Blockade of myeloid differentiation 2 attenuates diabetic nephropathy by reducing activation of the renin-angiotensin system in mouse kidneys

Background and Purpose: Both innate immunity and the renin-angiotensin system (RAS) play important roles in the pathogenesis of diabetic nephropathy (DN). Myeloid differentiation factor 2 (MD2) is a co-receptor of toll-like receptor 4 (TLR4) in innate immunity. While TLR4 is involved in the development of DN, the role of MD2 in DN has not been characterized. It also remains unclear whether the MD2/TLR4 signalling pathway is associated with RAS activation in diabetes. Experimental Approach: MD2 was blocked using siRNA or the low MW inhibitor, L6H9, in renal proximal tubular cells (NRK-52E cells) exposed to high concentrations of glucose (HG). In vivo, C57BL/6 and MD2−/− mice were injected with streptozotocin to induce Type 1 diabetes and nephropathy. Key Results: Inhibition of MD2 by genetic knockdown or the inhibitor L6H9 suppressed HG-induced expression of ACE and angiotensin receptors and production of angiotensin II in NRK-52E cells, along with decreased fibrosis markers (TGF-β and collagen IV). Inhibition of the MD2/TLR4-MAPKs pathway did not affect HG-induced renin overproduction. In vivo, using the streptozotocin-induced diabetic mice, MD2 was overexpressed in diabetic kidney. MD2 gene knockout or L6H9 attenuated renal fibrosis and dysfunction by suppressing local RAS activation and inflammation. Conclusions and Implications: Hyperglycaemia activated the MD2/TLR4-MAPKs signalling cascade to induce renal RAS activation, leading to renal fibrosis and dysfunction. Pharmacological inhibition of MD2 may be considered as a therapeutic approach to mitigate DN and the low MW inhibitor L6H9 could be a candidate for such therapy

Advances in Physalis molecular research: applications in authentication, genetic diversity, phylogenetics, functional genes, and omics

The plants of the genus Physalis L. have been extensively utilized in traditional and indigenous Chinese medicinal practices for treating a variety of ailments, including dermatitis, malaria, asthma, hepatitis, and liver disorders. The present review aims to achieve a comprehensive and up-to-date investigation of the genus Physalis, a new model crop, to understand plant diversity and fruit development. Several chloroplast DNA-, nuclear ribosomal DNA-, and genomic DNA-based markers, such as psbA-trnH, internal-transcribed spacer (ITS), simple sequence repeat (SSR), random amplified microsatellites (RAMS), sequence-characterized amplified region (SCAR), and single nucleotide polymorphism (SNP), were developed for molecular identification, genetic diversity, and phylogenetic studies of Physalis species. A large number of functional genes involved in inflated calyx syndrome development (AP2-L, MPF2, MPF3, and MAGO), organ growth (AG1, AG2, POS1, and CNR1), and active ingredient metabolism (24ISO, DHCRT, P450-CPL, SR, DUF538, TAS14, and 3β-HSB) were identified contributing to the breeding of novel Physalis varieties. Various omic studies revealed and functionally identified a series of reproductive organ development-related factors, environmental stress-responsive genes, and active component biosynthesis-related enzymes. The chromosome-level genomes of Physalis floridana Rydb., Physalis grisea (Waterf.) M. Martínez, and Physalis pruinosa L. have been recently published providing a valuable resource for genome editing in Physalis crops. Our review summarizes the recent progress in genetic diversity, molecular identification, phylogenetics, functional genes, and the application of omics in the genus Physalis and accelerates efficient utilization of this traditional herb

Myeloid-derived suppressor cells inhibit T cell activation through nitrating LCK in mouse cancers

Potent immunosuppressive mechanisms within the tumor microenvironment contribute to the resistance of aggressive human cancers to immune checkpoint blockade (ICB) therapy. One of the main mechanisms for myeloid-derived suppressor cells (MDSCs) to induce T cell tolerance is through secretion of reactive nitrogen species (RNS), which nitrates tyrosine residues in proteins involved in T cell function. However, so far very few nitrated proteins have been identified. Here, using a transgenic mouse model of prostate cancer and a syngeneic cell line model of lung cancer, we applied a nitroproteomic approach based on chemical derivation of 3-nitrotyrosine and identified that lymphocyte-specific protein tyrosine kinase (LCK), an initiating tyrosine kinase in the T cell receptor signaling cascade, is nitrated at Tyr394 by MDSCs. LCK nitration inhibits T cell activation, leading to reduced interleukin 2 (IL2) production and proliferation. In human T cells with defective endogenous LCK, wild type, but not nitrated LCK, rescues IL2 production. In the mouse model of castration-resistant prostate cancer (CRPC) by prostate-specific deletion of Pten, p53, and Smad4, CRPC is resistant to an ICB therapy composed of antiprogrammed cell death 1 (PD1) and anticytotoxic-T lymphocyte-associated protein 4 (CTLA4) antibodies. However, we showed that ICB elicits strong anti-CRPC efficacy when combined with an RNS neutralizing agent. Together, these data identify a previously unknown mechanism of T cell inactivation by MDSC-induced protein nitration and illuminate a clinical path hypothesis for combining ICB with RNS-reducing agents in the treatment of CRPC

Identification of the Effects of 5-Azacytidine on Porcine Circovirus Type 2 Replication in Porcine Kidney Cells

Porcine circovirus type 2 (PCV2) is the main pathogen causing post-weaning multisystemic wasting syndrome (PMWS), which mainly targets the body’s immune system and poses a serious threat to the global pig industry. 5-Azacytidine is a potent inhibitor of DNA methylation, which can participate in many important physiological and pathological processes, including virus-related processes, by inhibiting gene expression. However, the impact of 5-Aza on PCV2 replication in cells is not yet clear. We explored the impact of 5-Aza on PCV2 infection utilizing PK15 cells as a cellular model. Our objective was to gain insights that could potentially offer novel therapeutic strategies for PCV2. Our results showed that 5-Aza significantly enhanced the infectivity of PCV2 in PK15 cells. Transcriptome analysis revealed that PCV2 infection activated various immune-related signaling pathways. 5-Aza may activate the MAPK signaling pathway to exacerbate PCV2 infection and upregulate the expression of inflammatory and apoptotic factors

Histone Methyltransferase MLL1 Mediates Oxidative Stress and Apoptosis upon Deoxynivalenol Exposure in the Intestinal Porcine Epithelial Cells

Deoxynivalenol (DON), as a secondary metabolite of fungi, is continually detected in livestock feed and has a high risk to animals and humans. Moreover, pigs are very sensitive to DON. Recently, the role of histone modification has drawn people’s attention; however, few studies have elucidated how histone modification participates in the cytotoxicity or genotoxicity induced by mycotoxins. In this study, we used intestinal porcine epithelial cells (IPEC-J2 cells) as a model to DON exposure in vitro. Mixed lineage leukemia 1 (MLL1) regulates gene expression by exerting the role of methyltransferase. Our studies demonstrated that H3K4me3 enrichment was enhanced and MLL1 was highly upregulated upon 1 μg/mL DON exposure in IPEC-J2 cells. We found that the silencing of MLL1 resulted in increasing the apoptosis rate, arresting the cell cycle, and activating the mitogen-activated protein kinases (MAPKs) pathway. An RNA-sequencing analysis proved that differentially expressed genes (DEGs) were enriched in the cell cycle, apoptosis, and tumor necrosis factor (TNF) signaling pathway between the knockdown of MLL1 and negative control groups, which were associated with cytotoxicity induced by DON. In summary, these current results might provide new insight into how MLL1 regulates cytotoxic effects induced by DON via an epigenetic mechanism

Phase I study of adjuvant chemotherapy with nab‐paclitaxel and S‐1 for stage III Lauren's diffuse‐type gastric cancer after D2 resection (NORDICA study)

Abstract Purpose The prognosis of diffuse‐type gastric cancer (DGC) is poorer than that of intestinal type, but S‐1 is a potential treatment option in DGC. This study explored the maximal tolerated dose (MTD) and the recommended dose for phase II study (RP2D) of nab‐paclitaxel combined with S‐1 (AS regimen) as adjuvant chemotherapy in stage III DGC. Methods Patients with stage III DGC were recruited into this phase I dose‐escalation study between July 2019 and June 2020 in Zhongshan Hospital. Nab‐paclitaxel and S‐1 (80–120 mg/day, d1‐14, q3w) were administrated for 6 cycles, and then 8 cycles of S‐1 monotherapy were applied. The patients received nab‐paclitaxel at 180, 220, or 260 mg/m2 according to the 3 + 3 design based on dose‐limiting toxicity (DLT). The primary endpoint was RP2D. Secondary endpoints were the 1‐year disease‐free survival (DFS) rate and adverse events (AEs). Results One case experienced DLT in 180‐mg/m2 dose group, subsequently three additional subjects were enrolled. DLT was not observed in the 220‐ and 260‐mg/m2 dose groups (both n = 3). Therefore, the MTD has not reached, and the RP2D of nab‐paclitaxel would be 260 mg/m2. Five participants showed progressive disease, with three and two participants in the 180‐ and 220‐mg/m2 dose groups, respectively. The 6‐, 12‐, and 18‐month DFS rates were 100%, 63.6%, and 50.9%, respectively. The most frequently observed AEs were neutropenia (83.3%) and leukopenia (66.7%). Conclusion The RP2D of nab‐paclitaxel as adjuvant chemotherapy in DGC was 260 mg/m2. The AS regimen had a tolerable AE profile in stage III DGC

Pterostilbene Ameliorates Fumonisin B1-Induced Cytotoxic Effect by Interfering in the Activation of JAK/STAT Pathway

Fumonisin B1 (FB1) is a mycotoxin that poses a great threat to agricultural production and the health of humans and animals. Pterostilbene (PTE) is a natural plant polyphenolic compound with good anti-inflammatory, antioxidant and cell regeneration effects, yet its effectiveness in treating FB1-induced cytotoxicity remains to be explored. In this study, we used porcine alveolar macrophages (3D4/21) as a model to characterize the cytotoxicity induced by FB1, and to investigate the potential alleviating effect of PTE on FB1-induced cytotoxicity. We demonstrate that FB1 induces cytotoxicity, apoptosis, pro-inflammatory cytokine production and mitochondrial damage, which can be largely recovered by PTE treatment, suggesting the promising application of PTE to treat FB1-induced damage. Mechanistically, FB1 activates the JAK/STAT signaling pathway, while PTE attenuates FB1-induced cytotoxicity through the inhibition of key JAK/STAT genes such as JAK2 and STAT3. Overall, our study characterized the molecular mechanism for FB1-induced cytotoxicity and found PTE to be a promising component which can alleviate FB1-induced cytotoxicity by interfering in the activation of JAK/STAT pathway

Development of the Double Cyclic Peptide Ligand for Antibody Purification and Protein Detection

Development of a peptide-based affinity matrix and detection reagent is important for biomedical research and the biopharmaceutical industry. In the present work, we designed and synthesized an immunoglobin G (IgG)-binding peptide ligand, Fc-III-4C. Fc-III-4C is composed of 15 residues, and the 4 cysteine residues form 2 disulfide bonds to generate a double cyclic structure. The binding affinity of the Fc-III-4C peptide toward human IgG was determined to be 2.45 nM (<i>K</i>_d), which is higher than that of IgG with Protein A/G (Pro-A/G). Importantly, the Fc-III-4C peptide displayed high affinity to various IgGs from different species. Fc-III-4C immobilized agarose beads exhibited high stability and reusability when compared with that of the Pro-A/G-immobilized beads. The conjugate of Fc-III-4C with FITC was demonstrated to be suitable for immunofluorescence detection of proteins expressed in cells. These results demonstrate that the Fc-III-4C peptide is a useful affinity ligand for antibody purification and as a protein detection reagent

Prognostic Value of Immunoscore and PD-L1 Expression in Metastatic Colorectal Cancer Patients with Different RAS Status after Palliative Operation

Colorectal cancer (CRC) is the fifth leading cause of cancer death and the fifth most commonly diagnosed cancer in China. Approximately, 25% of CRC was in the advanced stage as diagnosed, and 40% of patients with CRC progress to metastatic colorectal cancer (mCRC). RAS mutation status is now routinely used to select their therapy. But it is still a question whether RAS mutation status is a prognostic marker. In our study, we detected RAS mutation, immunoscore (IS), and PD-L1 expression in 60 Chinese mCRC patients who received palliative operation. The Kaplan-Meier survival analysis showed that the overall survival (OS) in patients with RAS wild type was better than those with RAS mutated type. Moreover, in multivariate analysis, RAS mutation and PD-L1 expression were demonstrated to be the independent negative prognostic factors for OS (P=0.044, HR: 0.258, and 95% CI: 0.069–0.967; P=0.048, HR: 0.276, and 95% CI: 0.077–0,988). All results suggested that, combined with IS, PD-L1 expression and RAS status may be the prognostic indicators for mCRC patients with palliative operation