mM Of Glucose Research Articles

Melatonin Attenuates High Glucose-Induced Changes in Beta Amyloid Precursor Protein Processing in Human Neuroblastoma Cells.

Diabetes mellitus (DM), one of metabolic diseases, has been suggested as a risk factor for Alzheimer's disease (AD). However, how the metabolic pathway activates amyloid precursor protein (APP) processing enzymes then contributes to the increase of amyloid-beta (Aβ) production, is not clearly understood. In the present study, we aimed to examine the protective effect of melatonin against hyperglycemia-induced alterations in the amyloidogenic pathway. High concentration of glucose was used to induce hyperglycemia in human neuroblastoma SH-SY5Y cells. We found that 30mM glucose affected the expression of insulin receptors and glucose transporters, which indicated the disruption of glucose sensing. High glucose induced the activation of the phosphorylated protein kinase B (pAkt)/GSK-3β signaling pathway and a significant increase in the expression of β-site beta APP cleaving enzyme (BACE1), presenilin1 (PS1) and Aβ42. Pretreatment with melatonin significantly reversed these parameters. We also showed that these effects are similar to those effects in the presence of the GSK-3β blocker, N-(4-methoxybenyl)-N'-(5-nitro-1,3-thiazol-2-yl) urea (ARA) in glucose-treated hyperglycemic cells. These suggested that melatonin exerted an inhibitory effect on the activation of APP-cleaving enzymes via the GSK-3β signaling pathway. Pretreatment with luzindole, a melatonin receptor MT1 antagonist, significantly prevented the effect of melatonin on the glucose-induced increase level of APP processing enzymes. This suggested that melatonin attenuated the toxic effect on hyperglycemia involving the amyloidogenic pathway partially mediated via melatonin receptor. Taken together the present results suggested that melatonin has a beneficial role in preventing Aβ generation in a cellular model of hyperglycemia-induced DM.

Investigating the physiological relevance of ex vivo disc organ culture nutrient microenvironments using in silico modeling and experimental validation.

BackgroundEx vivo disc organ culture systems have become a valuable tool for the development and pre‐clinical testing of potential intervertebral disc (IVD) regeneration strategies. Bovine caudal discs have been widely selected due to their large availability and comparability to human IVDs in terms of size and biochemical composition. However, despite their extensive use, it remains to be elucidated whether their nutrient microenvironment is comparable to human degeneration.AimsThis work aims to create the first experimentally validated in silico model which can be used to predict and characterize the metabolite concentrations within ex vivo culture systems.Materials & MethodsFinite element models of cultured discs governed by previously established coupled reaction‐diffusion equations were created using COMSOL Multiphysics. Experimental validation was performed by measuring oxygen, glucose and pH levels within discs cultured for 7 days, in a static compression bioreactor.ResultsThe in silico model was successfully validated through good agreement between the predicted and experimentally measured concentrations. For an ex vivo organ cultured in high glucose medium (4.5 g/L or 25 mM) and normoxia, a larger bovine caudal disc (Cd1‐2 to Cd3‐4) had a central concentration of ~2.6 %O2, ~8 mM of glucose and a pH value of 6.7, while the smallest caudal discs investigated (Cd6‐7 and Cd7‐8), had a central concentration of ~6.5 %O2, ~12 mM of glucose and a pH value of 6.9.DiscussionThis work advances the knowledge of ex vivo disc culture microenvironments and highlights a critical need for optimization and standardization of culturing conditions.ConclusionUltimately, for assessment of cell‐based therapies and successful clinical translation based on nutritional demands, it is imperative that the critical metabolite values within organ cultures (minimum glucose, oxygen and pH values) are physiologically relevant and comparable to the stages of human degeneration.

Abstract P738: Matrix Metalloproteinase-3 (mmp3) Activation Impairs Endothelial Integrity and Increases Vascular Injury After Ischemic Stroke in Female Diabetic Rats

Introduction: Females patients with diabetes suffer from poor outcomes of ischemic stroke but underlying reasons are not fully understood. We have shown that 1) adult female diabetic rats develop greater infarct and hemorrhagic transformation (HT) leading to poorer outcomes after ischemic stroke, and 2) MMP3 activity is increased to a greater extent in female endothelial cells as well as the microvasculature of diabetic female rats than in males. This led us to hypothesize that MMP3 mediates disruption of endothelial integrity amplifying vascular injury in female diabetic rats. Methods: Diabetic female Wistar rats, subjected to 60 min MCAO, received a single dose of MMP3 inhibitor (UK356618; 15mg/kg; iv) or vehicle after reperfusion. On Day 3, adhesive removal time (ART), behavioral composite score, brain infarct size, edema and macroscopic HT were recorded. Primary brain microvascular endothelial cells (BMVECs) isolated from female rats were cultured in 25mM glucose plus 100μM sodium palmitate for 48 hours followed by hypoxia insult for 24 hours in the presence/absence of UK356618 (20nM). Endothelial phenotype and integrity were assessed. Results: Brain edema and HT scores were lower and outcomes were improved with MMP3 inhibition but infarct size was not different between the groups (Table). Hypoxia decreased tight junction protein occludin-1 while increasing transforming growth factor receptor-1 (TGF-R1), a key modulator of endothelial phenotype. Treatment with inhibitor UK356618 reversed these responses. Conclusions: The lack of a difference in infarct size with the treatment suggests that MMP3 inhibition improves short term outcomes in female diabetic rats via preservation of endothelial integrity. The decrease in TGF-R1 needs to be further investigated for long term effects of MMP3 inhibition on vascular restoration and recovery after stroke in diabetes.

Yeast-based microbial biofuel cell mediated by 9,10-phenantrenequinone

Microbial fuel cells can be efficiently used for simultaneous cleaning of wastewater and generation of electricity. This research demonstrates the applicability of Baker yeast cells in the design of microbial biofuel cells. The applicability the 9,10-phenantrenequinone (PQ) as a redox mediator in the design of yeast-based microbial cell (MFC) for the improvement of charge transfer through the yeast cell membrane and cell wall towards the electrode was evaluated. The viability of bakers' yeast and pure Saccharomyces cerevisiae cell strains was investigated by evaluating the growth velocity of cells in the presence of a different concentration of PQ in solution. The growth curves of bakers' yeast showed that they were more resistant to PQ. Electrochemical measurements were performed with PQ as a redox mediator, which was (i) dissolved in solution and (ii) adsorbed on a graphite electrode. Differently modified graphite electrodes (namely: (i) non-modified, (ii) yeast-modified, (iii) modified by PQ and yeast) were evaluated. The modified electrodes were evaluated as anodes of MFC. The dependence of potential on external resistance and generated power of MFC was evaluated. Maximal open circuit potential was 178 mV at 7.8 mM of glucose and 23 mM of potassium ferricyanide. Maximal power of BFC calculated at the same conditions was registered at 56 mV, and it reached 22.2 mW/m2 (at 30 mM of glucose). The application of PQ as a redox mediator for yeast-based MFC improves electron transfer through the yeast cell membrane and cell wall towards electrode without any noticeable decrease of yeast cell viability.

Development of a zebrafish screening model for diabetic retinopathy induced by hyperglycemia: Reproducibility verification in animal model

This study aimed at creating a zebrafish screening model for diabetic retinopathy, and evaluated the effects of aflibercept, which is being used to treated diabetic retinopathy. A morphological change occurred at 160 mM of glucose. The survival and hatching rate decreased in a dose-dependent manner. In the 130 mM glucose group, the retinal vessel diameter was more than double that in the normal group. The zebrafish embryo morphology changed in 200 μg/mL and 400 μg/mL at aflibercept. The survival and hatching rate decrease at 400 μg/mL. Aflibercept 100 μg/mL was a nontoxic and effective dose for the zebrafish diabetic retinopathy model. The expression of diabetic retinopathy inflammatory markers was increased in hyperglycemia. But the inflammation was improved by aflibercept in the zebrafish eye. In a zebrafish diabetic retinopathy model, the diameters of retinal vessels were reduced after treatment with aflibercept, and molecular biological and histopathological efficacy was confirmed. This model can serve for screening of new drug candidates for treatment of in diabetic retinopathy.

Evaluation of ITO/TiO2/Co3O4 as a non-enzymatic heterojunction electrode to glucose electrooxidation

Electroactive Co3O4 films were deposited by reactive magnetron sputtering (RMS) onto an assembly composed of a thin TiO2 layer over a commercial indium-doped tin oxide (ITO) conductor electrode, forming an ITO/TiO2/Co3O4 electrocatalytic platform. The platform was tested as a non-enzymatic device for glucose electrooxidation. The characterization of the electroactive TiO2/Co3O4 heterojunction was carried out by x-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscope (FE-SEM), and energy dispersive spectroscopy (EDS) techniques. It was shown that the Co3O4 top layer is homogeneous and free from undesirable secondary phases. The electrochemical measurements, characterization and performance, were carried out by cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). The cyclic voltammogram shows the linear dependence between the anodic and cathodic current peak of the redox process at the electrode surface, showing the electrochemical activity of the Co3+/Co4+ redox pair, as well as good reversibility and efficiency of charge transfer. From the chronoamperometric curves, two electrochemical parameters were estimated, the diffusion coefficient (D) and catalytic rate constant (kobs) of glucose with the values of 1.2 × 10−6 cm2 s−1 and 2.8 × 106 cm3 mol−1 s−1, respectively. The ITO/TiO2/Co3O4 heterojunction electrode showed an acceptable linear range from 10 to 1000 μM glucose concentration with a molar sensitivity (S) of 30.0 μA cm−2 mM−1 and a detection limit (LOD) of 1.42 μM (S/N = 3). These electrochemical results show the higher electroactivity of TiO2/Co3O4 heterojunction electrode than that of bare Co3O4 electrode and other literature results.

Exploring multi-step glucose oxidation kinetics at GOx-functionalized nanotextured gold surfaces with differential impedimetric technique

For a few past years, we can observe the enormous growth of investigations related to ultrasensitive electrochemical sensors capable of reliable determination of important body parameters and analytes. Utilized procedures rely on standard electrochemical methods, demanding electrode polarization, and information about the initial characteristics of the working electrode. More and more complex electrode materials are characterized however their electrochemical response is not fully understood or defined, affecting data reproducibility.Herein, we propose a novel protocol utilizing dynamic electrochemical impedance spectroscopy in galvanostatic mode (g-DEIS) to verify the sensor performance. The protocol was applied to study the response of Ti-Au nanotextured electrode depending on glucose concentration changes. The g-DEIS allowed to monitor complex mechanism occurring at the electrode/electrolyte interface with the continuously dosed glucose through electric parameters derivatives in analyte content. Our studies revealed a visible increase in electrode electric heterogeneity above 1.9 mM of glucose and gold nanoparticles’ oxidation above 3.8 mM, both influencing electrode kinetics. The results were confirmed using supporting cyclic voltammetry and x-ray photoelectron spectroscopy studies. The proposed protocol’s unique features could significantly spread further application of targetable biosensors for real-time diagnostics.

Synthesis of non-enzymatic biosensor based on selenium dioxide nanoparticles in order to detection of glucose under electrochemical method

In this project, a novel electrochemical biosensor was produced for the glucose recognition. Selenium dioxide Nanoparticle (SeNPs) synthesized a two-step process with a hydrothermal method. The SeNPs were characterized by X-ray diffraction (XRD). Also, the size distributions of nanoparticles were determined by dynamic light scattering (DLS), that more than 90 percent in the size range of 58–100 nm. The electrochemical performance of the SeNPs electrode for detection of glucose was investigated by cyclic voltammetry (CV). SeNPs show high electrocatalytic activity toward glucose oxidation in alkaline medium and are used for non-enzymatic electrochemical detection of glucose. The biosensor also had a linear response to glucose in the range of 0.5-2.5 mM and a low detection limit of 1.3 μM glucose (S/N=3). Therefore, the sensor shows great promise for simple, sensitive, and quantitative detection and screening of glucose and real sample (glucose in the human serum). This novel structured electrode holds great promise for the development of biosensors and other electrochemical devices.

Rational design of direct electron transfer type l-lactate dehydrogenase for the development of multiplexed biosensor

The development of wearable multiplexed biosensors has been focused on systems to measure sweat l-lactate and other metabolites, where the employment of the direct electron transfer (DET) principle is expected. In this paper, a fusion enzyme between an engineered l-lactate oxidase derived from Aerococcus viridans, AvLOx A96L/N212K mutant, which is minimized its oxidase activity and b-type cytochrome protein was constructed to realize multiplexed DET-type lactate and glucose sensors. The sensor with a fusion enzyme showed DET to a gold electrode, with a limited operational range less than 0.5 mM. A mutation was introduced into the fusion enzyme to increase Km value and eliminate its substrate inhibition to construct “b2LOxS”. Together with the employment of an outer membrane, the detection range of the sensor with b2LOxS was expanded up to 10 mM. A simultaneous lactate and glucose monitoring system was constructed using a flexible thin-film multiplexed electrodes with b2LOxS and a DET-type glucose dehydrogenase, and evaluated their performance in the artificial sweat. The sensors achieved simultaneous detection of lactate and glucose without cross-talking error, with the detected linear ranges of 0.5–20 mM for lactate and 0.1–5 mM for glucose, sensitivities of 4.1 nA/mM∙mm2 for lactate and 56 nA/mM∙mm2 for glucose, and limit of detections of 0.41 mM for lactate and 0.057 mM for glucose. The impact of the presence of electrochemical interferants (ascorbic acid, acetaminophen and uric acid), was revealed to be negligible. This is the first report of the DET-type enzyme based lactate and glucose dual sensing systems.

A novel neutral non-enzymatic glucose biofuel cell based on a Pt/Au nano-alloy anode

In this paper, we present a neutral non-enzymatic glucose biofuel cell (GBFC) based on a Pt/Au nano-alloy anode. We synthesize Pt/Au alloy anodes by the electrochemical deposition of a Pt/Au nano-alloy on the surface of a thin polyethylene terephthalate membrane with a uniformly distributed microhemispheric array. The experimental results demonstrate that the proposed GBFC can generate a maximum power density of 0.32 mW/cm2, an open-circuit voltage (Voc) of 0.42 V, and a short-circuit current (Isc) density of 2.67 mA/cm2 with 5 mM of glucose in a 0.1-M PBS (pH 7.4) solution while the cathode is being supplied with 7% saturated oxygen. The synergistic effect of the Pt/Au bimetallic alloy is found to improve the performance of the proposed GBFC. The proposed neutral non-enzymatic GBFC shows promising feasibility as an implantable power supply system for the provision of continuous and consistent electricity to a continuous glucose monitoring system.

Catalytic Activity of Atomic Gold-Decorated Polyaniline Support in Glucose Oxidation

Atomic-level gold clusters are decorated on a polyaniline (PANI) support by a cyclic atomic electrodeposition process, and the catalytic activity in the oxidation of glucose is studied. The evaluation is conducted by cyclic voltammetry using atomic-level gold clusters-decorated PANI (PANI/AuN, where N indicates the atomic size of the Au cluster and N = 1~3 in this study) as the working electrode and a solution containing 0 to 50.0 mM of glucose in phosphate-buffered saline. The catalytic activity is determined from the oxidation current observed at around +0.6 V vs. Ag/AgCl. The catalytic activity is found to be affected by the size of gold clusters decorated on the PANI/AuN, whereby the catalytic activity is low when N is 1 or 3. On the other hand, an obvious enhancement in the catalytic activity is observed for the PANI/Au2 electrode.

A study on the stability and sensitivity of mediator-based enzymatic glucose sensor measured by catalyst consisting of multilayer stacked via layer-by-layer

A catalyst consisting of carbon nanotube, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), polyacrylic acid (PAA), polyethylenimine (PEI), and glucose oxidase (GOx) (CNT/[TEMPO-PAA]/PEI/GOx) is developed to improve the stability and sensitivity of mediator based glucose sensor. In this catalyst, TEMPO is bonded with PAA to prevent the leaching out of TEMPO, which plays a crucial role in increasing the glucose sensitivity by instilling charges in it. The TEMPO-PAA composite is then linked to other components by electrostatic force. To confirm the chemical structure of the catalyst, its chemical bonds and surface charge are investigated by Fourier-transform infrared spectroscopy and zeta potential. When the stability and glucose sensitivity are measured, this catalyst preserves 80% of its initial catalytic activity for one week although other similar catalysts show far worse stability. In addition, the linear relationship of glucose concentration and reactivity of glucose oxidation shown in 1–10mM glucose range that corresponds to actual blood glucose concentration of human being indicates that this catalyst can induce excellent glucose sensitivity. In terms of selectivity, this catalyst reacts with blood glucose highly selectively, whereas this is not reacted with other eight different saccharides.

Non‐Invasive, Non‐Enzymatic, Biodegradable and Flexible Sweat Glucose Sensor and Its Electrochemical Studies

AbstractGlucose oxidase‐free polymer composite sensing material, made of polyelectrolytic cellulose derivatives cross‐linked by an organic polycarboxylic acid and enhanced by a plasticizer, is reported. The polymer composite is a nontoxic material and is also biodegradable that degrades within 15 days in the soil. The material is extremely flexible and yet resilient in such a way to explicitly fit for application in wearable sensors. Electrochemical analysis of the material for glucose sensing properties with artificial sweat as the electrolyte revealed surprising results. The lowest detection limit observed in chronoamperometric analysis was 0.4 mM of glucose. Impedimetric analysis showed significant drop in impedance at 0.5 mM addition of glucose. The cellulose composite material gets reduced into H3O+ and H+ ions, on addition of glucose, which is confirmed through square wave analysis, chrono‐amperometry, impedance and cyclic voltammetry results. The changes in the functional group were also confirmed by FTIR analysis taken before and after the addition of glucose. Results obtained by electrochemical analysis were well correlated with the proposed reaction mechanism. The flexibility and strength of the cellulose composite film was analysed with nano‐indenter, it also showed an excellent folding endurance withstanding up to 86960 folds. The biocompatibility nature of the material was also tested with the help of 3T3 fibroblast cells.

Epac1 Requires AMPK Phosphorylation to Regulate HMGB1 in the Retinal Vasculature.

PurposeTo investigate whether AMP-activated protein kinase (AMPK) is required for the reduction of high mobility group box 1 (HMGB1) by exchange proteins activated by cAMP 1 (Epac1) in the retinal vasculature.MethodsWe measured AMPK phosphorylation in normal and diabetic Epac1 floxed and cdh5/Epac1 Cre mice. We also treated primary human retinal endothelial cells (RECs) in normal (5-mM) or high (25-mM) glucose with an Epac1 agonist and AMPK or insulin-like growth factor receptor binding protein 3 siRNA. We measured protein levels of AMPK, sirtuin 1 (SIRT1), and HMGB1.ResultsAMPK phosphorylation was reduced in cdh5/Epac1 Cre mice, suggesting that Epac1 regulated AMPK actions. High-glucose culturing conditions reduced AMPK levels in RECs, but the levels were increased by the Epac1 agonist, supporting the idea that Epac1 regulates AMPK. The Epac1 agonist was not able to reduce HMGB1 levels or increase SIRT1 when AMPK was blocked by AMPK siRNA, thus demonstrating that Epac1 requires AMPK to regulate SIRT1 and HMGB1.ConclusionsEpac1 requires AMPK to increase SIRT1 and reduce HMGB1 in the diabetic retinal vasculature. This finding provides another pathway by which Epac1 may protect the retina during diabetes.

Efficient chemiluminescence harnessing via slow photons in sensitized TiO2 nanotubes for the photoelectrochemical biosensing

Abstract TiO2 nanotubes (TNTs) were fabricated by anodic oxidation and the partially reduced black-TNTs (B-TNTs) were obtained by electrochemical reduction. After the sensitization of B-TNTs with thioflavin T (B-TNTs-Th-T), the photo-electrode was used as a photoelectrochemical (PEC) biosensing of glucose. The uniform porous architecture of TNTs with a high surface to volume ratio is responsible for the photo-generated charge transfer and Th-T absorption and sensitization broadened the light absorption range and intensity. The favorable matching of energy levels between Th-T and B-TNTs allowed a fast electron transfer from excited Th-T to TNTs under chemiluminescence (CL). Furthermore, the bandgap of TNTs was red-shifted after the formation of B-TNTs and the red edge of the photonic stop-band was deliberately tuned to overlap with both the bandgap of the semiconducting material and the CL emission spectrum, by leading dual enhancement effects which enhanced the photocurrent unprecedentedly mainly owing to the “slow light effect”. The photo-electrode yielded 40 times higher photocurrent compared to TiO2 thin film coated counterpart indicating effectively harnessing of CL. The biosensor has a large linear measurement range of 0.027–5 mM with a LOD of 8 μM for glucose. The phenomenon “slow light effect” will pay the way for efficient light harnessing and management for commercially available more sensitive and inexpensive PEC devices in the future.

Proteomic study of in vitro osteogenic differentiation of mesenchymal stem cells in high glucose condition.

Patients with diabetes have been widely reported to be at an increased risk of secondary osteoporosis. Osteoporosis is caused by an imbalance in bone remodeling due to increased bone resorption and/or decreased osteoblast-dependent bone formation. In this study, mesenchymal stem cells (MSCs) were used as a disease model to determine the effects of high glucose levels on MSC-osteoblast development. The results indicated that under high glucose conditions, MSCs had reduced cell viability and increased number of β-galactosidase-positive cells. Furthermore, in vitro osteogenesis was shown to be reduced in MSCs cultured in osteogenic differentiation medium at 10, 25, and 40mM glucose as demonstrated by Alizarin red S staining and alkaline phosphatase activity assay. Moreover, a proteomic study was performed in MSCs cultured with 25 and 40mM glucose. The proteomic results demonstrated that 12 proteins were up- and downregulated in bone marrow-derived mesenchymal stem cells cultured with high glucose in a dose-dependent manner. The findings presented here contribute to our understanding of the mechanism of diabetes mellitus responsible for bone loss. However, the exact mechanism of action of hyperglycemia on bone deformability requires additional studies.

Enhanced electrochemical glucose sensing performance of CuO:NiO mixed oxides thin film by plasma assisted nitrogen doping

In this study plasma-assisted nitrogen doping of a CuO–NiO mixed oxide thin film was presented. The as prepared film was also applied as a glucose sensor. The nitrogen species generated during plasma ignition resulted in a beneficial phase transformation of CuO to Cu2O. Characterisation techniques such as XRD, SEM, EIS and Hall Effect etc. measurements were utilized to study the morphology, structural features, doping profile and electrical properties of the sensing material. Device performance electrochemical testing showed that the as-developed sensor (labelled as N–CuO/Cu2O:NiO) showed an ultra-fast response time of 2.5 s with high sensitivity (1131 μA/mM.cm2). The linear range of the sensor was calculated to be up to 2.74 mM of glucose and excellent selectivity towards glucose at an applied potential of +0.67 V vs Ag/AgCl in 0.1 M NaOH electrolyte solution. The limit of detection was calculated to be 20 μM for the N–CuO/Cu2O:NiO sensor. The N–CuO/Cu2O:NiO have smaller Tafel slope compared to pristine CuO and CuO:NiO mixed oxides. Enhanced electrochemical performance of the N–CuO/Cu2O:NiO originates from the improved electronic properties of the thin film.

A Smartphone-Based Fluorescence Microscope With Hydraulically Driven Optofluidic Lens for Quantification of Glucose

The traditional method for early diagnosis of diabetes is to detect urine or blood glucose levels. However, the present clinical detection methods cause either cross-infection or require expensive instruments with complex procedures of operation. In this work, a handheld smartphone-based fluorescence microscope with the tunable optofluidic lens and microfluidic assay is demonstrated for the facile detection of glucose concentration for the first time to our knowledge. The tunability of the optofluidic lens is based on the dynamic deformation of an elastomeric membrane driven by adjustable hydraulic pressure. And the glucose sensor integrates a smartphone, a tunable optofluidic lens, a microfluidic chip, a customized holder and some easily accessible optics. A low detection limit of 0.33 mM of glucose was achieved subjected to a linear range of detection from 0 to 6 mM glucose, which is evaluated with an enzymatic fluoresce method. These results show that the cost-effective miniaturized system can be used for early screening and diagnosis of diabetes and potentially some other onsite applications of clinical diagnosis and environment monitoring.

MOUSE UMBILICAL CORD MESENCHYMAL STEM CELL PARACRINE ALLEVIATES RENAL FIBROSIS IN DIABETIC NEPHROPATHY BY REDUCING MYOFIBROBLAST TRANSDIFFERENTIATION AND CELL PROLIFERATION AND UPREGULATING MMPS IN MESANGIAL CELLS

Special Medicine. Cell Transplantation and Gene Therapy. Transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) is currently considered as a novel therapeutic strategy for diabetic nephropathy (DN). However, the mechanisms by which UC-MSCs ameliorate renal fibrosis in DN are not well understood. Herein, we firstly investigated the therapeutic effects of mouse UC-MSC infusion on kidney structural and functional impairment in streptozotocin (STZ)-induced diabetic mice. We found that the repeated injection with mUC-MSCs alleviates albuminuria, glomerulus injury and fibrosis in DN mouse models. Next, mesangial cells were exposed to 5.6 mM glucose, 30mM glucose or mUC-MSC conditioned medium, and then performed western blotting, immunofluorescence, wound healing assay, and cell proliferation assay to measure extra cellular matrix (ECM) proteins and matrix metalloproteinases (MMPs), myofibroblast transdifferentiation (MFT), and cell proliferation. We demonstrated that mUC-MSC paracrine decreased the deposition of fibronectin and collagen I by inhibiting TGF-β1-triggered MFT and cell proliferation mediated by PI3K/Akt and MAPK signaling pathways, and elevating the levels of MMP2 and MMP9. Importantly, we provided the evidence that the anti-fibrosis role of mU-MSC paracrine in DN might be determined by exosomes shed by MSCs. Together, these findings reveal the mechanisms underlying the therapeutic effects of UC-MSCs on renal fibrosis in DN and provide the evidence for DN cell-free therapy based on UC-MSCs in the future. National Natural Science Foundation of China (no. 81671752, 81471715, 81771827, and 81201171). Natural Science Foundation of Hunan Province, China (no. 2017JJ3423). Hunan Provincial Science and Technology Department major project (no. 2018SK1020). Project of Health and Family Planning Commission of Hunan Province (no. 20160125).

Anti-inflammatory and anti-proliferative action of adiponectin mediated by insulin signaling cascade in human vascular smooth muscle cells.

After confirmation of the presence of adiponectin (ADPN) receptors and intra-cellular binding proteins in coronary artery smooth muscle cells (VSMC), we tested the hypotheses that, in acute insulin resistance: (i) the activation/inactivation of metabolic and mitogenic insulin signaling pathways are inversely affected by ADPN and, (ii) changes in VSMC migration/proliferation rates correlate with signal activity/inactivity. In primary cultures of VSMC exposed to high glucose and palmitate plus insulin, the expression of PI-3 kinase (Akt and m-TOR), MAP-Kinase (Erk and p-38) molecules, and inflammatory markers (TLR-4 and IkB-α) were assessed with Western blot, in the absence/presence of AdipoRon (AR). Migration and proliferation rates were measured in similar experimental conditions. There were decreases of ~ 25% (p-Akt) and 40-60% (p-mTOR) expressions with high glucose/palmitate, which reversed when AR was added were. Elevations in p-Erk and p-p38 expressions were obliterated by AR. Although, no changes were detected with high glucose and palmitate, when AR was added, a decline in inflammatory activity was substantiated by a ~ 50% decrease in TLR-4 and 40-60% increase in IkBα expression. Functional assays showed 10-20% rise in VSMC proliferation with high glucose and palmitate, but addition of AR lead to 15-25% decline. The degree of VSMC migration was reduced with AR addition by ~ 15%, ~ 35% and 55%, in VSMC exposed to 5mM, 25mM glucose and 25mM + 200µM palmitate, respectively. Changes in intracellular molecular messaging in experiments mimicking acute insulin resistance suggest that anti-inflammatory and anti-atherogenic actions of ADPN in VSMC are mediated via insulin signaling pathways.