Diabetic Mice Research Articles

Characterization and Role of Glucagon-Like Peptide 1 Receptor in the Lacrimal Gland: Novel Insights into Diabetic Dry Eye Pathogenesis.

This study aimed to investigate the expression of glucagon-like peptide 1 receptor (GLP-1R) in the lacrimal gland and explore the effects of topical application of GLP-1R agonist (GLP-1RA) on lacrimal gland function in a murine model of type 1 diabetes. Tear secretion was evaluated using phenol red threads, RNA sequencing (RNA-seq) was used to explore gene expression profiles associated with hyperglycemia-induced lacrimal gland injuries, and histological analysis was conducted to evaluate the degree of damage. The expression of GLP-1R in the lacrimal gland was first identified and a downregulation trend associated with diabetes was observed. RNA-seq data from lacrimal gland tissues revealed that differentially expressed genes (DEGs) were enriched in inflammatory response pathways. Histological analysis demonstrated persistent hyperglycemia-induced infiltration of inflammatory cells and progressive fibrosis in the lacrimal gland, resulting in atrophy and diminished tear secretion. Topical application of liraglutide effectively attenuated inflammation and alleviated fibrosis, thus promoting tear production in diabetic mice. Additionally, local intervention with liraglutide could promote autophagy degradation function in the lacrimal gland. This study represents the first validation of GLP-1R expression in the lacrimal gland and its downregulation induced by diabetes; furthermore, these findings demonstrate that topical administration of liraglutide eye drops, a GLP-1RA, can effectively mitigate hyperglycemia-induced damage in the lacrimal gland while enhancing tear secretion.

DNMT3b-mediated CpA methylation facilitates REST binding and gene silencing and exacerbates hippocampal demyelination in diabetic mice.

The remyelination process within the diabetes mellitus (DM) brain is inhibited, and dynamic interactions between DNA methylation and transcription factors are critical for this process. Repressor element-1 silencing transcription factor (REST) is a major regulator of oligodendrocyte differentiation, and the role of REST on DM remyelination remains to be investigated. Here, we investigated the effects of REST and DNA methylation on DM remyelination and explored the underlying mechanisms. In this study, using a diabetic mouse model, we found that myelin damage preceded neuronal damage and caused cognitive impairment in DM mice. Inhibition of REST by X5050 and DNMT3b by Naomycin A promoted myelin regeneration in the hippocampus and ameliorated cognitive deficits in DM mice. In addition, CpA methylation of the RE-1 locus of the CNTN1 gene was able to increase the binding capacity of REST. We also observed that CNTN1 promotes oligodendrocyte maturation, facilitates the ratio of microglia to pro-regenerative phenotype as well as enhances the ability of microglia to remove myelin debris. Our findings suggest that that REST and DNMT3b expression inhibit CNTN1 expression and exacerbate myelin damage. This mechanism of gene silencing may be associated with DNMT3b-mediated CpA methylation of the REST binding site in the promoter region of the CNTN1 gene. We also identified a role for CNTN1 in promoting oligodendrocyte precursor cell maturation and myelin debris removal during remyelination.

Vascular endothelial growth factor B-mediated fatty acid flux in the adipose-kidney axis contributes to lipotoxicity in diabetic kidney disease.

A common observation in diabetic kidney disease is lipid accumulation, but the mechanism(s) underlying this pathology is unknown. Inhibition of Vascular endothelial growth factor B (VEGF-B) signaling was shown to prevent glomerular lipid accumulation and ameliorated diabetic kidney disease in experimental models. Here, we examined kidney biopsies from patients with Type 2 (84 %) and Type 1 diabetes (16 %), combined with data mining of RNA-seq dataset analyses in patients with diabetic kidney disease. In glomeruli, mesangial cell-derived VEGF-B expression was increased, and glomerular lipid accumulation positively correlated with impaired kidney function. Tubular lipid accumulation also associated with kidney dysfunction but was independent of tubular-derived VEGF-B expression. In vitro, the uptake of the fatty acid analogue, BODIPY-FA, was quantified. VEGF-B treatment increased BODIPY-FA uptake in endothelial cells, whilst pre-incubation with neutralizing antibodies against VEGF-B and its receptor VEGFR1 abolished this uptake. Transcriptome analyses of kidney and white adipose tissue from diabetic macaques showed that VEGF-B expression was higher in white adipose tissue than in kidney, and expression of VEGF-B was increased in white adipose tissue from patients with diabetic kidney disease. Analyzes in diabetic transgenic mice demonstrated that expression of VEGF-B in adipocytes determined the lipolytic activity, dyslipidemia, kidney lipid accumulation and the development of diabetic kidney disease. Overall, VEGF-B is a regulator of kidney lipotoxicity in diabetic kidney disease, by controlling white adipose tissue lipolysis as well as endothelial fatty acid transport in glomeruli. Our data propose that assessment of kidney lipid accumulation, and VEGF-B expression can serve as biomarkers for early diabetic kidney disease.

Novel double-layered PLGA microparticles-dissolving microneedle (MPs-DMN) system for peptide drugs sustained release by transdermal delivery.

The combination of microparticles (MPs) with dissolving microneedles (DMN) represents a promising transdermal approach for the sustained release of biomacromolecule drug. In this study, we developed a double-layered microparticles-dissolving microneedle (MPs-DMN) system, which strategically concentrates PLGA MPs at the tip of the microneedle to achieve sustained release of peptide drugs through transdermal delivery. We selected exenatide (EXT) as a model peptide drug and established HPLC-UV and UPLC-MS methods for the quantitative analysis of the drug content of MPs-DMN and drug concentrations in plasma. Ultrasonication was utilized in the first step of the double emulsion solvent evaporation method to produce PLGA microparticles, achieving a high drug loading efficiency of 22.76 ± 0.64 %, surpassing the commercial products. The EXT-loaded microparticles were then mixed with 10 % w/v sucrose solution to form the first layer of the microneedle, and the mixture of the base solution was added to form the double-layered dissolving microneedle. Microscopic analysis revealed that the MPs were predominantly concentrated in the upper 50 % of the microneedle body, resulting in an impressive drug delivery efficiency of 92.86 ± 1.62 %. The MPs-DMN patch demonstrated the capability to 238.20 ± 5.79 μg of EXT within a compact area of 0.75 cm2, surpassing the capacities reported in existing research. The insertion and dissolution assessments exhibited rapid dissolution, maintaining the MPs as an effective drug reservoir within the skin. Pharmacokinetic assessments indicated that the long half-life (T1/2) of 466.4 ± 12.2 h and high relative bioavailability of 89.71 % for MPs-DMN. Furthermore, pharmacodynamic studies indicated that the MPs-DMN effectively controlled blood glucose levels below 20 mmol/L in diabetic (db/db) mouse for two weeks. These promising findings suggest that the MPs-DMN system could serve as a viable transdermal delivery method for the prolonged administration of peptide drugs.

San Huang Xiao Yan recipe promoted wound healing in diabetic ulcer mice by inhibiting Th17 cell differentiation.

Diabetic ulcer is a serious diabetes complication and a primary reason for amputations. For many years, the San Huang Xiao Yan (SHXY) recipe has served as a conventional remedy for these ulcers, effectively reducing inflammatory factors and exhibiting considerable therapeutic efficacy. However, the precise mechanism remains incompletely understood. To explore the efficacy and mechanisms of SHXY and its active ingredients in treating diabetic ulcer. A diabetic ulcer mouse model was established using C57BL/6J mice on a high-fat diet, followed by streptozotocin injection and skin damage. We investigated the bioactive compounds, key targets, and pharmacological mechanisms of SHXY in addressing diabetic ulcers through network pharmacology, molecular docking, both in vitro and in vivo validation experiments. One week after intragastric administration, SHXY can reduce inflammation and edema, increase collagen synthesis, and reduce the expression of RORγT and IL-17A without affecting Treg cells. In vitro, SHXY-containing serum inhibited the differentiation of Th17 cells but did not affect Treg and Th1 cells. Network pharmacology found that SHXY acts through inflammatory pathways, including TNF, IL-17, Th17 cell differentiation, HIF-1, and PI3K-Akt. SHXY and its candidate enhance healing in diabetic ulcers by modulating CD4+ T cells, particularly by inhibiting Th17 cell differentiation.

NOD alleles at Idd1 and Idd2 loci drive exocrine pancreatic inflammation.

Non-obese diabetic (NOD) mice spontaneously develop autoimmune diabetes and have enabled the identification of several loci associated with diabetes susceptibility, termed insulin-dependent diabetes (Idd). The generation of congenic mice has allowed the characterization of the impact of several loci on disease susceptibility. For instance, NOD.B6-Idd1 and B6.NOD-Idd1 congenic mice were instrumental in demonstrating that susceptibility alleles at the MHC locus (known as Idd1) are necessary but not sufficient for autoimmune diabetes progression. We previously showed that diabetes resistance alleles at the Idd2 locus provide significant protection from autoimmune diabetes onset, second to Idd1. In search of the minimal genetic factors required for T1D onset, we generated B6.Idd1.Idd2 double-congenic mice. Although the combination of Idd1 and Idd2 is not sufficient to induce diabetes onset, we observed immune infiltration in the exocrine pancreas of B6.Idd2 mice, as well as an increase in neutrophils and pancreatic tissue fibrosis. In addition, we observed phenotypic differences in T-cell subsets from B6.Idd1.Idd2 mice relative to single-congenic mice, suggesting epistatic interaction between Idd1 and Idd2 in modulating T-cell function. Altogether, these data show that Idd1 and Idd2 susceptibility alleles are not sufficient for autoimmune diabetes but contribute to inflammation and immune infiltration in the pancreas.

Exploring the molecular mechanisms for renoprotective effects of Huangkui capsule on diabetic nephropathy mice by comprehensive serum metabolomics analysis.

Huangkui capsule (HKC), a patent traditional Chinese medicine, has shown significant efficacy in managing chronic kidney disease (CKD), particularly diabetic nephropathy (DN). Previous studies have shown that HKC can alleviate kidney damage in DN. However, the exact mechanisms through which it exerts its effects remain unclear. This study aimed to elucidate the potential molecular mechanisms of HKC in treating kidney injury in type 1 diabetic nephropathy (T1DN) models through serum metabolomics, Chinmedomics, and molecular docking techniques. T1DN mouse models were induced by intraperitoneal injection of streptozotocin (STZ), resulting in the ACR value ten times that of the control group. The efficacy of HKC on T1DN was comprehensively evaluated in general conditions, renal coefficient, histopathology, and related biochemical indicators. UPLC-Q-TOF-MS/MS based serum metabolomics was employed to identify biomarkers of T1DN and evaluate the effects of HKC. Relevant pathways were analyzed, and followed by Protein-Protein Interaction network analysis to screen for key enzymes. By integrating the Chinmedomics strategy and molecular docking the relationship between these targets and active components was elucitaed. HKC resulted in a significant reduction in renal inflammation and fibrosis, as evidenced by the decreased levels of urinary ACR, blood TG, T-CHO, BUN, and renal TNF-α and VEGF-A, along with a reduction in the positive area of COL-1. Palmitic acid, stearic acid, arachidonic acid, pantothenic acid, and sphingosine-1-phosphate serve as key serum metabolite biomarkers for T1DN, involved in the biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, pantothenate and CoA biosynthesis, and sphingolipid metabolism. FASN, Cyp2e1, and Cyp4a32 are the key enzymes in the treatment of T1DN with HKC. Additionally, 8 key active components were identified in the serum of HKC-H, including quercetin, myricetin, isoquercitrin, hyperoside, hibifolin, gentisic acid 5-O-β-glucoside, floramanoside F, and quercetin-4'-O-glucoside, which are believed to interact with key enzymes. The active components of HKC influence Fasn, Cyp2e1, and Cy4a32, improving renal injury in T1DN. These findings provide new molecular insights for the future clinical application and research of HKC in treating T1DN.

Moringa isothiocyanate-1 mitigates the damage of oxidative stress and apoptosis in diabetic nephropathy mice.

Diabetic nephropathy (DN) is a prevalent cause of end-stage kidney disease worldwide. Moringa isothiocyanate-1 (MIC-1) has shown potential for DN management, however, the exact mechanisms remain unclear. This research intended to evaluate the impact and mechanism of MIC-1 on DN. Six C57BLKS/J-db/m mice served as controls. Eighteen C57BLKS/J-db/db mice were randomly separated into three groups: db/db, db/db + irbesartan (IBS), and db/db + MIC-1. Three weeks post-drug administration, the body weight and kidney weight of mice in each group were measured. Concurrently, serum creatinine (Scr), urine albumin, insulin, glycosylated hemoglobin (GHb), oxidative stress-, and inflammatory-related factors were determined. Additionally, the pathological injury, apoptosis, apoptosis-related markers, NLRP3, and ASC levels in the kidney tissues were examined utilizing H&E, Masson, PAS, TUNEL staining, and Western blot. MIC-1 decreased the body weight, kidney weight, the levels of Glu, Scr, and urine albumin in db/db mice. Moreover, MIC-1 significantly suppressed the levels of MDA, insulin, GHb, TNF-α, IL-1β, and IL-6, while increased the activities of SOD, CAT, and GPX in the serum of db/db mice. MIC-1 also mitigated the kidney tissue injury in db/db mice. Western blot assay showed that MIC-1 enhanced the Bcl-2 level and suppressed the Bax, cleaved caspase-3, cleaved caspase-9, NLRP3, ASC, and caspase-1 levels of the kidney tissues in db/db mice. MIC-1 ameliorated the kidney injury in DN mice, and its mechanism may be associated with the suppression of renal cell apoptosis, oxidative stress, and inflammatory responses.

Effect of carrot intake on glucose tolerance, microbiota, and gene expression in a type 2 diabetes mouse model.

Type 2 diabetes (T2D) pathophysiology involves insulin resistance (IR) and inadequate insulin secretion. Current T2D management includes dietary adjustments and/or oral medications such as thiazolidinediones (TZDs). Carrots have shown to contain bioactive acetylenic oxylipins that are partial agonists of the peroxisome proliferator-activated receptor γ (Pparg) that mimic the antidiabetic effect of TZDs without any adverse effects. TZDs exert hypoglycemic effects through activation of Pparg and through the regulation of the gut microbiota (GM) producing short-chain fatty acids (SCFAs), which impact glucose and energy homeostasis, promote intestinal gluconeogenesis, and influence insulin signaling pathways. This study investigated the metabolic effects of carrot intake in a T2D mouse model, elucidating underlying mechanisms. Mice were fed a low-fat diet (LFD), high-fat diet (HFD), or adjusted HFD supplemented with 10% carrot powder for 16 weeks. Oral glucose tolerance tests were conducted at weeks 0 and 16. Fecal, cecum, and colon samples, as well as tissue samples, were collected at week 16 during the autopsy. Results showed improved oral glucose tolerance in the HFD carrot group compared to HFD alone after 16 weeks. GM analysis demonstrated increased diversity and compositional changes in the cecum of mice fed HFD with carrot relative to HFD. These findings suggest the potential effect of carrots in T2D management, possibly through modulation of GM. Gene expression analysis revealed no significant alterations in adipose or muscle tissue between diet groups. Further research into carrot-derived bioactive compounds and their mechanisms of action is warranted for developing effective dietary strategies against T2D.

Loss of glomerular aldolase B in diabetic nephropathy promotes renal fibrosis via activating Akt/GSK/β-catenin axis.

Diabetic nephropathy (DN), characterized by a complex and multifaceted pathogenesis, stands as the foremost catalyst behind end-stage renal disease (ESRD). This study aims to analyze the level and non-metabolic role of glomerular aldolase B (ALDOB) in DN progression. Glomerular proteomics and transcriptome are analyzed from 50 DN patients and 25 controls, respectively. Human kidney biopsy, cultured podocytes and mouse models are employed to study ALDOB levels and function. ALDOB is strongly downregulated in DN-affected glomeruli, as well as in human and murine podocytes exposed to inflammatory cytokines. ALDOB reduction increases podocyte injury, while adenovirus-mediated ALDOB overexpression leads to substantial alleviation of renal injuries in a diabetic mouse model. Mechanistically, ALDOB reduction triggers the Akt/GSK/β-catenin signaling cascade within podocytes. Our findings reveal a novel non-metabolic role of glomerular ALDOB in protecting against podocyte injury and renal fibrosis.

Arsenic exposure accelerates type 1 diabetes mellitus progression via pyroptosis pathway in mice.

The relationship between arsenic exposure and the development of diabetes mellitus has garnered significant interest in recent years. However, current experimental studies have not definitively established the role of arsenic in the onset of diabetes mellitus. To investigate this relationship specifically concerning type 1 diabetes mellitus, Streptozocin (STZ) was utilized as an inducer to initiate the fundamental pathological changes associated with the disease. A high dose of STZ (50mg/kg) served as the positive control, while a low dose of STZ (20mg/kg) was administered in combination with arsenic at varying doses. The objective was to determine whether arsenic enhances the effects of STZ, thereby leading to an expedited onset and progression of type 1 diabetes mellitus. The preliminary investigation into the impact of arsenic exposure on experimental type 1 diabetic mice focused on the NLRP3/Caspase-1/GSDMD mediated pyroptosis pathway. The results showed that fasting blood glucose (FBG) was increased, glucose tolerance was impaired, insulin sensitivity was decreased, fasting serum insulin and the homeostatic model assessment-β (HOMA-β) were significantly reduced, hair arsenic content was increased, reactive oxygen species(ROS), interleukin (IL)-1β and IL-18 contents were increased, and the pathological morphology of pancreas was more serious in the combined group. Moreover, the expression levels of proteins associated with the NLRP3/Caspase-1/GSDMD-mediated pyroptosis pathway were elevated in the combined group. This study illustrates that exposure to arsenic, combined with low-dose STZ, not only leads to pancreatic injury in mice, impacting insulin secretion and causing elevated blood glucose levels, thereby hastening the progression of type 1 diabetes, but also induces pyroptosis in pancreatic tissues by influencing the NLRP3/Caspase-1/GSDMD signaling pathway, further facilitating the development of type 1 diabetes.

Herbal micelles-loaded ROS-responsive hydrogel with immunomodulation and microenvironment reconstruction for diabetic wound healing.

Persistent inflammation is a major cause of diabetic wounds that are difficult to heal. This is manifested in diabetic wounds with excessive reactive oxygen clusters (ROS), advanced glycation end products (AGE) and other inflammatory factors, and difficulty in polarizing macrophages toward inhibiting inflammation. Berberine is a natural plant molecule that inhibits inflammation; however, its low solubility limits its biological function through cytosis. In this study, we designed F127 micelles to encapsulate berberine with the aim of improving its solubility and bioavailability. Meanwhile, in order to achieve effective drug delivery at the wound site, we designed an injectable ferrocene-cyclodextrin self-assembled oxidation-reactive supramolecular hydrogel drug delivery system. Cellular experiments have shown that the hydrogel can reduce intracellular ROS and AGE production, attenuate cellular damage, promote macrophage polarization toward inhibition of inflammation, and reduce the secretion of inflammatory factors. In an animal model of diabetic mice, this hydrogel dressing reduces the level of inflammation in diabetic wounds, optimizes collagen deposition in diabetic wounds, and ultimately achieves high-quality diabetic wound healing. The work offers a straightforward and effective solution to the challenge of administering hydrophobic anti-inflammatory agents in the context of diabetic wound therapy.

Peanut Shell Extract Improves Markers of Glucose Homeostasis in Diabetic Mice by Modulating Gut Dysbiosis and Suppressing Inflammatory Immune Response.

There is strong evidence that the tripartite interaction between glucose homeostasis, gut microbiota, and the host immune system plays a critical role in the pathophysiology of type 2 diabetes mellitus (T2DM). We reported previously that peanut shell extract (PSE) improves mitochondrial function in db/db mice by suppressing oxidative stress and inflammation in the liver, brain, and white adipose tissue. This study evaluated the impacts of PSE supplementation on glucose homeostasis, liver histology, intestinal microbiome composition, and the innate immune response in diabetic mice. Fourteen db/db mice were randomly assigned to a diabetic group (DM, AIN-93G diet) and a PSE group (1% wt/wt PSE in the AIN-93G diet) for 5 weeks. Six C57BL/6J mice received the AIN-93G diet for 5 weeks (control group). Parameters of glucose homeostasis included serum insulin, HOMA-IR, HOMA-B, and the analysis of pancreatic tissues for insulin and glucagon. We assessed the innate immune response in the colon and liver using a microarray. Gut microbiome composition of cecal contents was analyzed using 16S rRNA gene amplicon sequencing. PSE supplementation improved glucose homeostasis (decreased serum insulin concentration, HOMA-IR, and HOMA-B) and reduced hepatic lipidosis in diabetic mice. PSE supplementation reversed DM-induced shifts in the relative abundance of amplicon sequence variants of Enterorhabdus, Staphylococcus, Anaerotruncus, and Akkermansia. Relative to the DM mice, the PSE group had suppressed gene expression levels of Cd8α, Csf2, and Irf23 and increased expression levels of Tyk2, Myd88, and Gusb in the liver. This study demonstrates that PSE supplementation improves T2DM-associated disorders of diabetic mice, in part due to the suppression of innate immune inflammation.

Human Keratin Matrices Suppress Matrix Metalloproteinase Activity to Support Wound Healing.

Elevated protease activity is a hallmark of non-healing chronic wounds. Though multiple biomaterials exist that are successful in treating wounds, their roles in modulating the enzymatic environment of the wound are only beginning to be elucidated. Because keratin has long been known to be resistant to degradation by most enzymes, we studied a keratin biomaterial, the human keratin matrix (HKM), in the presence of enzymes identified to contribute to wound chronicity: neutrophil-derived elastase (NE), matrix metalloproteinase 1 (MMP-1), and MMP-9. Upon finding the suppression of MMP-9 activity in the presence of HKM without reducing enzyme protein levels, we further studied the ability of HKM to bind metal ions in the wound and showed the reduction of Zn2+ ion concentration in the presence of HKM. Finally, because of the enzyme resistance of keratin and the suppression of wound enzymes, we demonstrated that HKM was durable in the wound environment, and did not degrade in wound healing efficacy when left in place for two weeks compared to one week in a diabetic mouse model of wound non-healing. In this way, we show HKM is a unique and effective biomaterial for the treatment of chronic wounds through the modulation of wound MMP activity.

Effect of Alkanna tinctoria Root Against MRSA and MDR-Pseudomonas aeruginosa Biofilms on Excision Wound in Diabetic Mice: Comparative Study Between Methanolic Extract and Traditional Hydrophobic Preparation.

Alkanna tinctoria, commonly called dyer's alkanet (family-Boraginaceae), is used traditionally in Saudi Arabia to treat skin infections. A methanolic extract and a traditional formulation of the root used in folklore were prepared. LC-MS analysis was conducted to identify probable compounds present in the extract and the traditional hydrophobic formulation. The in vivo activity on excision wound was evaluated in diabetic mice while crystal violet assay was employed for in vitro evaluation. Human keratinocyte (HaCaT) cells were used to study in vitro cytotoxic effects. Several probable phytoconstituents were revealed by LC-MS analysis in the methanolic extract and the traditional formulation, and three of the constituents were the same. The extract ointment and traditional hydrophobic extract exhibited antibacterial and antibiofilm activity against both tested pathogens. The methanolic extract was relatively more cytotoxic on HaCaT cells compared to the hydrophobic formulation. The methanolic extract ointment did not significantly affect the wound healing, whereas the traditional formulation accelerated wound healing in diabetic mice. The results revealed that A. tinctoria in its traditional formulation is an effective wound healing agent but the methanolic extract of the plant does not affect the healing of wounds.

Gallic acid ameliorates diabetic steatohepatitis in db/db mice fed with a high-fat diet

The term nonalcoholic fatty liver disease has been changed to metabolic dysfunction–associated steatotic liver disease (MASLD). MASLD and metabolic dysfunction–associated steatohepatitis (MASH) are complications arising from increased lipid accumulation in the liver. Previous studies have indicated that gallic acid (GA) induces immune modulation. In this study, we examined the effectiveness of GA in reducing serum lipid levels and lipid deposition in the liver and ameliorating steatohepatitis in a diabetic mouse model fed with a high-fat diet (HFD). Animal studies were conducted using db/m mice as the normal control group and db/db mice fed with a normal diet, db/db mice fed with an HFD, and db/db mice fed with an HFD supplemented with GA as the study groups. The serum parameters were higher in the db/db group than in the normal control group. The serum lipid profiles and liver fatty scores were significantly higher in the HFD group than in the db/m and db/db groups. However, the levels of liver antioxidants were significantly lower in the HFD group than in the db/m and db/db group. When diabetic mice were fed with both an HFD and GA, an improvement was observed in the serum lipid profiles and liver fatty deposition, with the amelioration of steatohepatitis and enhancement of liver antioxidant activity. GA inhibits MASH by upregulating the expression of miR-30a-3p and downregulating the expression of NF-κB. GA also increases the levels of antioxidant enzymes and ameliorates MASH in HFD-fed diabetic mice.

Serum metabolomics and 16S rRNA amplicon sequencing reveal the role of puerarin in alleviating bone loss aggravated by antidiabetic agent pioglitazone in type 2 diabetic mice

Ethnopharmacological relevancePioglitazone (PIO) was an anti type 2 diabetes (T2D) agent but caused bone loss and bone marrow fat accumulation. Puerarin (PUE) was a natural component of herbal medicine extracted from Pueraria lobata (Willd.) Ohwi and reduced glycemia and improved bone mass as a supplementary drug. A combination of PIO and PUE might be good for maintaining bone mass and blood glucose. Aim of the studyWe aimed to elucidate the potential correlation and underlying mechanisms of dietary supplement PUE in reducing side effects caused by PIO. Materials and methodsIn vitro, alkaline phosphatase (ALP) staining, alizarin S (ARS) staining and qRT-PCR were performed to detect the osteogenesis activity in MC3T3-E1 cells. In vivo, we established the T2D model by treating C57BL6/J mice with high-fat diets and streptozotocin (STZ). Micro-CT, hematoxylin and eosin (H&E) staining and tartrate-resistant acid phosphatase (TRAcP) staining were performed to observe the difference in skeletal phenotype. Serum metabolomics and 16S rRNA amplicon sequencing were applied to analyze the potential effect of the combination of PIO and PUE. ResultsWe showed that the PUE could increase ALP activity and mineralization nodes of MC3T3-E1 with PIO. PIO could aggravate bone loss but PUE alleviated the effect caused by PIO in T2D mice. PUE promoted alpha-linolenic acid metabolism and glycerophospholipid metabolism, and affected the alpha diversity of the gut microbiome by regulating the genera of Alloprevotella, Fusobacterium, Rodentibacter, etc. Correlation analysis indicated that sphingosine-1-phosphate, nonadecylic acid, and margaric acid were associated with the effect of PUE. ConclusionsTaken together, we demonstrated that PIO combined with PUE was able to lower blood sugar levels without causing bone loss. The effect of PUE mainly correlated with the genua of Alloprevotella, Fusobacterium, Rodentibacter, and Alistipes. Also, alpha-linolenic acid metabolism and glycerophospholipid metabolism were major targets of PUE.

Photo-controlled multifunctional hydrogel for photothermal sterilization and microenvironment amelioration of infected diabetic wounds

Diabetic foot ulcers are linked to a high disability rate, with no effective treatment currently available. Addressing infection, reducing oxidative stress, and safely managing chronic inflammation remain major challenges. In this study, a composite hydrogel dressing was developed using natural substances or clinically approved components (dopamine, D-alpha-tocopheryl polyethylene glycol succinate, and rhein). Upon near-infrared laser irradiation, the composite system rapidly heats and solidifies into a gel with photothermal antibacterial properties. Additionally, the decomposition of hydrogen peroxide releases oxygen, alleviating wound hypoxia. The hydrogel exhibited strong bactericidal activity against multiple bacterial strains. Without laser irradiation, the hydrogel effectively scavenged various free radicals and intracellular reactive oxygen species, restoring redox balance. Furthermore, it significantly reduced the expression of inflammatory cytokines, including interleukin-6 and interleukin-1β. In a diabetic mouse wound model infected with S. aureus, the mild photothermal therapy, combined with the antibacterial action of rhein, effectively managed bacterial infections, reduced inflammation, and promoted wound healing. Consequently, the photo-controlled therapeutic approach, offering antibacterial, antioxidant, and anti-inflammatory effects, holds promise for the effective treatment and management of infected diabetic wounds.

Cardiac fibroblast-specific expression of IL-37 confers the protective effects on fibrosis in diabetic cardiomyopathy mice by regulating SOCS3-STAT3 axis.

Human interleukin (IL)-37 is a constituent of the IL-1 family with potent anti-inflammatory and immunosuppressive attributes. It has been demonstrated extensive beneficial effects on various diseases; however, its role in the pathogenesis of diabetic cardiomyopathy (DCM) remains unclear. In vivo, DCM mouse model was established with streptozotocin injection and a high-fat diet in WT and cardiac fibroblasts (CFs) specific hIL-37b overexpression mice (IL-37-Tg). In vitro, primary mouse CFs were isolated from the hearts of adult mice and cultured with high levels of glucose and palmitic acid. Cardiac function of the mice was assessed using echocardiography. Masson staining, immunofluorescence, western blot and RT-PCR assays were employed to evaluate the expression of cardiac fibrosis and SOCS3-JAK2-STAT3 signaling pathway-related proteins. In this study, we found that CFs specific IL-37-Tg significantly ameliorated cardiac dysfunction and reduced collagen production by inhibiting the JAK2-STAT3 axis, as evidenced by the decreased levels of p-JAK2 and p-STAT3 in the heart of CFs specific IL-37-Tg DCM mice. The beneficial effects of IL-37 were consistently observed in CFs treated with high glucose (HG) and palmitic acid (PA). Moreover, we also discovered that the presence of IL-37 increased the expression of SOCS3, a crucial regulator of JAK/STAT signaling, in DCM mice and HG and PA-treated CFs. Finally, the anti-fibrotic action of IL-37 in HG and PA-treated CFs was abolished when either SOCS3 was genetically knocked down or JAK2/STAT3 was pharmacologically activated. Our findings indicate that IL-37 exerts its antifibrotic effect by promoting SOCS3-mediated JAK2-STAT3 inactivation and may be considered as a potential therapeutic agent for DCM.

Flavonoids from Ougan (Citrus suavissima Hort. ex Tanaka) peel exert hypoglycemic potency through inhibiting insulin resistance in HepG2 cells and regulating gut microbiota in diabetic mice

To fully and value-addedly utilize the citrus peel resource, flavonoids were extracted and purified from peel powder of Ougan (Citrus suavissima Hort. ex Tanaka) using an ultrasonic assisted ethanol solution extraction method and AB-8 macroporous resin purification. The obtained flavonoid extract from peel of Ougan (FEPO) was used for the hypoglycemic experiments in vitro and in vivo on glucose consumption in insulin resistance model HepG2 cells and streptozotocin induced diabetes model mice. A significant reduction of glucose consumption in the model cells while a significant increase in the treated were found in a dose-dependent manner, compared to 5.2241 ± 0.2201 mmol/L of the normal cells (P < 0.05). When the FEPO concentration was 80 μg/mL, the cell glucose consumption was 4.4055 ± 0.1772 mmol/L. Compared with those in the model group (diabetic mice), the fasting blood glucose in the FEPO intervened mice was significantly decreased (P < 0.05). FEPO intervention caused decreased levels of TC, TG, LDL-C, and increased HDL-C and insulin contents in the serums as well as ameliorative histopathology of the liver, kidney, and pancreas in diabetic mice. FEPO improved the gut microbiota structure of diabetic mouse by regulating its composition, especially significantly increasing the relative abundance of Lactobacillus, Ileibacterium, unclassified_f_Lachnospiracea, Romboutsia, norank_f_Muribaculaceae, Faecalibaculum and Coriobacteriaceae_UCG-002 (P < 0.05), while decreasing that of norank_f_norank_o_Clostridia_UCG-014, Lachnospiraceae_NK4A136_group and Candidatus_Saccharimonas. In conclusion, FEPO had good hypoglycemic efficacies both in vitro and in vivo as well as gut microbiota regulating effect.