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Wang H, Zhang Y, Zhang Y, Liu W, Wang J. Cryptotanshinone inhibits lung cancer invasion via microRNA-133a/matrix metalloproteinase 14 regulation. Oncol Lett 2019; 18:2554-2559. [PMID: 31452742 DOI: 10.3892/ol.2019.10580] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 04/04/2019] [Indexed: 12/24/2022] Open
Abstract
Cryptotanshinone inhibits the proliferative and colony formation abilities of human non-small cell lung cancer cells (NSCLCs). The present study reported that signal transducer and activator of transcription 3 is not the only target of cryptotanshinone during the inhibition of human NSCLCs. It was identified that cryptotanshinone upregulates the expression levels of microRNA (miR)-30d-5p, miR-126-3p, miR-133a, miR-338-3p and miR-451a, and downregulates miR-21-5p, miR-96-5p, miR-182-5p and miR-205-5p. Among these, miR-133a was the most significantly upregulated. miR-133a targets and downregulates the expression of matrix metalloproteinase (MMP)14; however, MMP15, MMP16 and MMP24 were determined to be unaffected. This process was identified to be independent of tissue inhibitor of metalloproteinases 2. Cryptotanshinone also suppresses the invasion of human NSCLCs, which may be due to the inhibited expression of MMP14. In conclusion, cryptotanshinone may serve as a potential therapeutic agent in the treatment of lung cancer.
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Affiliation(s)
- Huijuan Wang
- Department of Tumor Chemotherapy, Tumor Hospital of Wuwei, Wuwei, Gansu 733000, P.R. China
| | - Yanshan Zhang
- Department of Thoracic Surgery, Tumor Hospital of Wuwei, Wuwei, Gansu 733000, P.R. China
| | - Yingguo Zhang
- Department of Thoracic Surgery, Tumor Hospital of Wuwei, Wuwei, Gansu 733000, P.R. China
| | - Wenling Liu
- Department of Thoracic Surgery, Tumor Hospital of Wuwei, Wuwei, Gansu 733000, P.R. China
| | - Jihong Wang
- Department of Thoracic Surgery, Tumor Hospital of Wuwei, Wuwei, Gansu 733000, P.R. China
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2
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Abstract
Neurodegenerative disorders (NDDs) are characterized by neuronal death in the brain. The mechanism of the neuronal death is too complicated to be fully understood, although in many NDDs, aging and neurotoxins are known risk factors. In the central and peripheral nervous system, vasoactive intestinal peptide (VIP), a 28-amino acid neuropeptide, is released to support neuronal survival in both physiological and pathological condition. VIP can inhibit the neurodegeneration induced by the loss of neurons. The indirect protection effect is mainly mediated by glial cells through the production of neurotrophic factor(s) and inhibition of proinflammatory mediators. By remolding the structure and improving the transfer efficiency of VIP, its nerve protective function could be further improved. Its neuroprotective action and efficacy in inhibiting a broad range of inflammatory responses make VIP or related peptides becoming a novel therapeutic method to NDDs. In this review, we aim to summarize the relationship between VIP and NDDs.
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Affiliation(s)
- Guangxiu Deng
- a National Glycoengineering Research Center , Shandong University , Jinan , China
| | - Lan Jin
- a National Glycoengineering Research Center , Shandong University , Jinan , China
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Mubo AS, Ibukun OA. Medicinal plants used in the treatment of neurodegenerative disorders in some parts of Southwest Nigeria. ACTA ACUST UNITED AC 2015. [DOI: 10.5897/ajpp2014.4164] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Kleczkowska P, Kawalec M, Bujalska-Zadrozny M, Filip M, Zablocka B, Lipkowski AW. Effects of the Hybridization of Opioid and Neurotensin Pharmacophores on Cell Survival in Rat Organotypic Hippocampal Slice Cultures. Neurotox Res 2015; 28:352-60. [PMID: 26286504 DOI: 10.1007/s12640-015-9553-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/04/2015] [Accepted: 08/04/2015] [Indexed: 10/23/2022]
Abstract
Several neurotransmitter and neuromodulatory systems can control physiological glutamatergic activity. For example, opioid receptor ligands were shown to partially inhibit N-methyl-D-aspartic acid (NMDA) receptor-dependent glutamatergic excitotoxicity. Also, the endogenous tridecapeptide neurotensin (NT) was found to modulate excessive glutamate release and glutamate receptor activity in neurons. Alternatively to the one target-one drug approach, it has been well documented that hybrid compounds encompassing two pharmacophores in one molecular scaffold can represent more potent drugs. Moreover, such structures with dual activity can potentially enable a reduction of undesirable side effects and/or improved bioavailability. Herein, we describe the neuroprotective potential of an opioid-NT hybrid peptide (PK20), which was recently designed and synthesized within our group. The protective properties of PK20, assessed in an in vitro model of excitotoxic injury in organotypic hippocampal slice cultures subjected to NMDA, were compared to the effects caused by NT. Our results indicate that PK20 is a potent anti-neurodegenerative agent. Moreover, co-administered with NMDA, PK20 (25-100 ng/ml) dose-dependently reduced hippocampal cell death, determined by a decrease in the propidium iodide signal. We also report for the first time the significant NT-induced neuroprotective effect, as its application (50-100 ng/ml) to hippocampal slice cultures protected CA1 damage against neurotoxicity caused by NMDA.
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Affiliation(s)
- Patrycja Kleczkowska
- Department of Neuropeptides, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland. .,Department of Pharmacodynamics, Centre for Preclinical Research and Technology, CEPT, Medical University of Warsaw, 1B Banacha Str., 02-106, Warsaw, Poland.
| | - Maria Kawalec
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
| | - Magdalena Bujalska-Zadrozny
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, CEPT, Medical University of Warsaw, 1B Banacha Str., 02-106, Warsaw, Poland
| | - Małgorzata Filip
- Department of Toxicology, Faculty of Pharmacy, Jagiellonian University, College of Medicum, 9 Medyczna Str., 30-688, Kraków, Poland.,Laboratory of Drug Addiction Pharmacology, Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna Str., 31-343, Kraków, Poland
| | - Barbara Zablocka
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
| | - Andrzej W Lipkowski
- Department of Neuropeptides, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
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Expression of early growth response 1 affects miR-106a/signal transducer and activator of transcription 3 regulating cognitive impairment in ovariectomized mice. Menopause 2015; 21:1143-50. [PMID: 24686449 DOI: 10.1097/gme.0000000000000234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE This study aims to investigate the effects of early growth response 1 (Egr1) on miR-106a/signal transducer and activator of transcription 3 (STAT3) regulating cognitive impairment in an ovariectomy model. METHODS Using the Morris water maze test, we assessed escape latency and time spent in a quadrant among mice at 6, 8, and 12 weeks after ovariectomy and their age-matched controls (n = 15 each group). Egr1, miR-106a, and STAT3 messenger RNA expression (n = 7) in the hippocampus and cortex of mice at 6, 8, and 12 weeks after ovariectomy was detected by quantitative real-time polymerase chain reaction, whereas Egr1, phospho-STAT3 (p-STAT3), and STAT3 protein expression (n = 8) was evaluated by Western blot analysis. Moreover, alterations in miR-106a and STAT3 expression were investigated in neuroblastoma (SH-SY5Y) cells transfected with a human Egr1 interference fragment (si-Egr1) or an Egr1-overexpressing plasmid (GV141-Egr1), respectively. RESULTS Escape latency was significantly increased and time spent in a platform quadrant was reduced in mice at 12 weeks after ovariectomy compared with age-matched controls. Egr1 and miR-106a expression was obviously increased in the hippocampus and cortex at 12 weeks after ovariectomy, whereas STAT3 levels were decreased compared with 12-week controls. After SH-SY5Y cell transfection with the si-Egr1 fragment, miR-106a levels decreased and STAT3/p-STAT3 levels increased, whereas cotransfection of the miR-106a mimic caused a significant decrease in STAT3 levels. MiR-106a messenger RNA expression was significantly increased and STAT3/p-STAT3 protein levels were decreased by Egr1 overexpression, whereas simultaneous transfection with the miR-106a inhibitor inhibited alterations in STAT3 levels. CONCLUSIONS This study suggests that Egr1 decreases STAT3 expression via miR-106a in ovariectomized mice with cognitive impairment, indicating that Egr1 represents a potential target for therapeutic intervention in postmenopausal cognitive decline.
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New labeled derivatives of the neuroprotective peptide colivelin: Synthesis, characterization, and first in vitro and in vivo applications. Arch Biochem Biophys 2015; 567:83-93. [DOI: 10.1016/j.abb.2014.12.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/15/2014] [Accepted: 12/29/2014] [Indexed: 12/25/2022]
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Wu MN, Zhou LW, Wang ZJ, Han WN, Zhang J, Liu XJ, Tong JQ, Qi JS. Colivelin ameliorates amyloid β peptide-induced impairments in spatial memory, synaptic plasticity, and calcium homeostasis in rats. Hippocampus 2014; 25:363-72. [DOI: 10.1002/hipo.22378] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Mei-Na Wu
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Li-Wei Zhou
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Zhao-Jun Wang
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Wei-Na Han
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Jun Zhang
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Xiao-Jie Liu
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Jia-Qing Tong
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
| | - Jin-Shun Qi
- Department of Physiology, Key Laboratory of Cellular Physiology; Ministry of Education, Shanxi Medical University; Taiyuan China
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Protective effects of humanin on okadaic Acid-induced neurotoxicities in cultured cortical neurons. Neurochem Res 2014; 39:2150-9. [PMID: 25142935 DOI: 10.1007/s11064-014-1410-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 08/05/2014] [Accepted: 08/06/2014] [Indexed: 12/30/2022]
Abstract
Neurofibrillary tangles are pathological hallmarks of Alzheimer's disease (AD), which are mostly composed of hyperphosphorylated tau and directly correlate with dementia in AD patients. Okadaic acid (OA), a toxin extracted from marine life, can specifically inhibit protein phosphatases (PPs), including PP1 and Protein phosphatase 2A (PP2A), resulting in tau hyperphosphorylation. Humanin (HN), a peptide of 24 amino acids, was initially reported to protect neurons from AD-related cell toxicities. The present study was designed to test if HN could attenuate OA-induced neurotoxicities, including neural insults, apoptosis, autophagy, and tau hyperphosphorylation. We found that administration of OA for 24 h induced neuronal insults, including lactate dehydrogenase released, decreased of cell viability and numbers of living cells, neuronal apoptosis, cells autophagy and tau protein hyperphosphorylation. Pretreatment of cells with HN produced significant protective effects against OA-induced neural insults, apoptosis, autophagy and tau hyperphosphorylation. We also found that OA treatment inhibited PP2A activity and HN pretreatment significantly attenuated the inhibitory effects of OA. This study demonstrated for the first time that HN protected cortical neurons against OA-induced neurotoxicities, including neuronal insults, apoptosis, autophagy, and tau hyperphosphorylation. The mechanisms underlying the protections of HN may involve restoration of PP2A activity.
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Humanin rescues cultured rat cortical neurons from NMDA-induced toxicity not by NMDA receptor. ScientificWorldJournal 2014; 2014:341529. [PMID: 24959608 PMCID: PMC4052483 DOI: 10.1155/2014/341529] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/11/2014] [Accepted: 04/29/2014] [Indexed: 01/24/2023] Open
Abstract
Excitatory neurotoxicity has been implicated in many pathological situations and there is no effective treatment available. Humanin is a 24-aa peptide cloned from the brain of patients with Alzheimer's disease (AD). In the present study, excitatory toxicity was induced by N-methyl-D-aspartate (NMDA) in primarily cultured rat cortical neurons. MTT assessment, lactate dehydrogenase (LDH) release, and calcein staining were employed to evaluate the protective activity of humanin on NMDA induced toxicity. The results suggested that NMDA (100 μmol/L, 2.5 hr) triggered neuronal morphological changes, lactate dehydrogenase (LDH) release (166% of the control), reduction of cell viability (about 50% of the control), and the decrease of living cell density (about 50% of the control). When pretreated with humanin, the toxicity was suppressed. The living cells' density of humanin treated group was similar to that of control. The cell viability was attenuated dose-dependently (IC50 = 0.132 nmol/L). The LDH release was also neutralized in a dose-dependent manner. In addition, the intracellular Ca(2+) overloading triggered by NMDA reverted quickly and humanin could not inhibit it. These findings indicate that humanin can rescue cortical neurons from NMDA-induced toxicity in rat but not through interfering with NMDA receptor directly.
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Arslan PE, Chakrabartty A. Probing Alzheimer amyloid peptide aggregation using a cell-free fluorescent protein refolding method. Biochem Cell Biol 2009; 87:631-9. [PMID: 19767826 DOI: 10.1139/o09-038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fibrillation of the Alzheimer beta-amyloid peptide (Abeta) and (or) formation of toxic oligomers are key pathological events in Alzheimer's disease. Several strategies have been introduced to identify small molecule aggregation inhibitors, and based on these methods, a number of aggregation inhibitors have been identified. However, most of these methods use chemically synthesized Abeta42 peptides, which are difficult to maintain in a monomeric state at neutral pH where anti-aggregation screening is usually carried out. We have developed a cell-free Abeta42 aggregation assay based on fluorescence protein refolding. This assay utilizes nanomolar concentrations of protein. We genetically fused Abeta42 to the N-terminus of vYFP, a variant of of GFP, and expressed and purified the folded fusion protein. The refolding efficiency of Abeta42-vYFP fusion was inversely correlated with the solubility of Abeta42. Using fluorescence to monitor refolding of Abeta42-vYFP, we confirmed that Zn2+ binds to Abeta42 and increases its aggregation. The IC50 value estimated for Zn binding is 3.03 +/- 0.65 micromol/L. We also show that this technique is capable of monitoring the aggregation of chemically synthesized Abeta42.
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Affiliation(s)
- Pharhad Eli Arslan
- Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
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12
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Chiba T, Yamada M, Aiso S. Targeting the JAK2/STAT3 axis in Alzheimer's disease. Expert Opin Ther Targets 2009; 13:1155-67. [PMID: 19663649 DOI: 10.1517/14728220903213426] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Amyloid beta (Abeta) has long been implicated in the pathogenesis of Alzheimer's disease (AD). Little is known, however, about the intracellular events in neurons which lead to memory loss related to AD. Focusing on the fact that an AD-specific neuroprotective peptide named humanin (HN) inhibits AD-related neurotoxicity by activating the JAK2/STAT3 signaling axis, we recently found that age- and disease-dependent deterioration in the JAK2/STAT3 axis plays a critical role in the pathogenesis of AD. OBJECTIVE/METHODS Here we summarize the neuroprotective effect of HN and its derivative, named colivelin (CLN), and also review the roles of the JAK2/STAT3 axis in memory impairment related to AD. RESULTS/CONCLUSIONS The JAK2/STAT3 axis is a major transducer of HN-mediated neuroprotective activity. Abeta-dependent inactivation of the JAK2/STAT3 axis in hippocampal neurons causes cholinergic dysfunction via pre- and post-synaptic mechanisms, which leads to memory impairment related to AD. This provides not only a novel pathological hallmark of AD but also a novel target in AD therapy.
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Affiliation(s)
- Tomohiro Chiba
- Keio University School of Medicine, Department of Anatomy, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Abstract
Elevation of intracranial soluble amyloid-beta (Abeta) levels has been implicated in the pathogenesis of Alzheimer's disease (AD). Intracellular events in neurons, which lead to memory loss in AD, however, remain elusive. Humanin (HN) is a short neuroprotective peptide abolishing Abeta neurotoxicity. Recently, we found that HN derivatives activate the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling axis. We here report that an HN derivative named colivelin completely restored cognitive function in an AD model (Tg2576) by activating the JAK2/STAT3 axis. In accordance, immunofluorescence staining using a specific antibody against phospho- (p-) STAT3 revealed that p-STAT3 levels in hippocampal neurons age-dependently decreased in both AD model mice and AD patients. Intracerebroventricular administration of Abeta1-42 downregulated p-STAT3 whereas passive immunization with anti-Abeta antibody conversely restored hippocampal p-STAT3 levels in Tg2576 mice, paralleling the decrease in the brain Abeta burden. Abeta1-42 consistently modulated p-STAT3 levels in primary neurons. Pharmacological inhibition of the JAK2/STAT3 axis not only induced significant loss of spatial working memory by downregulating an acetylcholine-producing enzyme choline acetyltransferase but also desensitized the M(1)-type muscarinic acetylcholine receptor. Thus, we propose a novel theory accounting for memory impairment related to AD: Abeta-dependent inactivation of the JAK2/STAT3 axis causes memory loss through cholinergic dysfunction. Our findings provide not only a novel pathological hallmark in AD but also a novel target in AD therapy.
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Kunesová G, Hlavácek J, Patocka J, Evangelou A, Zikos C, Benaki D, Paravatou-Petsotas M, Pelecanou M, Livaniou E, Slaninova J. The multiple T-maze in vivo testing of the neuroprotective effect of humanin analogues. Peptides 2008; 29:1982-7. [PMID: 18647630 DOI: 10.1016/j.peptides.2008.06.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 06/25/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
Abstract
Humanin (HN) and its analogues have been shown to protect cells against death induced by various Alzheimer's disease (AD) genes and amyloid-beta-peptides in vitro; the analogues [Gly(14)]-HN and colivelin have also been shown to be potent in reversing learning and memory impairment induced by scopolamine or quinuclidinyl benzilate (QNB) in mice or rats in vivo using the Y-maze or multiple T-maze tests. This paper describes the activity of new peptides of the HN family, after i.p. administration, on QNB-induced impairment of spatial memory in the multiple T-maze test in rats. The following peptides have been studied: HN analogues truncated either on the C- or N-terminus, or analogues having a tert-Leu in place of Leu in the central part of the molecule, the active HN core PAGASRLLLLTGEIDLP (RG-PAGA) and its analogues having three or five leucines instead of four, and finally the recently described hybrid peptide colivelin (i.e. a peptide having the activity-dependent neurotrophic factor SALLRSIPA attached to the N-terminus of the active RG-PAGA) and its des-Leu- and plus-Leu-analogues. While the truncated analogues and most of the tert-Leu containing analogues were devoid of activity, the analogues of the RG-PAGA were active, i.e. they reversed the impairment of spatial memory irrespective of the number of Leu present in their sequence. The highest activity was shown by colivelin and its des-Leu-analogue. These results demonstrate the potential of HN analogues in the modulation of the cholinergic system, which plays an important role in the cognitive deficits associated with AD and other neurodegenerative diseases.
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Affiliation(s)
- Gabriela Kunesová
- Department of Toxicology, University of Defense, Trebesská 1575, 500 01 Hradec Králové, Czech Republic
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Singh BK, Mascarenhas DD. Bioactive peptides control receptor for advanced glycated end product-induced elevation of kidney insulin receptor substrate 2 and reduce albuminuria in diabetic mice. Am J Nephrol 2008; 28:890-9. [PMID: 18566543 DOI: 10.1159/000141042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 02/25/2008] [Indexed: 01/19/2023]
Abstract
BACKGROUND/AIMS Sixteen-week-old db/db mice exhibit significantly elevated blood glucose and albuminuria. Kidney mesangial cell matrix expansion and collagen IV synthesis correlate with disease progression, but the underlying mechanism is unclear. METHODS Adaptive biochemical datasets were generated in cultured 293 kidney cells and in db/db mice. RESULTS In animals receiving daily subcutaneous bolus injections (weeks 8-13) of 20 microg/day humanin or 40 microg/day protein kinase C (NPKC) (a PKC-beta2 inhibitor peptide), there was a significant reduction in albuminuria, insulin receptor substrate 2 (IRS-2) and phospho-Akt (Ser473) levels in kidney tissue extracts (p < 0.05 in all cases). Elevated IRS-2 (not IRS-1), altered Akt1 and selective phosphorylation of p-Akt/Ser473 and p-IRS-1/Ser307 (but not p-Akt/Thr308 or p-IRS-2/Ser731) are correlates of the receptor for advanced glycated end product activation and are linked to albuminuria in vivo, whereas in P38 peptide-treated animals, collagen IV synthesis can be uncoupled from albuminuria altogether. CONCLUSION Taken together, our results suggest that elevated IRS-2 and altered Akt phosphorylation may be more closely tied to the cause of diabetic kidney disease in db/db mice than mesangial matrix expansion per se, though both may originate from elevated circulatory glucose, and mesangial matrix expansion may independently exacerbate kidney dysfunction.
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Affiliation(s)
- Baljit K Singh
- Mayflower Organization for Research and Education, Inc., Sunnyvale, CA 94085, USA
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