[PK2/PKR1 signaling pathway participates in geniposide protection against diabetic nephropathy in mice].

This study aimed to investigate the effects of geniposide(GP) on the expression of prokineticin(PK2) and prokineticin receptor 1(PKR1) in db/db mice with diabetic nephropathy(DN), so as to explore how the PK2 signaling pathway participated in the pathological changes of DN and whether GP exerted the therapeutic effect through this signaling pathway. Male mice were randomly divided into four groups, namely db/m, db/db, db/db+GP, and db/m+GP groups, with five in each group. The mice in the db/db+GP and db/m+GP groups were gavaged with 150 mg·kg~(-1) GP for eight successive weeks. Afterwards, all the mice were sacrificed and the renal tissues were embedded. The morphological changes in glomerulus and renal tubules were observed by Masson and PAS staining. The expression levels of PK2, PKR1, and Wilm's Tumor Protein 1(WT_1) in podocytes were detected by immunohistochemistry, and the protein expression levels of PK2 and PKR1 in mouse kidney by Western blot. The morphological results showed serious glomerular and tubular fibrosis(Masson), high glomerular and tubular injury score(PAS), increased glomerular mesangial matrix, thickened basement membrane, exfoliated brush border of renal tubules, decreased WT_1 in glomerular podocytes, and massive loss of podocytes in the db/db group. After administration with GP, the glomerular and tubular fibrosis was alleviated, accompanied by improved glomerular basement membrane and renal tubule brush edge, and up-regulated WT_1. As revealed by further protein detection, in the db/db group, the expression levels of PK2 and PKR1 and p-Akt/Akt ratio declined, whereas the ratio of Bax/Bcl-2 rose. Ho-wever, PKR2 and p-ERK/ERK ratio did not change significantly. After administration with GP, the PK2 and PKR1 expression was elevated, and p-Akt/Akt ratio was increased. There was no obvious change in PKR2, Bax/Bcl-2 ratio, or p-ERK/ERK ratio. All these have demonstrated that GP improves the renal damage in DN mice, and PK2/PKR1 signaling pathway may be involved in such protection, which has provided reference for clinical treatment of DN with GP.

Accurate prediction of acute pancreatitis severity based on genome-wide cell free DNA methylation profiles.

BACKGROUND: Patients with severe acute pancreatitis (SAP) have a high mortality, thus early diagnosis and interventions are critical for improving survival. However, conventional tests are limited in acute pancreatitis (AP) stratification. We aimed to assess AP severity by integrating the informative clinical measurements with cell free DNA (cfDNA) methylation markers. METHODS: One hundred and seventy-five blood samples were collected from 61 AP patients at multiple time points, plus 24 samples from healthy individuals. Genome-wide cfDNA methylation profiles of all samples were characterized with reduced representative bisulfite sequencing. Clinical blood tests covering 93 biomarkers were performed on AP patients within 24 h. SAP predication models were built based on cfDNA methylation and conventional blood biomarkers separately and in combination. RESULTS: We identified 565 and 59 cfDNA methylation markers informative for acute pancreatitis and its severity. These markers were used to develop prediction models for AP and SAP with area under the receiver operating characteristic of 0.92 and 0.81, respectively. Twelve blood biomarkers were systematically screened for a predictor of SAP with a sensitivity of 87.5% for SAP, and a specificity of 100% in mild acute pancreatitis, significantly higher than existing blood tests. An expanded model integrating 12 conventional blood biomarkers with 59 cfDNA methylation markers further improved the SAP prediction sensitivity to 92.2%. CONCLUSIONS: These findings have demonstrated that accurate prediction of SAP by the integration of conventional and novel blood molecular markers, paving the way for early and effective SAP intervention through a non-invasive rapid diagnostic test.

The soybean CBL-interacting protein kinase, GmCIPK2, positively regulates drought tolerance and ABA signaling.

Calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) play important roles in plant environmental stress responses. However, the biological functions of the CBL-CIPK signaling pathway in the tolerance of soybean (Glycine max) to drought stress remain elusive. Here, we characterized the GmCIPK2 gene in soybean, and its expression was induced by drought stress and exogenous abscisic acid (ABA) treatments. The overexpression of GmCIPK2 enhanced drought tolerance in transgenic Arabidopsis and soybean hairy roots, whereas downregulation of GmCIPK2 expression in soybean hairy roots by RNA interference resulted in increased drought sensitivity. Further analysis showed that GmCIPK2 was involved in ABA-mediated stomatal closure in plants under drought stress conditions. GmCIPK2 increased the expression of ABA- and drought-responsive genes during drought stress. Additionally, yeast two-hybrid, pull-down, and bimolecular fluorescence complementation assays demonstrated that a positive regulator of drought stress, GmCBL1, physically interacted with GmCIPK2 on the plasma membrane. Collectively, our results demonstrated that GmCIPK2 positively regulates drought tolerance and ABA signaling in plants, providing new insights into the underlying mechanisms of how the CBL-CIPK signaling pathway contributes to drought tolerance in soybean.

Association between XPG polymorphisms and stomach cancer susceptibility in a Chinese population.

Xeroderma pigmentosum group G (XPG) protein plays an important role in the DNA repair process by cutting the damaged DNA at the 3' terminus. Previous studies have indicated some polymorphisms in the XPG gene are associated with stomach cancer susceptibility. We performed this hospital-based case-control study to evaluate the association of four potentially functional XPG polymorphisms (rs2094258 C>T, rs751402 C>T, rs2296147 T>C and rs873601G>A) with stomach cancer susceptibility. The four single nucleotide polymorphisms (SNPs) were genotyped in 692 stomach cancer cases and 771 healthy controls. Logistic regression analysis was conducted, and odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association of interest. Of the studied SNPs, XPG rs873601G>A polymorphism was found to significantly associate with stomach cancer susceptibility (AA versus GG/AG: OR = 1.31, 95% CI = 1.03-1.66, P = 0.027). Combined analysis of all SNPs revealed that the individuals with two of risk genotypes had a significantly increased stomach cancer risk (OR = 1.52, 95% CI = 1.13-2.06). In the stratification analysis, the association between the rs873601AA genotype and stomach cancer risk was observed in older group (>59 year), as well as patients with non-cardia stomach cancer. Further combined analysis indicated men, smokers, or non-drinkers more than one risk genotypes had a significantly increased stomach cancer risk. Our results indicate that XPG rs873601G>A polymorphism may be associated with the risk of stomach cancer. Further prospective studies with different ethnicities and large sample sizes are needed to validate our findings.

Transcriptional regulation of SlPYL, SlPP2C, and SlSnRK2 gene families encoding ABA signal core components during tomato fruit development and drought stress.

In order to characterize the potential transcriptional regulation of core components of abscisic acid (ABA) signal transduction in tomato fruit development and drought stress, eight SlPYL (ABA receptor), seven SlPP2C (type 2C protein phosphatase), and eight SlSnRK2 (subfamily 2 of SNF1-related kinases) full-length cDNA sequences were isolated from the tomato nucleotide database of NCBI GenBank. All SlPYL, SlPP2C, and SlSnRK2 genes obtained are homologous to Arabidopsis AtPYL, AtPP2C, and AtSnRK2 genes, respectively. Based on phylogenetic analysis, SlPYLs and SlSnRK2s were clustered into three subfamilies/subclasses, and all SlPP2Cs belonged to PP2C group A. Within the SlPYL gene family, SlPYL1, SlPYL2, SlPYL3, and SlPYL6 were the major genes involved in the regulation of fruit development. Among them, SlPYL1 and SlPYL2 were expressed at high levels throughout the process of fruit development and ripening; SlPYL3 was strongly expressed at the immature green (IM) and mature green (MG) stages, while SlPYL6 was expressed strongly at the IM and red ripe (RR) stages. Within the SlPP2C gene family, the expression of SlPP2C, SlPP2C3, and SlPP2C4 increased after the MG stage; SlPP2C1 and SlPP2C5 peaked at the B3 stage, while SlPP2C2 and SlPP2C6 changed little during fruit development. Within the SlSnRK2 gene family, the expression of SlSnRK2.2, SlSnRK2.3, SlSnRK2.4, and SlSnRK2C was higher than that of other members during fruit development. Additionally, most SlPYL genes were down-regulated, while most SlPP2C and SlSnRK2 genes were up-regulated by dehydration in tomato leaf.