Conclusions Our study indicates that NSC45586 was effective in promoting NP cell health, especially in males, suggesting that PHLPP plays a key role in NP cell homeostasis and that NSC45586 might be a potential drug candidate in treating IVD degeneration.
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Affiliation(s)
- Changli Zhang
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Madeleine D. Gordon
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Katherine M. Joseph
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | | | - Hicham Drissi
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
- Atlanta VA Health Care SystemDecaturGeorgiaUSA
| | - Svenja Illien‐Jünger
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
- Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
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Snyder K, Gorse K, Kochanek PM, Jackson TC. Neuronal RBM5 modulates cell signaling responses to traumatic and hypoxic-ischemic injury in a sex-dependent manner. Cell Death Discov 2023; 9:379. [PMID: 37848418 PMCID: PMC10582027 DOI: 10.1038/s41420-023-01677-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/22/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023] Open
Abstract
It is not clear if inhibiting the pro-death gene RNA binding motif 5 (RBM5) is neuroprotective in isolated primary neurons or if it regulates cell survival in a sex-dependent manner. Here we established sex-dichotomized primary cortical neuron cultures from transgenic mice harboring a floxed RBM5 gene-trap. Lentivirus-mediated expression of CRE was used to silence RBM5 expression. Male and female neurons were maintained in next-generation Neurobasal-Plus media and subjected to a mechanical stretch-injury (to model traumatic brain injury) or oxygen-glucose deprivation/OGD (to model ischemia). RBM5 KO did not affect 24 h post-injury survival as determined by lactate dehydrogenase (LDH) release, in either paradigm. In contrast, female KO neurons had increased spectrin breakdown products post-insult (in both models). Furthermore, in OGD, RBM5 KO in male neurons exacerbated injury-induced downregulation of pro-survival AKT activation (pAKT473) but conversely led to pAKT473 sparing in female neurons. Moreover, global proteomics identified 19 differentially expressed (DE) proteins in OGD-injured male neurons, and 102 DE proteins in injured female neurons. Two novel RBM5-regulated proteins (PIGQ and EST1C) were identified in injured male KO neurons, and 8 novel proteins identified in injured female KO neurons (S35A5, DHTK1, STX3, IF3M, RN167, K1C14, DYHS, and MED13). In summary, RBM5 inhibition does not modify neuronal survival in primary mouse neurons in 2 clinically relevant models of excitotoxic insult, but RBM5 does regulate intracellular responses to injury in a sex-dependent manner.
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Affiliation(s)
- Kara Snyder
- University of South Florida, Morsani College of Medicine, USF Health Heart Institute, MDD 0630, 560 Channelside Dr, Tampa, FL, 33602, USA
- University of South Florida, Morsani College of Medicine, Department of Molecular Pharmacology & Physiology, 12901 Bruce B Downs Blvd, Tampa, FL, 33612, USA
| | - Kiersten Gorse
- University of South Florida, Morsani College of Medicine, USF Health Heart Institute, MDD 0630, 560 Channelside Dr, Tampa, FL, 33602, USA
- University of South Florida, Morsani College of Medicine, Department of Molecular Pharmacology & Physiology, 12901 Bruce B Downs Blvd, Tampa, FL, 33612, USA
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, UPMC Children's Hospital of Pittsburgh, Rangos Research Center - 6th floor, Pittsburgh, PA, 15224, USA
| | - Travis C Jackson
- University of South Florida, Morsani College of Medicine, USF Health Heart Institute, MDD 0630, 560 Channelside Dr, Tampa, FL, 33602, USA.
- University of South Florida, Morsani College of Medicine, Department of Molecular Pharmacology & Physiology, 12901 Bruce B Downs Blvd, Tampa, FL, 33612, USA.
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Emerging roles of PHLPP phosphatases in the nervous system. Mol Cell Neurosci 2022; 123:103789. [PMID: 36343848 DOI: 10.1016/j.mcn.2022.103789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/15/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022] Open
Abstract
It has been more than a decade since the discovery of a novel class of phosphatase, the Pleckstrin Homology (PH) domain Leucine-rich repeat Protein Phosphatases (PHLPP). Over time, they have been recognized as crucial regulators of various cellular processes, such as memory formation, cellular survival and proliferation, maintenance of circadian rhythm, and others, with any deregulation in their expression or cellular localization causing havoc in any cellular system. With the ever-growing number of downstream substrates across multiple tissue systems, a web is emerging wherein the central point is PHLPP. A slight nick in the normal signaling cascade of the two isoforms of PHLPP, namely PHLPP1 and PHLPP2, has been recently found to invoke a variety of neurological disorders including Alzheimer's disease, epileptic seizures, Parkinson's disease, and others, in the neuronal system. Improper regulation of the two isoforms has also been associated with various disease pathologies such as diabetes, cardiovascular disorders, cancer, musculoskeletal disorders, etc. In this review, we have summarized all the current knowledge about PHLPP1 (PHLPP1α and PHLPP1β) and PHLPP2 and their emerging roles in regulating various neuronal signaling pathways to pave the way for a better understanding of the complexities. This would in turn aid in providing context for the development of possible future therapeutic strategies.
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PHLPP Inhibitor NSC74429 Is Neuroprotective in Rodent Models of Cardiac Arrest and Traumatic Brain Injury. Biomolecules 2022; 12:biom12101352. [DOI: 10.3390/biom12101352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022] Open
Abstract
Pleckstrin homology domain and leucine rich repeat protein phosphatase (PHLPP) knockout mice have improved outcomes after a stroke, traumatic brain injury (TBI), and decreased maladaptive vascular remodeling following vascular injury. Thus, small-molecule PHLPP inhibitors have the potential to improve neurological outcomes in a variety of conditions. There is a paucity of data on the efficacy of the known experimental PHLPP inhibitors, and not all may be suited for targeting acute brain injury. Here, we assessed several PHLPP inhibitors not previously explored for neuroprotection (NSC13378, NSC25247, and NSC74429) that had favorable predicted chemistries for targeting the central nervous system (CNS). Neuronal culture studies in staurosporine (apoptosis), glutamate (excitotoxicity), and hydrogen peroxide (necrosis/oxidative stress) revealed that NSC74429 at micromolar concentrations was the most neuroprotective. Subsequent testing in a rat model of asphyxial cardiac arrest, and in a mouse model of severe TBI, showed that serial dosing of 1 mg/kg of NSC74429 over 3 days improved hippocampal survival in both models. Taken together, NSC74429 is neuroprotective across multiple insult mechanisms. Future pharmacokinetic and pharmacodynamic (PK/PD) studies are warranted to optimize dosing, and mechanistic studies are needed to determine the percentage of neuroprotection mediated by PHLPP1/2 inhibition, or potentially from the modulation of PHLPP-independent targets.
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Farooq J, Snyder K, Janesko-Feldman K, Gorse K, Vagni V, Kochanek PM, Jackson TC. RNA Binding Motif 5 Gene Deletion Modulates Cell Signaling in a Sex-Dependent Manner but not Hippocampal Cell Death. J Neurotrauma 2022; 39:577-589. [PMID: 35152732 PMCID: PMC8978574 DOI: 10.1089/neu.2021.0362] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
RNA-binding motif 5 (RBM5) is a pro-death tumor suppressor gene in cancer cells. It remains to be determined if it is neurotoxic in the brain or rather if it plays a fundamentally different role in the central nervous system (CNS). Brain-specific RBM5 knockout (KO) mice were given a controlled cortical impact (CCI) traumatic brain injury (TBI). Markers of acute cellular damage and repair were measured in hippocampal homogenates 48 h post-CCI. Hippocampal CA1/CA3 cell counts were assessed 7 days post-CCI to determine if early changes in injury markers were associated with histological outcome. No genotype-dependent differences were found in the levels of apoptotic markers (caspase 3, caspase 6, and caspase 9). However, KO females had a paradoxical increase in markers of pro-death calpain activation (145/150-spectrin and breakdown products [SBDP]) and in DNA repair/survival markers. (pH2A.x and pCREB). CCI-injured male KOs had a significant increase in phosphorylated calcium/calmodulin-dependent protein kinase II (pCaMKII). Despite sex/genotype-dependent differences in KOs in the levels of acute cell signaling targets involved in cell death pathways, 7 day hippocampal neuronal survival did not differ from that of wild types (WTs). Similarly, no differences in astrogliosis were observed. Finally, gene analysis revealed increased estrogen receptor α (ERα) levels in the KO hippocampus in females and may suggest a novel mechanism to explain sex-dimorphic effects on cell signaling. In summary, RBM5 inhibition did not affect hippocampal survival after a TBI in vivo but did modify targets involved in neural signal transduction/Ca2+ signaling pathways. Findings here support the view that RBM5 may serve a purpose in the CNS that is dissimilar from its traditional pro-death role in cancer.
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Affiliation(s)
- Jeffrey Farooq
- University of South Florida, 7831, Molecular Pharmacology and Physiology, Tampa, Florida, United States
- USF Health Morsani College of Medicine, 33697, USF Health Heart Institute, Tampa, Florida, United States
| | - Kara Snyder
- University of South Florida, 7831, Molecular Pharmacology and Physiology, Tampa, Florida, United States
- USF Health Morsani College of Medicine, 33697, USF Health Heart Institute, Tampa, Florida, United States
| | - Keri Janesko-Feldman
- University of Pittsburgh School of Medicine, Critical Care Medicine, Pittsburgh, Pennsylvania, United States,
| | - Kiersten Gorse
- University of South Florida, 7831, Molecular Pharmacology and Physiology, Tampa, Florida, United States
- USF Health Morsani College of Medicine, 33697, USF Health Heart Institute, Tampa, Florida, United States
| | - Vincent Vagni
- University of Pittsburgh School of Medicine, Critical Care Medicine, Pittsburgh, Pennsylvania, United States,
| | - Patrick M. Kochanek
- University of Pittsburgh School of Medicine, Critical Care Medicine, John G. Rangos Research Center, Safar Center for Resuscitation Research, 4401 Penn Avenue, Pittsburgh, Pennsylvania, United States, 15224
- United States
| | - Travis C. Jackson
- University of South Florida, 7831, Molecular Pharmacology and Physiology, 4202 E Fowler Ave, Tampa, Florida, United States, 33620-9951
- USF Health Morsani College of Medicine, 33697, USF Health Heart Institute, 560 Channelside Dr, Tampa, Florida, United States, 33602
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Lemoine KA, Fassas JM, Ohannesian SH, Purcell NH. On the PHLPPside: Emerging roles of PHLPP phosphatases in the heart. Cell Signal 2021; 86:110097. [PMID: 34320369 PMCID: PMC8403656 DOI: 10.1016/j.cellsig.2021.110097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023]
Abstract
PH domain leucine-rich repeat protein phosphatase (PHLPP) is a family of enzymes made up of two isoforms (PHLPP1 and PHLPP2), whose actions modulate intracellular activity via the dephosphorylation of specific serine/threonine (Ser/Thr) residues on proteins such as Akt. Recent data generated in our lab, supported by findings from others, implicates the divergent roles of PHLPP1 and PHLPP2 in maintaining cellular homeostasis since dysregulation of these enzymes has been linked to various pathological states including cardiovascular disease, diabetes, ischemia/reperfusion injury, musculoskeletal disease, and cancer. Therefore, development of therapies to modulate specific isoforms of PHLPP could prove to be therapeutically beneficial in several diseases especially those targeting the cardiovascular system. This review is intended to provide a comprehensive summary of current literature detailing the role of the PHLPP isoforms in the development and progression of heart disease.
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Affiliation(s)
- Kellie A Lemoine
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Julianna M Fassas
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Shirag H Ohannesian
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Nicole H Purcell
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA; Cardiovascular Molecular Signaling, Huntington Medical Research Institutes, Pasadena, CA 91105, USA.
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Inampudi C, Ciccotosto GD, Cappai R, Crack PJ. Genetic Modulators of Traumatic Brain Injury in Animal Models and the Impact of Sex-Dependent Effects. J Neurotrauma 2021; 37:706-723. [PMID: 32027210 DOI: 10.1089/neu.2019.6955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a major health problem causing disability and death worldwide. There is no effective treatment, due in part to the complexity of the injury pathology and factors affecting its outcome. The extent of brain injury depends on the type of insult, age, sex, lifestyle, genetic risk factors, socioeconomic status, other co-injuries, and underlying health problems. This review discusses the genes that have been directly tested in TBI models, and whether their effects are known to be sex-dependent. Sex differences can affect the incidence, symptom onset, pathology, and clinical outcomes following injury. Adult males are more susceptible at the acute phase and females show greater injury in the chronic phase. TBI is not restricted to a single sex; despite variations in the degree of symptom onset and severity, it is important to consider both female and male animals in TBI pre-clinical research studies.
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Affiliation(s)
- Chaitanya Inampudi
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Giuseppe D Ciccotosto
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Roberto Cappai
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia
| | - Peter J Crack
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia
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Lupse B, Annamalai K, Ibrahim H, Kaur S, Geravandi S, Sarma B, Pal A, Awal S, Joshi A, Rafizadeh S, Madduri MK, Khazaei M, Liu H, Yuan T, He W, Gorrepati KDD, Azizi Z, Qi Q, Ye K, Oberholzer J, Maedler K, Ardestani A. Inhibition of PHLPP1/2 phosphatases rescues pancreatic β-cells in diabetes. Cell Rep 2021; 36:109490. [PMID: 34348155 PMCID: PMC8421018 DOI: 10.1016/j.celrep.2021.109490] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/06/2021] [Accepted: 07/14/2021] [Indexed: 12/16/2022] Open
Abstract
Pancreatic β-cell failure is the key pathogenic element of the complex metabolic deterioration in type 2 diabetes (T2D); its underlying pathomechanism is still elusive. Here, we identify pleckstrin homology domain leucine-rich repeat protein phosphatases 1 and 2 (PHLPP1/2) as phosphatases whose upregulation leads to β-cell failure in diabetes. PHLPP levels are highly elevated in metabolically stressed human and rodent diabetic β-cells. Sustained hyper-activation of mechanistic target of rapamycin complex 1 (mTORC1) is the primary mechanism of the PHLPP upregulation linking chronic metabolic stress to ultimate β-cell death. PHLPPs directly dephosphorylate and regulate activities of β-cell survival-dependent kinases AKT and MST1, constituting a regulatory triangle loop to control β-cell apoptosis. Genetic inhibition of PHLPPs markedly improves β-cell survival and function in experimental models of diabetes in vitro, in vivo, and in primary human T2D islets. Our study presents PHLPPs as targets for functional regenerative therapy of pancreatic β cells in diabetes.
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Affiliation(s)
- Blaz Lupse
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Karthika Annamalai
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Hazem Ibrahim
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Supreet Kaur
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Shirin Geravandi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Bhavishya Sarma
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Anasua Pal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sushil Awal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Arundhati Joshi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sahar Rafizadeh
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Murali Krishna Madduri
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Mona Khazaei
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Huan Liu
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Ting Yuan
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Wei He
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | | | - Zahra Azizi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran
| | - Qi Qi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jose Oberholzer
- Charles O. Strickler Transplant Center, University of Virginia Medical Center, Charlottesville, VA 22903, USA
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany.
| | - Amin Ardestani
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran.
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Trivedi A, Tercovich KG, Casbon AJ, Raber J, Lowell C, Noble-Haeusslein LJ. Neutrophil-specific deletion of Syk results in recruitment-independent stabilization of the barrier and a long-term improvement in cognitive function after traumatic injury to the developing brain. Neurobiol Dis 2021; 157:105430. [PMID: 34153467 DOI: 10.1016/j.nbd.2021.105430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/14/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
While traumatic brain injury (TBI) is the leading cause of death and disability in children, we have yet to identify those pathogenic events that determine the extent of recovery. Neutrophils are best known as "first responders" to sites of infection and trauma where they become fully activated, killing pathogens via proteases that are released during degranulation. However, this activational state may generate substantial toxicity in the young brain after TBI that is partially due to developmentally regulated inadequate antioxidant reserves. Neutrophil degranulation is triggered via a downstream signaling pathway that is dependent on spleen tyrosine kinase (Syk). To test the hypothesis that the activational state of neutrophils is a determinant of early pathogenesis and long-term recovery, we compared young, brain-injured conditional knockouts of Syk (sykf/fMRP8-cre+) to congenic littermates (sykf/f). Based upon flow cytometry, there was an extended recruitment of distinct leukocyte subsets, including Ly6G+/Ly6C- and Ly6G+/Ly6Cint, over the first several weeks post-injury which was similar between genotypes. Subsequent assessment of the acutely injured brain revealed a reduction in blood-brain barrier disruption to both high and low molecular weight dextrans and reactive oxygen species in sykf/fMRP8-cre+ mice compared to congenic littermates, and this was associated with greater preservation of claudin 5 and neuronal integrity, as determined by Western blot analyses. At adulthood, motor learning was less affected in brain-injured sykf/fMRP8-cre+ mice as compared to sykf/f mice. Performance in the Morris Water Maze revealed a robust improvement in hippocampal-dependent acquisition and short and long-term spatial memory retention in sykf/fMRP8-cre+ mice. Subsequent analyses of swim path lengths during hidden platform training and probe trials showed greater thigmotaxis in brain-injured sykf/f mice than sham sykf/f mice and injured sykf/fMRP8-cre+ mice. Our results establish the first mechanistic link between the activation state of neutrophils and long-term functional recovery after traumatic injury to the developing brain. These results also highlight Syk kinase as a novel therapeutic target that could be further developed for the brain-injured child.
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Affiliation(s)
- Alpa Trivedi
- Departments of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA; Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Kayleen G Tercovich
- Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Amy Jo Casbon
- Departments of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Jacob Raber
- Departments of Behavioral Neuroscience, Neurology, and Radiation Medicine, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA; Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Clifford Lowell
- Departments of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Linda J Noble-Haeusslein
- Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA; Departments of Neurology and Psychology, The Dell Medical School and the College of Liberal Arts, University of Texas, Austin, TX 78712, USA.
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11
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Weaver SR, Taylor EL, Zars EL, Arnold KM, Bradley EW, Westendorf JJ. Pleckstrin homology (PH) domain and Leucine Rich Repeat Phosphatase 1 (Phlpp1) Suppresses Parathyroid Hormone Receptor 1 (Pth1r) Expression and Signaling During Bone Growth. J Bone Miner Res 2021; 36:986-999. [PMID: 33434347 PMCID: PMC8131217 DOI: 10.1002/jbmr.4248] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/06/2020] [Accepted: 12/24/2020] [Indexed: 12/20/2022]
Abstract
Endochondral ossification is tightly controlled by a coordinated network of signaling cascades including parathyroid hormone (PTH). Pleckstrin homology (PH) domain and leucine rich repeat phosphatase 1 (Phlpp1) affects endochondral ossification by suppressing chondrocyte proliferation in the growth plate, longitudinal bone growth, and bone mineralization. As such, Phlpp1-/- mice have shorter long bones, thicker growth plates, and proportionally larger growth plate proliferative zones. The goal of this study was to determine how Phlpp1 deficiency affects PTH signaling during bone growth. Transcriptomic analysis revealed greater PTH receptor 1 (Pth1r) expression and enrichment of histone 3 lysine 27 acetylation (H3K27ac) at the Pth1r promoter in Phlpp1-deficient chondrocytes. PTH (1-34) enhanced and PTH (7-34) attenuated cell proliferation, cAMP signaling, cAMP response element-binding protein (CREB) phosphorylation, and cell metabolic activity in Phlpp1-inhibited chondrocytes. To understand the role of Pth1r action in the endochondral phenotypes of Phlpp1-deficient mice, Phlpp1-/- mice were injected with Pth1r ligand PTH (7-34) daily for the first 4 weeks of life. PTH (7-34) reversed the abnormal growth plate and long-bone growth phenotypes of Phlpp1-/- mice but did not rescue deficits in bone mineral density or trabecular number. These results show that elevated Pth1r expression and signaling contributes to increased proliferation in Phlpp1-/- chondrocytes and shorter bones in Phlpp1-deficient mice. Our data reveal a novel molecular relationship between Phlpp1 and Pth1r in chondrocytes during growth plate development and longitudinal bone growth. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
| | | | | | | | - Elizabeth W. Bradley
- Department of Orthopedic Surgery and Stem Cell Institute, University of Minnesota, Minneapolis, MN
| | - Jennifer J. Westendorf
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
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12
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Identification of Novel Targets of RBM5 in the Healthy and Injured Brain. Neuroscience 2020; 440:299-315. [PMID: 32335213 DOI: 10.1016/j.neuroscience.2020.04.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 11/20/2022]
Abstract
The tumor suppressor RNA-binding motif 5 (RBM5) regulates the expression levels and cassette exon-definition (i.e. splicing) of a select set of mRNAs in a tissue-specific manner. Most RBM5-regulated targets were identified in oncological investigations and frequently involve genes which mediate apoptotic cell death. Little is known about the role of RBM5 in the brain. Also, it is unclear if a brain injury may be required to detect RBM5 mediated effects on pro-apoptotic genes due to their low expression levels in the healthy adult CNS at baseline. Conditional/floxed (brain-specific) gene deleter mice were generated to elucidate CNS-specific RBM5 mRNA targets. Male/female mice were subjected to a severe controlled cortical impact (CCI) traumatic brain injury (TBI) in order to increase the background expression of pro-death mRNAs and facilitate testing of the hypothesis that RBM5 inhibition decreases post-injury upregulation of caspases/FAS in the CNS. As expected, a CCI increased caspases/FAS mRNA in the injured cortex. RBM5 KO did not affect their levels or splicing. Surprisingly, KO increased the mRNA levels of novel targets including casein kinase 2 alpha prime interacting protein (Csnka2ip/CKT2) - a gene not thought to be expressed in the brain, contrary to findings here. Twenty-two unique splicing events were also detected in KOs including increased block-inclusion of cassette exons 20-22 in regulating synaptic membrane exocytosis 2 (Rims2). In conclusion, here we used genome-wide transcriptomic analysis on healthy and injured RBM5 KO mouse brain tissue to elucidate the first known gene targets of this enigmatic RBP in this CNS.
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13
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Jackson TC, Janesko-Feldman K, Carlson SW, Kotermanski SE, Kochanek PM. Robust RBM3 and β-klotho expression in developing neurons in the human brain. J Cereb Blood Flow Metab 2019; 39:2355-2367. [PMID: 31566073 PMCID: PMC6890998 DOI: 10.1177/0271678x19878889] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
RNA binding motif 3 (RBM3) is a powerful neuroprotectant that inhibits neurodegenerative cell death in vivo and is a promising therapeutic target in brain ischemia. RBM3 is increased by the hormone fibroblast growth factor 21 (FGF21) in an age- and temperature-dependent manner in rat cortical neurons. FGF21 receptor binding is controlled by the transmembrane protein β-klotho, which is mostly absent in the adult brain. We discovered that RBM3/β-klotho is unexpectedly high in the human infant vs. adult brain (hippocampus/prefrontal cortex). The use of tissue homogenates in that study precluded a comparison of RBM3/β-klotho expression among different CNS cell-types, thus, omitted key evidence (i.e. confirmation of neuronal expression) that would otherwise provide a critical link to support their possible direct neuroprotective effects in humans. This report addresses that knowledge gap. High-quality fixed human hippocampus, cortex, and hypothalamic tissues were acquired from the NIH Neurobiobank (<1 yr (premature born) infants, 1 yr, 4 yr, and 34 yr). Dual labeling of cell-type markers vs. RBM3/β-klotho revealed enriched staining of targets in neurons in the developing brain. Identifying that RBM3/β-klotho is abundant in neurons in the immature brain is fundamentally important to guide protocol design and conceptual frameworks germane to future testing of these neuroprotective pathways in humans.
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Affiliation(s)
- Travis C Jackson
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Keri Janesko-Feldman
- Safar Center for Resuscitation Research, School of Medicine Children's Hospital of Pittsburgh of UPMC John G. Rangos Research Center, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shaun W Carlson
- Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn E Kotermanski
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, School of Medicine Children's Hospital of Pittsburgh of UPMC John G. Rangos Research Center, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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14
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Shao Z, Lv G, Wen P, Cao Y, Yu D, Lu Y, Li G, Su Z, Teng P, Gao K, Wang Y, Mei X. Silencing of PHLPP1 promotes neuronal apoptosis and inhibits functional recovery after spinal cord injury in mice. Life Sci 2018; 209:291-299. [PMID: 30114409 DOI: 10.1016/j.lfs.2018.08.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 08/04/2018] [Accepted: 08/11/2018] [Indexed: 12/21/2022]
Abstract
AIM Spinal cord injury (SCI) causes increased apoptosis of neurons, leading to irreversible dysfunction of the spinal cord. In this study, we investigated the effects of the progression of SCI and potential regulation of apoptosis after the Pleckstrin homology (PH) domain and leucine rich repeat protein phosphatase 1 (PHLPP1) gene was silenced. MAIN METHODS Spinal cord injection, and neuronal transfection with a recombinant adenovirus vector encoding small interfering RNA (siRNA) against PHLPP1 (AdsiPHLPP1) successfully silenced PHLPP1. These created in vivo and in vitro PHLPP1-silenced models, respectively, resulting in stable expression of the transgene in neurons. KEY FINDINGS The results showed that silencing of PHLPP1 evidently reduced levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) after SCI. Western blot analysis revealed that the mice injected with AdsiPHLPP1 showed increased the expression of pro-apoptotic factors (Bax and cleaved-caspase 3), and reduced levels of neurotrophic (BDNF) and anti-apoptotic (Bcl-2) factors, both in vivo and in vitro. The motor function of AdsiPHLPP1-injected mice was restored more slowly than that of wild type (WT) mice. In addition, the number of motor neurons surviving in the anterior horn of the spinal cord was also reduced after SCI. SIGNIFICANCE Our results confirm that silencing of PHLPP1 promotes neuronal apoptosis and inhibits functional recovery after injury in vivo and in vitro. Consequently, PHLPP1 represents a potential therapeutic target gene for the clinical treatment of SCI.
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Affiliation(s)
- Zhenya Shao
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Gang Lv
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Pushuai Wen
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Yang Cao
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Deshui Yu
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Yanyan Lu
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Gang Li
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Zichen Su
- Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Peng Teng
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Kang Gao
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China
| | - Yansong Wang
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China.
| | - Xifan Mei
- Department of Orthopedics, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China.
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