Calreticulin is important for the development of renal fibrosis and dysfunction in diabetic nephropathy

Calreticulin regulates hepatic stellate cell activation through modulating TGF-beta-induced Smad signaling

Liver fibrosis is characterized by excessive deposition of extracellular matrix (ECM) as a wound healing process. Activated hepatic stellate cells (HpSCs) are the major producer of the ECM and play a central role in liver fibrogenesis. It has been widely accepted that elimination of activated HpSCs or reversion to a quiescent state can be a feasible strategy for resolving the disease, further highlighting the urgent need for novel therapeutic targets. Calreticulin (CRT) is a molecular chaperone that normally resides in the endoplasmic reticulum (ER), important in protein folding and trafficking through the secretory pathway. CRT also plays a critical role in calcium (Ca2+) homeostasis, with its Ca2+ storage capacity. In the current study, we aimed to demonstrate its function in directing HpSC activation. In a mouse liver injury model, CRT was up-regulated in HpSCs. In cellular experiments, we further showed that this activation was through modulating the canonical TGF-β signaling. As down-regulation of CRT in HpSCs elevated intracellular Ca2+ levels through a form of Ca2+ influx, named store-operated Ca2+ entry (SOCE), we examined whether moderating SOCE affected TGF-β signaling. Interestingly, blocking SOCE had little effect on TGF-β-induced gene expression. In contrast, inhibition of ER Ca2+ release using the inositol trisphosphate receptor inhibitor 2-APB increased TGF-β signaling. Treatment with 2-APB did not alter SOCE but decreased intracellular Ca2+ at the basal level. Indeed, adjusting Ca2+ concentrations by EGTA or BAPTA-AM chelation further enhanced TGF-β-induced signaling. Our results suggest a crucial role of CRT in the liver fibrogenic process through modulating Ca2+ concentrations and TGF-β signaling in HpSCs, which may provide new information and help advance the current discoveries for liver fibrosis.

Calcium signaling crosstalk between the endoplasmic reticulum and mitochondria, a new drug development strategies of kidney diseases

Calcium (Ca2+) acts as a second messenger and constitutes a complex and large information exchange system between the endoplasmic reticulum (ER) and mitochondria; this process is involved in various life activities, such as energy metabolism, cell proliferation and apoptosis. Increasing evidence has suggested that alterations in Ca2+ crosstalk between the ER and mitochondria, including alterations in ER and mitochondrial Ca2+ channels and related Ca2+ regulatory proteins, such as sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), inositol 1,4,5-trisphosphate receptor (IP3R), and calnexin (CNX), are closely associated with the development of kidney disease. Therapies targeting intracellular Ca2+ signaling have emerged as an emerging field in the treatment of renal diseases. In this review, we focused on recent advances in Ca2+ signaling, ER and mitochondrial Ca2+ monitoring methods and Ca2+ homeostasis in the development of renal diseases and sought to identify new targets and insights for the treatment of renal diseases by targeting Ca2+ channels or related Ca2+ regulatory proteins.

Netrin G1 Ligand is a new stromal immunomodulator that promotes pancreatic cancer

Understanding pancreatic cancer biology is fundamental for identifying new targets and for developing more effective therapies. In particular, the contribution of the stromal microenvironment to pancreatic cancer tumorigenesis requires further exploration. Here, we report the stromal roles of the synaptic protein Netrin G1 Ligand (NGL-1) in pancreatic cancer, uncovering its pro-tumor functions in cancer-associated fibroblasts and in immune cells. We observed that the stromal expression of NGL-1 inversely correlated with patients' overall survival. Moreover, germline knockout (KO) mice for NGL-1 presented decreased tumor burden, with a microenvironment that is less supportive of tumor growth. Of note, tumors from NGL-1 KO mice produced less immunosuppressive cytokines and displayed an increased percentage of CD8 + T cells than those from control mice, while preserving the physical structure of the tumor microenvironment. These effects were shown to be mediated by NGL-1 in both immune cells and in the local stroma, in a TGF-β-dependent manner. While myeloid cells lacking NGL-1 decreased the production of immunosuppressive cytokines, NGL-1 KO T cells showed increased proliferation rates and overall polyfunctionality compared to control T cells. CAFs lacking NGL-1 were less immunosuppressive than controls, with overall decreased production of pro-tumor cytokines and compromised ability to inhibit CD8 + T cells activation. Mechanistically, these CAFs downregulated components of the TGF-β pathway, AP-1 and NFAT transcription factor families, resulting in a less tumor-supportive phenotype. Finally, targeting NGL-1 genetically or using a functionally antagonistic small peptide phenocopied the effects of chemotherapy, while modulating the immunosuppressive tumor microenvironment (TME), rather than eliminating it. We propose NGL-1 as a new local stroma and immunomodulatory molecule, with pro-tumor roles in pancreatic cancer.

Statement of Significance

Here we uncovered the pro-tumor roles of the synaptic protein NGL-1 in the tumor microenvironment of pancreatic cancer, defining a new target that simultaneously modulates tumor cell, fibroblast, and immune cell functions. This study reports a new pathway where NGL-1 controls TGF-β, AP-1 transcription factor members and NFAT1, modulating the immunosuppressive microenvironment in pancreatic cancer. Our findings highlight NGL-1 as a new stromal immunomodulator in pancreatic cancer.

Exercise alleviates renal interstitial fibrosis by ameliorating the Sirt1-mediated TGF-β1/Smad3 pathway in T2DM mice

Background

Renal interstitial fibrosis is the pathophysiological basis of type 2 diabetes mellitus (T2DM). Exercise appears to improve kidney interstitial fibrosis in T2DM, in which silent information regulator factor 2-related enzyme 1 (Sirt1) is a critical regulator. However, the role of Sirt1 in mediating exercise on renal tissue as well as its mechanism remains unknown.

Methods

T2DM mouse models were created using a high-fat diet mixed with streptozotocin, followed by 8 weeks of treadmill exercise and niacinamide (Sirt1 inhibitor) intervention. Kits for detecting biochemical indices of renal function were used. The pathological appearance and severity of renal tissue were examined using hematoxylin and eosin, Masson and immunohistochemical staining. The mRNA and protein expression of relevant signaling pathway factors were determined to use real-time reverse transcriptase-polymerase chain reaction and western blotting.

Results

T2DM can promote renal interstitial fibrosis, increase kidney index, serum creatinine, blood urea nitrogen and 24 h urinary total protein and cause pathological changes in renal tissue and affect renal function. After 8 weeks of exercise intervention, the biochemical indicators in the kidney of T2DM mice were decreased, Sirt1 expression was increased, the expression of TGF-β1, Smad3, collagen type I (COL1) and collagen type III (COL3) were decreased, and the renal interstitial fibrosis, renal tissue structural lesions and renal function were improved. However, after the nicotinamide intervention, renal interstitial fibrosis of T2DM mice was aggravated, and the improvement effect of exercise on renal interstitial fibrosis of T2DM mice was abolished.

Conclusion

The upregulation of Sirt1 expression by exercise can inhibit the transforming growth factor β1/Smad3 pathway, thereby inhibiting the expression and deposition of COL1 and COL3 in renal interstitium, thereby improving renal interstitial fibrosis in T2DM.

Identification and clinical validation of the role of anoikis-related genes in diabetic foot

This study aims to investigate the role of anoikis-related genes in diabetic foot (DF) by utilizing bioinformatics analysis to identify key genes associated with anoikis in DF. We selected the GEO datasets GSE7014, GSE80178 and GSE68183 for the extraction and analysis of differentially expressed anoikis-related genes (DE-ARGs). GO analysis and KEGG analysis indicated that DE-ARGs in DF were primarily enriched in apoptosis, positive regulation of MAPK cascade, anoikis, focal adhesion and the PI3K-Akt signalling pathway. Based on the LASSO and SVM-RFE algorithms, we identified six characteristic genes. ROC curve analysis revealed that these six characteristic genes had an area under the curve (AUC) greater than 0.7, indicating good diagnostic efficacy. Expression analysis in the validation set revealed downregulation of CALR in DF, consistent with the training set results. GSEA results demonstrated that CALR was mainly enriched in blood vessel morphogenesis, endothelial cell migration, ECM-receptor interaction and focal adhesion. The HPA database revealed that CALR was moderately enriched in endothelial cells, and CALR was found to interact with 63 protein-coding genes. Functional analysis with DAVID suggested that CALR and associated genes were enriched in the phagosome component. CALR shows promise as a potential marker for the development and treatment of DF.

Integrated metabolomics and proteomics reveal biomarkers associated with hemodialysis in end-stage kidney disease

Background: We hypothesize that the poor survival outcomes of end-stage kidney disease (ESKD) patients undergoing hemodialysis are associated with a low filtering efficiency and selectivity. The current gold standard criteria using single or several markers show an inability to predict or disclose the treatment effect and disease progression accurately. Methods: We performed an integrated mass spectrometry-based metabolomic and proteomic workflow capable of detecting and quantifying circulating small molecules and proteins in the serum of ESKD patients. Markers linked to cardiovascular disease (CVD) were validated on human induced pluripotent stem cell (iPSC)-derived cardiomyocytes. Results: We identified dozens of elevated molecules in the serum of patients compared with healthy controls. Surprisingly, many metabolites, including lipids, remained at an elevated blood concentration despite dialysis. These molecules and their associated physical interaction networks are correlated with clinical complications in chronic kidney disease. This study confirmed two uremic toxins associated with CVD, a major risk for patients with ESKD. Conclusion: The retained molecules and metabolite-protein interaction network address a knowledge gap of candidate uremic toxins associated with clinical complications in patients undergoing dialysis, providing mechanistic insights and potential drug discovery strategies for ESKD.

MYCT1 attenuates renal fibrosis and tubular injury in diabetic kidney disease

Tubulointerstitial abnormalities contribute to the progression of diabetic kidney disease (DKD). However, the underlying mechanism of the pathobiology of tubulointerstitial disease is largely unknown. Here, we showed that MYCT1 expression was downregulated in in vitro and in vivo DKD models. Adeno-associated virus (AAV)-Myct1 significantly attenuated renal dysfunction and tubulointerstitial fibrosis in diabetic db/db mice and downregulated Sp1 transcription and TGF-β1/SMAD3 pathway activation. In human proximal tubular epithelial cells, high glucose-induced high expression of SP1 and TGF-β1/SMAD3 pathway activation as well as overaccumulation of extracellular matrix (ECM) were abrogated by MYCT1 overexpression. Mechanistically, the binding of VDR to the MYCT1 promoter was predicted and confirmed using dual-luciferase reporter and ChIP analysis. VDR transcriptionally upregulates MYCT1. Our data reveal MYCT1 as a new and potential therapeutic target in treating DKD.

Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

pH/ROS-responsive propelled nanomotors for the active treatment of renal injury

Effective drugs that can be quickly delivered to and retained for a long time in the renal tubule are necessary for acute kidney injury (AKI) treatment. In this study, a gold nanoparticle-modified mesoporous silica (Au@MSN-NH₂)-camouflaged (methoxyphenyl)(morpholino)phosphinodithioic acid (GYY4137) asymmetrical nanosystem decorated with L-serine (S; an AKI-targeting agent) and D-Arg-dimethylTyr-Lys-Phe-NH₂ (TK-SS31; a reactive oxygen species (ROS)-sensitive thioketal linker/mitochondria-targeted antioxidant) was constructed for the treatment of renal tubule and mitochondrial injury as well as the synergistic and active treatment of AKI. Due to the enhanced permeability and retention (EPR) of nanomotors, they could progressively accumulate in renal sites. The asymmetrical nanosystem achieved effective drug distribution in the kidney as well as pH-responsive hydrogen sulfide (H₂S) release and ROS-responsive SS31 release, resulting in an active therapeutic effect mediated by nanomotor motion resulting from asymmetrical H₂S release.

Network pharmacology and bioinformatics study on the treatment of renal fibrosis with persicae semen-carthami flos drug pair

To use network pharmacology and bioinformatics technology to reveal the mechanism of persicae semen-carthami flos drug pair in the treatment of renal fibrosis (RF). Compounds in traditional Chinese medicine were obtained through the Herb database. Appropriate compounds and corresponding drug targets were screened out based on the 5 rules of Lipinski and pharmacokinetics. Screening of suitable disease miRNAs by microarray chips in the GEO database. Find differentially expressed genes by analyzing miRNAs. Protein-protein interaction analysis and enrichment analysis of therapeutic targets were performed using String database and Omicshare platform. Molecular docking via the DockThor platform. A total of 28 drug compounds and 228 drug targets were screened in this study. A total of 9 miRNAs and 6649 disease targets were obtained by GEO2R software analysis. Finally, 97 therapeutic targets were obtained. A total of 1124 Gene Ontology enrichment analysis results were obtained. Therapeutic targets play multiple roles in biological processes, molecular functions, and cellular organization. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the persicae semen-carthami flos drug pair played a role in the treatment of RF mainly through calcium signaling pathway, pathways in cancer, cAMP signaling pathway, and other pathways. Molecular docking showed that the traditional Chinese medicine compounds had good binding ability to the target. Persicae semen and carthami flos play a role in the treatment of RF through multiple targets and multiple pathways. It provides ideas and references for follow-up research and new drug development.

Calreticulin in renal fibrosis: A short review

Fibrosis is a common denominator of several pathological conditions. Over the last decade, Calreticulin has emerged as a critical player in the fibrotic processes in many tissues and organs. Here we review the recent advances in our understanding of the regulatory roles of Calreticulin in renal fibrosis. In particular, a proteomic screen that we performed more than 15 years ago, for the identification of novel components involved in the mechanisms of renal fibrosis, led to the observation that Calreticulin is associated with the initiation and progression of kidney fibrosis in a rodent model. We also showed that altered expression levels of Calreticulin in vitro and in vivo are significantly affecting the fibrotic phenotype in cellular systems and animal models, respectively. We also identified an upstream regulatory mechanism that mediates the transcriptional control of Calreticulin expression during the progression of renal fibrosis, by showing that the druggable orphan nuclear receptor NR5A2 and its SUMOylation is involved in this action. These data provide novel targets for future pharmacological interventions against fibrosis. In addition, further proteomic analysis uncovered a correlation between the up-regulation of Calreticulin and that of 14-3-3σ protein. Collectively, our previous observations suggest that Calreticulin is a central node in a regulatory axis that controls the initiation and progression of renal fibrosis.

Clonal haematopoiesis of indeterminate potential and impaired kidney function-A Danish general population study with 11 years follow-up

The myeloproliferative neoplasms are associated with chronic kidney disease but whether clonal haematopoiesis of indeterminate potential (CHIP) is associated with impaired kidney function is unknown. In the Danish General Suburban Population Study (N = 19 958) from 2010 to 2013, 645 individuals were positive for JAK2V617F (N = 613) or CALR (N = 32) mutations. Mutation-positive individuals without haematological malignancy were defined as having CHIP (N = 629). We used multiple and inverse probability weighted (IPW)-adjusted linear regression analysis to estimate adjusted mean (95% confidence interval) differences in estimated glomerular filtration rate (eGFR; ml/min/1.73 m² ) by mutation status, variant allele frequency (VAF%), blood cell counts, and neutrophil-to-lymphocyte ratio (NLR). We performed 11-year longitudinal follow-up of eGFR in all individuals. Compared to CHIP-negative individuals, the mean differences in eGFR were -5.6 (-10.3, -0.8, p = .02) for CALR, -11.9 (-21.4, -2.4, p = 0.01) for CALR type 2, and -10.1 (-18.1, -2.2, p = .01) for CALR with VAF ≥ 1%. The IPW-adjusted linear regression analyses showed similar results. NLR was negatively associated with eGFR. Individuals with CALR type 2 had a worse 11-year longitudinal follow-up on eGFR compared to CHIP-negative individuals (p = .004). In conclusion, individuals with CALR mutations, especially CALR type 2, had impaired kidney function compared to CHIP-negative individuals as measured by a lower eGFR at baseline and during 11-year follow-up.

miRNA-486-5p: signaling targets and role in non-malignant disease

MicroRNAs (miRNAs) are short non-coding RNAs, highly conserved between species, that are powerful regulators of gene expression. Aberrant expression of miRNAs alters biological processes and pathways linked to human disease. miR-486-5p is a muscle-enriched miRNA localized to the cytoplasm and nucleus, and is highly abundant in human plasma and enriched in small extracellular vesicles. Studies of malignant and non-malignant diseases, including kidney diseases, have found correlations with circulating miR-486-5p levels, supporting its role as a potential biomarker. Pre-clinical studies of non-malignant diseases have identified miR-486-5p targets that regulate major signaling pathways involved in cellular proliferation, migration, angiogenesis, and apoptosis. Validated miR-486-5p targets include phosphatase and tensin homolog (PTEN) and FoXO1, whose suppression activates phosphatidyl inositol-3-kinase (PI3K)/Akt signaling. Targeting of Smad1/2/4 and IGF-1 by miR-486-5p inhibits transforming growth factor (TGF)-β and insulin-like growth factor-1 (IGF-1) signaling, respectively. Other miR-486-5p targets include matrix metalloproteinase-19 (MMP-19), Sp5, histone acetyltransferase 1 (HAT1), and nuclear factor of activated T cells-5 (NFAT5). In this review, we examine the biogenesis, regulation, validated gene targets and biological effects of miR-486-5p in non-malignant diseases.

Thrombospondin-1 Signaling Through the Calreticulin/LDL Receptor Related Protein 1 Axis: Functions and Possible Roles in Glaucoma

Thrombospondin-1 (TSP-1) is a matricellular extracellular matrix protein. Matricellular proteins are components of the extracellular matrix (ECM) that regulate key cellular functions and impact ECM organization, but which lack direct primary structural roles in the ECM. TSP-1 expression is upregulated in response to injury, hypoxia, growth factor stimulation, inflammation, glucose, and by reactive oxygen species. Relevant to glaucoma, TSP-1 is also a mechanosensitive molecule upregulated by mechanical stretch. TSP-1 expression is increased in ocular remodeling in glaucoma in both the trabecular meshwork and in the optic nerve head. The exact roles of TSP-1 in glaucoma remain to be defined, however. It plays important roles in cell behavior and in ECM remodeling during wound healing, fibrosis, angiogenesis, and in tumorigenesis and metastasis. At the cellular level, TSP-1 can modulate cell adhesion and migration, protease activity, growth factor activity, anoikis resistance, apoptosis, and collagen secretion and matrix assembly and cross-linking. These multiple functions and macromolecular and receptor interactions have been ascribed to specific domains of the TSP-1 molecule. In this review, we will focus on the cell regulatory activities of the TSP-1 N-terminal domain (NTD) sequence that binds to cell surface calreticulin (Calr) and which regulates cell functions via signaling through Calr complexed with LDL receptor related protein 1 (LRP1). We will describe TSP-1 actions mediated through the Calr/LRP1 complex in regulating focal adhesion disassembly and cytoskeletal reorganization, cell motility, anoikis resistance, and induction of collagen secretion and matrix deposition. Finally, we will consider the relevance of these TSP-1 functions to the pathologic remodeling of the ECM in glaucoma.

Pancreatic INS-1 β-Cell Response to Thapsigargin and Rotenone: A Comparative Proteomics Analysis Uncovers Key Pathways of β-Cell Dysfunction

Insulin-secreting β-cells in the pancreatic islets are exposed to various endogenous and exogenous stressing conditions, which may lead to β-cell dysfunction or apoptosis and ultimately to diabetes mellitus. However, the detailed molecular mechanisms underlying β-cell's inability to survive under severe stresses remain to be explored. This study used two common chemical stressors, thapsigargin and rotenone, to induce endoplasmic reticulum (ER) and mitochondria stress in a rat insuloma INS-1 832/13 β-cell line, mimicking the conditions experienced by dysfunctional β-cells. Proteomic changes of cells upon treatment with stressors at IC₅₀ were profiled with TMT-based quantitative proteomics and further verified using label-free quantitive proteomics. The differentially expressed proteins under stress conditions were selected for in-depth bioinformatic analysis. Thapsigargin treatment specifically perturbed unfolded protein response (UPR) related pathways; in addition, 58 proteins not previously linked to the UPR related pathways were identified with consistent upregulation under stress induced by thapsigargin. Conversely, rotenone treatment resulted in significant proteome changes in key mitochondria regulatory pathways such as fatty acid β-oxidation, cellular respiration, citric acid cycle, and respiratory electron transport. Our data also demonstrated that both stressors increased reactive oxygen species production and depleted adenosine triphosphate synthesis, resulting in significant dysregulation of oxidative phosphorylation signaling pathways. These novel dysregulated proteins may suggest an alternative mechanism of action in β-cell dysfunction and provide potential targets for probing ER- and mitochondria stress-induced β-cell death.

Iopromide and Iodixanol in the Development of Postoperative Contrast Nephropathy in Patients with Renal Insufficiency: A Meta-Analysis

In order to compare the effects of iopromide and isoxazole on postoperative contrast-induced nephropathy in patients with renal insufficiency, the paper searches for randomized controlled trials and retrospective cohort studies comparing the effects of iopromide and iodixanol on renal function in patients with renal insufficiency after surgery. The data are extracted from eligible studies. We tried to assess the incidence of contrast-agent nephropathy, preoperative and postoperative serum creatinine indicators, and mortality. This paper includes 8 studies with a total of 1243 patients. The incidence of contrast-induced nephropathy in the iopromide group is higher than that in the iodixanol group, and there is no significant difference between the two groups in postoperative mortality and preoperative serum creatinine expression. Sensitivity analysis and funnel chart show that our research is robust and has low publication bias. Our research shows that in patients with renal insufficiency, the incidence of contrast-medium nephropathy in the iopromide group is higher than that in the iodixanol group. Iodixanol is safer and has less effect on patients' serum creatinine levels.

Damage-Associated Molecular Patterns (DAMPs) in Retinal Disorders

Damage-associated molecular patterns (DAMPs) are endogenous danger molecules released from the extracellular and intracellular space of damaged tissue or dead cells. Recent evidence indicates that DAMPs are associated with the sterile inflammation caused by aging, increased ocular pressure, high glucose, oxidative stress, ischemia, mechanical trauma, stress, or environmental conditions, in retinal diseases. DAMPs activate the innate immune system, suggesting their role to be protective, but may promote pathological inflammation and angiogenesis in response to the chronic insult or injury. DAMPs are recognized by specialized innate immune receptors, such as receptors for advanced glycation end products (RAGE), toll-like receptors (TLRs) and the NOD-like receptor family (NLRs), and purine receptor 7 (P2X7), in systemic diseases. However, studies describing the role of DAMPs in retinal disorders are meager. Here, we extensively reviewed the role of DAMPs in retinal disorders, including endophthalmitis, uveitis, glaucoma, ocular cancer, ischemic retinopathies, diabetic retinopathy, age-related macular degeneration, rhegmatogenous retinal detachment, proliferative vitreoretinopathy, and inherited retinal disorders. Finally, we discussed DAMPs as biomarkers, therapeutic targets, and therapeutic agents for retinal disorders.

A global analysis on the differential regulation of RNA binding proteins (RBPs) by TNF–α as potential modulators of metabolic syndromes

Metabolic syndrome (MetS) is associated with a group of conditions, which enhances the risk of diabetes, heart diseases and stroke in the affected individuals. Earlier reports from our lab have shown that Tumor necrosis factor-α (TNF-α) significantly modulates the expression of 56 genes at the alternative splicing level which are involved in various signaling and metabolic pathways (MetS genes) connected to MetS. These MetS genes were predicted to interact with various RNA-binding proteins (RBPs) when exposed to TNF-α, resulting changes in their alternative splicing patterns. Here we are presenting data of an RNA-Seq analysis, which identified 1218 unique, and significantly regulated genes by TNF-α, 15% of which are RBPs . Among the 1218 genes, 204 genes have been identified as MetS genes by the ingenuity pathway analysis, and 10% of the MetS genes are found as RBPs. Our results also show that TNF-α changes the phosphorylation status of certain RBPs such as SR proteins, crucial players in alternative splicing, possibly via changing the activation status of certain upstream signaling molecules which also act as upstream kinases for these proteins. Taken together, these findings suggest that TNF-α influences the regulation of the RBPs at the various levels for their expression, which may lead to the alteration of the splicing pattern of the MetS genes. MetS genes acting as RBPs and are modulated by TNF-α, predict the existence of highly interconnected mechanisms which require further analysis to understand their dual roles on the onset of these diseases.

Roles of SIRT6 in kidney disease: a novel therapeutic target

SIRT6 is an NAD+ dependent deacetylase that belongs to the mammalian sirtuin family. SIRT6 is mainly located in the nucleus and regulates chromatin remodeling, genome stability, and gene transcription. SIRT6 extensively participates in various physiological activities such as DNA repair, energy metabolism, oxidative stress, inflammation, and fibrosis. In recent years, the role of epigenetics such as acetylation modification in renal disease has gradually received widespread attention. SIRT6 reduces oxidative stress, inflammation, and renal fibrosis, which is of great importance in maintaining cellular homeostasis and delaying the chronic progression of kidney disease. Here, we review the structure and biological function of SIRT6 and summarize the regulatory mechanisms of SIRT6 in kidney disease. Moreover, the role of SIRT6 as a potential therapeutic target for the progression of kidney disease will be discussed. SIRT6 plays an important role in kidney disease. SIRT6 regulates mitochondrial dynamics and mitochondrial biogenesis, induces G2/M cycle arrest, and plays an antioxidant role in nephrotoxicity, IR, obstructive nephropathy, and sepsis-induced AKI. SIRT6 prevents and delays progressive CKD induced by hyperglycemia, kidney senescence, hypertension, and lipid accumulation by regulating mitochondrial biogenesis, and has antioxidant, anti-inflammatory, and antifibrosis effects. Additionally, hypoxia, inflammation, and fibrosis are the main mechanisms of the AKI-to-CKD transition. SIRT6 plays a critical role in the AKI-to-CKD transition and kidney repair through anti-inflammatory, antifibrotic, and mitochondrial quality control mechanisms. AKI Acute kidney injury, CKD Chronic kidney disease.

Calreticulin Deficiency Disturbs Ribosome Biogenesis and Results in Retardation in Embryonic Kidney Development

Nephrogenesis is driven by complex signaling pathways that control cell growth and differentiation. The endoplasmic reticulum chaperone calreticulin (Calr) is well known for its function in calcium storage and in the folding of glycoproteins. Its role in kidney development is still not understood. We provide evidence for a pivotal role of Calr in nephrogenesis in this investigation. We show that Calr deficiency results in the disrupted formation of an intact nephrogenic zone and in retardation of nephrogenesis, as evidenced by the disturbance in the formation of comma-shaped and s-shaped bodies. Using proteomics and transcriptomics approaches, we demonstrated that in addition to an alteration in Wnt-signaling key proteins, embryonic kidneys from Calr-/- showed an overall impairment in expression of ribosomal proteins which reveals disturbances in protein synthesis and nephrogenesis. CRISPR/cas9 mediated knockout confirmed that Calr deficiency is associated with a deficiency of several ribosomal proteins and key proteins in ribosome biogenesis. Our data highlights a direct link between Calr expression and the ribosome biogenesis.

Diabetic endotheliopathy: RNA-binding proteins as new therapeutic targets

Diabetic Endotheliopathy is widely regarded as a principal contributor to cardiovascular disease pathogenesis in individuals with Diabetes mellitus. The endothelium, the innermost lining of blood vessels, consists of an extensive monolayer of endothelial cells. Previously regarded as an interface, the endothelium is now accepted as an organ system with critical roles in vascular health; its dysfunction therefore is detrimental. Endothelial dysfunction induces blood vessel damage resulting in a restriction of blood and oxygen supply to tissues, the central pathology of cardiovascular disease. Hyperglycemic conditions have repeatedly been isolated as a pivotal inducer of endothelial cell dysfunction. Numerous studies have since proven hyperglycemic conditions to significantly alter the gene expression profile of endothelial cells, with this being largely attributable to the post-transcriptional regulation of RNA-binding proteins. In particular, the RBP Quaking-7 has recently emerged as a crucial mediator of diabetic endotheliopathy, with great potential to become a therapeutic target.