SMN haploinsufficiency promotes ischemia/ reperfusion-induced AKI-to-CKD transition by endoplasmic reticulum stress activation.

Acute kidney injury (AKI) and chronic kidney disease (CKD) are interconnected syndromes that represent a global public health challenge. Here, we identified a specific role of survival of motor neuron (SMN) in ischemia/reperfusion (I/R)-induced kidney injury and progression of CKD. SMN was an essential protein in all cell type and was reported to play important roles in multiple fundamental cellular homeostatic pathways. However, the function of SMN in experimental models of I/R-induced kidney fibrosis has not extensively studied. Genetic ablation of SMN or small interfering RNA-base knockdown of SMN expression aggravated the tubular injury and interstitial fibrosis. Administration of scAAV9-CB-SMN or epithelial cell overexpression of SMN reduced I/R-induced kidney dysfunction and attenuated AKI-to-CKD transition, indicating that SMN is vital for the preservation and recovery of tubular phenotype. Our data showed that the endoplasmic reticulum stress (ERS) induced by I/R was persistent and became progressively more severe in the kidney without SMN. On the contrary, overexpression of SMN prevented against I/R-induced ERS and tubular cell damage. In summary, our data collectively substantiate a critical role of SMN in regulating the ERS activation and phenotype of AKI-to-CKD transition that may contribute to renal pathology during injury and repair.

Empagliflozin alleviates myocardial I/R injury and cardiomyocyte apoptosis via inhibiting ER stress-induced autophagy and the PERK/ATF4/Beclin1 pathway.

To explore the mechanisms underlying the specific inhibitor targeting SGLT-2 empagliflozin in alleviating myocardial ischaemia-reperfusion (I/R) injury. A mouse model of I/R injury and H2O2-induced H9C2 cell model were established. The expressions of Bcl-2, Bax, LC3, Beclin1, GRP78, CHOP, PERK, ATF4, ATF6, IREα and P62 were examined by western blot, immunofluorescence or immunohistochemistry staining, respectively. The cardiac function was measured by echocardiography, TCC staining, lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) activity. Cell apoptosis was analysed by TUNEL, Annexin V/propidium iodide (PI) staining and caspase 3 and 9 activities. CCK-8 assay was used for analysing cell viability. PBA, TUDC and 3-MA were utilised for blocking ER stress and autophagy, respectively. Empagliflozin suppressed myocardial I/R injury in vivo and H2O2-induced cardiomyocyte apoptosis in vitro. Blockade of ER stress and autophagy inhibited H2O2-induced cardiomyocyte apoptosis. ER stress activated autophagy through the PERK signalling in H2O2-treated H9C2 cells. Empagliflozin suppressed ER stress-induced autophagy by inhibiting the PERK/ATF4/Beclin1 signalling. H2O2 and I/R-induced cardiomyocyte apoptosis was restrained by empagliflozin through inhibition of ER stress-induced autophagy. Empagliflozin suppressed ER stress-induced autophagy via suppressing the PERK/ATF4/Beclin1 signalling, thus alleviating myocardial I/R injury and cardiomyocyte apoptosis.

Sangerbox: A comprehensive, interaction-friendly clinical bioinformatics analysis platform.

In recent decades, with the continuous development of high-throughput sequencing technology, data volume in medical research has increased, at the same time, almost all clinical researchers have their own independent omics data, which provided a better condition for data mining and a deeper understanding of gene functions. However, for these large amounts of data, many common and cutting-edge effective bioinformatics research methods still cannot be widely used. This has encouraged the establishment of many analytical platforms, a portion of databases or platforms were designed to solve the special analysis needs of users, for instance, MG RAST, IMG/M, Qiita, BIGSdb, and TRAPR were developed for specific omics research, and some databases or servers provide solutions for special problems solutions. Metascape was designed to only provide functional annotations of genes as well as function enrichment analysis; BioNumerics and RidomSeqSphere+ perform multilocus sequence typing; CARD provides only antimicrobial resistance annotations. Additionally, some web services are outdated, and inefficient interaction often fails to meet the needs of researchers, such as our previous versions of the platform. Therefore, the demand to complete massive data processing tasks urgently requires a comprehensive bioinformatics analysis platform. Hence, we have developed a website platform, Sangerbox 3.0 (http://vip.sangerbox.com/), a web-based tool platform. On a user-friendly interface that also supports differential analysis, the platform provides interactive customizable analysis tools, including various kinds of correlation analyses, pathway enrichment analysis, weighted correlation network analysis, and other common tools and functions, users only need to upload their own corresponding data into Sangerbox 3.0, select required parameters, submit, and wait for the results after the task has been completed. We have also established a new interactive plotting system that allows users to adjust the parameters in the image; moreover, optimized plotting performance enables users to adjust large-capacity vector maps on the web site. At the same time, we have integrated GEO, TCGA, ICGC, and other databases and processed data in batches, greatly reducing the difficulty to obtain data and improving the efficiency of bioimformatics study for users. Finally, we also provide users with rich sources of bioinformatics analysis courses, offering a platform for researchers to share and exchange knowledge.

Irg1-itaconate axis protects against acute kidney injury via activation of Nrf2.

Acute kidney injury (AKI) is a common clinical implication with increased tissue damage, uncontrolled immune responses, and risk of mortality, in which ischemia-reperfusion injury (IRI) is one of the leading causes. As critical role for metabolic remodeling in inflammation, Irg1-itaconate axis has received much attention for its immunomodulation in the control of the inflammation. However, its role in the AKI and IRI remains unknown. Here, we found that Irg1 expression was negatively correlated with the expression of inflammatory cytokines during ischemia-reperfusion injury. And Irg1 deficiency promotes renal inflammation and ischemia-reperfusion injury in vivo. Itaconate treatment promoted the survival of WT mice from lethal ischemia and protected against renal IRI and systemic inflammation. Mechanistically, dimethyl itaconate protected renal cells from oxidative stress and prevented macrophage activation by enhancing the translocation of Nrf2 into the nuclei. Our study highlighted the importance of the Irg1-itaconate axis in the protecting against ischemia-reperfusion injury and acute kidney injury, providing potential therapeutic targets to control AKI.

Compositional Dependence of Pore Structure, Strengthand Freezing-Thawing Resistance of Metakaolin-Based Geopolymers.

The understanding of the composition dependent properties and freezing-thawing (F-T) resistance of geopolymer materials is vital to their applications in cold regions. In this study, metakaolin-based geopolymer (MKG) mortars were fabricated by controlling the Si/Al ratio and the Na/Al ratio. The pore structure and strength were measured by mercury intrusion porosimetry and compression tests, respectively, which both showed obvious correlations with the material composition. Mass loss, strength loss, visual rate, and microscopic observation were adopted to assess the changes of the material properties and microstructure caused by F-T loads. The results showed that the strength-porosity relationship roughly followed a linear plot. Increases of the Si/Al ratio increased the capillary pore volume, but decreased the gel pore volume and the F-T resistance. Increases of the Na/Al ratio decreased the gel pore, but roughly enhanced the F-T resistance. The MKG mortar at the Na/Al ratio of 1.26 showed the lowest total pore volume and the best F-T resistance. The mechanisms of our experimental observations were that the abundantly distributed air voids connected by the capillary pores facilitated the relaxation of hydraulic pressures induced by the freezing of the pore liquid. The findings of this work help better clarify the compositional dependence of the pore structure, strength, and freezing-thawing resistance of MKG materials and provide fundamental bases for their engineering applications in cold regions.

Boron-Doped PdCuAu Nanospine Assembly as an Efficient Electrocatalyst toward Formic Acid Oxidation.

Control of the composition and morphology of Pd-based electrocatalysts is a promising strategy for the development of efficient direct formic acid fuel cells. Herein, a two-step method is presented for the design of B-doped PdCuAu nanospine assemblies (B-PdCuAu NAs) using NaBH4 as the boron dopant. The boron content can be tailored easily by tuning the reaction time, and an optimal boron content is beneficial to promote the formic acid oxidation reaction. Such B-PdCuAu NAs exhibit superior mass and specific activities to commercial Pd black and PdCuAu NAs in alkaline solution. The excellent catalytic performance of B-PdCuAu NAs may arise from the increase in surface active sites and the electronic effect of boron modification. This work provides a facile synthesis of the B-doped metallic catalysts and highlights the boron modification in improving their performance as anode electrocatalysts for fuel cells.

Hollow PtPd Nanorods with Mesoporous Shells as an Efficient Electrocatalyst for the Methanol-Oxidation Reaction.

Tailoring the morphology and composition of platinum-based electrocatalysts is of significant importance for the development of highly efficient direct methanol fuel cells. Herein, we report a dual-templating method for the design of hollow PtPd nanorods with mesoporous shells (mPtPd HNRs). We found that F127 micelles favored the formation of mesoporous structures and that SiO2 nanorods served as a hard template for the creation of cavities. The well-developed mesopores, hollow structures, and bimetallic composition of the mPtPd HNRs afforded a sufficient number of active sites to facilitate the electrochemical oxidation of methanol, thereby leading to enhanced activity and stability. This strategy allowed for the reliable preparation of mesoporous hollow platinum-based electrocatalysts with desired compositions and morphologies for catalytic applications.

Survival Motor Neuron (SMN) Protein Insufficiency Exacerbates Renal Ischemia/Reperfusion Injury.

The survival of motor neuron (SMN) protein is ubiquitously involved in spliceosome assembly and ribonucleoprotein biogenesis. SMN protein is expressed in kidney and can affect cell death processes. However, the role of SMN in acute kidney injury (AKI) is largely unknown. In the current study, we found that the expression of SMN in the kidney was significantly reduced in both clinical ischemic AKI and a mouse model of renal ischemia-reperfusion injury (IRI). We then used SMN heterozygous knockout (SMN+/-) mice and found that the declines in renal function, tubular injury, and tubular cell apoptosis after experimental IRI were significantly more severe in SMN+/- mice than those in their wild-type littermates. Concomitantly, the canonical transcription factor nuclear factor-κb (NFκb) signaling was enhanced in ischemic SMN+/- mice. In vitro, cobalt dichloride (CoCl2) treatment reduced SMN expression in proximal tubular epithelial cells. In addition, CoCl2-induced apoptosis and activation of NFκb signaling pathway were enhanced by transient transfection of a small-interfering RNA (siRNA) against SMN while attenuated by transient transfection of a full-length SMN plasmid. Taken together, this study for the first time supported the protective role of SMN in ischemic AKI.

Trimetallic PtPdCo mesoporous nanopolyhedra with hollow cavities.

The rational design of metallic mesoporous nanoarchitectures with hollow cavities offers an effective way to boost their performance in various catalytic fields. Herein, we report a facile two-step strategy for the fabrication of trimetallic PtPdCo mesoporous nanopolyhedra with hollow cavities (PtPdCo MHNPs), in which Pd@PtPdCo core-shell mesoporous nanopolyhedra (Pd@PtPdCo MNPs) are directly prepared by a simple chemical reduction reaction followed by etching of the Pd cores. The PtPdCo MHNPs show enhanced electrocatalytic activity and durability for the methanol oxidation reaction, enabled by their mesoporous and hollow nanoarchitectures coupled with trimetallic compositions.

Direct fabrication of bi-metallic PdRu nanorod assemblies for electrochemical ammonia synthesis.

Electrochemical reduction of N2 represents a very attractive approach for sustainable NH3 production at environmental temperature and pressure. The design of highly branched Pd-based nanoarchitectonics is very important for the electrocatalytic N2 reduction reaction (NRR). Herein, we propose a very simple synthetic method for direct fabrication of unique bi-metallic PdRu nanorod assemblies (PdRu NRAs) with high yield in an aqueous solution. Owing to their branched shape together with bi-metallic compositions, the self-supported PdRu NRAs assembled with staggered nanorods show high catalytic activity and superior durability for the NRR. The presented direct synthetic strategy is very valuable for the design of active branched metallic catalysts for the NRR.

The role of galectin-3 in heart failure and cardiovascular disease.

Galectin-3, a ß-galactoside-binding lectin, is a new important player in the progression of heart failure (HF) and is also linked to poor outcome in patients with cardiovascular disease. Genetic or pharmacological inhibition of galectin-3 slows down the progression of myocardial inflammation, reduces collagen production, attenuates cardiac remodelling, and ameliorates cardiac function. In this review, we summarize recent progress in research on galectin-3 as a regulatory molecule involved in cardiovascular fibrosis in HF and its potential role in the diagnosis, risk assessment and treatment of cardiovascular diseases.

Correlation of neuroendocrine features with prognosis of non-small cell lung cancer.

The improvement in histological diagnostic tools, including neuroendocrine markers by immunohistochemistry (IHC), has led to increased recognition of non-small cell lung cancer (NSCLC) with neuroendocrine (NE) feature. However, little is known regarding the prevalence and clinical implications of NE feature in patients with NSCLC. In this study, we performed IHC in a tissue microarray containing 451 Chinese NSCLC cases, and analyzed correlation of the expression of neuroendocrine marker with pathological and clinical features of NSCLC. The result showed that NE feature in NSCLC was detectable in almost 30% of studied patients, and tumors with NE feature were significantly correlated with pathological classification, clinical stages and cell differentiation of NSCLC. Our data also revealed that NE feature indicated worse overall survival and disease free survival. Compared with mutant p53, NE markers showed more significance as for prognostic evaluation. Multi-factor COX analysis further suggested a potential clinical impact for NE feature as an independent indicator of poor prognosis for NSCLC patients.

Modulation of kidney urea transporter UT-A3 activity by alpha2,6-sialylation.

Two urea transporters, UT-A1 and UT-A3, are expressed in the kidney terminal inner medullary collecting duct (IMCD) and are important for the production of concentrated urine. UT-A1, as the largest isoform of all UT-A urea transporters, has gained much attention and been extensively studied; however, the role and the regulation of UT-A3 are less explored. In this study, we investigated UT-A3 regulation by glycosylation modification. A site-directed mutagenesis verified a single glycosylation site in UT-A3 at Asn279. Loss of the glycosylation reduced forskolin-stimulated UT-A3 cell membrane expression and urea transport activity. UT-A3 has two glycosylation forms, 45 and 65 kDa. Using sugar-specific binding lectins, the UT-A3 glycosylation profile was examined. The 45-kDa form was pulled down by lectin concanavalin A (Con A) and Galant husnivalis lectin (GNL), indicating an immature glycan with a high amount of mannose (Man), whereas the 65-kDa form is a mature glycan composed of acetylglucosamine (GlcNAc) and poly-N-acetyllactosame (poly-LacNAc) that was pulled down by wheat germ agglutinin (WGA) and tomato lectin, respectively. Interestingly, the mature form of UT-A3 glycan contains significant amounts of sialic acid. We explored the enzymes responsible for directing UT-A3 sialylation. Sialyltransferase ST6GalI, but not ST3GalIV, catabolizes UT-A3 α2,6-sialylation. Activation of protein kinase C (PKC) by PDB treatment promoted UT-A3 glycan sialylation and membrane surface expression. The PKC inhibitor chelerythrine blocks ST6GalI-induced UT-A3 sialylation. Increased sialylation by ST6GalI increased UT-A3 protein stability and urea transport activity. Collectively, our study reveals a novel mechanism of UT-A3 regulation by ST6GalI-mediated sialylation modification that may play an important role in kidney urea reabsorption and the urinary concentrating mechanism.

Doxazosin Stimulates Galectin-3 Expression and Collagen Synthesis in HL-1 Cardiomyocytes Independent of Protein Kinase C Pathway.

Doxazosin, a drug commonly prescribed for hypertension and prostate disease, increases heart failure risk. However, the underlying mechanism remains unclear. Galectin-3 is an important mediator that plays a pathogenic role in cardiac hypertrophy and heart failure. In the present study, we investigated whether doxazosin could stimulate galectin-3 expression and collagen synthesis in cultured HL-1 cardiomyocytes. We found that doxazosin dose-dependently induced galectin-3 protein expression, with a statistically significant increase in expression with a dose as low as 0.01 µM. Doxazosin upregulated collagen I and α-smooth muscle actin (α-SMA) protein levels and also induced apoptotic protein caspase-3 in HL-1 cardiomyocytes. Although we previously reported that activation of protein kinase C (PKC) stimulates galectin-3 expression, blocking the PKC pathway with the PKC inhibitor chelerythrine did not prevent doxazosin-induced galectin-3 and collagen expression. Consistently, doxazosin treatment did not alter total and phosphorylated PKC. These results suggest that doxazosin-stimulated galectin-3 is independent of PKC pathway. To determine if the α1-adrenergic pathway is involved, we pretreated the cells with the irreversible α-adrenergic receptor blocker phenoxybenzamine and found that doxazosin-stimulated galectin-3 and collagen expression was similar to controls, suggesting that doxazosin acts independently of α1-adrenergic receptor blockade. Collectively, we show a novel effect of doxazosin on cardiomycytes by stimulating heart fibrosis factor galectin-3 expression. The mechanism of action of doxazosin is not mediated through either activation of the PKC pathway or antagonism of α1-adrenergic receptors.

RNA-seq analysis of glycosylation related gene expression in STZ-induced diabetic rat kidney inner medulla.

UNLABELLED: The UT-A1 urea transporter is crucial to the kidney's ability to generate concentrated urine. Native UT-A1 from kidney inner medulla (IM) is a heavily glycosylated protein with two glycosylation forms of 97 and 117 kDa. In diabetes, UT-A1 protein abundance, particularly the 117 kD isoform, is significantly increased corresponding to an increased urea permeability in perfused IM collecting ducts, which plays an important role in preventing the osmotic diuresis caused by glucosuria. However, how the glycan carbohydrate structure change and the glycan related enzymes regulate kidney urea transport activity, particularly under diabetic condition, is largely unknown. In this study, using sugar-specific binding lectins, we found that the carbohydrate structure of UT-A1 is changed with increased amounts of sialic acid, fucose, and increased glycan branching under diabetic conditions. These changes were accompanied by altered UT-A1 association with the galectin proteins, ß-galactoside glycan binding proteins. To explore the molecular basis of the alterations of glycan structures, the highly sensitive next generation sequencing (NGS) technology, Illumina RNA-seq, was employed to analyze genes involved in the process of UT-A1 glycosylation using streptozotocin (STZ)-induced diabetic rat kidney. Differential gene expression analysis combining with quantitative PCR revealed that expression of a number of important glycosylation related genes were changed under diabetic conditions. These genes include the glycosyltransferase genes Mgat4a, the sialylation enzymes St3gal1 and St3gal4 and glycan binding protein galectin-3, -5, -8, and -9. In contrast, although highly expressed in kidney IM, the glycosyltransferase genes Mgat1, Mgat2, and fucosyltransferase Fut8, did not show any changes. CONCLUSIONS: In diabetes, not only is UT-A1 protein abundance increased but the protein's glycan structure is also significantly changed. UT-A1 protein becomes highly sialylated, fucosylated and branched. Consistently, a number of crucial glycosylation related genes are changed under diabetic conditions. The alteration of these genes may contribute to changes in the UT-A1 glycan structure and therefore modulate kidney urea transport activity and alleviate osmotic diuresis caused by glucosuria in diabetes.

Protein kinase C promotes cardiac fibrosis and heart failure by modulating galectin-3 expression.

Protein kinase C (PKC) and galectin-3 are two important mediators that play a key pathogenic role in cardiac hypertrophy and heart failure (HF). However, the molecular mechanisms and signaling pathways are not fully understood. In this study, we explored the relationship between and roles of PKC-α and galectin-3 in the development of HF. We found that activation of PKC by phorbol dibutyrate (PDB) increased galectin-3 expression by ~180%, as well as collagen I and fibronection accumulation in cultured HL-1 cardiomyocytes. Over-expression of galectin-3 in HL-1 cells increased collagen I protein production. Inhibition of galectin-3 by ß-lactose blocked PDB-induced galectin-3 and collagen production, indicating that galectin-3 mediates PKC-induced cardiac fibrosis. In rats subjected to pulmonary artery banding (PAB) to induce right ventricular HF, galectin-3 was increased by ~140% in the right ventricle and also by ~240% in left ventricle compared to control. The elevated galectin-3 is consistent with an increase of total and activated (phosphorylated) PKC-α, α-SMA and collagen I. Finally, we extended our findings to examine the role of angiotensin II (Ang II), which activates the PKC pathway and contributes to cardiac fibrosis and the development of HF. We found that Ang II activated the PKC-α pathway and increased galectin-3 expression and collagen production. This study provides a new insight into the molecular mechanisms of HF mediated by PKC-α and galectin-3. PKC-α promotes cardiac fibrosis and HF by stimulation of galectin-3 expression.