Exercise-Induced Reduction of IGF1R Sumoylation Attenuates Neuroinflammation in APP/PS1 Transgenic Mice.

INTRODUCTION: Alzheimer's Disease (AD), a progressive neurodegenerative disorder, is marked by cognitive deterioration and heightened neuroinflammation. The influence of Insulin-like Growth Factor 1 Receptor (IGF1R) and its post-translational modifications, especially sumoylation, is crucial in understanding the progression of AD and exploring novel therapeutic avenues. OBJECTIVES: This study investigates the impact of exercise on the sumoylation of IGF1R and its role in ameliorating AD symptoms in APP/PS1 mice, with a specific focus on neuroinflammation and innovative therapeutic strategies. METHODS: APP/PS1 mice were subjected to a regimen of moderate-intensity exercise. The investigation encompassed assessments of cognitive functions, alterations in hippocampal protein expressions, neuroinflammatory markers, and the effects of exercise on IGF1R and SUMO1 nuclear translocation. Additionally, the study evaluated the efficacy of KPT-330, a nuclear export inhibitor, as an alternative to exercise. RESULTS: Exercise notably enhanced cognitive functions in AD mice, possibly through modulations in hippocampal proteins, including Bcl-2 and BACE1. A decrease in neuroinflammatory markers such as IL-1ß, IL-6, and TNF-α was observed, indicative of reduced neuroinflammation. Exercise modulated the nuclear translocation of SUMO1 and IGF1R in the hippocampus, thereby facilitating neuronal regeneration. Mutant IGF1R (MT IGF1R), lacking SUMO1 modification sites, showed reduced SUMOylation, leading to diminished expression of pro-inflammatory cytokines and apoptosis. KPT-330 impeded the formation of the IGF1R/RanBP2/SUMO1 complex, thereby limiting IGF1R nuclear translocation, inflammation, and neuronal apoptosis, while enhancing cognitive functions and neuron proliferation. CONCLUSION: Moderate-intensity exercise effectively mitigates AD symptoms in mice, primarily by diminishing neuroinflammation, through the reduction of IGF1R Sumoylation. KPT-330, as a potential alternative to physical exercise, enhances the neuroprotective role of IGF1R by inhibiting SUMOylation through targeting XPO1, presenting a promising therapeutic strategy for AD.

The association of low serum uric acid with mortality in older people is modified by kidney function: National Health and Nutrition Examination Survey (NHANES) 1999-2018.

BACKGROUND: In older individuals, the role of low serum uric acid (SUA) as risk factor for mortality is debated. We therefore studied whether SUA levels, particularly low SUA concentrations, are associated with all-cause and cardiovascular (CV) mortality in older population, and to clarify potential effect modification of kidney function. METHODS: We identified 14,005 older people in National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2018. SUA was measured only at baseline. The relationship between SUA and mortality was assessed using Cox proportional hazards models and restricted cubic spline Cox regression stratified by the estimated glomerular filtration rate (eGFR). RESULTS: During mean 8.3 years of follow-up, 4852 all-cause death and 1602 CV death were recorded. A significant U-shaped association was observed between SUA with all-cause mortality, with the lowest risk concentration of 5.5 mg/dL. Comparing to the reference group (5 to 7 mg/dL), the HR of 2 to < 5 mg/dL group was 1.11 (1.03-1.21) and 1.14 (1.00-1.30). This relationship was more pronounced in participants with an eGFR ≥ 60 ml/min/1.73m2 (HR, 1.16; 95%CI, 1.06-1.28). This situation similarly occurred in Urine protein negative group (HR, 1.14; 95%CI, 1.04-1.25). CONCLUSIONS: Low SUA concentrations are associated with an increased risk in all-cause and CV mortality among older participants. Extremely low SUA concentrations are especially undesirable, especially in the older adults with normal kidney function.

Relationship between serum phosphorus and mortality in non-dialysis chronic kidney disease patients: evidence from NHANES 2001-2018.

BACKGROUND: Hyperphosphatemia is common in chronic kidney disease (CKD), associated with higher mortality in dialysis patients. Its impact in non-dialysis patients, especially those with preserved kidney function, remains uncertain. METHODS: A prospective cohort study was conducted using data from the National Health and Nutrition Examination Survey (2001-2008). Serum phosphorus was analyzed as a continuous variable, or categorized into three groups: < 3.5 mg/dL, 3.5 to < 4.5 mg/dL, and ≥ 4.5 mg/dL. Cox proportional hazards models were used to analyze the association between phosphorus with all-cause and cardiovascular disease (CVD) mortality, with or without adjustment for age, sex, race, hemoglobin, estimated glomerular filtration rate (eGFR), serum albumin, serum calcium, 25(OH)D, obesity, hypertension, diabetes, and CVD. RESULTS: A total of 7694 participants were included in the analysis, representing 28 million CKD patients in the United States. During mean 92 months of follow up, 2708 all-cause deaths (including 969 CVD deaths) were observed. Per 1 mg/dL increase in phosphorus was associated with a 13% and 24% increased risk of all-cause mortality (hazard ratio [HR], 1.13; 95%CI, 1.02-1.24) and CVD mortality (HR, 1.24; 95%CI, 1.07-1.45), respectively. Compared with the < 3.5 mg/dL, phosphorus ≥ 4.5 mg/dL was associated with a 28% and 57% increased risk of all-cause mortality (HR, 1.28; 95%CI, 1.05-1.55) and CVD mortality (HR, 1.57; 95CI, 1.19-2.08), respectively. In participants with eGFR < 60 ml/min/1.73m2, elevated phosphorus (≥ 4.5 mg/ dL) were significantly associated with increased risk of all-cause mortality (HR, 1.36; 95%CI, 1.07-1.72). No significant association was observed in eGFR ≥ 60 ml/min/1.73m2 group (HR, 1.31; 95%CI, 0.86-1.99). This correlation does not differ significantly between subgroups defined by eGFR level (P for interaction = 0.889). CONCLUSION: Serum phosphorus above 4.5 mg/dL is significantly associated with a 28% and 57% increased risk of all-cause and CVD death in non-dialysis CKD patients, respectively. This relationship still demonstrated in patients with eGFR < 60 ml/min/1.73m2. However, for population with eGFR ≥ 60 ml/min/1.73m2, further verification is needed.

Retrospective study: risk assessment model for osteoporosis-a detailed exploration involving 4,552 Shanghai dwellers.

Background: Osteoporosis, a prevalent orthopedic issue, significantly influences patients' quality of life and results in considerable financial burden. The objective of this study was to develop and validate a clinical prediction model for osteoporosis risk, utilizing computer algorithms and demographic data. Method: In this research, a total of 4,552 residents from Shanghai were retrospectively included. LASSO regression analysis was executed on the sample's basic characteristics, and logistic regression was employed for analyzing clinical characteristics and building a predictive model. The model's diagnostic capacity for predicting osteoporosis risk was assessed using R software and computer algorithms. Results: The predictive nomogram model for bone loss risk, derived from the LASSO analysis, comprised factors including BMI, TC, TG, HDL, Gender, Age, Education, Income, Sleep, Alcohol Consumption, and Diabetes. The nomogram prediction model demonstrated impressive discriminative capability, with a C-index of 0.908 (training set), 0.908 (validation set), and 0.910 (entire cohort). The area under the ROC curve (AUC) of the model was 0.909 (training set), 0.903 (validation set), and applicable to the entire cohort. The decision curve analysis further corroborated that the model could efficiently predict the risk of bone loss in patients. Conclusion: The nomogram, based on essential demographic and health factors (Body Mass Index, Total Cholesterol, Triglycerides, High-Density Lipoprotein, Gender, Age, Education, Income, Sleep, Alcohol Consumption, and Diabetes), offered accurate predictions for the risk of bone loss within the studied population.

L-shaped association of serum 25-hydroxyvitamin D with all-cause and cardiovascular mortality in older people with chronic kidney disease: results from the NHANES database prospective cohort study.

BACKGROUND: This study was conducted to assess the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cardiovascular disease (CVD) mortality in older people with chronic kidney disease (CKD) in the United States. METHODS: We identified 3230 CKD participants aged ≥ 60 years from the National Health and Nutrition Examination Survey (2001-2018). CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2. Mortality outcomes were determined by linkage to National Death Index (NDI) records through December 31, 2019. Restricted cubic spline based on Cox regression models were utilized to elucidate the nonlinear relationship between serum 25(OH)D concentrations and mortality in patients with CKD. RESULTS: During median 74 months of follow-up, 1615 all-cause death and 580 CVD death were recorded. We found an L-shaped association between serum 25(OH)D concentrations and all-cause and CVD mortality, reaching a plateau at 90 nmol/L. Accordingly, per one-unit increment in natural log-transformed 25(OH)D was associated with a 32% and 33% reduced risk of all-cause mortality (hazard ratio [HR] 0.68; 95%CI, 0.56 to 0.83) and CV mortality (HR 0.69; 95%CI, 0.49 to 0.97) in participants with serum 25(OH)D < 90 nmol/L, but no considerable difference was observed in participants with serum 25(OH)D ≥ 90 nmol/L. Compared with those in the deficiency group (< 50 nmol/L), insufficient (50 to < 75 nmol/L) and sufficient group (≥ 75 nmol/L) were significantly associated with lower all-cause mortality (HR,0.83; 95%CI, 0.71 to 0.97 and HR, 0.75; 95%CI, 0.64 to 0.89) and CV mortality (HR,0.87; 95%CI, 0.68 to 1.10 and HR, 0.77; 95%CI, 0.59 to < 1.0), respectively. CONCLUSION: An L-shaped relationship between serum 25(OH)D levels with all-cause and CVD mortality was observed in elderly CKD patients in the United States. A 25(OH)D concentration of 90 nmol/L may be the target to reduce the risk of premature death.

LNCRNA CDKN2B-AS1 regulates mesangial cell proliferation and extracellular matrix accumulation via miR-424-5p/HMGA2 axis.

BACKGROUND: Previous study has demonstrated that long noncoding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) was abnormally expressed in diabetic nephropathy (DN). However, the underlying mechanism that allows CDKN2B-AS1 in the progression of DN remains to be further elucidated. METHODS: Peripheral blood cells of 24 diabetes patients with DN and 20 without DN were collected. Human glomerular mesangial cells (HGMC) were cultured in high glucose or low glucose medium. The expression levels of CDKN2B-AS1, microRNA (miR)-424-5p and high mobility group AT hook 2 (HMGA2) were detected by quantitative real-time polymerase chain reaction or western blot. The target association between miR-424-5p and CDKN2B-AS1 or HMGA2 was confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. Cell proliferation, extracellular matrix (ECM) accumulation and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and western blot, respectively. RESULTS: CDKN2B-AS1 expression was up-regulated and miR-424-5p level was down-regulated in peripheral blood of DN patients and high glucose-treated HGMC cells. CDKN2B-AS1 was validated as a sponge of miR-424-5p. Silence of CDKN2B-AS1 repressed proliferation and ECM accumulation by increasing miR-424-5p. HMGA2 was a target of miR-424-5p and miR-424-5p overexpression inhibited proliferation, ECM accumulation and PI3K/AKT pathway by targeting HMGA2. Moreover, knockdown of CDKN2B-AS1 inhibited HMGA2 expression and PI3K/AKT pathway by increasing miR-424-5p. CONCLUSION: Knockdown of CDKN2B-AS1 suppressed proliferation, ECM accumulation and PI3K/AKT signaling by increasing miR-424-5p and decreasing HMGA2 in high glucose-treated HMGC cells.

Retracted Article: Long non-coding RNA TUG1 alleviates high glucose induced podocyte inflammation, fibrosis and apoptosis in diabetic nephropathy via targeting the miR-27a-3p/E2F3 axis.

Diabetic nephropathy (DN) is the most common cause of end-stage renal disease (ESRD) in developed countries. The long non-coding RNA (lncRNA) taurine upregulated gene 1 (TUG1) is associated with mitochondrial function in podocytes in DN. However, the detailed mechanism of TUG1 in DN has not yet been fully elucidated. In this study, we found that the expression levels of TUG1 and E2F transcription factor 3 (E2F3) were downregulated, and microRNA-27a-3p (miR-27a-3p) level was upregulated in DN tissues and HG-treated podocytes. Function analysis indicated that TUG1 overexpression inhibited inflammation, fibrosis and apoptosis in HG-induced podocytes. Rescue experiments demonstrated that miR-27a-3p reversed the suppression effects of TUG1 on apoptosis, fibrosis and inflammation in HG-stimulated podocytes, while E2F3 abrogated the promotion effects of miR-27a-3p on apoptosis, fibrosis and inflammation in HG-induced podocytes. Mechanical analysis revealed that TUG1 regulated E2F3 expression via sponging miR-27a-3p. In conclusion, our findings suggested that TUG1 alleviates high glucose induced inflammation, fibrosis and podocyte apoptosis in diabetic nephropathy via targeting the miR-27a-3p/E2F3 axis, providing a potential therapeutic target for treatment of DN.

Effect of microRNA-141 on the development of diabetic nephropathy through regulating AKT/AMPK signaling pathway by targeting insulin receptor substrate 2.

OBJECTIVE: The aim of this study was to explore the effect of microRNA-141 (miR-141) on the development of diabetic nephropathy (DN) and its potential mechanism. METHODS: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of miR-141 in peripheral blood of DN patients. Cell apoptosis was measured by flow cytometry. The expression levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay. The expression level of insulin receptor substrate 2 (IRS2) was analyzed by RT-qPCR and Western blot analysis. The targeting regulatory sites were predicted by Targetscan and luciferase assay was conducted to confirm the relationship between miR-141 and IRS2. The expression levels of protein kinase B (AKT)/adenosine monophosphate protein kinase (AMPK)-related proteins were investigated by Western blot analysis. RESULTS: MiR-141 was upregulated in peripheral blood of DN patients (P < 0.05). Upregulation of miR-141 significantly promoted apoptosis ( P < 0.05) and the expression of TNF-α and IL-6 ( P < 0.05). However, downregulation of miR-141 inhibited cell apoptosis ( P < 0.05) and productions of TNF-α and IL-6 ( P < 0.05). Moreover, miR-141 displayed a negatively regulatory effect on IRS2 abundance, and overexpression of IRS2 reversed the inhibitory effect of miR-141 on development of DN cells ( P < 0.05). Besides, knockdown of miR-141 significantly promoted the expressions of AKT/AMPK-related proteins ( P < 0.05), which was attenuated by inhibition of IRS2 ( P < 0.05). CONCLUSION: MiR-141 promoted DN progression through regulating AKT/AMPK signaling pathway by targeting IRS2.

[Repair of articular cartilage defects by autologous bone mesenchymal stem cells and allogeneic costal chondrocytes in the knee of Wuzhishan miniature pigs].

OBJECTIVE: To investigate the feasibility of construction of tissue engineered cartilage by co-culture of bone marrow mesenchymal stem cells (BMSCs) and costal chondrocytes (CCs), and to provide theoretical basis and experimental basis for clinical repair of articular cartilage defects by Wuzhishan miniature pig knee cartilage defects with co-cultured cells.
 Methods: Density gradient centrifugation method was used to isolate BMSCs from Wuzhishan miniature pig. The double enzyme digestion method was used to isolate CCs. The passage 3 generation of BMSCs and passage 2 generation of CCs were randomly divided into 3 groups: a co-culture group of BMSCs:CCs for 1:2 (Group A), a simple CCs (Group B), and a simple BMSCs (Group C). The cell growth curve was drawn, and the content of glycosaminoglycan (GAG) of external separation in chondrocytes was determined. The 12 Wuzhishan miniature pigs were randomly divided into a co-culture cells/collagen membrane experimental group, a collagen membrane control group and the blank group. In the co-culture cells/collagen membrane experimental group, the co-cultured cells/collagen membrane were implanted into the cartilage defects of the mandibular condyle; in the collagen membrane control group, only collagen membrane was implanted; while in the blank group, nothing was implanted. Six animals were sacrificed at 8 and 16 weeks after surgery respectively (2 animals in each group). General observation, cartilage histological score and histopathological examination were carried out.
 Results: The BMSCs and co-culture cells grew well. The biological activity of CCs was good. After 16 weeks of operation, the repair tissues in the co-cultured cells/collagen membrane experimental group showed hyaline cartilage features: smooth, flat, and integrated well with the surrounding cartilage and subchondral bone. The collagen membrane in the collagen membrane control group was fibrously repaired. Repair tissue gross score in the co-culture cells/collagen membrane experimental group was significantly better than that in the collagen membrane control group and the blank group (both P<0.05), but there was no significant difference between the collagen membrane control group and the blank group (P>0.05).
 Conclusion: BMSCs, CCs and co-cultured cells can function as the seed cells for cartilage tissue engineering, and the co-culture cells (BMSCs:CCs=1:2) possess more advantages; the short-term effect of co-culture cells with collagen membrane on repairing cartilage defects is satisfied.