The outcome and related risk factors of unvaccinated patients with end-stage kidney disease during the Omicron pandemic: a multicentre retrospective study.

OBJECTIVES: The study aims to identify the outcome and the related factors of unvaccinated patients with end-stage kidney disease during the Omicron pandemic. DESIGN: A multicentre retrospective study of patients with end-stage kidney disease undergone maintenance haemodialysis (HD) in China. SETTING: 6 HD centres in China. PARTICIPANTS: A total of 654 HD patients who tested positive for SARS-CoV-2 were ultimately included in the study. OUTCOME MEASURES: The primary outcomes of interest were adverse outcomes, including hospitalisation due to COVID-19 and all-cause mortality. RESULTS: The average age of the patients was 57 years, with 33.6% of them being over 65 years. Among the patients, 57.5% were male. During the follow-up period, 158 patients (24.2%) experienced adverse outcomes, and 93 patients (14.2%) died. The majority of patients (88/158) developed adverse outcomes within 30 days, and most deaths (77/93) occurred within 1 month. An advanced multivariable Cox regression analysis identified that adverse outcomes were associated with various factors while all-cause mortality was related to advanced age, male gender, high levels of C reactive protein (CRP) and low levels of prealbumin. The Kaplan-Meier curves demonstrated significantly higher all-cause mortality rates in the older, male, high CRP and low prealbumin subgroups. CONCLUSIONS: Among unvaccinated HD patients with confirmed Omicron infections, various factors were found to be linked to adverse outcomes. Notably, age, sex, CRP and prealbumin had a substantial impact on the risk of all-cause mortality.

Bone morphogenetic protein 10 and atrial fibrillation.

Background: The association between bone morphogenetic protein 10 (BMP10) and atrial fibrillation (AF) has been widely investigated by observational studies, but their causal relationships remain inconclusive. Here, we aimed to evaluate the causal effect of BMP10 on the risk of AF through single-nucleotide polymorphisms. Methods: A Mendelian randomization (MR) analytic framework was applied to data from two BMP10-specific genome-wide association studies comprising a total of 11,036,163 single-nucleotide polymorphisms of European ancestry. Instrument genetic variants associated with BMP10 were selected. A total of 12 AF-specific genome-wide association studies comprising a total of 5,095,117 European participants were included. Summary statistic-based methods of inverse variance weighted, MR Egger, weighted median, simple mode, and weighted mode methods were used. Pleiotropy and sensitivity were assessed. Results: Specific to AF-specific genome-wide association studies, we found that BMP10 was not associated with AF among different methods (all P > 0.05). We further identified no significant horizontal pleiotropy (all P > 0.05) and no fundamental impact among various data. Conclusions: This large-scale population study upon data from BMP10- and AF-specific genome-wide association studies and a longitudinal biobank cohort indicates plausible non-causal associations between BMP10 and AF in the European populations. Further studies regarding ancestral diversity are warranted to validate such causal associations.

A Case of High-Altitude Renal Syndrome.

Wang, Si-Yang, Jun Liang, and Jing-Hong Zhao. A Case of High-Altitude Renal Syndrome. High Alt Med Biol. 00:000-000, 2024.-Epidemiological studies have confirmed that high-altitude exposure increases the risk of proteinuria. The concept of high-altitude renal syndrome (HARS) was proposed in 2011. HARS is a group of clinical syndromes consisting of high-altitude polycythemia, hyperuricemia, systemic hypertension, and microalbuminuria. At present, no standardized and unified treatment methods of HARS have been proposed. We report a case of HARS without other organ involvement in a young man exposed to high altitude. Decreasing the red blood cell count and hemodynamic changes as soon as possible may be of great importance for reducing proteinuria. In addition, angiotensin receptor blockers are effective in the treatment of HARS.

Apoptosis-resistant megakaryocytes produce large and hyperreactive platelets in response to radiation injury.

BACKGROUND: The essential roles of platelets in thrombosis have been well recognized. Unexpectedly, thrombosis is prevalent during thrombocytopenia induced by cytotoxicity of biological, physical and chemical origins, which could be suffered by military personnel and civilians during chemical, biological, radioactive, and nuclear events. Especially, thrombosis is considered a major cause of mortality from radiation injury-induced thrombocytopenia, while the underlying pathogenic mechanism remains elusive. METHODS: A mouse model of radiation injury-induced thrombocytopenia was built by exposing mice to a sublethal dose of ionizing radiation (IR). The phenotypic and functional changes of platelets and megakaryocytes (MKs) were determined by a comprehensive set of in vitro and in vivo assays, including flow cytometry, flow chamber, histopathology, Western blotting, and chromatin immunoprecipitation, in combination with transcriptomic analysis. The molecular mechanism was investigated both in vitro and in vivo, and was consolidated using MK-specific knockout mice. The translational potential was evaluated using a human MK cell line and several pharmacological inhibitors. RESULTS: In contrast to primitive MKs, mature MKs (mMKs) are intrinsically programmed to be apoptosis-resistant through reprogramming the Bcl-xL-BAX/BAK axis. Interestingly, mMKs undergo minority mitochondrial outer membrane permeabilization (MOMP) post IR, resulting in the activation of the cyclic GMP-AMP synthase-stimulator of IFN genes (cGAS-STING) pathway via the release of mitochondrial DNA. The subsequent interferon-ß (IFN-ß) response in mMKs upregulates a GTPase guanylate-binding protein 2 (GBP2) to produce large and hyperreactive platelets that favor thrombosis. Further, we unmask that autophagy restrains minority MOMP in mMKs post IR. CONCLUSIONS: Our study identifies that megakaryocytic mitochondria-cGAS/STING-IFN-ß-GBP2 axis serves as a fundamental checkpoint that instructs the size and function of platelets upon radiation injury and can be harnessed to treat platelet pathologies.

Guided vs. conventional anti-platelet therapy for patients with acute coronary syndrome: A meta-analysis of randomized controlled trials.

Background: Whether guided antiplatelet therapy in patients with acute coronary syndrome (ACS) is effective in improving net clinical benefits compared with conventional antiplatelet therapy remains controversial. Therefore, we assessed the safety and efficacy of guided antiplatelet therapy in patients with ACS and undergoing percutaneous coronary intervention. Method: We searched PubMed, EMBASE, and Cochrane Library databases to select the relevant randomized controlled trials comparing the guided and conventional antiplatelet therapy in patients with ACS. The primary and safety outcomes are major adverse cardiovascular events (MACE) and major bleeding, respectively. The efficacy outcomes included myocardial infarction, stent thrombosis, all-cause death, and cardiovascular death. We selected the relative risk (RR) and 95% confidence intervals (CIs) as effect size and calculated it using the Review Manager software. In addition, we evaluated the final results by trial sequential analysis (registered by PROSPERO, CRD 42020210912). Results: We selected seven randomized controlled trials and included 8,451 patients in this meta-analysis. Guided antiplatelet therapy can significantly reduce the risk of MACE (RR 0.64, 95% CI 0.54-0.76, P < 0.00001), myocardial infarction (RR 0.62, 95% CI 0.49-0.79, P = 0.0001), all-cause death (RR 0.61, 95% CI 0.44-0.85, P = 0.003), and cardiovascular death (RR 0.66, 0.49-0.90, P = 0.009). In addition, there is no significant difference between the two groups in stent thrombosis (RR 0.67, 95% CI 0.44-1.03, P = 0.07) and major bleeding (RR 0.86, 95% CI 0.65-1.13, P = 0.27). The subgroup analysis showed that the guided group based on genotype tests could bring benefits in MACE and myocardial infarction. Conclusions: The guided antiplatelet therapy is not only associated with a comparable risk of bleeding but also with a lower risk of MACE, myocardial infarction, all-cause death, cardiovascular death, and stent thrombosis than the conventional strategy in patients with ACS.

Effects of high altitude on renal physiology and kidney diseases.

The hypobaric and hypoxic conditions of high-altitude areas exert adverse effects on the respiratory, circulatory and nervous systems. The kidneys have an abundant blood supply (20%-25% of cardiac output) and high blood flow; thus, they are susceptible to the effects of hypoxia. However, the effects of acute and chronic exposure to high altitudes on renal physiology and pathology are not fully understood. Moreover, few studies have investigated the impact of high-altitude exposure on patients with chronic kidney disease or acute kidney injury. In this review, we summarized changes in renal physiology and renal pathology due to high-altitude exposure as well as the impact of high-altitude exposure on existing kidney diseases, with the aim of informing the prevention and treatment of kidney diseases at high altitudes.

A Chinese family of autosomal recessive polycystic kidney disease identified by whole exome sequencing.

BACKGROUND: Autosomal recessive polycystic kidney disease (ARPKD) is an autosomal recessive hepatorenal fibrocystic syndrome. The majority of ARPKD patients progress to end-stage renal disease. Precise molecular diagnosis of ARPKD has proven valuable for understanding its mechanism and selecting optimal therapy. METHODS: A Chinese family with ARPKD was recruited in current study. The clinical characteristics of ARPKD patient were collected from medical records and the potential responsible genes were studied by the whole exome sequencing (WES). Candidate pathogenic variants were validated by Sanger sequencing. RESULTS: Both renal manifestation and hepatobiliary phenotype were observed. WES revealed compound heterozygous mutations of polycystic kidney and hepatic disease 1 genes, NM_138694: c.751G>T, (p.Asp251Tyr) and c.3998_4004delACCTGAA (p.Asn1333Thr fs × 13), which were confirmed by Sanger sequencing. Moreover, the mutations in the proband and its affected sib were co-segregated with the phenotype. CONCLUSIONS: The novel mutation in polycystic kidney and hepatic disease 1 gene identified by WES might be molecular pathogenic basis of this disorder.

Pramipexole in peritoneal dialysis patients with restless legs syndrome (RLS): a protocol for a multicentre double-blind randomised controlled trial.

INTRODUCTION: Restless legs syndrome (RLS) is a common neurological sensorimotor disorder among patients with end stage renal disease. This clinical trial aimed to provide evidence on the efficacy and safety of pramipexole in patients with uremic RLS receiving peritoneal dialysis (PD). METHODS AND ANALYSIS: This is a 12-week, multicentre, randomised, double-blind, placebo-controlled clinical trial. In total, 104 patients with uremic RLS receiving PD will be enrolled from four hospitals and randomly assigned in a 1:1 ratio to either placebo or pramipexole. We will determine the efficacy of pramipexole in the improvement of International RLS Study Group Rating Scale as the primary outcome, while responder rates for other RLS scales at week 12, change from baseline to week 12 for psychological status, sleep disorder and quality of life and blood pressure represent the secondary outcomes. ETHICS AND DISSEMINATION: The study was approved by the ethics committees of Peking University First Hospital, Xinqiao hospital of Army Medical University, Cangzhou Center Hospital and Peking University Shenzhen Hospital. The results will be disseminated in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03817554.

Mesangial Cells and Renal Fibrosis.

The main cellular constituents in glomerular mesangium are mesangial cells, which account for approximately 30-40% of the total cells in the glomerulus. Together with the mesangial matrix, mesangial cells form the glomerular basement membrane (GBM) in the glomerulus, whose main function is to perform the filtration. Under the pathologic conditions, mesangial cells are activated, leading to hyperproliferation and excess extracellular matrix (ECM). Moreover, mesangial cells also secrete several kinds of inflammatory cytokines, adhesion molecules, chemokines, and enzymes, all of which participate in the process of renal glomerular fibrosis. During the past years, researchers have revealed the roles of mesangial cells and the associated signal pathways involved in renal fibrosis. In this section, we will discuss how mesangial cells are activated and its contributions to renal fibrosis, as well as the molecular mechanisms and novel anti-fibrotic agents. Full understanding of the contributions of mesangial cells to renal fibrosis will benefit the clinical drug developing.

Effect of Phosphatase and Tensin Homologue on Chromosome 10 on Angiotensin II-Mediated Proliferation, Collagen Synthesis, and Akt/P27 Signaling in Neonatal Rat Cardiac Fibroblasts.

Cardiac fibroblasts (CFs) play a key role in cardiac fibrosis by regulating the balance between extracellular matrix synthesis and breakdown. Although phosphatase and tensin homologue on chromosome 10 (PTEN) has been found to play an important role in cardiovascular disease, it is not clear whether PTEN is involved in functional regulation of CFs. In the present study, PTEN was overexpressed in neonatal rat CFs via recombinant adenovirus-mediated gene transfer. The effects of PTEN overexpression on cell-cycle progression and angiotensin II- (Ang II-) mediated regulation of collagen metabolism, synthesis of matrix metalloproteinases, and Akt/P27 signaling were investigated. Compared with uninfected cells and cells infected with green fluorescent protein-expressing adenovirus (Ad-GFP), cells infected with PTEN-expressing adenovirus (Ad-PTEN) significantly increased PTEN protein and mRNA levels in CFs (P < 0.05). The proportion of CFs in the G1/S cell-cycle phase was significantly higher for PTEN-overexpressing cells. In addition, Ad-PTEN decreased mRNA expression and the protein synthesis rate of collagen types I and III and antagonized Ang II-induced collagen synthesis. Overexpression of PTEN also decreased Ang II-induced matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) production as well as gelatinase activity. Moreover, Ad-PTEN decreased Akt expression and increased P27 expression independent of Ang II stimulation. These results suggest that PTEN could regulate its functional effects in neonatal rat CFs partially via the Akt/P27 signaling pathway.

[Smad7 instead of Smad6 blocks epithelial-mesenchymal transition induced by TGF-beta in human renal proximal tubule epithelial cells].

AIM: To investigate whether Smad6 and Smad7 can regulate TGF-beta-induced epithelial-mesenchymal transition in human renal proximal tubule epithelial cells. METHODS: Two recombinant adeno-associated viruses (AAV) expressing Smad6 and Smad7 genes were produced without helper virus and then they were delivered into human renal proximal tubule epithelial cells (HKCs). The cells were randomly divided into normal controls, TGF-beta1-treated group, Smad7-infected control, LacZ-infected control, TGF-beta1+Smad7 group or TGF-beta1+Smad6 group, and TGF-beta1 + LacZ group. 10 microg/L of TGF-beta1 was added into the cell culture at the time of 15 min, 30 min, 60 min, and 120 min and the third day. The levels of phospho-Smad2, alpha-smooth muscle actin (alpha-SMA) and E-cadherin proteins were measured by Western blot. The concentration of hydroxyproline excreted into the culture supernatant was determinated by ELISA. The morphological changes of the cells detected by inverted microscope. RESULTS: Compared with the cells in absence of TGF-beta1, the expression level of P-Smad2 in HKCs increased at 15 min, 30 min, 60 min, and 120 min with the TGF-beta1 stimulation. It reached peak at 30 min. TGF-beta1 treatment for 72 hours resulted in significant up-regulation of alpha-SMA protein expression and hydroxyproline secretion, but a marked decrease in E-cadherin expression in the culture of HKCs. 10 microg/L of TGF-beta1 treatment for 72 hours also resulted in marked alteration in cell morphology. The cells lost their regular cuboidal appearance, and become elongated and spindle shaped. In the Smad7-infected cells, the overexpression of Smad7 resulted in a marked decrease of alpha-SMA protein and hydroxyproline synthesis, but a increase of E-cadherin protein, as well as the retainment of epithelial phenotypic appearance. These effects were associated with the inhibition of TGF-induced Smad2 activation, whereas the overexpression of Smad6 had no effect on the TGF-beta-induced changes in HKCs. CONCLUSION: The overexpression of Smad7 instead of Smad6 can efficiently inhibit TGF-beta-induced epithelial-mesenchymal transition by blocking Smad2 activation in human renal proximal tubule epithelial cells.

[Construction and expression of adeno-associated virus vectors of Smad 6 and Smad 7 genes in human renal tubule epithelial cells].

AIM: To construct the adeno-associated virus(AAV) vectors of Smad 6 and Smad 7 genes and observe their expressions in human renal tubule epithelial cells. METHODS: The plasmids pcDNA3-Smad 6/flag and pcDNA3-Smad 7/flag were digested with BamH I and Xho I. Then the Smad 6/flag and Smad 7/flag gene fragments were cloned into plasmid pAAV-MCS, respectively to construct the recombinant pAAV-Smad 6/flag and pAAV-Smad 7/flag plasmids. The recombinant expression plasmid or pAAV-LacZ plasmid were co-transfected into the HEK 293 cells with pHelper and pAAV-RC by calcium-phosphate precipitation method. Recombinant AAV-2 viral particles were prepared from infected HEK293 cells and then were used to infect human renal tubule epithelial cells (HKCs), The expressions of Smad 6 and Smad 7 in HKCs were demonstrated by immunocytochemical staining. RESULTS: The recombinant AAV vectors of Smad 6 or Smad 7 genes were constructed and expressed in the HKCs successfully. CONCLUSION: These results indicate that AAV can deliver Smad 6 and Smad 7 genes to renal cells in-vitro, suggesting the recombinant AAV can be used for gene therapy of renal fibrosis.