A simple method for estimating the coarse lateral root biomass of shrubs using ground-penetrating radar: Validation by Caragana microphylla Lam. in Inner Mongolia.

The potential increases in carbon stocks in arid regions due to recent shrub encroachment have attracted extensive interest among both ecologists and carbon policy analysts. Quantifying the shrub root biomass amount in these ecosystems is essential to understanding the ecological changes occurring. In this paper, we proposed a simple nondestructive method for estimating the coarse lateral root biomass of shrubs based on the root counts obtained from ground-penetrating radar (GPR) radargrams. Root data were gathered via field experiments using GPR with antenna center frequencies of 900 MHz and 400 MHz. Five Caragana microphylla Lam. shrubs of different sizes were selected for measuring objects, and a total of 40 GPR survey lines were established for GPR data acquisition. The soil profile wall excavation method was used to obtain the total root biomass from each radargram. A model for estimating the root biomass was built by establishing the relationship between the root biomass in each profile and the root counts interpreted from the radargrams. According to the mathematical relationship between the root diameter and root biomass, the proxy root radius was derived, which could explain the rationality of the proposed model from the biological mechanism. The established model provided high confidence in estimating the root dry biomass using the GPR data obtained at the two antenna frequencies (R2= 0.73 for 900 MHz and R2= 0.71 for 400 MHz). The leave-one-out cross-validation results showed that the model exhibits satisfactory performance. This study expands the application of geophysical methods in root research and offers a new simplified method for estimating the root biomass from GPR data under field conditions.

Dietary long-chain fatty acids promote colitis by regulating palmitoylation of STAT3 through CD36-mediated endocytosis.

The Western diet, characterized by its high content of long-chain fatty acids (LCFAs), is widely recognized as a significant triggering factor for inflammatory bowel disease (IBD). While the link between a high-fat diet and colitis has been observed, the specific effects and mechanisms remain incompletely understood. Our study provides evidence that the diet rich in LCFAs can disrupt the integrity of the intestinal barrier and exacerbate experimental colitis in mice. Mechanistically, LCFAs upregulate the signal transducer and activator of transcription-3 (STAT3) pathway in the inflammatory model, and STAT3 knockout effectively counters the pro-inflammatory effects of LCFAs on colitis. Specifically, palmitic acid (PA), a representative LCFA, enters intestinal epithelial cells via the cluster of differentiation 36 (CD36) pathway and participates in the palmitoylation cycle of STAT3. Inhibiting this cycle using pharmacological inhibitors like 2-Bromopalmitate (2-BP) and ML349, as well as DHHC7 knockdown, has the ability to alleviate inflammation induced by PA. These findings highlight the significant role of dietary LCFAs, especially PA, in the development and progression of IBD. Diet adjustments and targeted modulation offer potential therapeutic strategies for managing this condition. Model of LCFAs involvement in the palmitoylation cycle of STAT3 upon internalization into cells. Following cellular uptake through CD36, LCFAs are converted to palmitoyl-CoA. In the presence of DHHC7, palmitoyl-CoA binds to STAT3 at the C108 site, forming palmitoylated STAT3. Palmitoylation further promotes phosphorylation at the Y705 site of STAT3. Subsequently, palmitoylated STAT3 undergoes depalmitoylation by APT2 and translocates to the nucleus to exert its biological functions.

Zinc-sensing receptor activation induces endothelium-dependent hyperpolarization-mediated vasorelaxation of arterioles.

BACKGROUND: The micronutrient zinc (Zn2+) is critical for cell function as intracellular signaling and endogenous ligand for Zn2+ sensing receptor (ZnR). Although cytosolic Zn2+ (cyt) signaling in the vascular system was studied previously, role of the ZnR has not been explored in vascular physiology. METHODS: ZnR-mediated relaxation response of human submucosal arterioles and the mesenteric arterioles from wide-type (WT), ZnR-/- and TRPV4-/- mice were determined by a Mulvany-style wire myograph. The perfused vessel density (PVD) of mouse mesenteric arterioles was also measured in in vivo study. The expression of ZnR in arterioles and vascular endothelial cells (VEC) were examined by immunofluorescence staining, and its function was characterized in VEC by Ca2+ imaging and patch clamp study. RESULTS: ZnR expression was detected on human submucosal arterioles, murine mesenteric arterioles and VEC but not in ZnR-/- mice. ZnR activation predominately induced endothelium-dependent hyperpolarization (EDH)-mediated vasorelaxation of arterioles in vitro and in vivo via Ca2+ signaling, which is totally different from endothelium-dependent vasorelaxation via Zn2+ (cyt) signaling reported previously. Furthermore, ZnR-induced vasorelaxation via EDH was significantly impaired in ZnR-/- and TRPV4-/- mice. Mechanistically, ZnR induced endothelium-dependent vasorelaxation predominately via PLC/IP3/IP3R and TRPV4/SOCE. The role of ZnR in regulating Ca2+ signaling and ion channels on VEC was verified by Ca2+ imaging and patch clamp techniques. CONCLUSION: ZnR activation induces endothelium-dependent vasorelaxation of resistance vessels predominately via TRPV4/Ca2+/EDH pathway. We therefore not only provide new insights into physiological role of ZnR in vascular system but also may pave a potential pathway for developing Zn2+-based treatments for vascular disease.

Regulatory role of Piezo1 channel in endothelium-dependent hyperpolarization-mediated vasorelaxation of small resistance vessels and its anti-inflammatory action.

AIMS: Although endothelial Piezo1 channel is known to induce NO-mediated vasorelaxation of conduit vessels, it remains largely unknown if it can induce endothelial-dependent hyperpolarization (EDH)-mediated vasorelaxation of resistance vessels. Therefore, the present study aims to investigate Piezo1/EDH-mediated vasorelaxation in health and its involvement in ulcerative colitis (UC) and sepsis, two intractable and deadly inflammatory diseases. MAIN METHODS: The tension of the second-order branch of mouse mesenteric artery was measured via the Danish DMT600M microvascular measurement system. The changes in cytoplasmic calcium ([Ca2+]cyt) signaling in vascular endothelial cells were detected by fluorescent calcium assay, and the membrane potential changes were monitored by patch clamp. Experimental murine models of UC and sepsis were induced by dextran sulfate sodium (DSS) and lipopolysaccharides (LPS), respectively. KEY FINDINGS: A selective activator of Piezo1 channel, Yoda1, dose-dependently induced vasorelaxation of the second-order branch of mouse mesenteric artery in an endothelium-dependent manner. The endothelial Piezo1 channel mediated the vasorelaxation through EDH mechanism by a functional coupling of Piezo1 and TRPV4 channels. Their function and coupling were verified by [Ca2+]cyt imaging and patch clamp study in single endothelial cells. Moreover, while ACh-induced vasorelaxation played a major role in health, it was significantly impaired in the pathogenesis of UC and sepsis; however, Piezo1/EDH-mediated vasorelaxation remained intact. Finally, Piezo1/EDH-mediated vasorelaxation recovered ACh-induced vasorelaxation impaired in UC and sepsis. SIGNIFICANCE: Piezo1/TRPV4/EDH-mediated vasorelaxation rescues the impaired ACh-induced vasorelaxation to likely recover hemoperfusion to organs, leading to organ protection against UC and sepsis. Our study not only suggests that endothelial Piezo1, TRPV4 and KCa channels are the potential therapeutic targets, but also implies that Piezo1 activators may benefit to prevent/treat UC and sepsis.

2'-Fucosyllactose restores the intestinal mucosal barrier in ulcerative colitis by inhibiting STAT3 palmitoylation and phosphorylation.

BACKGROUND & AIMS: 2'-Fucosyllactose (2'-FL), the primary constituent of human milk oligosaccharides, has been identified as a potential regulator of inflammation in inflammatory bowel disease. Despite this recognition, the specific mechanisms through which 2'-FL alleviates ulcerative colitis (UC) remain ambiguous. This study seeks to investigate the potential anti-inflammatory properties of 2'-FL concerning intestinal inflammation and uncover the associated mechanisms. METHODS: C57BL/6J mice were orally administered a daily dose of 500 mg/kg 2'-FL for 11 consecutive days, followed by the induction of colitis using 3 % (wt/vol) dextran sulfate sodium (DSS) for the final 6 days. Subsequently, a comprehensive range of techniques, including an Acyl-biotin exchange assay, fluorescein-isothiocyanate-labeled dextran assay, histopathology, ELISA, quantitative real-time PCR, Western blot, immunofluorescence staining, immunohistochemistry staining, Alcian blue-periodic acid schiff staining, TdT-mediated dUTP nick end labeling, transmission electron microscopy, iTRAQ quantitative proteomics, bioinformatics analysis, and the generation of signal transducer and activator of transcription 3 (STAT3) knockout mice, were employed to explore the relevant molecular mechanisms. RESULTS: Administration of 2'-FL significantly ameliorated DSS-induced colitis in mice and enhanced the integrity of the intestinal mucosal barrier. 2'-FL downregulated the phosphorylation of STAT3 and inhibited STAT3-related signaling pathways in colon tissues, which, in turn, reduced inflammatory responses. Interestingly, knockdown of STAT3 attenuated the protective effects of 2'-FL, highlighting that 2'-FL-mediated inflammatory attenuation is dependent on STAT3 expression. Additionally, 2'-FL could influence STAT3 activation by modulating the palmitoylation and depalmitoylation of STAT3. CONCLUSIONS: 2'-FL promotes the recovery of the intestinal mucosal barrier and suppresses inflammation in ulcerative colitis by inhibiting the palmitoylation and phosphorylation of STAT3.

Zinc pyrithione induces endothelium-dependent hyperpolarization-mediated mesenteric vasorelaxation in healthy and colitic mice.

BACKGROUND: Although Zinc pyrithione (ZPT) could lower blood pressure by inducing vasorelaxation, it is unclear if it is able to induce vasorelaxation of mesenteric arterioles in health and ulcerative colitis (UC) to exert anti-colitic action. METHODS: The vasorelaxation of the second-order branch of the mesenteric artery from wide type (WT) mice, TRPV1-/-(KO) mice, and TRPV4-/-(KO) mice was determined using a Mulvany-style wire myograph. Calcium imaging and patch clamp were applied to analyze the actions of ZPT in human vascular endothelial cells. Mouse model of UC was used to evaluate the anti-colitic action of ZPT. RESULTS: ZPT dose-dependently induced mesenteric vasorelaxation predominately through endothelium-dependent hyperpolarization (EDH), which could be attenuated by intracellular Zn2+ and Ca2+ chelators TPEN and BAPTA-AM. The ZPT/EDH-mediated vasorelaxation via TRPV1, TRPV4 and TRPA1 channels was verified by a combination of selective pharmacological inhibitors and TRPV1-KO and TRPV4-KO mice. Moreover. ZPT induced Ca2+ entry via vascular endothelial TRPV1/4 and TRPA1 channels and enhanced membrane non-selective currents through these channels. Notably, ZPT exerted anti-colitic effects by rescuing the impaired acetylcholine (ACh)-induced mesenteric vasorelaxation in colitic mice. CONCLUSIONS: ZPT/Zn2+ induces EDH-mediated mesenteric vasorelaxation through activating endothelial multiple TRPV1/4 and TPPA1 channels in health, and rescues the impaired ACh-induced vasorelaxation to exert anti-colitic action. Our study may open a new avenue of potential vessel-specific targeted therapy for UC.

Cl- induces endothelium-dependent mesenteric arteriolar vasorelaxation through the NKCC1/TRPV4/NCX axis.

AIMS: Although absorbed NaCl increases intestinal blood flow to facilitate absorption and transportation, it is unclear if it can directly mediate mesenteric arterial relaxation. We aimed to investigate and test our hypothesis that Cl- induces mesenteric arterial vasorelaxation via endothelium-dependent hyperpolarization (EDH). MAIN METHODS: We used wire myograph to study NaCl-induced vasorelaxation of mesenteric arteries isolated from mice. Cl-, Ca2+ and K+ imaging was performed in human vascular endothelial cells pre-treated with pharmacological agents. KEY FINDINGS: The Cl- concentration-dependently induced vasorelaxation of mesenteric arteries likely through EDH. The Cl--induced vasorelaxation was attenuated in TRPV4 KO mice and inhibited by selective blockers of Na+-K+-2Cl- cotransporter 1 (NKCC1) (bumetanide, 10 µM), transient receptor potential vanilloid 4 (TRPV4) (RN-1734, 40 µM), and small conductance Ca2+-activated K+ channels (SKCa) (apamin, 3 µM)/ intermediate conductance Ca2+-activated K+ channels (IKCa) (TRAM-34, 10 µM) and myoendothelial gap junction (18α-glycyrrhetinic acid, 10 µM), but enhanced by a selective activator of IKCa/SKCa (SKA-31, 0.3 µM). Cl- decreased intracellular K+ concentrations in endothelial cells, which was reversed by apamin (200 nM) plus TRAM-34 (500 nM). Extracellular Cl- raised intracellular Cl- concentrations in endothelial cells, which was attenuated by bumetanide (10 µM). Finally, Cl- induced a transient Ca2+ signaling via TRPV4 in endothelial cells, which became sustained when the Ca2+ exit mode of Na+-Ca2+ exchanger (NCX) was blocked. SIGNIFICANCE: Cl- induces a pure EDH-mediated vasorelaxation of mesenteric arteries through activation of endothelial NKCC1/TRPV4/NCX axis. We have provided a novel insight into the role of Cl--induced vasorelaxation via EDH mechanism.

Estrogen receptor subtype mediated anti-inflammation and vasorelaxation via genomic and nongenomic actions in septic mice.

Aim: Sepsis is a life-threatening disease with high mortality worldwide. Septic females have lower severity and mortality than the males, suggesting estrogen exerts a protective action, but nothing is known about the role of vascular endothelial estrogen receptor subtypes in this process. In the present study, we aimed to study the estrogen receptors on mesenteric arterioles in normal and sepsis mice and to elucidate the underlying mechanisms. Methods: Sepsis was induced in mice by intraperitoneal injection of LPS. The changes in the expression and release of the serum and cell supernatant proinflammatory cytokines, including TNF-α, IL-1ß and IL-6, were measured by qPCR and ELISA, and the functions of multiple organs were analyzed. The functional activities of mouse mesenteric arterioles were determined by a Mulvany-style wire myograph. The expression of phospholipase C (PLC) and inositol 1,4,5-trisphosphate receptor (IP3R) in endothelial cells were examined by Western blot and their functions were characterized by cell Ca2+ imaging. Results: Septic female mice had higher survival rate than the male mice, and pretreatment with E2 for 5 days significantly improved the survival rate and inhibited proinflammatory cytokines in septic male mice. E2 ameliorated pulmonary, intestinal, hepatic and renal multiple organ injuries in septic male mice; and ER subtypes inhibited proinflammatory cytokines in endothelial cells via PLC/IP3R/Ca2+ pathway. E2/ER subtypes immediately induced endothelial-derived hyperpolarization (EDH)-mediated vasorelaxation via PLC/IP3R/Ca2+ pathway, which was more impaired in septic male mice. E2/ER subtypes could rescue the impaired acetylcholine (ACh)-induced EDH-mediated vasorelaxation in septic male mice. Conclusions: E2 through ER subtypes mediates anti-inflammation and vasorelaxation via genomic and nongenomic actions in sepsis. Mechanistically, activation of endothelial ER subtypes reduces proinflammatory cytokines and induces EDH-mediated vasorelaxation via PLC/IP3R/Ca2+ pathway, leading to amelioration of sepsis-induced organ injury and survival rate.

Close association of PFASs exposure with hepatic fibrosis than steatosis: evidences from NHANES 2017-2018.

Multiple animals and in vitro studies have demonstrated that perfluoroalkyl and polyfluoroalkyl substances (PFASs) exposure causes liver damage associated with fat metabolism. However, it is lack of population evidence for the correlation between PFAS exposure and nonalcoholic fatty liver disease (NAFLD). A cross-sectional analysis was performed of 1150 participants aged over 20 from the US. Liver ultrasound transient elastography was to identify the participants with NAFLD and multiple biomarkers were the indicators for hepatic steatosis and hepatic fibrosis. Logistics regression and restricted cubic splines models were used to estimate the association between PFASs and NAFLD. PFASs had not a significant association with NAFLD after adjustment. The hepatic steatosis indicators including fatty liver index, NAFLD liver fat score, and Framingham steatosis index were almost not significantly correlated with PFASs exposure respectively. But fibrosis indicators including fibrosis-4 index (FIB-4), NAFLD fibrosis score, and Hepamet fibrosis score were positively correlated with each type of PFASs exposure. After adjustment by gender, age, race, education, and poverty income rate, there was also a significant correlation between PFOS and FIB-4 with 0.07 (0.01, 0.13). The mixed PFASs were associated with FIB-4, with PFOS contributing the most (PIP = 1.000) by the Bayesian kernel machine regression model. The results suggested PFASs exposure appeared to be more closely associated with hepatic fibrosis than steatosis, and PFOS might be the main cause of PFASs associated with hepatic fibrosis.Key messagesCurrent exposure doses of PFAS did not significantly change the risk of developing NAFLD.PFASs exposure appeared to be more closely associated with hepatic fibrosis than steatosis.PFOS might be the main cause of PFASs associated with hepatic fibrosis.

Spatial-temporal characteristics of geological disaster resilience in poverty and disaster-prone areas in China: a case study of Ganzi Prefecture.

Under the tremendous challenges of frequent disasters, disaster resilience is imperative for risk reduction and sustainable management in poverty and disaster-prone areas. Ganzi Prefecture has a complicated topography and vulnerable ecosystems. Geological disasters have historically been the most serious risks in the region. To fully understand the potential risks and strengthen resilience, the study investigates the resilience level of 18 counties in Ganzi. Firstly, the paper develops a multidimensional index system based on the Baseline Resilience Indicators for Communities (BRIC) framework. And the entropy weighting method is used to calculate Ganzi's disaster resilience level from the aspects of "society-economy-infrastructure-environment." Then, the study uses exploratory spatial data (ESDA) to analyze the spatial-temporal evolution of disaster resilience. Finally, Geodetector is used to investigate the main driving factors of disaster resilience and their interactions. The results indicated that Ganzi's disaster resilience had maintained an upward trend from 2011 to 2019, with significant spatial divergence, which shows high resilience in the southeast and low resilience in the northwest. The economic indicator is the driving factor in the spatial difference of disaster resilience, and the interaction factor has a significantly stronger explanatory power for resilience. Therefore, the government should strengthen ecotourism development to help alleviate poverty in special industries and promote synergistic regional development.

Association between perfluoroalkyl and polyfluoroalkyl internal exposure and serum α-Klotho levels in middle-old aged participants.

Purpose: Exposure to perfluoroalkyl and polyfluoroalkyl substances causes oxidative stress, which is strongly associated with adverse health effects. Klotho protein plays an anti-aging role via antioxidation activity. Methods: We investigated the levels of serum α-Klotho and PFAS exposure in adults who participated in the National Health and Nutrition Examination Survey from 2013 to 2016. A nationally representative subsample of 1,499 adults aged 40-79 years was analyzed for the associations of serum α-Klotho levels with serum PFAS exposures by correlation analysis and multiple general linear models. Of note, the potential confounding factors including age and gender were adjusted. Quantile-based g-computation models were used to assess the effects of mixed PFAS exposure on serum α-Klotho levels. Results: The weighted geometric mean of serum α-Klotho was 791.38 pg/mL for the subjects during 2013-2016. After adjusting for potential confounders, serum Klotho levels showed a statistically significant downward trend with increasing quartiles of PFOA and PFNA. Multivariate adjusted general linear regression analysis showed that increased exposure to PFNA was substantially associated with lower serum levels of α-Klotho, and each 1-unit increase in PFNA concentration was accompanied by a 20.23 pg/mL decrease in α-Klotho level; while no significant association was observed between other PFAS exposures and serum α-Klotho levels. It was negatively correlated between α-Klotho and Q4 for PFNA relative to the lowest quartile (Q1) of exposure (P = 0.025). It was found that the strongest negative correlation between PFNA exposure and serum α-Klotho levels was in the middle-aged (40-59 years) female participants. Furthermore, the mixture of the four PFAS substances showed an overall inverse association with serum α-Klotho concentrations, with PFNA being the major contributor. Conclusions: Taken together, in a representative sample of the U.S. middle-aged and elderly populations, serum concentrations of PFAS, especially PFNA, have been negatively associated with serum levels of α-Klotho, which is strongly associated with cognition and aging. It was important to note that the majority of associations were limited to middle-aged women. It will be meaningful to clarify the causal relationship and the pathogenic mechanisms of PFAS exposure and α-Klotho levels, which is helpful to aging and aging-related diseases.

Effects of intensive blood pressure lowering on cerebral ischaemia in thrombolysed patients: insights from the ENCHANTED trial.

Background: Intensive blood pressure lowering may adversely affect evolving cerebral ischaemia. We aimed to determine whether intensive blood pressure lowering altered the size of cerebral infarction in the 2196 patients who participated in the Enhanced Control of Hypertension and Thrombolysis Stroke Study, an international randomised controlled trial of intensive (systolic target 130-140 mm Hg within 1 h; maintained for 72 h) or guideline-recommended (systolic target <180 mm Hg) blood pressure management in patients with hypertension (systolic blood pressure >150 mm Hg) after thrombolysis treatment for acute ischaemic stroke between March 3, 2012 and April 30, 2018. Methods: All available brain imaging were analysed centrally by expert readers. Log-linear regression was used to determine the effects of intensive blood pressure lowering on the size of cerebral infarction, with adjustment for potential confounders. The primary analysis pertained to follow-up computerised tomography (CT) scans done between 24 and 36 h. Sensitivity analysis were undertaken in patients with only a follow-up magnetic resonance imaging (MRI) and either MRI or CT at 24-36 h, and in patients with any brain imaging done at any time during follow-up. This trial is registered with ClinicalTrials.gov, number NCT01422616. Findings: There were 1477 (67.3%) patients (mean age 67.7 [12.1] y; male 60%, Asian 65%) with available follow-up brain imaging for analysis, including 635 patients with a CT done at 24-36 h. Mean achieved systolic blood pressures over 1-24 h were 141 mm Hg and 149 mm Hg in the intensive group and guideline group, respectively. There was no effect of intensive blood pressure lowering on the median size (ml) of cerebral infarction on follow-up CT at 24-36 h (0.3 [IQR 0.0-16.6] in the intensive group and 0.9 [0.0-12.5] in the guideline group; log Δmean -0.17, 95% CI -0.78 to 0.43). The results were consistent in sensitivity and subgroup analyses. Interpretation: Intensive blood pressure lowering treatment to a systolic target <140 mm Hg within several hours after the onset of symptoms may not increase the size of cerebral infarction in patients who receive thrombolysis treatment for acute ischaemic stroke of mild to moderate neurological severity. Funding: National Health and Medical Research Council of Australia; UK Stroke Association; UK Dementia Research Institute; Ministry of Health and the National Council for Scientific and Technological Development of Brazil; Ministry for Health, Welfare, and Family Affairs of South Korea; Takeda.

The CaSR/TRPV4 coupling mediates pro-inflammatory macrophage function.

AIM: Although calcium-sensing receptor (CaSR) and transient receptor potential vanilloid 4 (TRPV4) channels are functionally expressed on macrophages, it is unclear if they work coordinately to mediate macrophage function. The present study investigates whether CaSR couples to TRPV4 channels and mediates macrophage polarization via Ca2+ signaling. METHODS: The role of CaSR/TRPV4/Ca2+ signaling was assessed in lipopolysaccharide (LPS)-treated peritoneal macrophages (PMs) from wild-type (WT) and TRPV4 knockout (TRPV4 KO) mice. The expression and function of CaSR and TRPV4 in PMs were analyzed by immunofluorescence and digital Ca2+ imaging. The correlation factors of M1 polarization, CCR7, IL-1ß, and TNFα were detected using q-PCR, western blot, and ELISA. RESULTS: We found that PMs expressed CaSR and TRPV4, and CaSR activation-induced marked Ca2+ signaling predominately through extracellular Ca2+ entry, which was inhibited by selective pharmacological blockers of CaSR and TRPV4 channels. The CaSR activation-induced Ca2+ signaling was significantly attenuated in PMs from TRPV4 KO mice compared to those from WT mice. Moreover, the CaSR activation-induced Ca2+ entry via TRPV4 channels was inhibited by blocking phospholipases A2 (PLA2)/cytochromeP450 (CYP450) and phospholipase C (PLC)/Protein kinase C (PKC) pathways. Finally, CaSR activation promoted the expression and release of M1-associated cytokines IL-1ß and TNFɑ, which were attenuated in PMs from TRPV4 KO mice. CONCLUSION: We reveal a novel coupling of the CaSR and TRPV4 channels via PLA2/CYP450 and PLC/PKC pathways, promoting a Ca2+ -dependent M1 macrophage polarization. Modulation of this coupling and downstream pathways may become a potential strategy for the prevention/treatment of immune-related disease.

Construction of Vicinal All-Carbon Stereogenic Centers via Copper-Catalyzed Asymmetric Decarboxylative Propargylation: Enantio- and Diastereoselective Synthesis of Substituted Spirolactones.

The formation of vicinal all-carbon quaternary stereocenters remains a formidable challenge. We report herein the synthesis of such highly congested structural dyads by copper-catalyzed decarboxylative propargylation between propargyl carbonates and indanone-based nucleophiles. The implementation of diphenylethylenediamine (DPEN)-based ligands is the key to success. A wide range of functional groups was tolerated, delivering the indanone-based spirolactones in good yields with high diastereo- and enantioselectivity. The mechanistic observations suggest the capability of the new copper complex to enable stereocontrolled addition to copper-allenylidene species.

Effects of the genetic knockout of the ß-1,3-galactosyltransferase 2 on spatial learning and neurons in the adult mouse hippocampus and somatosensory cortex.

OBJECTIVE: Glycosyltransferases contribute to the biosynthesis of glycoproteins, proteoglycans and glycolipids and play essential roles in various processes in the brain, such as learning and memory, brain development, neuronal survival and neurodegeneration. ß-1,3-galactosyltransferase 2 (B3galt2) belongs to the ß-1,3-galactosyltransferase gene family and is highly expressed in the brain. Recent studies have indicated that B3galt2 plays a vital role in ischemic stroke through several signaling pathways in a mouse model. However, the function of B3galt2 in the brain remains poorly understood. METHODS: The genotypes of mice were determined by PCR. To verify B3galt2 expression in an adult mouse brain, X-gal staining was performed in 6-month-old B3galt2 heterozygous (B3galt2+/-) mice. Using adult B3galt2 homozygous (B3galt2-/-), heterozygous and wild-type (WT) littermates, spatial learning and memory were determined by the Morris Water Maze test, and neurotoxicity and synaptic plasticity were examined by immunofluorescence. RESULTS: B3galt2 was highly expressed in the adult mouse hippocampus and cortex, especially in the hippocampal dentate gyrus. Compared to that of WT mice, the spatial learning ability of adult B3galt2-/- mice was impaired. B3galt2 mutations also caused neuronal loss and synaptic dysfunction in the hippocampus and somatosensory cortex, and these changes were more obvious in B3galt2-/- mice than in B3galt2+/- mice. CONCLUSIONS: The findings indicate that B3galt2 plays an important role in cognitive function, neuronal maintenance and synaptic plasticity in the adult mouse brain. This study suggests that genetic and/or pharmacological manipulation of glycosyltransferases may be a novel strategy for elucidating the mechanism of and managing various brain disorders.

Epidemiological characteristics of community-acquired pneumonia and effects from the COVID-19 pandemic in Shenzhen of China.

OBJECTIVE: This study aimed to observe the impact of the coronavirus disease 2019 (COVID-19) pandemic on the incidence of non-COVID-19 community-acquired pneumonia (CAP) in Shenzhen of China, offering new ideas for evaluating the effects of non-pharmaceutical interventions. METHODS: A retrospective analysis was conducted of inpatients with pneumonia from 2017 to 2021. Epidemiological characteristics of CAP and effects from the COVID-19 pandemic were analyzed by the basic characteristics, time distribution, etiology and disease burden. RESULTS: There were a total of 5746 CAP inpatient cases included from 2017 to 2021. The number of CAP hospitalizations decreased during the pandemic from 2020 to 2021, with seasonal variations of being higher in spring and winter and lower in summer and autumn, whereas it was prevalent throughout the year prior to the pandemic. The children group decreased significantly during the pandemic, with a 15% decrease in the share of CAP inpatients. The detection rates of bacteria and mycoplasma decreased in CAP patients, while the detection rate of the virus increased, and the number of moderate and severe cases reduced more than that of the mild. CONCLUSION: Non-pharmaceutical interventions from COVID-19 have led to a decrease in the number of CAP inpatients, especially for children, with a specific seasonal prevalence in spring and winter, when the prevention interventions should be strengthened further for adults during the pandemic.

Glycyrrhizic Acid Mitigates Tripterygium-Glycoside-Tablet-Induced Acute Liver Injury via PKM2 Regulated Oxidative Stress.

Tripterygium glycoside tablet (TGT), as a common clinical drug, can easily cause liver damage due to the narrow therapeutic window. Glycyrrhizic acid (GA) has a hepatoprotective effect, but the characteristics and mechanism of GA's impact on TGT-induced acute liver injury by regulating oxidative stress remain unelucidated. In this study, TGT-induced acute liver injury models were established in vitro and in vivo. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT), lactate dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) were quantified. The anti-apoptotic effect of GA was tested using flow cytometry. Potential target proteins of GA were profiled via activity-based protein profiling (ABPP) using a cysteine-specific (IAA-yne) probe. The results demonstrate that GA markedly decreased the concentrations of ALT, AST, AKP, MDA, LDH, TNF-α, IL-1ß and IL-6, whereas those of SOD, GSH and CAT increased. GA could inhibit TGT-induced apoptosis in BRL-3A cells. GA bound directly to the cysteine residue of PKM2. The CETSA and enzyme activity results validate the specific targets identified. GA could mitigate TGT-induced acute liver injury by mediating PKM2, reducing oxidative stress and inflammation and reducing hepatocyte apoptosis.

New roles of N6-methyladenosine methylation system regulating the occurrence of non-alcoholic fatty liver disease with N6-methyladenosine-modified MYC.

Non-alcoholic fatty liver disease (NAFLD) has become a major chronic disease in contemporary society, affected by N6-methyladenosine (m6A) RNA methylation, one of the most common RNA modifications. Compared with healthy control, m6A RNA methyltransferase 3 (METTL3) and METTL14 increased, while Wilms tumor 1-associated protein (WTAP) and RNA-binding motif protein 15 (RBM15) decreased significantly in NAFLD, and the m6A demethylases fat mass and obesity-associated protein (FTO) elevated. Meanwhile, the m6A binding proteins, YT521-B homology (YTH) domain-containing 1 (YTHDC1), YTHDC2, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1), heterogeneous nuclear ribonucleoprotein C (HNRNPC), and HNRNPA2B1 were decreased, while eukaryotic translation initiation factor 3 subunit H (EIF3H) was increased significantly. All these changes of m6A regulators had significant differences between healthy control and NAFLD, but no differences between the NAFL and NASH group. The expression level of RBM15, HNRNPC, and HNRNPA2B1 were related to body fat index. RBM15, YTHDC2, HNRNPC, HNRNPA2B1, and EIF3H were related to steatosis. Also, KIAA1429 and YTH domain family 1 (YTHDF1) were related to lobular inflammation. Taken together, m6A regulators were involved in the occurrence of NAFLD. More importantly, abnormal MYC was determined as a key link to m6A regulation of NAFLD. The higher MYC mRNA level was accompanied by higher HDL cholesterol and unsaturated fatty acid proportions, as well as lower fat mass, glucose, and transaminase. Taken together, dysregulation of m6A methylation caused steatosis and fibrosis, affecting the occurrence of NAFLD, and MYC might be its potential target.

Novel Roles of RNA m6A Methylation Regulators in the Occurrence of Alzheimer's Disease and the Subtype Classification.

Alzheimer's disease (AD) is one of the most common forms of dementia, closely related to epigenetic factors. N6-methyladenosine (m6A) is the most abundant RNA modification, affecting the pathogenesis and development of neurodegenerative diseases. This study was the first exploration of the combined role of 25 common m6A RNA methylation regulators in AD through the integrated bioinformatics approaches. The 14 m6A regulators related to AD were selected by analyzing differences between AD patients and normal controls. Based on the selected m6A regulators, AD patients could be well classified into two m6A models using consensus clustering. The two clusters of patients had different immune profiles, and m6A regulators were associated with the components of immune cells. Additionally, there were 19 key AD genes obtained by screening differential genes through weighted gene co-expression network and least absolute shrinkage and selection operator regression analysis, which were highly associated with important m6A regulators during the occurrence of AD. More interestingly, NOTCH2 and NME1 could be potential targets for m6A regulation of AD. Taken together, these findings indicate that dysregulation of m6A methylation affects the occurrence of AD and is vital for the subtype classification and immune infiltration of AD.

Effect of theaflavin-3,3'-digallate on leptin-deficient induced nonalcoholic fatty liver disease might be related to lipid metabolism regulated by the Fads1/PPARδ/Fabp4 axis and gut microbiota.

Nonalcoholic fatty liver disease (NAFLD), one of the risk factors for hepatitis, cirrhosis, and even hepatic carcinoma, has been a global public health problem. The polyphenol compound theaflavin-3,3'-digallate (TF3), mainly extracted from black tea, has been reported to produce an effect on hypoglycemic and antilipid deposition in vitro. In our study, we further investigated the function and novel mechanisms of TF3 in protecting NAFLD in vivo. By using leptin-deficient obese (ob/ob) mice with NAFLD symptoms, TF3 treatment prevented body weight and waistline gain, reduced lipid accumulation, and alleviated liver function injury, as well as decreased serum lipid levels and TG levels in livers in ob/ob mice, observing no side effects. Furthermore, the transcriptome sequencing of liver tissue showed that TF3 treatment corrected the expression profiles of livers in ob/ob mice compared with that of the model group. It is interesting to note that TF3 might regulate lipid metabolism via the Fads1/PPARδ/Fabp4 axis. In addition, 16S rRNA sequencing demonstrated that TF3 increased the abundance of Prevotellaceae_UCG-001, norank_f_Ruminococcaceae, and GCA-900066575 and significantly decreased that of Parvibacter. Taken together, the effect of TF3 on NAFLD might be related to lipid metabolism regulated by the Fads1/PPARδ/Fabp4 axis and gut microbiota. TF3 might be a promising candidate for NAFLD therapy.