scholarly journals KU-32, a Novel Drug for Diabetic Neuropathy, Is Safe for Human Islets and ImprovesIn VitroInsulin Secretion and Viability

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Kevin Farmer ◽  
S. Janette Williams ◽  
Lesya Novikova ◽  
Karthik Ramachandran ◽  
Sonia Rawal ◽  
...  
Keyword(s):  
Hsp90 Inhibitor ◽  
Human Islets ◽  
Clinical Indices ◽  
And Function ◽  
Insulin Staining ◽  
Novel Drug ◽  
Alamarblue Assay

KU-32 is a novel, novobiocin-based Hsp90 inhibitor that protects against neuronal glucotoxicity and reverses multiple clinical indices of diabetic peripheral neuropathy in a rodent model. However, any drug with potential for treating diabetic complications must also have no adverse effects on the function of pancreatic islets. Thus, the goal of the current study was to assess the effect of KU-32 on thein vitroviability and function of human islets. Treating human islets with KU-32 for 24 hours showed no toxicity as assessed using the alamarBlue assay. Confocal microscopy confirmed that with a minimum of 2-day exposure, KU-32 improved cellular viability by blocking apoptosis. Functionally, isolated human islets released more glucose-stimulated insulin when preincubated in KU-32. However, diabetic BKS-db/db mice, a model for type 2 diabetes, administered KU-32 for 10 weeks did not show any significant changes in blood glucose and insulin levels, despite having greater insulin staining/beta cell in the pancreas compared to untreated BKS db/db mice. In summary, KU-32 did not harm isolated human islets and may even be protective. However, the effect does not appear significant enough to alter thein vivometabolic parameters of diabetic mice.

scholarly journals Neratinib protects pancreatic beta cells in diabetes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Amin Ardestani ◽  
Sijia Li ◽  
Karthika Annamalai ◽  
Blaz Lupse ◽  
Shirin Geravandi ◽  
...  
Keyword(s):  
Pancreatic Beta Cells ◽  
Cell Function ◽  
Cell Mass ◽  
Human Islets ◽  
Β Cells ◽  
Β Cell

Abstract The loss of functional insulin-producing β-cells is a hallmark of diabetes. Mammalian sterile 20-like kinase 1 (MST1) is a key regulator of pancreatic β-cell death and dysfunction; its deficiency restores functional β-cells and normoglycemia. The identification of MST1 inhibitors represents a promising approach for a β-cell-protective diabetes therapy. Here, we identify neratinib, an FDA-approved drug targeting HER2/EGFR dual kinases, as a potent MST1 inhibitor, which improves β-cell survival under multiple diabetogenic conditions in human islets and INS-1E cells. In a pre-clinical study, neratinib attenuates hyperglycemia and improves β-cell function, survival and β-cell mass in type 1 (streptozotocin) and type 2 (obese Leprdb/db) diabetic mouse models. In summary, neratinib is a previously unrecognized inhibitor of MST1 and represents a potential β-cell-protective drug with proof-of-concept in vitro in human islets and in vivo in rodent models of both type 1 and type 2 diabetes.

scholarly journals Differential Telomere Processing by Borrelia Telomere Resolvases In Vitro but Not In Vivo

2006 ◽  
Vol 188 (21) ◽  
pp. 7378-7386 ◽  
Author(s):  
Yvonne Tourand ◽  
Troy Bankhead ◽  
Sandra L. Wilson ◽  
Adrienne D. Putteet-Driver ◽  
Alan G. Barbour ◽  
...  
Keyword(s):  
Structure And Function ◽  
Borrelia Hermsii ◽  
Discernible Effect ◽  
Causative Agents ◽  
And Function ◽  
Segmented Genome ◽  
Species Hybridization

ABSTRACT Causative agents of Lyme disease and relapsing fever, including Borrelia burgdorferi and Borrelia hermsii, respectively, are unusual among bacteria in that they possess a segmented genome with linear DNA molecules terminated by hairpin ends, known as telomeres. During replication, these telomeres are processed by the essential telomere resolvase, ResT, in a unique biochemical reaction known as telomere resolution. In this study, we report the identification of the B. hermsii resT gene through cross-species hybridization. Sequence comparison of the B. hermsii protein with the B. burgdorferi orthologue revealed 67% identity, including all the regions currently known to be crucial for telomere resolution. In vitro studies, however, indicated that B. hermsii ResT was unable to process a replicated B. burgdorferi type 2 telomere substrate. In contrast, in vivo cross-species complementation in which the native resT gene of B. burgdorferi was replaced with B. hermsii resT had no discernible effect, even though B. burgdorferi strain B31 carries at least two type 2 telomere ends. The B. burgdorferi ResT protein was also able to process two telomere spacing mutants in vivo that were unresolvable in vitro. The unexpected differential telomere processing in vivo versus in vitro by the two telomere resolvases suggests the presence of one or more accessory factors in vivo that are normally involved in the reaction. Our current results are also expected to facilitate further studies into ResT structure and function, including possible interaction with other Borrelia proteins.

Tongxinluo Inhibits Renal Fibrosis in Diabetic Nephropathy: Involvement of the Suppression of Intercellular Transfer of TGF-β1-Containing Exosomes from GECs to GMCs

2017 ◽  
Vol 45 (05) ◽  
pp. 1075-1092 ◽  
Author(s):  
Xiao-Ming Wu ◽  
Yan-Bin Gao ◽  
Li-Ping Xu ◽  
Da-Wei Zou ◽  
Zhi-Yao Zhu ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Mesangial Cells ◽  
Glomerular Mesangial Cells ◽  
Intercellular Transfer ◽  
Beneficial Effects ◽  
Renal Structure ◽  
And Function

Glomerular mesangial cells (GMCs) activation is implicated in the pathogenesis of diabetic nephropathy (DN). Our previous study revealed that high glucose (HG)-treated glomerular endothelial cells (GECs) produce an increased number of TGF-[Formula: see text]1-containing exosomes to activate GMCs through the TGF-[Formula: see text]1/Smad3 signaling pathway. We also identified that Tongxinluo (TXL), a traditional Chinese medicine, has beneficial effects on the treatment of DN in DN patients and type 2 diabetic mice. However, it remained elusive whether TXL could ameliorate renal structure and function through suppression of intercellular transfer of TGF-[Formula: see text]1-containing exosomes from GECs to GMCs. In this study, we demonstrate that TXL can inhibit the secretion of TGF-[Formula: see text]1-containing exosomes from HG-treated GECs. Furthermore, exosomes produced by HG induced-GECs treated with TXL cannot trigger GMC activation, proliferation and extracellular matrix (ECM) overproduction both in vitro and in vivo. These results suggest that TXL can prevent the transfer of TGF-[Formula: see text]1 from GECs to GMCs via exosomes, which may be one of the mechanisms of TXL in the treatment of DN.

scholarly journals Type-2 pericytes participate in normal and tumoral angiogenesis

2014 ◽  
Vol 307 (1) ◽  
pp. C25-C38 ◽  
Author(s):  
Alexander Birbrair ◽  
Tan Zhang ◽  
Zhong-Min Wang ◽  
Maria Laura Messi ◽  
John D. Olson ◽  
...  
Keyword(s):  
Blood Perfusion ◽  
Tissue Growth ◽  
Cellular Target ◽  
Vascular Insufficiency ◽  
Inhibition Of Angiogenesis ◽  
And Function

Tissue growth and function depend on vascularization, and vascular insufficiency or excess exacerbates many human diseases. Identification of the biological processes involved in angiogenesis will dictate strategies to modulate reduced or excessive vessel formation. We examine the essential role of pericytes. Their heterogeneous morphology, distribution, origins, and physiology have been described. Using double-transgenic Nestin-GFP/NG2-DsRed mice, we identified two pericyte subsets. We found that Nestin-GFP−/NG2-DsRed+ (type-1) and Nestin-GFP+/NG2-DsRed+ (type-2) pericytes attach to the walls of small and large blood vessels in vivo; in vitro, type-2, but not type-1, pericytes spark endothelial cells to form new vessels. Matrigel assay showed that only type-2 pericytes participate in normal angiogenesis. Moreover, when cancer cells were transplanted into Nestin-GFP/NG2-DsRed mice, type-1 pericytes did not penetrate the tumor, while type-2 pericytes were recruited during its angiogenesis. As inhibition of angiogenesis is a promising strategy in cancer therapy, type-2 pericytes may provide a cellular target susceptible to signaling and pharmacological manipulation in treating malignancy. This work also reports the potential of type-2 pericytes to improve blood perfusion in ischemic hindlimbs, indicating their potential for treating ischemic illnesses.

scholarly journals Chronic marijuana usage by human pancreas donors is associated with impaired islet function

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258434
Author(s):  
Meirigeng Qi ◽  
John S. Kaddis ◽  
Kuan-Tsen Chen ◽  
Jeffrey Rawson ◽  
Keiko Omori ◽  
...  
Keyword(s):  
High Glucose ◽  
Cannabinoid Receptor ◽  
Marijuana Use ◽  
Human Islets ◽  
Immunofluorescent Staining ◽  
Human Pancreas ◽  
And Function

We investigated the effect of chronic marijuana use, defined as 4 times weekly for more than 3 years, on human pancreatic islets. Pancreata from deceased donors who chronically used marijuana were compared to those from age, sex and ethnicity matched non-users. The islets from marijuana-users displayed reduced insulin secretion as compared to islets from non-users upon stimulation with high glucose (AUC, 3.41 ± 0.62 versus 5.14 ±0.47, p<0.05) and high glucose plus KCl (AUC, 4.48 ± 0.41 versus 7.69 ± 0.58, p<0.001). When human islets from chronic marijuana-users were transplanted into diabetic mice, the mean reversal rate of diabetes was 35% versus 77% in animals receiving islets from non-users (p<0.01). Immunofluorescent staining for cannabinoid receptor type 1 (CB1R) was shown to be colocalized with insulin and enhanced significantly in beta cells from marijuana-users vs. non-users (CB1R intensity/islet area, 14.95 ± 2.71 vs. 3.23 ± 0.87, p<0.001). In contrast, CB1R expression was not co-localized with glucagon or somatostatin. Furthermore, isolated islets from chronic marijuana-users appeared hypertrophic. In conclusion, excessive marijuana use affects islet endocrine phenotype and function in vitro and in vivo. Given the increasing use of marijuana, our results underline the importance of including lifestyle when evaluating human islets for transplantation or research.

scholarly journals Molecular and Cellular Mechanisms of Metformin in Cervical Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2545
Author(s):  
Ya-Hui Chen ◽  
Po-Hui Wang ◽  
Pei-Ni Chen ◽  
Shun-Fa Yang ◽  
Yi-Hsuan Hsiao
Keyword(s):  
Cervical Cancer ◽  
Potential Role ◽  
Treatment Options ◽  
Cellular Mechanisms ◽  
Anticancer Effects ◽  
Clinical Benefits ◽  
Underlying Mechanisms

Cervical cancer is one of the major gynecologic malignancies worldwide. Treatment options include chemotherapy, surgical resection, radiotherapy, or a combination of these treatments; however, relapse and recurrence may occur, and the outcome may not be favorable. Metformin is an established, safe, well-tolerated drug used in the treatment of type 2 diabetes; it can be safely combined with other antidiabetic agents. Diabetes, possibly associated with an increased site-specific cancer risk, may relate to the progression or initiation of specific types of cancer. The potential effects of metformin in terms of cancer prevention and therapy have been widely studied, and a number of studies have indicated its potential role in cancer treatment. The most frequently proposed mechanism underlying the diabetes–cancer association is insulin resistance, which leads to secondary hyperinsulinemia; furthermore, insulin may exert mitogenic effects through the insulin-like growth factor 1 (IGF-1) receptor, and hyperglycemia may worsen carcinogenesis through the induction of oxidative stress. Evidence has suggested clinical benefits of metformin in the treatment of gynecologic cancers. Combining current anticancer drugs with metformin may increase their efficacy and diminish adverse drug reactions. Accumulating evidence is indicating that metformin exerts anticancer effects alone or in combination with other agents in cervical cancer in vitro and in vivo. Metformin might thus serve as an adjunct therapeutic agent for cervical cancer. Here, we reviewed the potential anticancer effects of metformin against cervical cancer and discussed possible underlying mechanisms.

scholarly journals Experimental Type 2 Diabetes Differently Impacts on the Select Functions of Bone Marrow-Derived Multipotent Stromal Cells

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 268
Author(s):  
Jonathan Ribot ◽  
Cyprien Denoeud ◽  
Guilhem Frescaline ◽  
Rebecca Landon ◽  
Hervé Petite ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Bone Marrow ◽  
Stromal Cells ◽  
Adipogenic Differentiation ◽  
Therapeutic Modality ◽  
Multipotent Stromal Cells ◽  
Cell Therapies

Bone marrow-derived multipotent stromal cells (BMMSCs) represent an attractive therapeutic modality for cell therapy in type 2 diabetes mellitus (T2DM)-associated complications. T2DM changes the bone marrow environment; however, its effects on BMMSC properties remain unclear. The present study aimed at investigating select functions and differentiation of BMMSCs harvested from the T2DM microenvironment as potential candidates for regenerative medicine. BMMSCs were obtained from Zucker diabetic fatty (ZDF; an obese-T2DM model) rats and their lean littermates (ZL; controls), and cultured under normoglycemic conditions. The BMMSCs derived from ZDF animals were fewer in number, with limited clonogenicity (by 2-fold), adhesion (by 2.9-fold), proliferation (by 50%), migration capability (by 25%), and increased apoptosis rate (by 2.5-fold) compared to their ZL counterparts. Compared to the cultured ZL-BMMSCs, the ZDF-BMMSCs exhibited (i) enhanced adipogenic differentiation (increased number of lipid droplets by 2-fold; upregulation of the Pparg, AdipoQ, and Fabp genes), possibly due to having been primed to undergo such differentiation in vivo prior to cell isolation, and (ii) different angiogenesis-related gene expression in vitro and decreased proangiogenic potential after transplantation in nude mice. These results provided evidence that the T2DM environment impairs BMMSC expansion and select functions pertinent to their efficacy when used in autologous cell therapies.

scholarly journals Grafts Derived from an α-Synuclein Triplication Patient Mediate Functional Recovery but Develop Disease-Associated Pathology in the 6-OHDA Model of Parkinson’s Disease

2020 ◽  
pp. 1-14
Author(s):  
Shelby Shrigley ◽  
Fredrik Nilsson ◽  
Bengt Mattsson ◽  
Alessandro Fiorenzano ◽  
Janitha Mudannayake ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Lines ◽  
Functional Recovery ◽  
Embryonic Stem ◽  
Hesc Line ◽  
Alternative Source ◽  
And Function

Background: Human induced pluripotent stem cells (hiPSCs) have been proposed as an alternative source for cell replacement therapy for Parkinson’s disease (PD) and they provide the option of using the patient’s own cells. A few studies have investigated transplantation of patient-derived dopaminergic (DA) neurons in preclinical models; however, little is known about the long-term integrity and function of grafts derived from patients with PD. Objective: To assess the viability and function of DA neuron grafts derived from a patient hiPSC line with an α-synuclein gene triplication (AST18), using a clinical grade human embryonic stem cell (hESC) line (RC17) as a reference control. Methods: Cells were differentiated into ventral mesencephalic (VM)-patterned DA progenitors using an established GMP protocol. The progenitors were then either terminally differentiated to mature DA neurons in vitro or transplanted into 6-hydroxydopamine (6-OHDA) lesioned rats and their survival, maturation, function, and propensity to develop α-synuclein related pathology, were assessed in vivo. Results: Both cell lines generated functional neurons with DA properties in vitro. AST18-derived VM progenitor cells survived transplantation and matured into neuron-rich grafts similar to the RC17 cells. After 24 weeks, both cell lines produced DA-rich grafts that mediated full functional recovery; however, pathological changes were only observed in grafts derived from the α-synuclein triplication patient line. Conclusion: This data shows proof-of-principle for survival and functional recovery with familial PD patient-derived cells in the 6-OHDA model of PD. However, signs of slowly developing pathology warrants further investigation before use of autologous grafts in patients.

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