High CD133 expression in proximal tubular cells in diabetic kidney disease: good or bad?

BACKGROUND: Proximal tubular cells (PTCs) play a critical role in the progression of diabetic kidney disease (DKD). As one of important progenitor markers, CD133 was reported to indicate the regeneration of dedifferentiated PTCs in acute kidney disease. However, its role in chronic DKD is unclear. Therefore, we aimed to investigate the expression patterns and elucidate its functional significance of CD133 in DKD. METHODS: Data mining was employed to illustrate the expression and molecular function of CD133 in PTCs in human DKD. Subsequently, rat models representing various stages of DKD progression were established. The expression of CD133 was confirmed in DKD rats, as well as in human PTCs (HK-2 cells) and rat PTCs (NRK-52E cells) exposed to high glucose. The immunofluorescence and flow cytometry techniques were utilized to determine the expression patterns of CD133, utilizing proliferative and injury indicators. After overexpression or knockdown of CD133 in HK-2 cells, the cell proliferation and apoptosis were detected by EdU assay, real-time cell analysis and flow analysis. Additionally, the evaluation of epithelial, progenitor cell, and apoptotic indices was performed through western blot and quantitative RT-PCR analyses. RESULTS: The expression of CD133 was notably elevated in both human and rat PTCs in DKD, and this expression increased as DKD progressed. CD133 was found to be co-expressed with CD24, KIM-1, SOX9, and PCNA, suggesting that CD133+ cells were damaged and associated with proliferation. In terms of functionality, the knockdown of CD133 resulted in a significant reduction in proliferation and an increase in apoptosis in HK-2 cells compared to the high glucose stimulus group. Conversely, the overexpression of CD133 significantly mitigated high glucose-induced cell apoptosis, but had no impact on cellular proliferation. Furthermore, the Nephroseq database provided additional evidence to support the correlation between CD133 expression and the progression of DKD. Analysis of single-cell RNA-sequencing data revealed that CD133+ PTCs potentially play a role in the advancement of DKD through multiple mechanisms, including heat damage, cell microtubule stabilization, cell growth inhibition and tumor necrosis factor-mediated signaling pathway. CONCLUSION: Our study demonstrates that the upregulation of CD133 is linked to cellular proliferation and protects PTC from apoptosis in DKD and high glucose induced PTC injury. We propose that heightened CD133 expression may facilitate cellular self-protective responses during the initial stages of high glucose exposure. However, its sustained increase is associated with the pathological progression of DKD. In conclusion, CD133 exhibits dual roles in the advancement of DKD, necessitating further investigation.

Protective effect of Cordyceps sinensis against diabetic kidney disease through promoting proliferation and inhibiting apoptosis of renal proximal tubular cells.

BACKGROUND: Diabetic kidney disease (DKD) has mainly been considered as a glomerular disease. Our previous study showed that the progression of DKD was highly correlated with the dysfunction of renal proximal tubular cells. Fermented Cordyceps sinensis (CS), a substitute for natural CS, is a prominent herb widely used in China, and has exhibited excellent efficacy on DKD. However, the underlying mechanisms remain poorly understood. METHODS: The database analysis was used to identify the main therapeutic targets and pathways of CS involved in DKD treatment. Next, the protective effects of fermented CS on high glucose (HG, 30 mM) induced HK-2 cell injury was validated through cell proliferation and apoptosis assay, including CCK-8, EdU and TUNEL. Finally, quantitative real­time PCR (qRT-PCR) and western blotting were used to verify key target genes. RESULTS: Our results revealed that 9 main targets (RELA, JNK1, PTEN, VEGFA, EGF, ERK2, CASP3, AKT1, MMP9) were recognized as key therapeutic targets with excellent binding affinity screened by database analysis and molecular docking. The biological processes were identified by Gene Ontology (GO) enrichment, which appeared mainly involved in the positive regulation of cell proliferation as well as the negative regulation of apoptosis. The verification experiments in vitro revealed that fermented CS significantly attenuated the HG-induced cytotoxicity and apoptosis, and promoted the proliferation of HK-2 cells. Moreover, fermented CS significantly downregulated the expressions of Bax, Caspase-3, VEGFA, P-AKT and P-ERK, and upregulated the expression of PTEN compared with that of HG group. CONCLUSION: Our results demonstrate that the fermented CS has nephroprotective effects significantly, which functions via promoting proliferation and inhibiting apoptosis of renal proximal tubular cells, likely by targeting Caspase-3, Bax, VEGFA and PTEN. Furthermore, AKT and ERK signaling pathway may be the critical mechanisms underlying the efficacy of fermented CS in DKD treatment.

Crosstalk between proximal tubular epithelial cells and other interstitial cells in tubulointerstitial fibrosis after renal injury.

The energy needs of tubular epithelial components, especially proximal tubular epithelial cells (PTECs), are high and they heavily depend on aerobic metabolism. As a result, they are particularly vulnerable to various injuries caused by factors such as ischemia, proteinuria, toxins, and elevated glucose levels. Initial metabolic and phenotypic changes in PTECs after injury are likely an attempt at survival and repair. Nevertheless, in cases of recurrent or prolonged injury, PTECs have the potential to undergo a transition to a secretory state, leading to the generation and discharge of diverse bioactive substances, including transforming growth factor-ß, Wnt ligands, hepatocyte growth factor, interleukin (IL)-1ß, lactic acid, exosomes, and extracellular vesicles. By promoting fibroblast activation, macrophage recruitment, and endothelial cell loss, these bioactive compounds stimulate communication between epithelial cells and other interstitial cells, ultimately worsening renal damage. This review provides a summary of the latest findings on bioactive compounds that facilitate the communication between these cellular categories, ultimately leading to the advancement of tubulointerstitial fibrosis (TIF).

The association between serum selenium levels and pathological features of papillary thyroid cancer in 284 patients.

Objective: The relationship between serum selenium levels and papillary thyroid cancer (PTC), especially the pathological features, still remains controversial. We conducted this study to investigate the relationship between serum selenium levels and PTC in a Chinese population. Methods: Cross-sectional data of 284 patients with PTC were collected from the First Affiliated Hospital of Shandong First Medical University. The general clinical characteristics, serum selenium levels, and tumor pathological features were described in PTC. The association between serum selenium levels and pathological features in PTC was analyzed using SPSS 26.0 statistical software. Results: Our results showed that the median serum selenium level was 79.15 µg/L (IQR: 71.00 - 86.98 µg/L) in PTC patients. Serum selenium levels were lower in females than males (p = 0.035). Serum selenium levels were negatively correlated with the number of lymph node metastases (p = 0.048). High serum selenium (OR = 0.397, 95%CI: 0.217 - 0.725) and diastolic blood pressure (OR = 1.028, 95%CI: 1.005 - 1.051) were related factors for the incidence of bilateral tumors. High serum selenium (OR = 0.320, 95%CI: 0.166 - 0.617) and diastolic blood pressure (OR = 1.066, 95%CI: 1.031 - 1.103) were related factors for tumor multifocal incidence. Conclusions: The serum selenium levels of PTC patients in females were lower than males. High serum selenium levels might be a protective factor in PTC patients. Further research is necessary to better understand the influence of selenium on PTC progression.

Thyroid diseases are associated with coronavirus disease 2019 infection.

Background: In 2019, there was a global outbreak of new coronary pneumonia. Studies have found that the severity of patients with new coronary pneumonia may be related to their comorbidities. This article discusses the impact of thyroid disease on the severity of new coronary pneumonia through a meta-analysis and provides new treatment ideas for the later treatment and recovery of new coronary pneumonia. Methods: Databases including PubMed, Embase, Cochrane Library, SINOMED, China national knowledge infrastructure (CNKI), and Wanfang for coronavirus disease 2019 (COVID-19) infection and thyroid diseases were searched. Reference lists of all eligible articles and related previous review articles were handsearched. Fifty-three articles were included to conduct the meta-analysis. Results: Fifty-three articles with 12,022 COVID-19 infection patients were included in this meta-analysis. The proportion of patients with thyroid diseases in all COVID-19 infection patients fluctuates between 0% and 88.46%. Of the 53 included studies, 22 studies reported the severity of COVID-19 infection and grouped. The fixed-effects model was used to merge odds ratio (OR) values, and the pooled effect size in favor of non-severe patients is 2.62 (95% CI = 1.96-3.49, P < 0.0001), which means that patients with severe COVID-19 infection are more likely to have thyroid diseases. The analysis subgrouped into Asia and Europe shows that patients with COVID-19 severe infection in Asia are 3.77 times more likely to have thyroid diseases than non-severe patients (fixed-effects model: OR = 3.77, 95% CI = 2.66-5.35, P < 0.00001). No significant statistical heterogeneity was found by the heterogeneity analysis (chi-square = 19.85, P = 0.34, I 2 = 9%). Severe COVID-19 infection patients are more likely to be complicated by hypothyroidism and low T3 syndrome. The pooled ORs with fixed-effects model are 3.72 (95% CI = 1.62-8.58, P = 0.002) and 5.86 (95% CI = 2.79-12.33, P < 0.00001), respectively. Conclusion: COVID-19 infection patients with thyroid diseases are very common, and severe patients are more likely to have thyroid diseases. Asian COVID-19 infection, hypothyroidism patients, and patients with low T3 syndrome are more likely to progress to severe condition. Systematic Review Registration: https://inplasy.com, identifier INPLASY202190079.

Empagliflozin reduces diffuse myocardial fibrosis by extracellular volume mapping: A meta-analysis of clinical studies.

Objective: The aim of the study was to evaluate the effect of empagliflozin on diffuse myocardial fibrosis by cardiac magnetic resonance (CMR) T1 mapping. Research methods and procedures: Databases including PubMed, Cochrane library, Embase, and Sinomed for clinical studies of empagliflozin on myocardial fibrosis were searched. Two authors extracted the data and evaluated study quality independently. Weighted mean difference (WMD) and 95% confidence intervals (CI) were used for continuous variables. Review Manager 5.3 was used to performed the analysis. Results: Six studies were included in this meta-analysis. One of the six studies was assessed as poor quality by the assessment of methodological quality; however, the remaining five studies were considered good. The WMD value of △extracellular volume (ECV) was merged by the fixed-effect model, and the pooled effect size was -1.48 (95% CI -1.76 to -1.21, P < 0.00001), which means in favor of empagliflozin. Heterogeneity analysis did not find any heterogeneity (chi2 = 0.39, P = 0.82, I 2 = 0%). In addition, empagliflozin had a tendency to reduce ECV compared to treatment before with no statistical significance (WMD = -0.29, 95% CI -1.26 to 0.67, P = 0.55; heterozygosity test, chi2 = 2.66, P = 0.45, I 2 = 0%). The WMD value of △native T1 was also merged by the fixed-effect model, but the pooled effect size showed neither statistical difference between empagliflozin and placebo treatment (WMD = -5.40, 95% CI -21.63 to 10.83, P = 0.51) nor heterogeneity (chi2 = 0.05, P = 0.83, I 2 = 0%). Conclusions: Empagliflozin has cardiovascular benefits by reducing diffuse myocardial fibrosis. ECV could act as a non-invasive imaging tool to assess diffuse myocardial fibrosis and monitor disease progression. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=324804, identifier: CRD42022324804.

Abnormal Glucose Metabolism Parameters and the Aggressiveness of Differentiated Thyroid Carcinoma: A Hospital-Based Cross-Section Study in China.

Purpose: The correlation of abnormal glucose metabolism and thyroid carcinoma, especially the aggressiveness of thyroid cancer, still remains controversial. We conducted this study to investigate the relationship between abnormal glucose metabolism parameters and differentiated thyroid carcinoma (DTC) in the Chinese population. Materials and Methods: The study was designed as a hospital-based case-control study and was approved by the Ethics Committee of our hospital and registered in the Clinical Trial Protocol Registration and Results System (Registration code: NCT03006289). From January 1, 2018 to June 30, 2021, a total of 377 DTC patients were enrolled in the study. Demographic and general characteristics, details of thyroid surgery and histopathological results, hematological test indicators were collected. Glucose metabolism parameters were calculated. Variables were analyzed by t-test, ANOVA, chi-squared analysis and Fisher's exact test. Pearson bi-variate correlation and Spearman's correlation analysis were used for bi-variate analysis. Results: More than 40% of patients with DTC were multifocality, more than half were extra-glandular invasion, and nearly 85% complied by lymph node metastasis. The prevalence of diabetes mellitus (DM) was about 10.08% in DTC patients. It was found that the proportion of postprandial 2 h blood glucose ≥11.1mmol/L and HbA1c ≥6.5% was significantly higher than the known proportion of DM (17.8%, 16.7% vs. 10.08%). Additionally, 87.3% of the DTC patients in this study had varying degrees of insulin resistance. Further analysis found that higher T staging was associated with higher levels of area under curve of C-peptide (P = 0.029), insulin sensitivity index (P = 0.012) and C-peptide sensitivity index (P = 0.016). A delayed peak of insulin secretion was found to be positive related with capsule invasion (r = 0.206, P = 0.004). In patients without a DM history, homeostasis model assessment of insulin resistance (P = 0.017), insulin sensitivity index (P = 0.019) and C-peptide sensitivity index (P = 0.020) were statistic associated with T staging. Also, the glucose metabolism parameter at 3-hour after a meal was related to a larger number of metastatic lymph nodes. Conclusion: Abnormal glucose metabolism, namely, DM, hyperinsulinemia and insulin resistance, were significantly associated with the carcinogensis and aggressiveness of DTC.

Manganese exposure induces permeability in renal glomerular endothelial cells via the Smad2/3-Snail-VE-cadherin axis.

Manganese (Mn) is an essential micronutrient. However, it is well established that Mn overexposure causes nervous system diseases. In contrast, there are few reports on the effects of Mn exposure on glomerular endothelium. In the present study, the potential effects of Mn exposure on glomerular endothelium were evaluated. Sprague Dawley rats were used as a model of Mn overexposure by intraperitoneal injection of MnCl2·H2O at 25 mg/kg body weight. Mn exposure decreased expression of vascular endothelial-cadherin, a key component of adherens junctions, and increased exudate from glomeruli in Sprague Dawley rats. Human renal glomerular endothelial cells were cultured with different concentration of Mn. Exposure to 0.2 mM Mn increased permeability of human renal glomerular endothelial cell monolayers and decreased vascular endothelial-cadherin expression without inducing cytotoxicity. In addition, Mn exposure increased phosphorylation of mothers against decapentaplegic homolog 2/3 and upregulated expression of zinc finger protein SNAI1, a negative transcriptional regulator of vascular endothelial-cadherin. Our data suggest Mn exposure may contribute to development of glomerular diseases by inducing permeability of glomerular endothelium.

Hypercholesterolemia Is an Associated Factor for Risk of Differentiated Thyroid Cancer in Chinese Population.

BACKGROUND: Hyperlipidemia has been hypothesized as a risk factor for thyroid cancer. However, the association between hypercholesterolemia and thyroid cancer is unclear, especially in Chinese population without available published data. We conducted this study to investigate the relationship between hypercholesterolemia and differentiated thyroid cancer (DTC) in Chinese population. METHODS: Three thousand seven hundred forty-eight patients were enrolled in the study, including 2,021 DTC patients and 1,727 benign subjects with benign thyroid nodules. Demographic characteristics, medical history, and clinical hematological examination were collected. Stratified analyses of association between hypercholesterolemia and risk of DTC were done. Multivariable logistic regression models were used to estimate the association between hypercholesterolemia and the risk of thyroid nodules being malignant. This study protocol was approved by the ethics committee of Shandong Provincial Qianfoshan Hospital and assigned in ClinicalTrials.gov protocol registration and results system (NCT03006289, https://clinicaltrials.gov/ct2/show/NCT03006289). RESULTS: The level of serum total cholesterol in patients with DTC is higher than that in benign subjects (P < 0.001). After adjusting hypercholesterolemia, age (P < 0.001), triglyceride (P = 0.003), and thyroid stimulating hormone (TSH) (P < 0.001) are found to be confounding factors. The risk of DTC in patients younger than 45 years old is 2.08 times than that of patients older than 45 years old (odds ratio = 0.48, 95% CI (0.38, 0.61), P < 0.001). A high TSH level is highly associated with the increased risk of DTC (P < 0.001). The multivariable logistic regression analysis revealed that the absence of hypercholesterolemia could reduce the risk of thyroid nodules being malignant (odds ratio = -0.75, 95% CI (-1.39, -0.12), P = 0.02). Comparing to the higher level of serum total cholesterol (>5.7 mmol/L), the closer the serum total cholesterol level is to normal (3.17-5.7 mmol/L), the less the risk of thyroid nodules being malignant is, and this difference is statistically significant (odds ratio = -0.67, 95% CI (-1.31, -0.03), P = 0.040). However, this difference is not found in the group of patients with lower level of total cholesterol (<3.17 mmol/L, odds ratio = 0.43, 95% CI (-1.22, 2.09), P = 0.068), suggesting that hypocholesterolemia is not a protective factor in the risk of thyroid nodules being malignant. CONCLUSIONS: Hypercholesterolemia is an associated factor for risk of DTC in Chinese population.

Exploration of the establishment of manganese poisoning rat model and analysis of discriminant methods.

OBJECTIVE: We explored methods to establish an animal model of manganese poisoning and evaluate the feasibility of the determination method. METHODS: Twenty-four specific pathogen-free male rats were randomly divided into four groups: control, low-dose (15.0 mg/kg), middle-dose (25.0 mg/kg), and high-dose (50.0 mg/kg). Intraperitoneal injection of MnCl2·H2O was administered every 48 h for three months. Rats were tested for behavior, muscle tension, and with a balance beam experiment at the end of each month. Three months later, the rats were sacrificed and brain tyrosine hydroxylase (TH) expression levels were measured. RESULTS: Rats in each group exhibited changes in behavior, muscle tone, and balance after exposure to manganese, and the scores of each test for the high-dose and middle-dose groups were statistically different from the low-dose and control groups. Finally, a rat model of manganese poisoning was identified with the TH expression less than 30% of the normal value. We find that the modeling success rate of the middle-dose and high-dose groups were 66.67% and 100%, respectively. In addition, there were negative correlations between the three assessment methods such as behavioral tests and TH expression levels. CONCLUSIONS: Intraperitoneal injection of MnCl2·H2O (25 mg/kg) can successfully establish a manganese poisoning rat model with low mortality rate. Muscle tension, balance beam, and behavioral tests can be used as preliminary determination methods for modeling.

Gene sequence screening for manganese poisoning-susceptible genes and analysis of gene interaction effects.

Manganese poisoning is a common occupational disease, studies have found that the susceptibility to manganese poisoning differs in individuals. We adopted genome-wide sequencing methods to screen for susceptibility genes involved in gene-mediated metabolic pathways from the perspective of manganese poisoning. We identified 18,439 genes in this study, including 14,272 known genes and 4398 new genes. We then selected 17 differential genes using p values, of which 7 genes were down-regulated and 10 genes were up-regulated. Possible interaction genes for each differential gene were selected according to the String database. Sgk1, HCRTr1, HspB1, Rem2, Oprd1, ATF5, and TRHr identified in this study may be involved in oxidative stress mechanisms, dopamine (DA) synthesis, and neuronal survival during apoptosis and may affect susceptibility to manganese poisoning.