PEGylated ß-Cell-Targeting Exosomes from Mesenchymal Stem Cells Improve ß Cell Function and Quantity by Suppressing NRF2-Mediated Ferroptosis.

Background: The depletion of ß cell mass is widely recognized as a significant contributor to the progression of type 2 diabetes mellitus (T2DM). Exosomes derived from mesenchymal stem cells (MSC-EXOs) hold promise as cell-free therapies for treating T2DM. However, the precise effects and mechanisms through which MSC-EXO affects ß cell function remain incompletely understood, and the limited ability of MSC-EXO to target ß cells and the short blood circulation time hampers its therapeutic effectiveness. Methods: The effects of MSC-EXO were investigated in T2DM mice induced by a high-fat diet combined with STZ. Additionally, the high glucose-stimulated INS-1 cell line was used to investigate the potential mechanism of MSC-EXO. Michael addition reaction-mediated chemical coupling was used to modify the surface of the exosome membrane with a ß-cell-targeting aptamer and polyethylene glycol (PEG). The ß-cell targeting and blood circulation time were evaluated, and whether this modification enhanced the islet-protective effect of MSC-EXO was further analyzed. Results: We observed that the therapeutic effects of MSC-EXO on T2DM manifested through the reduction of random blood glucose levels, enhancement of glucose and insulin tolerance, and increased insulin secretion. These effects were achieved by augmenting ß cell mass via inhibiting nuclear factor erythroid 2-related factor 2 (NRF2)-mediated ferroptosis. Mechanistically, MSC-EXOs play a role in the NRF2-mediated anti-ferroptosis mechanism by transporting active proteins that are abundant in the AKT and ERK pathways. Moreover, compared to MSC-EXOs, aptamer- and PEG-modified exosomes (Apt-EXOs) were more effective in islet protection through PEG-mediated cycle prolongation and aptamer-mediated ß-cell targeting. Conclusion: MSC-EXO suppresses NRF2-mediated ferroptosis by delivering bioactive proteins to regulate the AKT/ERK signaling pathway, thereby improving the function and quantity of ß cells. Additionally, Apt-EXO may serve as a novel drug carrier for islet-targeted therapy.

Association of social determinants, lifestyle, and metabolic factors with mortality in Chinese adults: A nationwide 10-year prospective cohort study.

Nationwide estimates of the impact of common modifiable risk factors on mortality remain crucial. We aim to assess the influence of social determinants, lifestyle, and metabolic factors on mortality in 174,004 adults aged ≥40 years from the China Cardiometabolic Disease and Cancer Cohort (4C) Study. We reveal that 17 modifiable factors are independently associated with mortality, accounting for 64.8% of all-cause mortality, 77.4% of cardiovascular mortality, and 44.8% of cancer mortality. Low education emerges as the leading factor for both all-cause and cancer mortality, while hypertension is predominant for cardiovascular mortality. Moreover, low gross domestic product per capita and high ambient particulate matter with a diameter of <2.5 µm (PM2.5) air pollution account for 7.8% and 4.3% for all-cause mortality, respectively, using a different method. Gender-specific analyses reveal distinct patterns, with women's mortality primarily associated with social determinants and men exhibiting stronger associations with lifestyle factors. Targeted health interventions are essential to mitigate mortality risks effectively in China.

Serum Medium-Chain Fatty Acids and the Risk of Incident Diabetes: Findings from the 4C Study.

CONTEXT: Emerging studies have revealed associations between dietary medium-chain fatty acids (MCFAs) and glucose homeostasis. However, the relationship between serum MCFAs and the incidence of diabetes, and potential interactions with genetic predisposition, remains unclear in prospective cohort studies. OBJECTIVE: To investigate associations and genetic susceptibility between serum MCFAs and diabetes risk. METHODS: We investigated baseline serum MCFAs (n=5) in a nested case-control study comprising incident diabetes cases (n=1,707) and matched normoglycemic control subjects (n=1,707) from the China Cardiometabolic Disease and Cancer Cohort Study. Associations between MCFAs and type 2 diabetes mellitus (T2DM) were examined, both overall and stratified by diabetes genetic susceptibility. Genetic risk scores (GRS) were calculated based on 86 T2DM-associated genetic variants. RESULTS: In the fully adjusted conditional logistic regression model, serum octanoic acid and nonanoic acid exhibited inverse dose-response relationships with diabetes risk, showing odds ratios (95% confidence intervals) of 0.90 (0.82-0.98) and 0.84 (0.74-0.95), respectively. Subgroup analysis demonstrated that inverse associations between MCFAs and incident diabetes were more pronounced among individuals with physical inactivity (Pinteraction = 0.042, 0.034, and 0.037, for octanoic, nonanoic and decanoic acid, respectively). Moreover, inverse associations of octanoic acid with diabetes risk were notably enhanced among individuals with high genetic risk compared to those with low genetic risk. Significant interactions were observed between octanoic acid and GRS on T2DM risk (Pinteraction = 0.003). CONCLUSIONS: These findings provide evidence supporting inverse associations between serum MCFAs and T2DM risk, and reveal potential interplay between genetic susceptibility and circulating octanoic acid in modulating diabetes risk.

Mesenchymal stromal cells ameliorate mitochondrial dysfunction in α cells and hyperglucagonemia in type 2 diabetes via SIRT1/FoxO3a signaling.

Dysregulation of α cells results in hyperglycemia and hyperglucagonemia in type 2 diabetes mellitus (T2DM). Mesenchymal stromal cell (MSC)-based therapy increases oxygen consumption of islets and enhances insulin secretion. However, the underlying mechanism for the protective role of MSCs in α-cell mitochondrial dysfunction remains unclear. Here, human umbilical cord MSCs (hucMSCs) were used to treat 2 kinds of T2DM mice and αTC1-6 cells to explore the role of hucMSCs in improving α-cell mitochondrial dysfunction and hyperglucagonemia. Plasma and supernatant glucagon were detected by enzyme-linked immunosorbent assay (ELISA). Mitochondrial function of α cells was assessed by the Seahorse Analyzer. To investigate the underlying mechanisms, Sirtuin 1 (SIRT1), Forkhead box O3a (FoxO3a), glucose transporter type1 (GLUT1), and glucokinase (GCK) were assessed by Western blotting analysis. In vivo, hucMSC infusion improved glucose and insulin tolerance, as well as hyperglycemia and hyperglucagonemia in T2DM mice. Meanwhile, hucMSC intervention rescued the islet structure and decreased α- to ß-cell ratio. Glucagon secretion from αTC1-6 cells was consistently inhibited by hucMSCs in vitro. Meanwhile, hucMSC treatment activated intracellular SIRT1/FoxO3a signaling, promoted glucose uptake and activation, alleviated mitochondrial dysfunction, and enhanced ATP production. However, transfection of SIRT1 small interfering RNA (siRNA) or the application of SIRT1 inhibitor EX-527 weakened the therapeutic effects of hucMSCs on mitochondrial function and glucagon secretion. Our observations indicate that hucMSCs mitigate mitochondrial dysfunction and glucagon hypersecretion of α cells in T2DM via SIRT1/FoxO3a signaling, which provides novel evidence demonstrating the potential for hucMSCs in treating T2DM.

J-shaped association of the triglyceride glucose-body mass index with new-onset diabetes.

The triglyceride glucose-body mass index (TyG-BMI) is a convenient and clinically significant indicator of insulin resistance. This study aims to investigate the correlation between TyG-BMI and the onset of new-onset diabetes and determine an optimal reflection point for TyG-BMI. An analysis was conducted on 1917 participants from the risk evaluation of cancers in Chinese diabetic individuals: a lONgitudinal (REACTION) study. Participants were categorized based on their TyG-BMI, and the relationship between TyG-BMI and the incidence of new-onset diabetes was explored through logistic regression models, smoothed curve fitting with restricted cubic spline, and a two-piecewise logistic regression model. The mean age of the participants was 57.60 ± 8.89 years, with 66.5% being females. The mean TyG-BMI was 223.3 ± 32.8. Ultimately, 137 individuals (7.1%) progressed to diabetes after three years. After adjusting for covariates, TyG-BMI exhibited a positive correlation with new-onset diabetes (odd ratios (OR) for each standard deviation increase = 1.330, 95% CI 1.110-1.595). The relationship between TyG-BMI and new-onset diabetes was non-linear, with a inflcetion point at 202.9. This study reveals a positive non-linear relationship between TyG-BMI and the risk of new-onset diabetes in Chinese middle-aged and elderly individuals. When TyG-BMI exceeds 202.9, there is a significantly heightened risk of new-onset diabetes. These findings offer valuable insights for preventing new-onset diabetes.

Association between triglyceride glucose index and breast cancer in 142,184 Chinese adults: findings from the REACTION study.

Background: The triglyceride glucose (TyG) index has been associated with an increased risk in breast cancer. However, this association remains unclear among the Chinese population. This study aimed to investigate whether the TyG index is associated with the risk of prevalent breast cancer in Chinese women. Methods: This cross-sectional study included 142,184 women from the REACTION (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal) Study, which recruited adults aged 40 years or older from 25 centers across mainland China between 2011 and 2012. The TyG index was calculated according to the formula: Ln (fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). Multivariable-adjusted logistic regression models were used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs) regarding the associations between the TyG index and breast cancer. Results: Multivariable-adjusted logistic regression analysis showed that compared with the lowest quartile of the TyG index, the highest quartile of the TyG index was significantly associated with an increased risk of prevalent breast cancer, with an OR (95% CI) of 1.61 (1.19-2.17). In the stratified analysis, the association of each 1 SD increase in the TyG index with risk of prevalent breast cancer was more dominant in individuals with menarche at age 13-17, those who were postmenopausal, those with a history of breastfeeding, and those who had two to four children, with the ORs (95% CIs) of 1.35 (1.09-1.68), 1.27 (1.05-1.54), 1.26 (1.05-1.52), and 1.32 (1.08-1.62), respectively. Moreover, among those without discernible insulin resistance (homeostatic model assessment-insulin resistance [HOMA-IR] ≥2.5), hyperglycemia and dyslipidemia, each 1 SD increase in the TyG index was associated with a 1.36-fold increase in breast cancer risk, with an OR (95% CI) of 2.36 (1.44-3.87). Conclusion: The TyG index is significantly associated with the prevalent breast cancer risk among middle-aged and elderly Chinese women.

Activation of the Wnt/ß-catenin signalling pathway enhances exosome production by hucMSCs and improves their capability to promote diabetic wound healing.

BACKGROUND: The use of stem cell-derived exosomes (Exos) as therapeutic vehicles is receiving increasing attention. Exosome administration has several advantages over cell transplantation, thus making exosomes promising candidates for large-scale clinical implementation and commercialization. However, exosome extraction and purification efficiencies are relatively low, and therapeutic heterogeneity is high due to differences in culture conditions and cell viability. Therefore, in this study, we investigated a priming procedure to enhance the production and therapeutic effects of exosomes from human umbilical cord mesenchymal stem cells (hucMSCs). After preconditioning hucMSCs with agonists/inhibitors that target the Wnt/ß-catenin pathway, we assessed both the production of exosomes and the therapeutic efficacy of the optimized exosomes in the context of diabetic wound healing, hoping to provide a safer, more stable and more effective option for clinical application. RESULTS: The Wnt signalling pathway agonist CHIR99021 increased exosome production by 1.5-fold without causing obvious changes in the characteristics of the hucMSCs or the size of the exosome particles. Further studies showed that CHIR99021 promoted the production of exosomes by facilitating exocytosis. This process was partly mediated by SNAP25. To further explore whether CHIR99021 changed the cargo that was loaded into the exosomes and its therapeutic effects, we performed proteomic and transcriptomic analyses of exosomes from primed and control hucMSCs. The results showed that CHIR99021 significantly upregulated the expression of proteins that are associated with cell migration and wound healing. Animal experiments confirmed that, compared to control hucMSC-derived exosomes, CHIR99021-pretreated hucMSC-derived exosomes (CHIR-Exos) significantly accelerated wound healing in diabetic mice, enhanced local collagen deposition, promoted angiogenesis, and reduced chronic inflammation. Subsequent in vitro experiments confirmed that the CHIR-Exos promoted wound healing by facilitating cell migration, inhibiting oxidative stress-induced apoptosis, and preventing cell cycle arrest. CONCLUSIONS: The Wnt agonist CHIR99021 significantly increased exosome secretion by hucMSCs, which was partly mediated by SNAP25. Notably, CHIR99021 treatment also significantly increased the exosomal levels of proteins that are associated with wound healing and cell migration, resulting in enhanced acceleration of wound healing. All of these results suggested that pretreatment of hucMSCs with CHIR99021 not only promoted exosome production but also improved the exosome therapeutic efficacy, thus providing a promising option for large-scale clinical implementation and commercialization.

Association of circulating long-chain free fatty acids and incident diabetes risk among normoglycemic Chinese adults: a prospective nested case-control study.

BACKGROUND: Long-chain free fatty acids (FFAs) are associated with risk of incident diabetes. However, a comprehensive assessment of the associations in normoglycemic populations is lacking. OBJECTIVES: Our study aimed to comprehensively investigate the prospective associations and patterns of FFA profiles with diabetes risk among normoglycemic Chinese adults. METHODS: This is a prospective nested case-control study from the China Cardiometabolic Disease and Cancer Cohort (4C) study. We quantitatively measured 53 serum FFAs using a targeted metabolomics approach in 1707 incident diabetes subjects and 1707 propensity score-matched normoglycemic controls. Conditional logistic regression models were employed to estimate odds ratios (ORs) for associations. Least Absolute Shrinkage and Selection Operator (LASSO) penalty regression and quantile g-computation (qg-comp) analyses were implemented to estimate the association between multi-FFA exposures and incident diabetes. RESULTS: The majority of odd-chain FFAs exhibited an inverse association with incident diabetes, wherein the ORs per SD increment of all 7 saturated fatty acids (SFAs), monounsaturated fatty acid (MUFA) 15:1, and polyunsaturated fatty acid (PUFA) 25:2 were ranging from 0.79 to 0.88 (95% CIs ranging between 0.71 and 0.97). Even-chain FFAs comprised 99.3% of total FFAs and displayed heterogeneity with incident diabetes. SFAs with 18-26 carbon atoms are inversely linked to incident diabetes, with ORs ranging from 0.81 to 0.86 (95% CIs ranging between 0.73 and 0.94). MUFAs 26:1 (OR: 0.85; 95% CI: 0.76, 0.94), PUFAs 20:4 (OR: 0.84; 95% CI: 0.75, 0.94), and 24:2 (OR: 0.87; 95% CI: 0.78, 0.97) demonstrated significant associations. In multi-FFA exposure model, 24 FFAs were significantly associated with incident diabetes, most of which were consistent with univariate results. The mixture OR was 0.78 (95% CI: 0.61, 0.99; P = 0.04159). Differential correlation network analysis revealed pre-existing perturbations in intraclass and interclass FFA coregulation before diabetes onset. CONCLUSIONS: These findings underscore the variations in diabetes risk associated with FFAs across chain length and unsaturation degree, highlighting the importance of recognizing FFA subtypes in the pathogenesis of diabetes.

Clinical and functional characterization of a novel KCNJ11 (c.101G > A, p.R34H) mutation associated with maturity-onset diabetes mellitus of the young type 13.

PURPOSE: This study aimed to describe the clinical features, diagnostic and therapeutic course of a patient with MODY13 caused by KCNJ11 (c.101G > A, p.R34H) and how it contributes to the pathogenesis of MODY13, and to explore new therapeutic targets. METHODS: Whole-exome sequencing was used to screen prediagnosed individuals and family members with clinically suspected KCNJ11 mutations. Real-time fluorescence quantitative PCR, western blotting, thallium flux of potassium channels, glucose-stimulated insulin secretion (GSIS), and immunofluorescence assays were used to analyze the regulation of insulin secretion by the KCNJ11 mutant in MIN6 cells. Daily blood glucose levels were continuously monitored for 14 days in the proband using the ambulatory blood glucose meter (SIBIONICS). RESULTS: Mutation screening of the entire exon of the gene identified a heterozygous KCNJ11 (c.101G > A, p.R34H) mutation in the proband and his mother. Cell-based GSIS assays after transfection of MIN6 using wild-type and mutant plasmids revealed that this mutation impaired insulin secretory function. Furthermore, we found that this impaired secretory function is associated with reduced functional activity of the mutant KCNJ11 protein and reduced expression of the insulin secretion-associated exocytosis proteins STXBP1 and SNAP25. CONCLUSION: For the first time, we revealed the pathogenic mechanism of KCNJ11 (c.101G > A, p.R34H) associated with MODY13. This mutant can cause alterations in KATP channel activity, reduce sensitivity to glucose stimulation, and impair pancreatic ß-cell secretory function by downregulating insulin secretion-associated exocytosis proteins. Therefore, oral sulfonylurea drugs can lower blood glucose levels through pro-insulinotropic effects and are more favorable for patients with this mutation.

Analysis of the association between high antioxidant diet and lifestyle habits and diabetic retinopathy based on NHANES cross-sectional study.

Oxidative stress plays a crucial role in increasing the risk of developing diabetic retinopathy (DR). The oxidative balance score (OBS) and the composite dietary antioxidant index (CDAI) are two tools for assessing the effects of diet and lifestyle on oxidative stress. The aim of this study was to investigate the association between OBS, CDAI and the occurrence of DR. After controlling for potential confounders, OBS was negatively associated with DR with an odds ratio (OR) of 0.976 and a 95% confidence interval (CI) of 0.956-0.996, suggesting that for every unit increase in OBS, the risk of DR was reduced by 2.4%. In contrast, the relationship between OBS and CDAI was not significant (P > 0.05), suggesting that it was OBS, not CDAI, that contributed to the reduced risk of diabetic retinopathy. After adjusting for potential confounders, OBS was negatively associated with DR (OR: 0.976; 95% CI 0.956-0.996), but this association was not found in CDAI (P > 0.05), suggesting that for every one-unit increase in OBS, there was a 2.4% reduction in the risk of developing DR. This study suggests that a diet and lifestyle high in OBS reduces the risk of developing DR, which provides a rationale for nutritional interventions to prevent DR.

Novel insights into immune-related genes associated with type 2 diabetes mellitus-related cognitive impairment.

BACKGROUND: The cognitive impairment in type 2 diabetes mellitus (T2DM) is a multifaceted and advancing state that requires further exploration to fully comprehend. Neuroinflammation is considered to be one of the main mechanisms and the immune system has played a vital role in the progression of the disease. AIM: To identify and validate the immune-related genes in the hippocampus associated with T2DM-related cognitive impairment. METHODS: To identify differentially expressed genes (DEGs) between T2DM and controls, we used data from the Gene Expression Omnibus database GSE125387. To identify T2DM module genes, we used Weighted Gene Co-Expression Network Analysis. All the genes were subject to Gene Set Enrichment Analysis. Protein-protein interaction network construction and machine learning were utilized to identify three hub genes. Immune cell infiltration analysis was performed. The three hub genes were validated in GSE152539 via receiver operating characteristic curve analysis. Validation experiments including reverse transcription quantitative real-time PCR, Western blotting and immunohistochemistry were conducted both in vivo and in vitro. To identify potential drugs associated with hub genes, we used the Comparative Toxicogenomics Database (CTD). RESULTS: A total of 576 DEGs were identified using GSE125387. By taking the intersection of DEGs, T2DM module genes, and immune-related genes, a total of 59 genes associated with the immune system were identified. Afterward, machine learning was utilized to identify three hub genes (H2-T24, Rac3, and Tfrc). The hub genes were associated with a variety of immune cells. The three hub genes were validated in GSE152539. Validation experiments were conducted at the mRNA and protein levels both in vivo and in vitro, consistent with the bioinformatics analysis. Additionally, 11 potential drugs associated with RAC3 and TFRC were identified based on the CTD. CONCLUSION: Immune-related genes that differ in expression in the hippocampus are closely linked to microglia. We validated the expression of three hub genes both in vivo and in vitro, consistent with our bioinformatics results. We discovered 11 compounds associated with RAC3 and TFRC. These findings suggest that they are co-regulatory molecules of immunometabolism in diabetic cognitive impairment.

Multi-functional composite dressings with sustained release of MSC-SLP and anti-adhesion property for accelerating wound healing.

Exudate management is of significant clinical value for the treatment of acute wound. Various wound dressings have been developed to restore the function of injured tissues and promote wound healing, but proper exploiting the healing factors inside exudate and achieving anti-adhesion wound care remains a challenge. Herein, we present a novel multi-functional composite dressing (MCD) by coupling supernatant lyophilized powder of mesenchymal stem cells (MSC-SLP) with a sandwich-structured wound dressing (SWD). The developed MCDs demonstrated unique unidirectional drainage capability, stable anti-adhesion characteristics, and improved wound healing performance. The designed SWD with both superhydrophobic inner surface and liquid-absorption ability of mid layer enables the dressings exhibit desired anti-adhesion property to neoformative granulation tissues, favorable shielding effect to exogenous bacteria, as well as appropriate exudate-retaining capability and unidirectional exudate-absorption property. The introduction of MSC-SLP in SWD was demonstrated to further improve wound healing quality. Compared to medical gauze, the synergic effect of SWD and MSC-SLP significantly accelerates wound healing rate by over 30%, avoids tissue avulsion when changing dressings, and produces a flat-smooth closure surface. More importantly, the wound treated with MCDs presents more skin accessory organs and blood vessels in regenerated tissues than other groups. In vivo/vitro biocompatibility evaluations indicated little toxicity, demonstrating the biosecurity of the developed dressings. The proposed method offers great potential in clinical applications particularly for chronic wound treatments.

Body size, insulin sensitivity, metabolic health and risk of cardiovascular disease in Chinese adults: Insights from the China Cardiometabolic Disease and Cancer Cohort (4C) study.

AIMS: To assess the excess risk of cardiovascular disease (CVD) associated with different criteria for metabolic health, and the interplay of body size, insulin sensitivity and metabolic health with CVD risk. MATERIALS AND METHODS: We conducted a prospective study involving 115 638 participants from the China Cardiometabolic Disease and Cancer Cohort (4C) Study. Metabolic health was defined using three different definitions: (1) insulin sensitivity defined by homeostatic model assessment of insulin resistance index; (2) absence of metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III criteria; and (3) simultaneous absence of metabolic abnormalities (diabetes, hypertension, dyslipidaemia). The primary endpoint was a composite of incident CVD events comprising the first occurrence of myocardial infarction, stroke, heart failure, or cardiovascular death. RESULTS: During a mean 3.61-year follow-up period, obese individuals with insulin sensitivity (multivariable-adjusted hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.37-2.08), or without metabolic syndrome (HR 1.46, 95% CI 1.13-1.89) still exhibited increased CVD risks, when compared to their normal-weight counterparts. Otherwise, those with obesity but simultaneous absence of metabolic abnormalities demonstrated similar CVD risk compared to normal-weight individuals (HR 0.91, 95% CI 0.53-1.59). CVD risk increased with the number of abnormalities across body mass index categories, regardless of insulin sensitivity. CONCLUSIONS: This study emphasizes the need for refined definitions of metabolic health and advocates for meticulous screening for metabolic abnormalities to reduce cardiovascular risks, even in individuals with normal weight and insulin sensitivity.

Injectable thermosensitive selenium-containing hydrogel as mesenchymal stem cell carrier to improve treatment efficiency in limb ischemia.

Limb ischemia is a refractory disease characterized by persistent inflammation, insufficient angiogenesis, and tissue necrosis. Although mesenchymal stem cells (MSCs) have shown potential for treating limb ischemia, their therapeutic effects are limited by low engraftment rates. Therefore, developing an optimal MSC delivery system that enhances cell viability is imperative. Selenium, known for its cytoprotective properties in various cell types, offers a potential strategy to enhance therapeutic effect of MSCs. In this study, we evaluated the cytoprotective effects of selenium on MSCs, and developed an injectable thermosensitive selenium-containing hydrogel based on PLGA-PEG-PLGA triblock copolymer, as a cell carrier to improve MSC viability after engraftment. The biocompatibility, biodegradability, and cytoprotective capabilities of selenium-containing hydrogels were assessed. Furthermore, the therapeutic potential of MSCs encapsulated within a thermosensitive selenium-containing hydrogel in limb ischemia was evaluated using cellular and animal experiments. Selenium protects MSCs from oxidative damage by upregulating GPX4 through a transcriptional mechanism. The injectable thermosensitive selenium-containing hydrogel exhibited favorable biocompatibility, biodegradability, and antioxidant properties. It can be easily injected into the target area in liquid form at room temperature and undergoes gelation at body temperature, thereby preventing the diffusion of selenium and promoting the cytoprotection of MSCs. Furthermore, MSCs encapsulated within the selenium-containing hydrogel effectively inhibited macrophage M1 polarization while promoting macrophage M2 polarization, thus accelerating angiogenesis and restoring blood perfusion in ischemic limbs. This study demonstrated the potential of an injectable thermosensitive selenium-containing hydrogel as a promising method for MSC delivery. By addressing the challenge of low retention rate, which is a major obstacle in MSC application, this strategy effectively improves limb ischemia.

Didymin protects pancreatic beta cells by enhancing mitochondrial function in high-fat diet-induced impaired glucose tolerance.

PURPOSE: Prolonged exposure to plasma free fatty acids (FFAs) leads to impaired glucose tolerance (IGT) which can progress to type 2 diabetes (T2D) in the absence of timely and effective interventions. High-fat diet (HFD) leads to chronic inflammation and oxidative stress, impairing pancreatic beta cell (PBC) function. While Didymin, a flavonoid glycoside derived from citrus fruits, has beneficial effects on inflammation dysfunction, its specific role in HFD-induced IGT remains yet to be elucidated. Hence, this study aims to investigate the protective effects of Didymin on PBCs. METHODS: HFD-induced IGT mice and INS-1 cells were used to explore the effect and mechanism of Didymin in alleviating IGT. Serum glucose and insulin levels were measured during the glucose tolerance and insulin tolerance tests to evaluate PBC function and insulin resistance. Next, RNA-seq analysis was performed to identify the pathways potentially influenced by Didymin in PBCs. Furthermore, we validated the effects of Didymin both in vitro and in vivo. Mitochondrial electron transport inhibitor (Rotenone) was used to further confirm that Didymin exerts its ameliorative effect by enhancing mitochondria function. RESULTS: Didymin reduces postprandial glycemia and enhances 30-minute postprandial insulin levels in IGT mice. Moreover, Didymin was found to enhance mitochondria biogenesis and function, regulate insulin secretion, and alleviate inflammation and apoptosis. However, these effects were abrogated with the treatment of Rotenone, indicating that Didymin exerts its ameliorative effect by enhancing mitochondria function. CONCLUSIONS: Didymin exhibits therapeutic potential in the treatment of HFD-induced IGT. This beneficial effect is attributed to the amelioration of PBC dysfunction through improved mitochondrial function.

Identification and functional characterization of compound heterozygous CYP11B1 gene mutations.

PURPOSE: 11ß-Hydroxylase deficiency (11ß-OHD) is the second leading cause of congenital adrenal hyperplasia (CAH), a rare autosomal recessive disease caused by mutations in the CYP11B1 gene. We previously reported the case of a male Chinese patient with typical 11ß-OHD symptoms. Sanger sequencing revealed that the patient carried a splice-site mutation, c.595+1G>A in the CYP11B1 gene. His mother and sister harbored the heterozygous mutation, c.595+1G>A. Paradoxically, Sanger sequencing did not detect any abnormality in the CYP11B1 gene of his father and brother. Therefore, in this study, we aimed to further explore the exact genetic etiology of 11ß-OHD in this pedigree and analyze the functional consequence of the c.595+1G>A mutation. METHODS: Gemomic DNA was extracted from the peripheral blood leukocytes of the family members and normal control individuals, followed by quantitative real-time polymerase chain reaction (qPCR) to detect the copy number of the target CYP11B1 gene fragment. Mutation analysis was also performed via whole-exome sequencing (WES) followed by Sanger sequencing validation. In vitro minigene assay was also performed to investigate the impact of the c.595+1G>A mutation on pre-mRNA splicing. RESULTS: qPCR results suggested a heterozygous deletion encompassing position c.595+1 along with flanking exonic and intronic sequences in the CYP11B1 gene of the patient and his father. WES followed by Sanger sequencing verified that the patient carried compound heterozygous mutations in the CYP11B1 gene, including a novel 2840-bp deletion (c.395+661_c.1121+180del) and c.595+1G>A, while his father carried the heterozygous c.395+661_c.1121+180del mutation. No other novel CYP11B1 mutations were found in the rest of the family members. Furthermore, minigene assay revealed that the c.595+1G>A mutation resulted in a 70-bp deletion of exon 3 in the mRNA, and this altered the reading frame at amino acid 176 and created a premature stop codon at amino acid 197. CONCLUSION: We identified a novel 2840-bp-sized large deletion and confirmed that the c.595+1G>A mutation disrupts normal pre-mRNA splicing. Either mutation could significantly alter the reading frame and abolish CYP11B1 enzyme activity. Therefore, our findings widen the mutation spectrum of CYP11B1 and provide an accurate diagnosis of 11ß-OHD at a molecular genetic level.

Association of congenital iodine deficiency syndrome and differentiated thyroid cancer: a Mendelian randomization study.

BACKGROUND: The effect of iodine deficiency, especially during the fetal period, on thyroid cancer risk remains unclear. The evidence from observational studies is controversial because of the inevitable confounding factors. We studied the causal effect of congenital iodine deficiency on differentiated thyroid cancer (DTC) based on Mendelian randomization (MR). METHODS: Two-Sample MR analysis was performed using data from published genome-wide association studies, including congenital iodine deficiency syndrome (CIDS) (353 cases, 187,684 controls) and DTC (649 cases, 431 controls) data. RESULTS: There was a causal relationship between CIDS and DTC (P < 0.05), with CIDS increasing the DTC risk by 37.4% (OR = 1.374, 95%CI = 1.110-1.700). Heterogeneity tests and tests of multiple validities indicated that the results were solid and reliable (all P < 0.05). CONCLUSIONS: Fetal iodine deficiency increases the risk of DTC, so future clinical studies should focus on the effect of iodine supplementation during pregnancy to reduce the risk of thyroid cancer in the offspring.

Didymin alleviates metabolic dysfunction-associated fatty liver disease (MAFLD) via the stimulation of Sirt1-mediated lipophagy and mitochondrial biogenesis.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) is one of the most prevalent metabolic syndromes worldwide. However, no approved pharmacological treatments are available for MAFLD. Chenpi, one kind of dried peel of citrus fruits, has traditionally been utilized as a medicinal herb for liver diseases. Didymin is a newly identified oral bioactive dietary flavonoid glycoside derived from Chenpi. In this study, we investigated the therapeutic potential of Didymin as an anti-MAFLD drug and elucidated its underlying mechanisms. METHODS: High-fat diet (HFD)-induced MAFLD mice and alpha mouse liver 12 (AML12) cells were utilized to evaluate the effects and mechanisms of Didymin in the treatment of MAFLD. Liver weight, serum biochemical parameters, and liver morphology were examined to demonstrate the therapeutic efficacy of Didymin in MAFLD treatment. RNA-seq analysis was performed to identify potential pathways that could be affected by Didymin. The impact of Didymin on Sirt1 was corroborated through western blot, molecular docking analysis, microscale thermophoresis (MST), and deacetylase activity assay. Then, a Sirt1 inhibitor (EX-527) was utilized to confirm that Didymin alleviates MAFLD via Sirt1. Western blot and additional assays were used to investigate the underlying mechanisms. RESULTS: Our results suggested that Didymin may possess therapeutic potential against MAFLD in vitro and in vivo. By promoting Sirt1 expression as well as directly binding to and activating Sirt1, Didymin triggers downstream pathways that enhance mitochondrial biogenesis and function while reducing apoptosis and enhancing lipophagy. CONCLUSIONS: These suggest that Didymin could be a promising medication for MAFLD treatment. Furthermore, its therapeutic effects are mediated by Sirt1.

Mof plays distinct roles in hepatic lipid metabolism under healthy or non-alcoholic fatty liver conditions.

The disturbance of hepatic lipid metabolism has a strong association with non-alcoholic fatty liver disease (NAFLD) and diabetes. Mof, an acetyltransferase involved in obesity and carbon metabolism, has not been thoroughly examined in its connection to hepatic metabolism. We aimed to explore the impact of Mof on hepatic lipid metabolism. The alteration of Mof expression was found in both obese mice and NAFLD human liver. The genes regulated by Mof were closely associated with lipid metabolism. In normal mice or hepatic cells, the down-regulation or inhibition of Mof resulted in increased lipid accumulation due to decreased PPARα expression. Conversely, in diet-induced obesity (DIO) mice or hepatic cells treated with palmitic acid, the inhibition of Mof led to improved lipid metabolism, attributed to the reduction in p-mTOR/mTOR levels. In summary, Mof exhibited distinct roles in lipid metabolism under different conditions. The inhibition of Mof may hold potential as a therapeutic target for hepatic lipid metabolism disturbances.

BRAFV600E genetic testing should be recommended for Bethesda III or V thyroid nodules based on fine-needle aspiration.

The preoperative diagnosis of thyroid nodules now routinely includes BRAFV600E genetic testing in most provincial and municipal hospitals in China. This study identified the most suitable patients of thyroid nodule for BRAFV600E genetic testing. We retrospectively collected data of patients from the Hospital Information System that had undergone fine needle aspiration biopsy (FNAB) from May 2019 to December 2021. Data of FNAB, BRAFV600E genetic testing, and post-surgical pathological diagnosis were collected. A total of 12,392 patients were included in this study. Among them, 7,010 patients underwent solely FNAB, while 5,382 patients had both FNAB and BRAFV600E genetic testing. In the FNAB group, 2,065 thyroid nodules were surgically removed, with a 93.12% malignancy rate. In the FNAB + BRAF group, 2,005 nodules were dissected, and the malignancy rate was 98.20%. However, it was evident that in the subgroups, the combination of FNAB and BRAFV600E genetic testing only benefited Bethesda III (p < 0.001) and V (p = 0.001) nodules. Overall, the combination of FNAB with BRAFV600E genetic testing significantly improved the malignancy rate of surgical thyroid nodes at our hospital when compared to FNAB alone. The subgroup analysis showed that BRAFV600E genetic testing only benefited Bethesda III and V nodules. These findings provide a clinical reference for rationally selecting the most suitable population for BRAFV600E genetic testing.