Exosomes derived from umbilical cord-derived mesenchymal stem cells exposed to diabetic microenvironment enhance M2 macrophage polarization and protect against diabetic nephropathy.

The role of mesenchymal-stem-cell-derived exosomes (MSCs-Exo) in the regulation of macrophage polarization has been recognized in several diseases. There is emerging evidence that MSCs-Exo partially prevent the progression of diabetic nephropathy (DN). This study aimed to investigate whether exosomes secreted by MSCs pre-treated with a diabetic environment (Exo-pre) have a more pronounced protective effect against DN by regulating the balance of macrophages. Exo-pre and Exo-Con were isolated from the culture medium of UC-MSCs pre-treated with a diabetic mimic environment and natural UC-MSCs, respectively. Exo-pre and Exo-Con were injected into the tail veins of db/db mice three times a week for 6 weeks. Serum creatinine and serum urea nitrogen levels, the urinary protein/creatinine ratio, and histological staining were used to determine renal function and morphology. Macrophage phenotypes were analyzed by immunofluorescence, western blotting, and quantitative reverse transcription polymerase chain reaction. In vitro, lipopolysaccharide-induced M1 macrophages were incubated separately with Exo-Con and Exo-pre. We performed microRNA (miRNA) sequencing to identify candidate miRNAs and predict their target genes. An miRNA inhibitor was used to confirm the role of miRNAs in macrophage modulation. Exo-pre were more potent than Exo-Con at alleviating DN. Exo-pre administration significantly reduced the number of M1 macrophages and increased the number of M2 macrophages in the kidney compared to Exo-Con administration. Parallel outcomes were observed in the co-culture experiments. Moreover, miR-486-5p was distinctly expressed in Exo-Con and Exo-pre groups, and it played an important role in macrophage polarization by targeting PIK3R1 through the PI3K/Akt pathway. Reducing miR-486-5p levels in Exo-pre abolished macrophage polarization modulation. Exo-pre administration exhibited a superior effect on DN by remodeling the macrophage balance by shuttling miR-486-5p, which targets PIK3R1.

The phenotype and related gene expressions of macrophages in adipose tissue of T2D mice following MSCs infusion.

BACKGROUND: Infusion of mesenchymal stem cells (MSCs) induces polarization of M2 macrophages in adipose tissue of type 2 diabetes (T2D) mice. Studies have shown that M2 macrophages were divided into four sub-phenotypes (M2a, M2b, M2c and M2d) with different functions, and manuscripts have also confirmed that macrophages co-cultured with MSCs were not matched with known four phenotype macrophages. Therefore, our study explored the phenotype and related gene expressions of macrophages in the adipose tissue of T2D mice with/without MSCs infusion. METHODS: We induced a T2D mouse model by using high-fat diets and streptozotocin (STZ) injection. The mice were divided into three groups: the control group, the T2D group, and the MSCs group. MSCs were systemically injected once a week for 6 weeks. The phenotype of macrophages in adipose tissue was detected via flow cytometric analysis. We also investigated the gene expression of macrophages in different groups via SMART-RNA-sequencing and quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR). RESULTS: The present study found that the macrophages of adipose tissue in the MSCs group were polarized to the M2 phenotype mixed with four sub-phenotypes. Besides, M2a and M2c held a dominant position, while M2b and M2d (tumor-associated macrophages, TAMs) exhibited a decreasing trend after infusion of MSCs. Moreover, the MSCs group did not appear to express higher levels of tumor-associated, inflammation-associated, or fibrosis-associated genes in comparison to the T2D group. CONCLUSION: The present results unveiled that the macrophage phenotype was inclined to be present in a hybridity state of four M2 sub-phenotypes and the genes related to tumor-promoting, pro-inflammation and pro-fibrosis were not increased after MSCs injection.

A higher TyG index level is more likely to have enhanced incidence of T2DM and HTN comorbidity in elderly Chinese people: a prospective observational study from the reaction study.

BACKGROUND: Triglyceride glucose index (TyG index) was related with both type 2 diabetes (T2DM) and hypertension (HTN). Prospective studies linking the TyG index to the incidence of T2DM and HTN comorbidity remain unclear. This study aimed to to explore the longitudinal association between TyG and new-onset T2DM with HTN. METHODS: 4,434 subjects (1249 males and 3185 females) without initial T2DM and HTN were followed up for 7 years. This study was conducted from November 2011 to August 2018 in the Gucheng, Laoshan and Jinding communities of Beijing. The incidence of T2DM with HTN during the 7-year follow-up was identified as the endpoint. The TyG index was divided into four quartiles: the < 25% level, the 25-50% level, the 50-75% level and the ≥ 75% level. The relationships between the TyG index and T2DM with HTN were evaluated by Cox proportional hazards regression models. RESULTS: During 7 years, the augmented trend of T2DM with HTN was observed in the participants. After adjusting for all confounding factors, compared with those in the lowest quartile of TyG index, the population in the highest quartile of TyG index had a higher risk of T2DM with HTN (hazard ratio (HR), 2.878; 95% confidence intervals (95% CI), 1.230-6.731, P = 0.015), however, the association remained significant only in the female population (HR 2.753, 95% CI, 1.061-7.139, p = 0.037). The TyG had superior predictive ability of increased risk of T2DM with HTN for the populations of older age (≥ 65 years) (HR 2.694, 95% CI 1.212-5.989, p = 0.015), higher eGFR (≥ 90 mL/(min·1.73 m2)) (HR 2.603, 95% CI 1.164-5.818, p = 0.020) or obesity (BMI ≥ 28 kg/m2) (HR 2.547, 95% CI 1.001-6.478, p = 0.020). CONCLUSION: A population with a higher TyG index level was more likely to have an enhanced incidence of T2DM and HTN comorbidity. TyG index could have the significance of clinical in early protection against T2DM with HTN.

Diabetic microenvironment preconditioning of adipose tissue-derived mesenchymal stem cells enhances their anti-diabetic, anti-long-term complications, and anti-inflammatory effects in type 2 diabetic rats.

BACKGROUND: Mesenchymal stem cells (MSCs) exert anti-diabetic effects and improve long-term complications via secretory effects that regulate macrophage polarisation and attenuate inflammation. Enhancing the efficacy of MSCs needs to be explored further. The in vitro culture microenvironment influences the secretory profile of MSCs. Therefore, we hypothesised that a diabetic microenvironment would promote the secretion of cytokines responsible for macrophage polarisation, further attenuating systemic inflammation and enhancing the effects of MSCs on type 2 diabetes (T2D) and long-term diabetic complications. METHODS: Preconditioned adipose-derived mesenchymal stem cells (pre-ADSCs) were obtained after co-cultivating ADSCs in a diabetic metabolic environment (including high sugar, advanced glycation end-product, and lipopolysaccharides). The regulatory effects of pre-ADSCs on macrophages were observed in vitro. A T2D rat model was induced with a high-fat diet for 32 weeks combined with an intraperitoneal injection of streptozotocin. Sprague-Dawley (SD) rats were divided into four groups: normal group, diabetes without treatment group (PBS), ADSC treatment group, and pre-ADSC treatment group. ADSCs and pre-ADSCs were intravenously administered weekly to SD rats for 6 months, and then glucose homeostasis and long-term diabetic complications were evaluated in each group. RESULTS: The secretion of cytokines related to M2 macrophage polarisation (IL-6, MCP-1, etc.) was increased in the pre-ADSC group in the in vitro model. Pre-ADSC treatment significantly maintained blood glucose homeostasis, reduced insulin resistance, promoted islet regeneration, and ameliorated the complications related to diabetes in rats (chronic kidney disease, non-alcoholic steatohepatitis, lung fibrosis, and cataract) compared to the ADSC group (P < 0.05). Additionally, the number of anti-inflammatory M2 macrophage phenotypes was enhanced in tissues following pre-ADSC injections. Moreover, the expression of pro-inflammatory genes (iNOS, TNF-α, IL-1ß) was reduced whereas that of anti-inflammatory genes (Arg1, CD206, and Il-10) was increased after cultivation with pre-ADSCs. CONCLUSION: Diabetic microenvironment-preconditioned ADSCs effectively strengthen the capacity against inflammation and modulate the progress of long-term T2D complications.

Sex Differences in Hypercortisolism and Glucose-Metabolism Disturbances in Patients with Mild Autonomous Cortisol Secretion: Findings From a Single Center in China.

Background and objective: Mild autonomous cortisol secretion (MACS) presents with a marked female preponderance, but whether the sex difference in its distribution has any relevance to the presentation and outcome of the disease is unknown. The aim of this study was therefore to compare biochemical indices of hypercortisolism and impaired glucose metabolism between male and female patients with MACS. Method: We enrolled a total of 98 patients with autonomous/possible autonomous cortisol secretion in our study, and indices of hypercortisolism and glucose metabolism were collected and compared between the male and female patients. Logistic regression models were used to evaluate the association between sex and cortisol-secretory ability, as well as between the latter and glucose metabolism. In addition, we conducted further stratified analyses according to the degree of autonomous cortisol secretion and menopausal status. Results: Cortisol levels at 00:00 and 08:00 h after a 1-mg dexamethasone suppression test (DST) and low-dose DST were significantly higher in female than in male MACS patients, and the inhibition rate of 1-mg DST was lower in the women than in the men. This significant difference still remained after adjusting for age, BMI, and the course of the disease. Logistic regression analysis revealed a significant association between autonomous cortisol secretion and fasting C-peptide, as well as with the C-peptide-to-glucose ratio in females relative to male patients. In addition, stratified analyses indicated that this association was observed only among women with autonomous cortisol secretion and who were premenopausal. Conclusion: The level of autonomic cortisol secretion in female patients with MACS was higher than in male patients, and the association between autonomous cortisol secretory ability and glucose homeostasis was only noted in patients with autonomous cortisol secretion and in premenopausal women. This phenomenon will, however, require closer follow-up.

Human umbilical cord-derived mesenchymal stem cells alleviate insulin resistance in diet-induced obese mice via an interaction with splenocytes.

BACKGROUND: Previous research has demonstrated that the spleen plays an important role in mesenchymal stem cell (MSC)-mediated alleviation of acute inflammation, as MSC infusion increases the spleen-derived anti-inflammatory cytokine interleukin 10 (IL-10) levels. However, studies on splenic involvement in MSC-induced protection against chronic inflammatory diseases are limited. Obesity is characterized by chronic low-grade inflammation, a key driver of insulin resistance. This study aims to evaluate the effects of MSCs on obesity-related insulin resistance and explore the underlying mechanism, particularly regarding splenic involvement. METHODS: We induced obesity in mice by feeding them high-fat diets for 20 weeks. Human umbilical cord-derived MSCs (UC-MSCs) were systemically infused into the obese mice once per week for 6 weeks. Systemic glucose metabolic homeostasis and insulin sensitivity in epididymal adipose tissue (EAT) were evaluated. Then, we conducted in vivo blockade of IL-10 during UC-MSC infusion by intraperitoneally administrating an IL-10-neutralizing antibody twice per week. We also investigated the therapeutic effects of UC-MSCs on obese mice after removal of the spleen by splenectomy. RESULTS: UC-MSC infusions improved systemic metabolic homeostasis and alleviated insulin resistance in EAT but elicited no change in weight. Despite rare engraftment of UC-MSCs in EAT, UC-MSC infusions attenuated insulin resistance in EAT by polarizing macrophages into the M2 phenotype, coupled with elevated serum IL-10 levels. In vivo blockade of IL-10 blunted the effects of UC-MSCs on obese mice. Furthermore, UC-MSCs overwhelmingly homed to the spleen, and the ability of UC-MSCs to elevate serum IL-10 levels and alleviate insulin resistance was impaired in the absence of the spleen. Further in vivo and in vitro studies revealed that UC-MSCs promoted the capacity of regulatory T cells (Treg cells) to produce IL-10 in the spleen. CONCLUSIONS: Our results demonstrated that UC-MSCs elevated serum IL-10 levels and subsequently promoted macrophage polarization, leading to alleviation of insulin resistance in EAT. The underlying mechanism was that UC-MSCs improved the capacity of Treg cells to produce IL-10 in the spleen. Our findings indicated that the spleen played a critical role in amplifying MSC-mediated immunomodulatory effects, which may contribute to maximizing MSC efficacy in clinical applications in the future.

Metabolic Score for Insulin Resistance, a novel score to evaluate insulin sensitivity, is associated with the urinary albumin-to-creatinine ratio in Chinese adults: A cross-sectional REACTION study.

AIMS/INTRODUCTION: The Metabolic Score for Insulin Resistance (METS-IR) is a novel non-insulin-based metabolic index used as a substitution marker of insulin resistance. However, whether METS-IR is associated with the urinary albumin-to-creatinine ratio (UACR) is not well known. Therefore, we explored the associations between METS-IR and UACR, and compared the discriminative ability of METS-IR and its components for elevated UACR. MATERIALS AND METHODS: This study included 37,290 participants. METS-IR was calculated as follows: (Ln[2 × fasting blood glucose + fasting triglyceride level] × body mass index) / (Ln [high-density lipoprotein cholesterol]). Participants were divided into four groups on the basis of METS-IR: <25%, 25-49%, 50-74% and ≥75%. Logistic regression analyses were carried out to determine the associations between METS-IR versus its components (fasting blood glucose, triglyceride level, body mass index and high-density lipoprotein cholesterol) with UACR. RESULTS: Participants with the highest quartile METS-IR presented a more significant trend toward elevated UACR than toward its components (odds ratio 1.260, 95% confidence interval 1.152-1.378, P < 0.001 in all participants; odds ratio 1.321, 95% confidence interval 1.104-1.579, P = 0.002 in men; odds ratio 1.201, 95% confidence interval 1.083-1.330, P < 0.001 in women). There were significant associations between METS-IR and UACR in younger participants (aged <65 years for women and aged 55-64 years for men). Increased METS-IR was significantly associated with UACR in men with fasting blood glucose ≥5.6 or postprandial blood glucose ≥7.8 mmol/L and systolic blood pressure ≥120 or diastolic blood pressure ≥80 mmHg. The relationships were significant in women with diabetes and hypertension. CONCLUSIONS: Increased METS-IR was significantly associated with elevated UACR, its discriminative power for elevated UACR was superior to that of its components.

Association between nonalcoholic fatty liver and increased low-level albuminuria in postmenopausal women in China: A cross-sectional study.

BACKGROUND: Several studies have suggested that nonalcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD). The excretion of low-level albuminuria (LLA) elevates as the prevalence of CVD increases. However, few studies have explored the association between NAFLD and LLA. METHODS: This cross-sectional study included 31 147 Chinese adults (7664 men and 23 483 women). The "normal" level of albuminuria as determined by the urinary albumin to creatinine ratio (UACR) was below 30 mg/g. LLA was defined as a higher level within the "normal" albuminuria range (5.54 mg/g < LLA≤29.9 mg/g). The participants with NAFLD were defined as having a fatty liver index (FLI) ≥ 60. The FLI was calculated using the Bedogni equation. RESULTS: A positive association was found between UACR and FLI through multivariate linear regression analyses (nonstandardized ß ± SE: .047 ± 0.004, P <.001). The logistic regression analyses revealed that NAFLD had adjusted odds ratios (ORs) showing a significant relationship with LLA in models 1 to 4 (all subjects: OR, 1.207; 95% CI, 1.098-1.326; women: OR, 1.43; 95% CI, 1.26-1.63; all P <.001); however, we did not find significant adjusted ORs among the men. In the stratified analyses, the relationship between NAFLD and LLA was significant among postmenopausal women with a body mass index ≥24 but <28 kg/m2 , fasting plasma glucose ≥5.6 but <7.0 mmol/L, or postprandial plasma glucose ≥7.8 but <11.1 mmol/L and those aged below 60 years without moderate-intensity exercise. CONCLUSIONS: A noteworthy association between NAFLD and LLA was found among postmenopausal women who had borderline blood glucose values, were overweight, and did not engage in moderate-intensity physical activity.

Association Between Hypertriglyceridemic Waist Phenotype and Increased Urinary Albumin-Creatinine Ratio in Chinese Adults: The REACTION Study.

PURPOSE: The hypertriglyceridemic waist (HTGW) phenotype can predict cardiovascular disease (CVD) risk. Additionally, strong evidence indicates that elevated urinary albumin-creatinine ratio (UACR) is associated with increased prevalence of CVD. However, few studies have explored the association between the HTGW phenotype and UACR. PATIENTS AND METHODS: In this cross-sectional descriptive study, a total of 40,674 subjects (28,562 women and 12,112 men older than 40 years) were recruited from seven different geographic regional centres. The HTGW phenotype was defined as increased triglyceride levels (triglyceride ≥ 1.5 mmol/L for female and ≥2.0 mmol/L for male) and waist circumference (WC; WC ≥ 85 for female and WC ≥ 90 cm for male). Logistic regression analyses were performed to assess the relationship between UACR and the HTGW phenotype. RESULTS: Subjects with the HTGW phenotype showed a more significant trend towards increased excretion of UACR [among all subjects, odds ratio (OR) = 1.303, 95% CI: 1.132-1.499, P < 0.001; among men, OR = 1.406, 95% CI: 1.057-1.870, P = 0.019; among women, OR = 1.268, 95% CI: 1.074-1.496, P = 0.005]. Furthermore, the stratified analysis showed that the OR for high-risk significantly increased in individuals in the HTGW group aged below 65 years, with 5.6 ≤ fasting blood glucose < 7.0 or 7.8 ≤ post-load blood glucose <11.1 mmol/L, 120 ≤ systolic blood pressure < 140 or 80 ≤ diastolic blood pressure < 90, 24 ≤ body mass index < 28 kg/m2, and estimated globular filtration rate > 90 mL/min per 1.73 m2. CONCLUSION: This study has advanced the understanding of visceral obesity and our results supported the fact that the HTGW phenotype is associated with elevated UACR excretion among general Chinese adults.