Cathepsin S (CTSS) in IgA nephropathy: an exploratory study on its role as a potential diagnostic biomarker and therapeutic target.

Introduction: IgA nephropathy (IgAN), a prevalent form of glomerulonephritis globally, exhibits complex pathogenesis. Cathepsins, cysteine proteases within lysosomes, are implicated in various physiological and pathological processes, including renal conditions. Prior observational studies have suggested a potential link between cathepsins and IgAN, yet the precise causal relationship remains unclear. Methods: We conducted a comprehensive bidirectional and multivariable Mendelian randomization (MR) study using publicly available genetic data to explore the causal association between cathepsins and IgAN systematically. Additionally, immunohistochemical (IHC) staining and enzyme-linked immunosorbent assay (ELISA) were employed to evaluate cathepsin expression levels in renal tissues and serum of IgAN patients. We investigated the underlying mechanisms via gene set variation analysis (GSVA), gene set enrichment analysis (GSEA), and immune cell infiltration analysis. Molecular docking and virtual screening were also performed to identify potential drug candidates through drug repositioning. Results: Univariate MR analyses demonstrated a significant link between increased cathepsin S (CTSS) levels and a heightened risk of IgAN. This was evidenced by an odds ratio (OR) of 1.041 (95% CI=1.009-1.073, P=0.012) as estimated using the inverse variance weighting (IVW) method. In multivariable MR analysis, even after adjusting for other cathepsins, elevated CTSS levels continued to show a strong correlation with an increased risk of IgAN (IVW P=0.020, OR=1.037, 95% CI=1.006-1.069). However, reverse MR analyses did not establish a causal relationship between IgAN and various cathepsins. IHC and ELISA findings revealed significant overexpression of CTSS in both renal tissues and serum of IgAN patients compared to controls, and this high expression was unique to IgAN compared with several other primary kidney diseases such as membranous nephropathy, minimal change disease and focal segmental glomerulosclerosis. Investigations into immune cell infiltration, GSEA, and GSVA highlighted the role of CTSS expression in the immune dysregulation observed in IgAN. Molecular docking and virtual screening pinpointed Camostat mesylate, c-Kit-IN-1, and Mocetinostat as the top drug candidates for targeting CTSS. Conclusion: Elevated CTSS levels are associated with an increased risk of IgAN, and this enzyme is notably overexpressed in IgAN patients' serum and renal tissues. CTSS could potentially act as a diagnostic biomarker, providing new avenues for diagnosing and treating IgAN.

Renal amyloidogenic leukocyte chemotactic factor 2 combined with IgA nephropathy: A case report.

RATIONALE: Amyloidogenic leukocyte chemotactic factor 2 (ALECT2) was recently considered as a new clinicopathologic type of amyloid, which frequently affects kidney in adults and results in different degrees of renal insufficiency and failure with or without proteinuria. Here, we present a case of combining LECT2-associated renal amyloidosis with immunoglobulin (Ig)A nephropathy. PATIENT CONCERNS: A 71-year-old Chinese man presented with edema of both lower extremities. DIAGNOSES: There was pale eosinophilic material strongly positive for the Congo red stain in interstitium with demonstrated apple green birefringence under polarized light. Immunofluorescent stain was positive for IgA deposits (4+), IgG deposits (2+), C3 deposits (3+) within the mesangium and capillary wall. Immunohistochemistry was positive for κ (+), λ (2+) in mesangial area, and LECT2 (2+) in the interstitium. On electron microscopy, there were electron-dense deposits within mesangial area and subendothelial and randomly orientated and nonbranching fibrils 10 nm in size found in the interstitium areas. Liquid chromatography tandem mass spectrometry was performed on peptides extracted from Congo red-positive, microdissected areas of the paraffin-embedded kidney specimen. LECT 2-associated renal amyloidosis with IgA nephropathy was pathologically confirmed by renal biopsy. INTERVENTIONS: Steroids (60 mg/d) were used to treat IgA nephropathy daily. Antihypertensive treatment was switched to an angiotensin-converting enzyme inhibitor. OUTCOMES: One year after diagnosis, creatine remained stable in the normal range, and 24-hour proteinuria decreased to 2.9 g. LESSONS: To date, ALECT2 has still not been comprehensively investigated. The findings of this research provide insights for concurrent IgA nephropathy with ALECT2.

The Effects of Resistant Starch on Biomarkers of Inflammation and Oxidative Stress: A Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to investigate the effects of resistant starch (RS) on inflammation and oxidative stress related indicators. PubMed, Embase and The Cochrane library were systematically searched to find randomized controlled trials (RCTs) of RS intervention up to February 2020. We used from the effect size, as estimated by the standardized mean difference (SMD) with 95% confidence intervals (95%CI) to perform the random method meta-analysis, with P value ≦0.05 as statistically significant. The 16 included trials with 17 effect sizes included a total of 739 participants in this paper. The intervention duration was from 2 weeks to 3 months. The analysis indicated that RS decreases the levels of tumor necrosis factor-α (TNF-α) (SMD = -0.711; 95%CI: -1.227, -0.194; P = 0.007) and interleukin 6 (IL-6) (SMD = -0.609; 95%CI: -0.924, -0.294; P < 0.001), increases total antioxidant capacity (TAC) (SMD = 2.543, 95% CI: 0.069: 5.017, P = 0.044). No significant effects on C-reactive protein (CRP) (SMD = -0.583; 95%CI: -1.270, 0.104; P = 0.096), superoxide dismutase (SOD) (SMD = 0.091; 95%CI: -0.156, 0.338; P = 0.471), and malondialdehyde (MDA) (SMD = -0.320; 95%CI: -0.907, 0.266; P = 0.285). Subgroup analysis shown that CRP level significant reduced in subjects from the east (SMD = -1.501; 95%CI: -2.662, -0.340; P = 0.011) or suffering from diseases (SMD: -1.057; 95%CI: -1.999, -0.115; P = 0.028).Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.2019284.

miR-155-5p upregulation ameliorates myocardial insulin resistance via mTOR signaling in chronic alcohol drinking rats.

BACKGROUND: Chronic alcohol intake is associated with an increased risk of alcoholic cardiomyopathy, which may present with pathological changes such as myocardial insulin resistance, leading to ventricular dilation and cardiac dysfunction. Although a correlation between microRNA-155 (miR-155) and insulin signaling has been identified, the underlying mechanism has not been elucidated to date. The purpose of the study was to determine whether overexpression of miR-155-5p in vivo could ameliorate chronic alcohol-induced myocardial insulin resistance and cardiac dysfunction. MATERIAL AND METHODS: Wistar rats were fed with either alcohol or water for 20 weeks to establish chronic alcohol intakes model. Then the alcohol group were divided into three groups: model group, miRNA-155 group and AAV-NC group. Rats undergoing alcohol treatment were injected with AAV-miRNA-155 (adeno-associated virus 9) or its negative control AAV-NC, respectively. Gene expression was determined by real-time PCR, and protein expression was determined by western blot. Echocardiography was performed to assess terminal cardiac function. Insulin responsiveness was determined through the quantification of phosphorylated insulin receptor substrate 1 (ser 307) and phosphorylated insulin receptor (Tyr 1185) levels. RESULTS: We found that cardiac function was attenuated in chronic alcohol intake rats, with an activated mammalian target of rapamycin (mTOR) signaling pathway, accompanied by an increase in p-IRS1(ser 307) and a decrease in p-IR (Tyr 1185) level in myocardial tissue. Also, alcohol drinking significantly up-regulated miR-155-5p level and its overexpression decreased p-IRS1 (ser 307) and increased p-IR (Tyr 1185) levels, and meanwhile inhibited the mTOR signaling pathway. CONCLUSION: miR-155-5p upregulation ameliorates myocardial insulin resistance via the mTOR signaling in chronic alcohol drinking rats. We propose that miR-155 may serve as a novel potential therapeutic target for alcoholic heart disease.

Effects of Vitamin D Supplementation in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis.

CONTEXT: Vitamin D (VD) has been found to play a key role in nonalcoholic fatty liver disease (NAFLD). This meta-analysis explored the effects of VD supplementation in patients with NAFLD. METHODS: The PubMed, EMBASE, and the Cochrane Library databases were searched to find randomized control trials (RCTs) that measured the changes between the VD supplement group and the control group until May 2019. Standard mean difference (SMD) with 95% confidence intervals (CI) was calculated when data units were different, otherwise weighted mean difference (WMD) and 95% CI was calculated. Heterogeneity was assessed using the I2 statistic. RESULTS: Eight RCTs with 624 individuals were extracted. The main indicators, including serum alanine aminotransferase (WMD = -0.052; 95% CI: -3.740, 3.636; P = 0.978) and aspartate aminotransferase concentrations (WMD = -0.479; 95% CI: -2.791, 1.833; P = 0.685) were not significantly different between the intervention and placebo groups. In addition, no significant intergroup difference was observed in the following secondary indicators: fasting blood glucose (WMD = 0.466; 95% CI: -5.313, -10.879; P = 0.061), homeostasis model assessment (WMD = 0.380, 95% CI: -0.162, 0.923; P = 0.169), serum insulin concentration (WMD = 0.760; 95% CI: -0.532, 2.052; P = 0.249), high-density lipoprotein (WMD = -0.012; 95% CI: -0.188, 0.164; P = 0.891), and low-density lipoprotein (WMD = -0.115; 95% CI: -3.849, -3.620; P = 0.952). CONCLUSIONS: The results indicate that VD supplementation does not improve liver enzymes, insulin resistance, glucose metabolism parameters, and lipid levels in patients with NAFLD.

miR-155-5p alleviates ethanol-induced myocardial insulin resistance in H9C2 cells via regulating the mTOR signalling pathway.

Alcohol exposure impairs myocardium insulin sensitivity, which links to heart dysfunction. miR-155 regulates mTOR signaling pathway and is involved in multiple functions. However, the underlying mechanism of miR-155 in ethanol-induced myocardial insulin resistance remains unclear. Here, in this study we aimed to identify the role of miR-155 in myocardial insulin sensitivity and the involvement of mTOR pathway. H9C2 cells were cultured with or without 100 mM ethanol for 24 h. miR-155-5p inhibitor, miR-155-5p mimics or their respective negative control (inhibitor NC and mimic NC) were transfected to regulate miR-155-5p expression. mTOR signaling, including Ras homolog enriched in brain (Rheb), rapamycin insensitive companion of mTOR (Rictor) and ribosomal protein S6 kinase B2 (S6K2), was investigated by western blotting and qPCR, and insulin responsiveness was evaluated by glucose uptake and phosphorylation of insulin receptor substrate-1 (p-IRS1). The miR-155-5p level increased under ethanol exposure, accompanied by a decrease in glucose uptake, an increase in p-IRS1(ser 307) and activation of the mTOR signaling pathway in H9C2 cells. In addition, miR-155-5p downregulation decreased the glucose uptake, increased the p-IRS1(ser 307) level and activated the mTOR signaling pathway. miR-155-5p upregulation increased the glucose uptake, decreased the p-IRS1(ser 307) level and suppressed the mTOR signaling pathway. Collectively, these findings suggest miR-155-5p upregulation ameliorates myocardial insulin resistance via mTOR signaling in vitro, and miR-155-5p downregulation attenuates myocardial insulin resistance, which might become a potential therapeutic target for alcohol-induced cardiomyopathy.

12-Lipoxygenase Inhibition on Microalbuminuria in Type-1 and Type-2 Diabetes Is Associated with Changes of Glomerular Angiotensin II Type 1 Receptor Related to Insulin Resistance.

(1) BACKGROUND: 12-lipoxygenase (12-LO) is involved in the development of diabetic nephropathy (DN). In the present study, we investigated whether 12-LO inhibition may ameliorate type-2 DN (T2DN) by interfering with insulin resistance (IR); (2) METHODS: Rat glomerular mesangial cells, glomeruli and skeletal muscles were isolated and used in this study. Kidney histological changes were confirmed by periodic-acid Schiff staining; mRNA expression was detected by competitive reverse transcription polymerase chain reaction; and the protein level was determined by Western blot and the enzyme-linked immunosorbent assay, respectively; (3) RESULTS: The inhibition of 12-LO attenuated microalbuminuria (MAU) increases in type-2 diabetic rats, but not in type-1 diabetic rats. Infusion of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) significantly increased the expression of angiotensin II (Ang II) and Ang II type 1 receptor (AT1R), but decreased the expression of AT1R-associated protein (ATRAP) in rat glomeruli, compared to the control. An in vitro study revealed that both 12(S)-HETE and insulin upregulated AT1R expression in rat mesangial cells. In the presence of p38 mitogen-activated protein kinase (MAPK) inhibitor, SB202190, the 12(S)-HETE-induced ATRAP reduction was significantly abolished. Interestingly, 12-LO inhibition did not influence AT1R expression in type-1 diabetic rats, but significantly abolished the increased AT1R and Ang II expression in glomeruli of type-2 diabetic rats. Furthermore, the inhibition of 12-LO significantly corrected impaired insulin sensitivity and fast serum insulin level, as well as the p-AMP-activated protein kinase (AMPK) reduction in skeletal muscle of type-2 diabetic rats; (4) CONCLUSION: The inhibition of 12-LO potentially ameliorated MAU by preventing IR through the downregulation of glomerular AT1R expression in T2DN.

Effect of angiotensin II type 1 receptor blocker on 12-lipoxygenase activity and slit diaphragm protein expression in type 2 diabetic rat glomeruli.

BACKGROUND: The 12-lipoxygenase (12-LO) and angiotensin II (Ang II) interaction plays an important role in diabetic nephropathy (DN). Proteinuria in DN is associated with decreased slit diaphragm proteins including nephrin and P-cadherin. Therefore, we investigated whether Ang II type 1 receptor (AT1) blocker (ARB) regulates 12-LO activity and slit diaphragm protein expression in diabetic rat glomeruli. METHOD: Glomeruli were isolated with the sieving method, and classified into small glomeruli (SG; 75-µm sieve) and large glomeruli (LG; 125-µm sieve). RESULTS: 12(S)-HETE, a lipid product of 12-LO, was increased by Ang II in the glomeruli. Infusion of 12(S)-HETE and Ang II significantly decreased nephrin expression in LG, but increased it in SG compared to control. Glomerular P-cadherin expression was reduced after Ang II and 12(S)-HETE treatment without differences between LG and SG. ARB did not influence glycemic levels but completely abolished the increases in 12(S)-HETE, AT1 expression, and proteinuria in diabetic rats. Nephrin expression was significantly reduced in LG but increased in SG in diabetic rats compared to control. P-cadherin expression decreased in both diabetic LG and SG. The abnormalities of nephrin and P-cadherin were partially but significantly reversed by ARB. CONCLUSION: ARB potentially ameliorates DN via the up-regulation of glomerular nephrin and P-cadherin expression through the inhibition of 12-LO activation in the glomeruli of rats with DN.

Morphological structure of the infraorbital canal using three-dimensional reconstruction.

Our study aim was to evaluate the initial position accurately and the direction of infraorbital canal approximately by analyzing the parameters of infraorbital canal. This study was based on 64-slice computed tomographic multiple planar reconstruction technique and can improve the success rate of infraorbital nerve blockade. The following observations and measurements were carried out in 224 normal infraorbital canals (112 people): the length, angle, and adjoined relations of initial infraorbital canal, to reveal the anatomic characteristics of the canals and to compare the difference between left and right or male and female. Six indicators were measured: (1) the length of initial infraorbital canal; (2) the distance between skin and the first obvious turn of infraorbital canal along the direction of initial infraorbital canal (the depth of puncture); (3) the vertical distance between infraorbital canal and nasal septum; (4) the vertical distance between infraorbital canal and infraorbital rim; (5) the angle between the infraorbital canal and the Frankfort plane; and (6) the angle between the infraorbital canal and the sagittal plane. The difference was statistically significant between 2 sides on the depth of puncture. For other values, the differences between left and right and between women and men were of no statistical significance.

Measurement of jugular foramen to the adjacent structures with thin-section computed tomographic image.

This study aimed to measure the bilateral internal aperture of the jugular foramen to internal acoustic pore, bilateral external aperture of the jugular foramen to occipital condyle, and atlas transverse process, so as to provide imaging evidence for different ways of clinical operation and smoothen the operation by protecting important nerves and blood vessels in this area. We scan 120 volunteers' skulls on computed tomography who had no skull base lesions. High-resolution spiral computed tomography multiplane reformation is used to rebuild the three-dimensional reconstruction of the brain. The difference of our study from others is that we select some specific sections to make the measurement more accurately.