Identification and RNAi-based function analysis of trehalase family genes in Frankliniella occidentalis (Pergande).

BACKGROUND: Insects utilize trehalases (TREs) to regulate energy metabolism and chitin biosynthesis, which are essential for their growth, development, and reproduction. TREs can therefore be used as potential targets for future insecticide development. However, the roles of TREs in Frankliniella occidentalis (Pergande), a serious widespread agricultural pest, remain unclear. RESULTS: Three TRE genes were identified in F. occidentalis and cloned, and their functions were then investigated via feeding RNA interference (RNAi) and virus-induced gene silencing (VIGS) assays. The results showed that silencing FoTRE1-1 or FoTRE1-2 significantly decreased expression levels of FoGFAT, FoPGM, FoUAP, and FoCHS, which are members of the chitin biosynthesis pathway. Silencing FoTRE1-1 or FoTRE2 significantly down-regulated FoPFK and FoPK, which are members of the energy metabolism pathway. These changes resulted in 2-fold decreases in glucose and glycogen content, 2-fold increases in trehalose content, and 1.5- to 2.0-fold decreases in chitinase activity. Furthermore, knocking down FoTRE1-1 or FoTRE1-2 resulted in deformed nymphs and pupae as a result of hindered molting. The VIGS assay for the three FoTREs revealed that FoTRE1-1 or FoTRE2 caused shortened ovarioles, and reduced egg-laying and hatching rates. CONCLUSION: The results suggest that FoTRE1-1 and FoTRE1-2 play important roles in the growth and development of F. occidentalis, while FoTRE1-1 and FoTRE2 are essential for its reproduction. These three genes could be candidate targets for RNAi-based management and control of this destructive agricultural pest. © 2024 Society of Chemical Industry.

Uridine diphosphate glucosyltransferases are involved in spinosad resistance in western flower thrips Frankliniella occidentalis (Pergande).

Uridine diphosphate glucosyltransferases (UGTs) play crucial roles in the insect detoxification system and are associated with pesticide resistance. Our previous transcriptomic analysis of spinosad-susceptible (Ivf03) and resistant (NIL-R) Frankliniella occidentalis revealed numerous upregulated UGT genes in the NIL-R strain, suggesting their potential contribution to spinosad resistance. To investigate this hypothesis, here we conducted UGT activity assays and spinosad induction experiments, employing RNA interference (RNAi) techniques for gene function validation. We found significantly elevated UGT activity in the NIL-R strain compared to Ivf03, with 5-nitrouracil showing a substantial synergistic effect on the resistant strain. Eighteen UGT genes were identified in F. occidentalis, with gene expansion and duplication observed within families UGT466, 467, and 468. Ten out of the eighteen UGTs exhibited higher expression levels in NIL-R, specifically FoUGT466B1, FoUGT468A3, and FoUGT468A4 consistently being upregulated across nymphs, males, and females. RNAi-based functional validation targeting these three UGT genes led to increased susceptibility to spinosad in a life stage-, sex-, and dose-dependent manner. These results indicate that UGTs are indeed involved in spinosad resistance in F. occidentalis, and the effects are dependent on life stage, sex, and dose. Therefore, sustainable control for F. occidentalis resistance should always consider these differential responses.

SGLT2 inhibitors for prevention of cardiorenal events in people with type 2 diabetes without cardiorenal disease: A meta-analysis of large randomized trials and cohort studies.

To investigate whether sodium glucose cotransporter 2 inhibitors (SGLT2is) can reduce important cardiorenal endpoints in type 2 diabetic adults without established cardiovascular disease (ECD), in those without heart failure (HF), and in those without chronic kidney disease (CKD). We searched PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL) and clinicaltrials.gov. Event-driven randomized controlled trials (RCTs) and cohort studies were included. We conducted random-effects meta-analysis, respectively based on RCTs and cohort studies, on eight cardiorenal endpoints in three type 2 diabetic subgroups. Thirteen large studies were included. Meta-analysis of RCTs showed the high quality evidences: compared with placebo, SGLT2is significantly reduced the risk of major adverse cardiovascular events, cardiovascular death or hospitalization for HF, and progression of CKD in type 2 diabetic adults without ECD [HRs (95 % CIs): 0.88 (0.82, 0.94), 0.76 (0.70, 0.82), and 0.59 (0.52, 0.66), respectively; risk differences (95 % CIs): -1.6 (-2.4, -0.8), -2.6 (-3.3, -2.0), and -2.4 (-2.8, -2.0) per 1000 patient-years, respectively], in those without HF [HRs (95 % CIs): 0.89 (0.82, 0.95), 0.74 (0.67, 0.81), and 0.61 (0.55, 0.67), respectively; risk differences (95 % CIs): -1.7 (-2.9, -0.8), -5.8 (-7.3, -4.2), and -2.3 (-2.6, -1.9) per 1000 patient-years, respectively], and in those without CKD [HRs (95 % CIs): 0.88 (0.82, 0.94), 0.77 (0.71, 0.83), and 0.63 (0.57, 0.70), respectively; risk differences (95 % CIs): -2.4 (-3.6, -1.2), -6.1 (-7.6, -4.5), and -2.2 (-2.6, -1.8) per 1000 patient-years, respectively]. Meta-analysis of cohort studies also showed the benefits of SGLT2is on the three composite outcomes in the three diabetic subgroups. SGLT2is also significantly reduced some other cardiorenal endpoints in these diabetic subgroups. SGLT2is can significantly reduce important cardiorenal events in type 2 diabetic adults without ECD, in those without HF, and in those without CKD; which supports SGLT2is used in these diabetic subpopulations to prevent cardiorenal events.

Mangiferin alleviates hypertension induced by hyperuricemia via increasing nitric oxide releases.

Mangiferin, a natural glucosyl xanthone, was confirmed to be an effective uric acid (UA)- lowering agent with dual action of inhibiting production and promoting excretion of UA. In this study, we aimed to evaluate the effect of mangiferin on alleviating hypertension induced by hyperuricemia. Mangiferin (30, 60, 120 mg/kg) was administered intragastrically to hyperuricemic rats induced by gavage with potassium oxonate (750 mg/kg). Systolic blood pressure (SBP), serum levels of UA, nitric oxide (NO), C-reactionprotein (CRP) and ONOO- were measured. The mRNA and protein levels of endothelial nitric oxide synthase (eNOS), intercellular adhesion molecule-1 (ICAM-1), CRP were also analyzed. Human umbilical vein endothelial cells (HUVECs) were used in vitro studies. Administration of mangiferin significantly decreased the serum urate level and SBP at 8 weeks and last to 12 weeks. Further more, mangiferin could increase the release of NO and decrease the level of CRP in blood. In addition, mangiferin reversed the protein expression of eNOS, CRP, ICAM-1 and ONOO- in aortic segments in hyperuricemic rats. The results in vitro were consistent with the observed results in vivo. Taken together, these data suggested that mangiferin has played an important part in alleviating hypertension induced by hyperuricemia via increasing NO secretion and improving endothelial function.