Hyperglycemia-induced oxidative stress exacerbates mitochondrial apoptosis damage to cochlear stria vascularis pericytes via the ROS-mediated Bcl-2/CytC/AIF pathway.

OBJECTIVES: Diabetes is closely linked to hearing loss, yet the exact mechanisms remain unclear. Cochlear stria vascularis and pericytes (PCs) are crucial for hearing. This study investigates whether high glucose induces apoptosis in the cochlear stria vascularis and pericytes via elevated ROS levels due to oxidative stress, impacting hearing loss. METHODS: We established a type II diabetes model in C57BL/6J mice and used auditory brainstem response (ABR), Evans blue staining, HE staining, immunohistochemistry, and immunofluorescence to observe changes in hearing, blood-labyrinth barrier (BLB) permeability, stria vascularis morphology, and apoptosis protein expression. Primary cultured stria vascularis pericytes were subjected to high glucose, and apoptosis levels were assessed using flow cytometry, Annexin V-FITC, Hoechst 33342 staining, Western blot, Mitosox, and JC-1 probes. RESULTS: Diabetic mice showed decreased hearing thresholds, reduced stria vascularis density, increased oxidative stress, cell apoptosis, and decreased antioxidant levels. High glucose exposure increased apoptosis and ROS content in pericytes, while mitochondrial membrane potential decreased, with AIF and cytochrome C (CytC) released from mitochondria to the cytoplasm. Adding oxidative scavengers reduced AIF and CytC release, decreasing pericyte apoptosis. DISCUSSION: Hyperglycemia may induce mitochondrial apoptosis of cochlear stria vascularis pericytes through oxidative stress.

Distribution of lipid droplets in hippocampal neurons and microglia: impact of diabetes and exercise.

Neuroinflammation, aging, and neurodegenerative disorders are associated with excessive accumulation of neutral lipids in lipid droplets (LDs) in microglia. Type 2 diabetes mellitus (T2DM) may cause neuroinflammation and is a risk factor for neurodegenerative disorders. Here, we show that hippocampal pyramidal neurons contain smaller, more abundant LDs than their neighboring microglia. The density of LDs varied between pyramidal cells in adjacent subregions, with CA3 neurons containing more LDs than CA1 neurons. Within the CA3 region, a gradual increase in the LD content along the pyramidal layer from the hilus toward CA2 was observed. Interestingly, the high neuronal LD content correlated with less ramified microglial morphotypes. Using the db/db model of T2DM, we demonstrated that diabetes increased the number of LDs per microglial cell without affecting the neuronal LD density. High-intensity interval exercise induced smaller changes in the number of LDs in microglia but was not sufficient to counteract the diabetes-induced changes in LD accumulation. The changes observed in response to T2DM may contribute to the cerebral effects of T2DM and provide a mechanistic link between T2DM and neurodegenerative disorders.

Bromodomain Protein Inhibition Protects ß-Cells from Cytokine-Induced Death and Dysfunction via Antagonism of NF-κB Pathway.

Cytokine-induced ß-cell apoptosis is a major pathogenic mechanism in type 1 diabetes (T1D). Despite significant advances in understanding its underlying mechanisms, few drugs have been translated to protect ß-cells in T1D. Epigenetic modulators such as bromodomain-containing BET (bromo- and extra-terminal) proteins are important regulators of immune responses. Pre-clinical studies have demonstrated a protective effect of BET inhibitors in an NOD (non-obese diabetes) mouse model of T1D. However, the effect of BET protein inhibition on ß-cell function in response to cytokines is unknown. Here, we demonstrate that I-BET, a BET protein inhibitor, protected ß-cells from cytokine-induced dysfunction and death. In vivo administration of I-BET to mice exposed to low-dose STZ (streptozotocin), a model of T1D, significantly reduced ß-cell apoptosis, suggesting a cytoprotective function. Mechanistically, I-BET treatment inhibited cytokine-induced NF-kB signaling and enhanced FOXO1-mediated anti-oxidant response in ß-cells. RNA-Seq analysis revealed that I-BET treatment also suppressed pathways involved in apoptosis while maintaining the expression of genes critical for ß-cell function, such as Pdx1 and Ins1. Taken together, this study demonstrates that I-BET is effective in protecting ß-cells from cytokine-induced dysfunction and apoptosis, and targeting BET proteins could have potential therapeutic value in preserving ß-cell functional mass in T1D.

A translational model of chronic diabetic nephropathy in the Nile grass rat.

Diabetic nephropathy (DN) is a major healthcare challenge for individuals with diabetes and associated with increased cardiovascular morbidity and mortality. The existing rodent models do not fully represent the complex course of the human disease. Hence, developing a translational model of diabetes that reproduces both the early and the advanced characteristics of DN and faithfully recapitulates the overall human pathology is an unmet need. Here, we introduce the Nile grass rat (NGR) as a novel model of DN and characterize key pathologies underlying DN. NGRs spontaneously developed insulin resistance, reactive hyperinsulinemia, and hyperglycemia. Diabetic NGRs evolved DN and the key histopathological aspects of the human advanced DN, including glomerular hypertrophy, infiltration of mononuclear cells, tubular dilatation, and atrophy. Enlargement of the glomerular tufts and the Bowman's capsule areas accompanied the expansion of the Bowman's space. Glomerular sclerosis, renal arteriolar hyalinosis, Kimmelsteil-Wilson nodular lesions, and protein cast formations in the kidneys of diabetic NGR occurred with DN. Diabetic kidneys displayed interstitial and glomerular fibrosis, key characteristics of late human pathology as well as thickening of the glomerular basement membrane and podocyte effacement. Signs of injury included glomerular lipid accumulation, significantly more apoptotic cells, and expression of KIM-1. Diabetic NGRs became hypertensive, a known risk factor for kidney dysfunction, and showed decreased glomerular filtration rate. Diabetic NGRs recapitulate the breadth of human DN pathology and reproduce the consequences of chronic kidney disease, including injury and loss of function of the kidney. Hence, NGR represents a robust model for studying DN-related complications and provides a new foundation for more detailed mechanistic studies of the genesis of nephropathy, and the development of new therapeutic approaches.

Transplantation of bioengineered dermal derived matrix-scaffold in combination with hyperbaric oxygen therapy improves wound healing in diabetic rats.

Successful treatment of diabetic wounds requires multifactorial approaches. Herein we investigated the effects of a bioengineered three-dimensional dermal derived matrix-scaffold (DMS) in combination with hyperbaric oxygen (HBO) in repairing of wound model in diabetic rats. Thirty days after induction of diabetes, a circular wound was created and treatments were performed for 21 days. Animals were randomly allocated into the untreated group, DMS group, HBO group, and DMS+HBO group. On days 7, 14, and 21, tissue samples were obtained for stereological, molecular, and tensiometrical assessments. Our results showed that the wound closure rate, volume of new dermis and epidermis, numerical density fibroblasts and blood vessels, collagen density, and biomechanical characterize were significantly higher in the treatment groups than in the untreated group, and these changes were more obvious in the DMS+HBO ones. Moreover, the expression of TGF-ß, bFGF, miRNA-21, miRNA-146a, and VEGF genes were meaningfully upregulated in treatment groups compared to the untreated group and were greater in the DMS+HBO group. This is while expression of TNF-α and IL-1ß, as well as the numerical density of neutrophil and macrophage decreased more considerably in the DMS+HBO group than in the other groups. Overall, using both DMS engraftment and HBO treatment has more effects on diabetic wound healing.

Exendin-4, a glucagon-like peptide-1 receptor agonist, alleviates muscular dysfunction and wasting in a streptozotocin-induced diabetic mouse model compared to metformin.

Diabetic muscular atrophy is becoming a fast-growing problem worldwide, including sarcopenia, which is associated with substantial mortality and morbidity risk. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been marketed and suggested to exert protective effects on not only glycemic control but also diabetic complications in diabetic patients. In this study, we investigated the therapeutic use of GLP-1RAs exendin-4, compared to antidiabetic drug metformin, for the intervention of muscular dysfunction during diabetic conditions using a streptozotocin (STZ)-induced diabetic mouse model. The results showed that both exendin-4 and metformin could effectively alleviate hyperglycemia in diabetic mice, and also counteract diabetes-induced muscle weight loss, weaker grip, and changes in muscle fiber cross-sectional area distribution. Unexpectedly, exendin-4, but not metformin, enhanced the increased kidney weight and histological change in diabetic mice. Taken together, these findings suggest that both exendin-4 and metformin could effectively improve the diabetic hyperglycemia and muscular dysfunction; but exendin-4 may aggravate the nephropathy in STZ-induced diabetic mice.

Methanolic Extract of Phoenix Dactylifera Confers Protection against Experimental Diabetic Cardiomyopathy through Modulation of Glucolipid Metabolism and Cardiac Remodeling.

The incidence of cardiovascular disorders is continuously rising, and there are no effective drugs to treat diabetes-associated heart failure. Thus, there is an urgent need to explore alternate approaches, including natural plant extracts, which have been successfully exploited for therapeutic purposes. The current study aimed to explore the cardioprotective potential of Phoenix dactylifera (PD) extract in experimental diabetic cardiomyopathy (DCM). Following in vitro phytochemical analyses, Wistar albino rats (N = 16, male; age 2-3 weeks) were fed with a high-fat or standard diet prior to injection of streptozotocin (35 mg/kg i.p.) after 2 months and separation into the following four treatment groups: healthy control, DCM control, DCM metformin (200 mg/kg/day, as the reference control), and DCM PD treatment (5 mg/kg/day). After 25 days, glucolipid and myocardial blood and serum markers were assessed along with histopathology and gene expression of both heart and pancreatic tissues. The PD treatment improved glucolipid balance (FBG 110 ± 5.5 mg/dL; insulin 17 ± 3.4 ng/mL; total cholesterol 75 ± 8.5 mg/dL) and oxidative stress (TOS 50 ± 7.8 H2O2equiv./L) in the DCM rats, which was associated with preserved structural integrity of both the pancreas and heart compared to the DCM control (FBG 301 ± 10 mg/dL; insulin 27 ± 3.4 ng/mL; total cholesterol 126 ± 10 mg/dL; TOS 165 ± 12 H2O2equiv./L). Gene expression analyses revealed that PD treatment upregulated the expression of insulin signaling genes in pancreatic tissue (INS-I 1.69 ± 0.02; INS-II 1.3 ± 0.02) and downregulated profibrotic gene expression in ventricular tissue (TGF-ß 1.49 ± 0.04) compared to the DCM control (INS-I 0.6 ± 0.02; INS-II 0.49 ± 0.03; TGF-ß 5.7 ± 0.34). Taken together, these data indicate that Phoenix dactylifera may offer cardioprotection in DCM by regulating glucolipid balance and metabolic signaling.

PDK4-mediated Nrf2 inactivation contributes to oxidative stress and diabetic kidney injury.

Diabetic kidney disease (DKD) is often featured with redox dyshomeostatis. Pyruvate dehydrogenase kinase 4 (PDK4) is the hub for DKD development. However, the mechanism by which PDK4 mediates DKD is poorly understood. The current work aimed to elucidate the relationship between PDK4 and DKD from the perspective of redox manipulation. Oxidative stress was observed in the human proximal tubular cell line (HK-2 cells) treated with a high concentration of glucose and palmitic acid (HGL). The mechanistic study showed that PDK4 could upregulate Kelch-like ECH-associated protein 1 (Keap1) in HGL-treated HK-2 cells through the suppression of autophagy, resulting in the depletion of nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of redox homeostasis. At the cellular level, pharmacological inhibition or genetic knockdown of PDK4 could boost Nrf2, followed by the increase of a plethora of antioxidant enzymes and ferroptosis-suppression enzymes. Meanwhile, the inhibition or knockdown of PDK4 remodeled iron metabolism, further mitigating oxidative stress and lipid peroxidation. The same trend was observed in the DKD mice model. The current work highlighted the role of PDK4 in the development of DKD and suggested that PDK4 might be a promising target for the management of DKD.

Mannan-Binding Lectin Is Associated with Inflammation and Kidney Damage in a Mouse Model of Type 2 Diabetes.

Autoreactivity of the complement system may escalate the development of diabetic nephropathy. We used the BTBR OB mouse model of type 2 diabetes to investigate the role of the complement factor mannan-binding lectin (MBL) in diabetic nephropathy. Female BTBR OB mice (n = 30) and BTBR non-diabetic WT mice (n = 30) were included. Plasma samples (weeks 12 and 21) and urine samples (week 19) were analyzed for MBL, C3, C3-fragments, SAA3, and markers for renal function. Renal tissue sections were analyzed for fibrosis, inflammation, and complement deposition. The renal cortex was analyzed for gene expression (complement, inflammation, and fibrosis), and isolated glomerular cells were investigated for MBL protein. Human vascular endothelial cells cultured under normo- and hyperglycemic conditions were analyzed by flow cytometry. We found that the OB mice had elevated plasma and urine concentrations of MBL-C (p < 0.0001 and p < 0.001, respectively) and higher plasma C3 levels (p < 0.001) compared to WT mice. Renal cryosections from OB mice showed increased MBL-C and C4 deposition in the glomeruli and increased macrophage infiltration (p = 0.002). Isolated glomeruli revealed significantly higher MBL protein levels (p < 0.001) compared to the OB and WT mice, and no renal MBL expression was detected. We report that chronic inflammation plays an important role in the development of DN through the binding of MBL to hyperglycemia-exposed renal cells.

Single-cell transcriptome analysis reveals distinct cell populations in dorsal root ganglia and their potential roles in diabetic peripheral neuropathy.

Diabetic peripheral neuropathy (DPN) is a common complication associated with diabetes, and can affect quality of life considerably. Dorsal root ganglion (DRG) plays an important role in the development of DPN. However, the relationship between DRG and the pathogenesis of DPN still lacks a thorough exploration. Besides, a more in-depth understanding of the cell type composition of DRG, and the roles of different cell types in mediating DPN are needed. Here we conducted single-cell RNA-seq (scRNA-seq) for DRG tissues isolated from healthy control and DPN rats. Our results demonstrated DRG includes eight cell-type populations (e.g., neurons, satellite glial cells (SGCs), Schwann cells (SCs), endothelial cells, fibroblasts). In the heterogeneity analyses of cells, six neuron sub-types, three SGC sub-types and three SC sub-types were identified, additionally, biological functions related to cell sub-types were further revealed. Cell communication analysis showed dynamic interactions between neurons, SGCs and SCs. We also found that the aberrantly expressed transcripts in sub-types of neurons, SGCs and SCs with DPN were associated with diabetic neuropathic pain, cell apoptosis, oxidative stress, etc. In conclusion, this study provides a systematic perspective of the cellular composition and interactions of DRG tissues, and suggests that neurons, SGCs and SCs play vital roles in the progression of DPN. Our data may provide a valuable resource for future studies regarding the pathophysiological effect of particular cell type in DPN.

YAP1-mediated dysregulation of ACE-ACE2 activity augments cardiac fibrosis upon induction of hyperglycemic stress.

BACKGROUND: Diabetic stress acts on the cardiac tissue to induce cardiac hypertrophy and fibrosis. Diabetes induced activated renin angiotensin system (RAS) has been reported to play a critical role in mediating cardiac hypertrophy and fibrosis. Angiotensin converting enzyme (ACE) in producing Angiotensin-II, promotes cardiomyocyte hypertrophy and fibrotic damage. ACE2, a recently discovered molecule structurally homologous to ACE, has been reported to be beneficial in reducing the effect of RAS driven pathologies. METHODS: In vivo diabetic mouse model was used and co-labelling immunostaining assay have been performed to analyse the fibrotic remodeling and involvement of associated target signaling molecules in mouse heart tissue. For in vitro analyses, qPCR and western blot experiments were performed in different groups for RNA and protein expression analyses. RESULTS: Fibrosis markers were observed to be upregulated in the diabetic mouse heart tissue as well as in high glucose treated fibroblast and cardiomyocyte cells. Hyperglycemia induced overexpression of YAP1 leads to increased expression of ß-catenin (CTNNB1) and ACE with downregulated ACE2 expression. The differential expression of ACE/ACE2 promotes TGFB1-SMAD2/3 pathway in the hyperglycemic cardiomyocyte and fibroblast resulting in increased cardiac fibrotic remodeling. CONCLUSION: In the following study, we have reported YAP1 modulates the RAS signaling pathway by inducing ACE and inhibiting ACE2 activity to augment cardiomyocyte hypertrophy and fibrosis in hyperglycemic condition. Furthermore, we have shown that hyperglycemia induced dysregulation of ACE-ACE2 activity by YAP1 promotes cardiac fibrosis through ß-catenin/TGFB1 dependent pathway.

Mode of cell death in the penile cavernous tissue of type 1 diabetes mellitus rats.

BACKGROUND: Diabetes mellitus commonly causes endothelial cell and smooth muscle cell death in penile cavernous tissue. AIM: The study sought to study the mode of cell death in the penile cavernous tissue in type 1 diabetic rats. METHODS: A total of 36 Sprague Dawley rats 10 weeks of age were randomly divided into 2 groups: a normoglycemic group and type 1 diabetic group (intraperitoneal injection of Streptozotocin (STZ), 60 mg/kg). We randomly selected 6 rats from each group for tests at the end of 11, 14, and 18 weeks of age, respectively. All rats were able to eat and drink freely. The ratio of maximum intracavernous pressure to mean arterial pressure, concentration of serum testosterone, level of nitric oxide in the penile cavernosum, and expression of active caspase-1 (pyroptosis) and active caspase-3 (apoptosis) were determined. OUTCOMES: At the end of weeks 4 and 8 of type 1 diabetes, the proportions of endothelial cells and smooth muscle cells undergoing apoptosis and pyroptosis in penile cavernous tissue are different. RESULTS: The ratio of maximum intracavernous pressure to mean arterial pressure and nitric oxide levels were significantly lower in the 4- and 8-week diabetic groups than in the normoglycemic group (P < .01). Penile endothelial cell pyroptosis (5.67 ± 0.81%), smooth muscle cell apoptosis (23.72 ± 0.48%), total cell pyroptosis (9.67 ± 0.73%), and total apoptosis (10.52 ± 1.45%) were significantly greater in the 4-week diabetic group than in the normoglycemic group (P < .01). The proportion of endothelial cell pyroptosis (24.4 ± 3.69%), endothelial cell apoptosis (22.13 ± 2.43%), total cell pyroptosis (14.75 ± 0.93%), and total apoptosis (14.82 ± 1.08%) in the penile tissues of the 8-week diabetic group were significantly greater than those in the normoglycemic group (P < .01).The 8-week survival proportions of diabetic endothelial cells (38.86 ± 8.85%) and smooth muscle cells (44.46 ± 2.94%) was significantly lower than the 4-week survival proportions of endothelial cells (93.17 ± 8.07%) and smooth muscle cells (75.12 ± 4.76%) (P < .05). CLINICAL TRANSLATION: Inhibition of cell death by different methods at different stages may be the key to the treatment of type 1 diabetes-induced erectile dysfunction. STRENGTHS AND LIMITATIONS: The effect of type 1 diabetes on other types of cell death in penile cavernous tissue needs further study. CONCLUSION: The mode of death of endothelial cells in the cavernous tissue of the penis in the early stage in diabetic rats is dominated by pyroptosis, and the death of smooth muscle cells is dominated by apoptosis. Endothelial cell and smooth muscle cell death are not consistent at different stages of diabetes progression.

Microglia Involvement into Acute and Chronic Brain Damage in Diabetic Rats: Impact of GLP-1RA and SGLT-2i.

BACKGROUND: Acute and chronic brain damage in type 2 diabetes mellitus (DM) determines the need to investigate the neuroprotective potential of glucose-lowering drugs. The purpose was to directly compare the neuroprotective effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) with different duration of action and sodium-glucose cotransporter-2 inhibitors (SGLT-2i) in type 2 diabetic rats with and without stroke. METHODS: DM was modelled using high-fat diet and nicotinamide+streptozotocin protocol. The following groups (n = 15 each) were formed: DM without treatment, treatment with liraglutide, dulaglutide, canagliflozin as well as control group without DM and treatment. After 8 weeks, 10 rats from each group underwent middle cerebral artery occlusion. In the reperfusion period neurological deficit, neuroglial damage markers and brain necrosis were evaluated. Brain slices from the remaining 5 animals in each group were histologically examined for microglial activation and neuronal damage. RESULTS: Brain damage was similar in "DM" and "Control" (17.53 [14.23; 26.58] and 15.87 [13.40; 22.68] % of total brain volume, respectively). All study drugs diminished damage volume comparing with "DM" and "Control" whereas the necrosis volume in "DM+Liraglutide" was smaller than in "DM+Canagliflozin" and did not significantly differ from "DM+Dulaglutide" (2.9 [1.83; 4.71], 6.17 [3.88; 8.88] and 4.57 [3.27; 7.90] %). The neurological deficit was more prominent in "DM" than in "Control", while all the drugs demonstrated similar positive effect. Neurofilament light chains (NLC) did not differ between "DM" and "Control". Dulaglutide and canagliflozin caused a marked decrease in NLC. Protein S100BB level was similar in "DM" and "Control". Liraglutide caused the largest S100BB decrease, while canagliflozin did not influence it. In chronic brain ischaemia, all drugs increased the number of normal neurons, but GLP-1RAs had a more pronounced effect. DM was accompanied by increased number of activated microglial cells in Cornu Ammonis (CA)1 hippocampal region. Both GLP-1RAs reduced the number of Iba-1-positive cells, with dulaglutide being more effective than liraglutide, whereas canagliflozin did not affect this parameter. CONCLUSIONS: GLP-1RAs and SGLT-2i have neuroprotective properties against acute and chronic brain damage in diabetic rats, although the infarct-limiting effect of GLP-1RAs may be more pronounced. GLP-1RAs and SGLT-2i exert their protective effects by directly influencing neuronal survival, whereas GLP-1RAs also affect microglia.

Simultaneous regulation of AGE/RAGE signaling and MMP-9 expression by an immunomodulating hydrogel accelerates healing in diabetic wounds.

PURPOSE: In chronic hyperglycemia, the advanced glycation end product (AGE) interacts with its receptor (RAGE) and contributes to impaired wound healing by inducing oxidative stress, generating dysfunctional macrophages, and prolonging the inflammatory response. Additionally, uncontrolled levels of proteases, including metallomatrix protease-9 (MMP-9), in the diabetic wound bed degrade the extracellular matrix (ECM) and biological cues that augment healing. A multifunctional antimicrobial hydrogel (Immuno-gel) containing RAGE and MMP-9 inhibitors can regulate the wound microenvironment and promote scar-free healing. RESULTS: Immuno-gel was characterized and the wound healing efficacy was determined in vitro cell culture and in vivo diabetic Wistar rat wound model using ELISA, Western blot, and Immunofluorescence staining. The Immuno-gel exhibited a highly porous morphology with excellent in vitro cytocompatibility. AGE-stimulated macrophages treated with the Immuno-gel released higher levels of pro-healing cytokines in vitro. In the hydrogel-wound interface of diabetic Wistar rats, Immuno-gel treatment significantly reduced MMP-9 and NF-κB expression and enhanced pro-healing (M2) macrophage population and pro-healing cytokines. CONCLUSION: Altogether, this study suggests that Immuno-gel simultaneously attenuates macrophage dysfunction through the inhibition of AGE/RAGE signaling and reduces MMP-9 overexpression, both of which favor scar-free healing. The combinatorial treatment with RAGE and MMP-9 inhibitors via Immuno-gel simultaneously modulates the diabetic wound microenvironment, making it a promising novel treatment to accelerate diabetic wound healing.

Kiwifruit (Actinidia deliciosa) aqueous extract improves hyperglycemia, testicular inflammation, apoptosis, and tissue structure induced by Streptozotocin via oxidative stress inhibition.

Diabetes mellitus (DM) is a well-known hyperglycemic metabolic condition identified by oxidative stress and biological function disruption. Kiwifruit is a valuable source of polyphenols and vitamin C with great antioxidant, nutritional, and health-promoting effects. Therefore, this study was initiated to explore the antioxidant and anti-hyperglycemic effects of kiwifruit aqueous extract (KFE) against oxidative injury and testis dysfunction in rats with diabetes. Twenty-four male Wistar Albino rats (160-170 g) were divided into four groups: Group 1 served as the control, Group 2 supplemented orally with kiwifruit extract (KFE; 1 g/kg/day) for one month, Group 3 was treated with a single streptozotocin dose (STZ; 50 mg/kg ip), and Group 4 where the diabetic rats were administered with KFE, respectively. According to the results, the GC-MS analysis of KFE revealed several main components with strong antioxidant properties. In diabetic rats, lipid peroxidation and hyperglycemia were accompanied by perturbations in hormone levels and sperm characteristics. Antioxidant enzymes, glutathione content, aminotransferase, phosphatase activities, and protein content were decreased. Furthermore, histology, immunohistochemical PCNA expression, and histochemical analysis of collagen, DNA, RNA, and total protein. were altered in rat testis sections, supporting the changes in biochemistry. Furthermore, diabetic rats supplemented with KFE manifested considerable amendment in all the tested parameters besides improved tissue structure and gene expressions (NF-kB, p53, IL-1ß, Bax, IL-10, and Bcl2) relative to the diabetic group. In conclusion, KFE has beneficial effects as it can improve glucose levels and testis function, so it might be used as a complementary therapy in DM.

[Construction of a mouse model of type 2 diabetes induced by high fat diet alone and evaluation of pathological changes].

The purpose of the present study was to investigate the modeling time of type 2 diabetes mellitus (T2DM) mouse model induced by high fat diet (HFD) alone and the effects of HFD on the pathology and function of organs related to glucose and lipid metabolism. C57BL/6 mice were fed with normal diet (NC group) or HFD (HFD group). The time of successful T2DM modeling was evaluated by measuring body weight, fasting blood glucose and glucose tolerance at time points of 0, 4, 8, 12, 16 and 20 weeks. The functional and pathological changes of glucose and lipid metabolism related organs were evaluated by detecting insulin tolerance, plasma lipid levels, vascular function, as well as HE staining of pancreas and liver. The results showed that compared with the NC group, the HFD group had significantly increased body weight after 8 weeks of HFD. After 16 weeks of HFD, the HFD group exhibited impaired fasting glucose tolerance. After 20 weeks of HFD, the HFD group mice reached diabetic state, showing impaired glucose tolerance and insulin resistance, islet volume reduction and vacuolar degeneration; Large number of lipid droplets appeared in liver cells, and the level of AMPK phosphorylation in liver tissue was significantly increased in the HFD groups, compared with the NC group; There was endothelial dependent diastolic dysfunction in the thoracic aorta of the HFD group; Compared with the NC group, the HFD group mice showed a significant increase in urinary protein levels. These results suggest that T2DM mouse model can be successfully established by HFD induction alone for 20 weeks. The model is characterized by insulin resistance, fatty liver, hyperlipidemia, vascular dysfunction, renal dysfunction and pathological changes of islet and liver cells, which are similar to those of T2DM patients. Therefore it can be used as an ideal animal model for T2DM research.

Smooth muscle NF90 deficiency ameliorates diabetic atherosclerotic calcification in male mice via FBXW7-AGER1-AGEs axis.

Hyperglycemia accelerates calcification of atherosclerotic plaques in diabetic patients, and the accumulation of advanced glycation end products (AGEs) is closely related to the atherosclerotic calcification. Here, we show that hyperglycemia-mediated AGEs markedly increase vascular smooth muscle cells (VSMCs) NF90/110 activation in male diabetic patients with atherosclerotic calcified samples. VSMC-specific NF90/110 knockout in male mice decreases obviously AGEs-induced atherosclerotic calcification, along with the inhibitions of VSMC phenotypic changes to osteoblast-like cells, apoptosis, and matrix vesicle release. Mechanistically, AGEs increase the activity of NF90, which then enhances ubiquitination and degradation of AGE receptor 1 (AGER1) by stabilizing the mRNA of E3 ubiquitin ligase FBXW7, thus causing the accumulation of more AGEs and atherosclerotic calcification. Collectively, our study demonstrates the effects of VSMC NF90 in mediating the metabolic imbalance of AGEs to accelerate diabetic atherosclerotic calcification. Therefore, inhibition of VSMC NF90 may be a potential therapeutic target for diabetic atherosclerotic calcification.

Renal Tissue-Derived Exosomal miRNA-34a in Diabetic Nephropathy Induces Renal Tubular Cell Fibrosis by Promoting the Polarization of M1 Macrophages.

Background: Diabetic nephropathy (DN) is the leading cause of chronic kidney disease, and the activation and infiltration of phagocytes are critical steps of DN. This study aimed to explore the mechanism of exosomes in macrophages and diabetes nephropathy and the role of miRNA-34a, which might provide a new path for treating DN. Materials and Methods: The DN model was established, and the success of the model establishment was confirmed by detecting general indicators, HE staining, and immunohistochemistry. Electron microscopy and NanoSight Tracking Analysis (NTA) were used to see the morphology and size of exosomes. MiRNA-34a inhibitor, miRNA-34a mimics, pc-PPARGC1A, and controls were transfected in macrophages with or without kidney exosomal. A dual-luciferase reporter gene experiment verifies the targeting relationship between miRNA-34a and PPARGC1A. After exosomal culture, macrophages are co-cultured with normal renal tubular cells to detect renal tubular cell fibrosis. Q-PCR and western blot were undertaken to detect related RNA and proteins. Results: An animal model of diabetic nephropathy was successfully constructed. Macrophages could phagocytose exosomes. After ingesting model exosomes, M1 macrophages were activated, while M2 macrophages were weakened, indicating the model mice's kidney exosomes caused the polarization. MiRNA-34a inhibitor increased PPARGC1A expression. MiRNA-34a expressed higher in diabetic nephropathy Model-Exo. MiRNA-34a negatively regulated PPARGC1A. PPARGC1A rescued macrophage polarization and renal tubular cell fibrosis. Conclusion: Exosomal miRNA-34a of tubular epithelial cells promoted M1 macrophage activation in diabetic nephropathy via negatively regulating PPARGC1A expression, which may provide a new direction for further exploration of DN treatment.

Transplantation of hyaluronic acid and menstrual blood-derived stem cells accelerated wound healing in a diabetic rat model.

Diabetic wounds require a multifactorial approach because several factors are involved in its occurrence. Herein we investigated whether transplantation of hyaluronic acid (HA) in combination with menstrual blood derived stem cells (MenSCs) could promote healing in diabetic rats. Thirty days after induction of diabetes, sixty animals were randomly planned into four equal groups: the untreated group, HA group, MenSC group, and HA+MenSC group. Sampling was done for histological, molecular, and tensiometrical assessments. Our results indicated that the wound contraction rate, volumes of new epidermis and dermis, collagen density, as well as tensiometrical parameter were considerably increased in the treatment groups compared to the untreated group and these changes were more obvious in the HA+MenSC ones. In addition, the expression levels of TGF-ß and VEGF genes were significantly upregulated in treatment groups in comparison with the untreated group and were greater in the HA+MenSC group. This is while expression levels of TNF-α and IL-1ß genes were more considerably downregulated in the HA+MenSC group than the other groups. We concluded that the combined use of HA and MenSCs has more effects on diabetic wound healing.

A crucial role of adenosine deaminase in regulating gluconeogenesis in mice.

Adenosine deaminase (ADA) catalyzes the irreversible deamination of adenosine (ADO) to inosine and regulates ADO concentration. ADA ubiquitously expresses in various tissues to mediate ADO-receptor signaling. A significant increase in plasma ADA activity has been shown to be associated with the pathogenesis of type 2 diabetes mellitus. Here, we show that elevated plasma ADA activity is a compensated response to high level of ADO in type 2 diabetes mellitus and plays an essential role in the regulation of glucose homeostasis. Supplementing with more ADA, instead of inhibiting ADA, can reduce ADO levels and decrease hepatic gluconeogenesis. ADA restores a euglycemic state and recovers functional islets in db/db and high-fat streptozotocin diabetic mice. Mechanistically, ADA catabolizes ADO and increases Akt and FoxO1 phosphorylation independent of insulin action. ADA lowers blood glucose at a slower rate and longer duration compared to insulin, delaying or blocking the incidence of insulinogenic hypoglycemia shock. Finally, ADA suppresses gluconeogenesis in fasted mice and insulin-deficient diabetic mice, indicating the ADA regulating gluconeogenesis is a universal biological mechanism. Overall, these results suggest that ADA is expected to be a new therapeutic target for diabetes.