Comprehensive Analysis of Fatty Acid Metabolism in Diabetic Nephropathy from the Perspective of Immune Landscapes, Diagnosis and Precise Therapy.

Objective: Diabetic nephropathy (DN) represents the principal cause of end-stage renal diseases worldwide, lacking effective therapies. Fatty acid (FA) serves as the primary energy source in the kidney and its dysregulation is frequently observed in DN. Nevertheless, the roles of FA metabolism in the occurrence and progression of DN have not been fully elucidated. Methods: Three DN datasets (GSE96804/GSE30528/GSE104948) were obtained and combined. Differentially expressed FA metabolism-related genes were identified and subjected to DN classification using "ConsensusClusterPlus". DN subtypes-associated modules were discovered by "WGCNA", and module genes underwent functional enrichment analysis. The immune landscapes and potential drugs were analyzed using "CIBERSORT" and "CMAP", respectively. Candidate diagnostic biomarkers of DN were screened using machine learning algorithms. A prediction model was constructed, and the performance was assessed using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). The online tool "Nephroseq v5" was conducted to reveal the clinical significance of the candidate diagnostic biomarkers in patients with DN. A DN mouse model was established to verify the biomarkers' expression. Results: According to 39 dysregulated FA metabolism-related genes, DN samples were divided into two molecular subtypes. Patients in Cluster B exhibited worse outcomes with a different immune landscape compared with those in Cluster A. Ten potential small-molecular drugs were predicted to treat DN in Cluster B. The diagnostic model based on PRKAR2B/ANXA1 was created with ideal predictive values in early and advanced stages of DN. The correlation analysis revealed significant association between PRKAR2B/ANXA1 and clinical characteristics. The DN mouse model validated the expression patterns of PRKAR2B/ANXA1. Conclusion: Our study provides new insights into the role of FA metabolism in the classification, immunological pathogenesis, early diagnosis, and precise therapy of DN.

Telbivudine-induced rhabdomyolysis in a patient undergoing haemodialysis: A case report and review of literature.

Herein, we describe a case of acute rhabdomyolysis in a man in his early 50s undergoing haemodialysis and receiving the antiviral drug, telbivudine, for chronic hepatitis B virus (HBV) infection. Following diagnosis by electromyography (EMG), magnetic resonance image (MRI) scans and laboratory data (i.e., elevated serum creatinine kinase (CK) and myoglobin) telbivudine was discontinued and the patient was treated with methylprednisolone. While his CK and myoglobin levels decreased rapidly, his muscle weakness and pain improved slowly. Learning points include: patients undergoing haemodialysis and concomitantly receiving antiviral treatment for HBV, should have their serum levels of CK and myoglobin monitored regularly; treatment with corticosteroids maybe required; relief from rhabdomyolysis-induced muscle weakness and pain may be slow due to nerve fibre damage.

Inhibition of Fatty Acid ß-Oxidation by Fatty Acid Binding Protein 4 Induces Ferroptosis in HK2 Cells Under High Glucose Conditions.

BACKGRUOUND: Ferroptosis, which is caused by an iron-dependent accumulation of lipid hydroperoxides, is a type of cell death linked to diabetic kidney disease (DKD). Previous research has shown that fatty acid binding protein 4 (FABP4) is involved in the regulation of ferroptosis in diabetic retinopathy. The present study was constructed to explore the role of FABP4 in the regulation of ferroptosis in DKD. METHODS: We first detected the expression of FABP4 and proteins related to ferroptosis in renal biopsies of patients with DKD. Then, we used a FABP4 inhibitor and small interfering RNA to investigate the role of FABP4 in ferroptosis induced by high glucose in human renal proximal tubular epithelial (HG-HK2) cells. RESULTS: In kidney biopsies of DKD patients, the expression of FABP4 was elevated, whereas carnitine palmitoyltransferase-1A (CP-T1A), glutathione peroxidase 4, ferritin heavy chain, and ferritin light chain showed reduced expression. In HG-HK2 cells, the induction of ferroptosis was accompanied by an increase in FABP4. Inhibition of FABP4 in HG-HK2 cells changed the redox state, sup-pressing the production of reactive oxygen species, ferrous iron (Fe2+), and malondialdehyde, increasing superoxide dismutase, and reversing ferroptosis-associated mitochondrial damage. The inhibition of FABP4 also increased the expression of CPT1A, reversed lipid deposition, and restored impaired fatty acid ß-oxidation. In addition, the inhibition of CPT1A could induce ferroptosis in HK2 cells. CONCLUSION: Our results suggest that FABP4 mediates ferroptosis in HG-HK2 cells by inhibiting fatty acid ß-oxidation.

Analysis of Pyroptosis-Related Immune Signatures and Identification of Pyroptosis-Related LncRNA Prognostic Signature in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is a common urinary system malignant tumor with a high incidence and recurrence rate. Pyroptosis is a kind of programmed cell death caused by inflammasomes. More and more evidence had confirmed that pyroptosis plays a very significant part in cancer, and it is controversial whether pyroptosis promotes or inhibits tumors. Consistently, its potential role in ccRCC treatment efficacy and prognosis remains unclear. In this study, we systematically investigated the role of pyroptosis in the ccRCC samples from The Cancer Genome Atlas (TCGA) database. Based on the differentially expressed pyroptosis-related genes (DEPRGs), we identified three pyroptosis subtypes with different clinical outcomes, immune signatures, and responses to immunotherapy. Gene set variation analysis (GSVA), Gene Ontology (GO) analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that pyroptosis activation meant infiltration of more immune cells that is conducive to tumor progression. To further investigate the immunomodulatory effect of pyroptosis in ccRCC, we constructed a pyroptosis-score based on the common differential prognostic genes of the three pyroptosis subtypes. It was found that patients with high pyroptosis-score were in an unfavorable immune environment and the prognosis was worse. Gene set enrichment analysis suggested that immune-related biological processes were activated in the high pyroptosis-score group. Then, the least absolute shrinkage and selection operator (LASSO) Cox regression was implemented for constructing a prognostic model of eight pyroptosis-related long noncoding RNAs (PRlncRNAs) in the TCGA dataset, and the outcomes revealed that, compared with the low-risk group, the model-based high-risk group was intently associated with poor overall survival (OS). We further explored the relationship between high- and low-risk groups with tumor microenvironment (TME), immune infiltration, and drug therapy. Finally, we constructed and confirmed a robust and reliable PRlncRNA pairs prediction model of ccRCC, identified PRlncRNA, and verified it by experiments. Our findings suggested the potential role of pyroptosis in ccRCC, offering new insights into the prognosis of ccRCC and guiding effectual targeted therapy and immunotherapy.

ZIP14 is involved in iron deposition and triggers ferroptosis in diabetic nephropathy.

Ferroptosis is caused by lipid peroxidation and iron accumulation and can cause cell death. Abnormally expressed iron transporters are involved in ferroptosis in a variety of diseases. ZRT/IRT-like protein 14 (ZIP14) is a transport protein that can mediate cellular uptake of iron, zinc, and manganese. Herein, we have tested the hypothesis that the divalent metal transporter ZIP14 is involved in the initiation of ferroptosis in diabetic nephropathy (DN). DN was induced in 8-week-old male rats by streptozotocin before analysis of the degree of renal tubular injury. In addition, an in vitro model of DN in human kidney proximal tubular cell line was used. We showed that ZIP14 was up-regulated and ferrous iron (Fe2+) levels increased both in vivo and in vitro. Expression of glutathione peroxidase 4 and the level of glutathione were reduced, whereas that of malondialdehyde (MDA) increased. Ferrostatin-1 (Fer-1) treatment reduced the expression of ZIP14 and the levels of Fe2+ and MDA, which is consistent with ferroptosis. Fer-1 improved kidney function in DN rats. This was characterized by urine levels of protein-to-creatinine ratio, α1-microglobulin, and N-acetyl-ß-D-glucosaminidase. Our study demonstrates a novel role for ZIP14 in diabetic kidney injury mediated by ferroptosis, and suggests a potential new therapeutic approach for the treatment of diabetic nephropathy.

Punicalagin Inhibited Inflammation and Migration of Fibroblast-Like Synoviocytes Through NF-κB Pathway in the Experimental Study of Rheumatoid Arthritis.

BACKGROUND: The aggressive phenotype of fibroblast-like synoviocytes (FLSs) is essential in the synovitis and bone destruction in rheumatoid arthritis (RA). Punicalagin is a natural polyphenol extracted in pomegranate juice, which possesses antioxidant, anti-inflammatory and anti-tumor properties suggesting it may be a potent drug for RA therapy. However, there is paucity of information on its effect in RA. OBJECTIVE: To investigate the effects of punicalagin on synovial inflammation and bone destruction in RA. METHODS: FLSs were isolated from synovial tissue of RA patients. The mRNA levels were evaluated by quantitative real-time PCR. Western blot was used for protein level measurements. The secretion of pro-inflammatory cytokines and metalloproteinases (MMPs) was detected by ELISA assays. Edu staining assays were carried out to investigate the proliferation of FLSs. Cell migration was assessed by Boyden chambers, wound scratch assays and F-actin staining in vitro. The intracellular translocation of nuclear factor kappa B (NF-κB) was investigated using immunofluorescence. The effects of punicalagin in vivo were measured by using collagen-induced arthritis (CIA) mice. RESULTS: Punicalagin treatments significantly reduced the TNF-α induced expressions of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8 and IL-17A) and MMPs (MMP-1 and MMP-13) of RA FLSs. Punicalagin also suppressed the proliferation and migration of RA FLSs. Moreover, punicalagin (50mg/kg/d) alleviated arthritis severity and bone destruction, and decreased serum IL-6 and TNF-α in CIA mice. Further mechanism studies indicated that punicalagin blocked NF-κB activation via suppressing phosphorylation of IKK and IkBα, and preventing the translocation of 65. CONCLUSION: Our findings suggested that punicalagin might be one of natural therapeutic compounds for relieving RA progress via suppressing FLSs inflammation and migration through modulating NF-κB pathways.

Serum prealbumin is a predictive biomarker for stroke-associated infection after an ischemic stroke.

BACKGROUND: Several prior studies have linked serum prealbumin (PA) as a predictor for perioperative infection. However, whether peripheral blood PA levels can be used as an indicator of stroke-associated infection (SAI) is still unclear. In this study, we attempt to find whether serum PA is a meaningful predictor in SAI after an ischemic stroke, so as to provide theoretical basis for clinical treatment. METHODS: Consecutive patients with acute ischemic stroke who were admitted to our hospital were enrolled and serum PA was collected. A prospective study was conducted to observe the predictive value of PA in the SAI incident in ischemic stroke patients. RESULTS: Of 104 patients, 29 (27.9%) developed an SAI after 7 d of follow-up. The stroke with SAI group had significantly lower PA levels than the stroke without SAI group ( p < 0.05). The optimal cutoff value for predicting SAI was PA ≤ 191 mg/L, with sensitivity and specificity of 58.62% and 81.33%, respectively. Kaplan-Meier survival analysis showed that stroke patients with low serum PA level (PA ≤ 191 mg/L) had a higher SAI rates (log-rank test, χ2 = 16.870, p < 0.001). Cox regression analysis showed that PA ≤ 191 mg/L (hazard ratio = 3.207; 95% CI, 1.430-7.190, p = 0.005) was an independent risk factor for SAI. CONCLUSIONS: Early detection of serum PA during the acute phase of ischemic stroke may help us to identify at-risk SAI patients, and hence rapidly guide the intervention to prevent SAI.