The acquisition of cold sensitivity during TRPM8 ion channel evolution.

To cope with temperature fluctuations, molecular thermosensors in animals play a pivotal role in accurately sensing ambient temperature. Transient receptor potential melastatin 8 (TRPM8) is the most established cold sensor. In order to understand how the evolutionary forces bestowed TRPM8 with cold sensitivity, insights into both emergence of cold sensing during evolution and the thermodynamic basis of cold activation are needed. Here, we show that the trpm8 gene evolved by forming and regulating two domains (MHR1-3 and pore domains), thus determining distinct cold-sensitive properties among vertebrate TRPM8 orthologs. The young trpm8 gene without function can be observed in the closest living relatives of tetrapods (lobe-finned fishes), while the mature MHR1-3 domain with independent cold sensitivity has formed in TRPM8s of amphibians and reptiles to enable channel activation by cold. Furthermore, positive selection in the TRPM8 pore domain that tuned the efficacy of cold activation appeared late among more advanced terrestrial tetrapods. Interestingly, the mature MHR1-3 domain is necessary for the regulatory mechanism of the pore domain in TRPM8 cold activation. Our results reveal the domain-based evolution for TRPM8 functions and suggest that the acquisition of cold sensitivity in TRPM8 facilitated terrestrial adaptation during the water-to-land transition.

Discovery of novel cGAS inhibitors based on natural flavonoids.

Cyclic GMP-AMP synthase (cGAS) plays an important role in the inflammatory response. It has been reported that aberrant activation of cGAS is associated with a variety of immune-mediated inflammatory disorders. The development of small molecule inhibitors of cGAS has been considered as a promising therapeutic strategy for the diseases. Flavonoids, a typical class of natural products, are known for their anti-inflammatory activities. Although cGAS is closely associated with inflammation, the potential effects of natural flavonoid compounds on cGAS have been rarely studied. Therefore, we screened an in-house natural flavonoid library by pyrophosphatase (PPiase) coupling assay and identified novel cGAS inhibitors baicalein and baicalin. Subsequently, crystal structures of the two natural flavonoids in complex with human cGAS were determined, which provide mechanistic insight into the anti-inflammatory activities of baicalein and baicalin at the molecular level. After that, a virtual screening based on the crystal structures of baicalein and baicalin in complex with human cGAS was performed. As a result, compound C20 was identified to inhibit both human and mouse cGAS with IC50 values of 2.28 and 1.44 µM, respectively, and its detailed interactions with human cGAS were further revealed by the X-ray crystal structure determination. These results demonstrate the potential of natural products used as hits in drug discovery and provide valuable hints for further development of cGAS inhibitors.

Structure-Based Design of Potent Peptidomimetic Inhibitors Covalently Targeting SARS-CoV-2 Papain-like Protease.

The papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a critical role in the proteolytic processing of viral polyproteins and the dysregulation of the host immune response, providing a promising therapeutic target. Here, we report the structure-guide design of novel peptidomimetic inhibitors covalently targeting SARS-CoV-2 PLpro. The resulting inhibitors demonstrate submicromolar potency in the enzymatic assay (IC50 = 0.23 µM) and significant inhibition of SARS-CoV-2 PLpro in the HEK293T cells using a cell-based protease assay (EC50 = 3.61 µM). Moreover, an X-ray crystal structure of SARS-CoV-2 PLpro in complex with compound 2 confirms the covalent binding of the inhibitor to the catalytic residue cysteine 111 (C111) and emphasizes the importance of interactions with tyrosine 268 (Y268). Together, our findings reveal a new scaffold of SARS-CoV-2 PLpro inhibitors and provide an attractive starting point for further optimization.

Predictors of successful discontinuation from renal replacement therapy during AKI: A meta-analysis.

The predictors of weaning time of renal replacement therapy (RRT) remain controversial for special patients suffering from acute kidney injury (AKI). The present work aims to perform a meta-analysis to evaluate proper predictors of RRT weaning in AKI patients. We systematically searched EMBASE, PubMed, and Cochrane Central Register of Controlled trials for literatures between 1984 and June 2019. Studies evaluating predictors of weaning success of RRT in patients of AKI were included. Random-effects model or fixed-effects model meta-analyses were performed to compute a standard mean difference (SMD). Newcastle-Ottawa Scale was employed to assess the risk of bias. We included 10 observational trials including 1453 patients. Twelve predictors including urine output, serum creatinine, serum urea, mean arterial pressure, central venous pressure, lactate, serum potassium, serum bicarbonate, pH value, SOFA score, urinary urea, and urinary creatinine were identified, showing urine output (p = 0.0000), serum creatinine (p = 0.008), serum potassium (p = 0.02), serum bicarbonate (p = 0.01), pH value (p = 0.03), urinary urea (p = 0.002), and urinary creatinine (p = 0.02) were significantly associated with weaning success. With the limited evidence, we speculate that urine output, serum creatinine, serum potassium, serum bicarbonate, pH value, urinary urea, and urinary creatinine might be associated with successful weaning.

Low lean mass and cognitive performance: data from the National Health and Nutrition Examination Surveys.

BACKGROUND: Low lean mass and cognitive impairment are both age-related diseases. In addition, these conditions share many risk factors. However, the association between them has been controversial in recent years. OBJECTIVE: To investigate the association between low lean mass and cognitive performance in U.S. adults using NHANES data from 1999 to 2002. METHODS: A total of 2550 participants were identified in the National Health and Nutrition Examination Survey Database (1999-2002). The independent variable was low lean mass, and the dependent variable was cognitive performance. Men and women were classified as having low lean mass if appendicular lean mass (ALM) adjusted for BMI (ALMBMI) was < 0.789 and < 0.512, respectively. Cognitive performance was assessed using the Digit Symbol Substitution Test (DSST). Higher scores on the DSST indicated better cognitive performance. The covariates included sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status. RESULTS: For the primary outcome, our multivariate linear regression analysis indicated that participants without low lean mass were associated with better cognitive performance (ß = 1.50; 95% CI [0.12-2.89]). Subgroup analysis results indicated that the association was similar in sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status. CONCLUSIONS: Participants without low lean mass were associated with better cognitive performance. We might be able to improve cognitive performance by treating low lean mass, thus providing an opportunity for intervention at a younger age.

Vascular calcification is associated with Wnt-signaling pathway and blood pressure variability in chronic kidney disease rats.

AIM: Vascular calcification (VC) is a common complication in chronic kidney disease (CKD) and has been shown to be associated with increased cardiovascular events and mortality. This study was to explore the role of Wnt-signaling pathway in CKD VC, and the association between VC and blood pressure variability (BPV) which is a risk factor of cardiovascular events. METHODS: Adult male Sprague-Dawley rats were divided into adenine-induced CKD group (n = 5), 5/6 nephrectomy CKD group (n = 5), sham group (n = 5) and control group (n = 5). Low-calcium-high-phosphate diets were introduced to induce vascular calcification. Both daytime (hour-to-hour during the day) and mid-term (day-to-day for 9 days) blood pressure (BP) were collected and analyzed for BPV metrics. At sacrifice, kidney, heart and aorta samples were taken for histological analyses. Calcium deposition in aorta was identified with Alizarin Red stain and graded. Immunohistochemistry stain and western blot were performed for Wnt3a, Wnt5a, ß-catenin, sclerostin, osteopontin, and α-SMA. RESULTS: Compared with control rats, CKD rats suffered from markedly severer VC (Grade 2.6 ± 0.2 and 1.8 ± 0.8 vs 0.0 ± 0.0 and 0.2 ± 0.4, P = .0010). VC was positively correlated with vascular Wnt3a and ß-catenin expression (P = .0032 and .0000), but not significantly associated with Wnta5a or sclerostin. Besides, CKD rats showed increased BPV (P < .001), which was also positively correlated with VC. CONCLUSION: We confirmed that CKD rats had enhanced Wnt-signaling in vascular tissue and severer aorta calcification together with increased BPV. Wnt pathway may be a potential target in future VC and BPV management in CKD.

Association of mineral content outside of bone with coronary artery calcium and 1-year cardiovascular prognosis in maintenance hemodialysis patients.

Coronary artery calcifications (CACs) are common among maintenance hemodialysis (MHD) patients and associated with increased morbidity and mortality due to cardiovascular events. The insight into chronic kidney disease-mineral and bone disorder (CKD-MBD) established a correlation between dysregulated mineral metabolism and CACs. This study aimed to identify the association of mineral content outside of bone (MCOB) with CACs and cardiovascular events in MHD patients. In the pilot prospective study with no intervention, patients underwent body composition assessment by body composition monitor after hemodialysis and computed tomography examination using the Agatston scoring method simultaneously within a week. The primary end point included cardiovascular events and cardiovascular death. Correlations and receiver operating characteristic analysis elucidated the associations of MCOB with CACs; multivariate analysis assessed the cardiovascular risk for groups with different MCOB. One hundred three eligible patients with an average age of 48 (35-63) years old were enrolled and followed up to 12 (11-12.5) months, among which 52.4% had detectable CACs at baseline. MCOB showed an inverse correlation with Agatston score and significantly discriminated the patients with Agatston score > 0 (AUC = 0.737; P < 0.001) and 400 (AUC = 0.733; P < 0.001). MCOB ≤ 9.2657 mg/kg was an independent risk factor for CACs (OR = 4.853; P = 0.044) and strong predictor for cardiovascular morbidity and mortality (HR = 10.108; P = 0.042), as well as rehospitalization (HR = 2.689; P = 0.004). MCOB inversely correlated with the presence and extent of CACs, and could discriminate Agatston score > 0 and 400, which also presented as an independent indicator for CKD-MBD and 1-year cardiovascular prognosis in adult MHD patients. Additional studies are required for identifying this issue.

The Association between Long- and Intra-Dialytic Blood Pressure Variability with All-Cause Mortality in Hemodialysis Patients.

BACKGROUND: Blood pressure variability (BPV) is a potential prognostic predictor for all-cause mortality. OBJECTIVES: We conducted a retrospective cohort study to compare the prognostic value of long-term BPV with intra-dialytic BPV in hemodialysis (HD) patients. MATERIALS AND METHODS: We included 611 HD patients and collected their baseline blood pressure (BP) measurements for 1 year and monitored them for 40 months. Long-term BPV was assessed by pre-dialysis BP SD and pre-dialysis absolute BP residual metric. Intra-dialytic BPV was assessed by intra-dialytic BP average real variability and intra-dialytic absolute BP residual. RESULTS: Long-term systolic BPV showed a weak correlation with mean BP, but a stronger correlation with intra-dialytic BPV. High long-term systolic blood pressure (SBP) SD and long-term SBP residual metrics were associated with high all-cause mortality (p = 0.0084 and 0.0056, respectively), while no such association was found for intra-dialytic BPV or diastolic BPV. According to receiver operating characteristic curve with mortality as dependent variable, long-term SBP residual metric showed the strongest prognostic ability (area under curve [AUC] 0.679, p = 0.0006), which was even stronger in patients with BP ≥140/90 mm Hg (AUC 0.713, p = 0.0004). After completely adjusting for confounders, long-term SBP residual metric remained significantly associated with all-cause mortality (hazard ratio 1.628 per quartile; 95% CI 1.086-2.441). CONCLUSIONS: Our results suggest long-term SBP residual metric to be a better predictor of all-cause mortality in HD patients, which could be used as an additional target for BP management.

Association of Peridialysis Blood Pressure and Its Variability with Cardiovascular Events in Hemodialysis Patients.

BACKGROUND/AIMS: Blood pressure variability (BPV) is a novel cardiovascular risk factor for the population undergoing hemodialysis (HD). METHODS: We conducted a retrospective cohort study of 526 HD patients. Four short-term peridialysis BPV metrics were analyzed: systolic blood pressure (SBP) change, SBP coefficient of variation (CV), SBP intradialytic average real variability (ARV), and absolute SBP residual. Multi variate analysis with Cox regression models were used to account for the potential confounders. RESULTS: Short-term BPV is found to be affected by age, pre-dialysis SBP, antihypertensive drugs, dialysis time, and vascular access. Calcium-channel blockers (CCBs) were found to be associated with lower BPV than those on non-CCB therapy or no antihypertensive drugs. Patients dialyzed in the morning had a greater absolute SBP change than those dialyzed in the afternoon or evening. Patients using fistulas had a lower BPV than catheters. Higher BPV metrics including SBP CV (unadjusted hazard ratio [HR]: 1.37, 95% confidence interval [CI] 1.14-1.66, p=0.001), SBP intradialytic ARV (unadjusted HR: 1.46, 95% CI: 1.20-1.77, p< 0.001), and SBP residual (unadjusted HR: 1.47, 95% CI: 1.21-1.79, p< 0.001) were associated with a greater risk of cardiovascular events. After complete multivariate adjustment for other potential confounders, the HR remained statistically significant for SBP intradialytic ARV (HR 1.31, 95% CI: 1.04-1.66, p=0.024). CONCLUSION: Peridialytic BPV may be a potential target for improved blood pressure (BP) management in HD patients. Each short-term BPV metric has different advantages and disadvantages and should be applied according to the clinical context and purpose.

[Research Status of Application of Gold Nanoparticles in Medical Biotechnology].

In recent years, gold nanoparticles (GNPs) have attracted more and more attention for their unique physical, chemical and biological properties, and are emerging as optical probes and biocompatibility materials for use. With the application of nanogold labeling technology in the medical field, detection techniques using GNPs as immune markers will become a major labeling technique, and will have wide applications in basic and clinical medicine. In this article, recent research progress on the applications of GNPs in the detection of pathogens, nucleic acids, and proteins and in the preparation of biosensors is reviewed.

Molecular epidemiology of coxsackievirus A6 associated with outbreaks of hand, foot, and mouth disease in Tianjin, China, in 2013.

Since 2008, Mainland China has undergone widespread outbreaks of hand, foot, and mouth disease (HFMD). In order to determine the characteristics of epidemics and enteroviruses (EV) associated with HFMD in Tianjin, in northern China, epidemiological and virological data from routine surveillance were collected and analyzed. In Tianjin, a persistent epidemic of HFMD was demonstrated during 2008-2013, involving 102,705 mild, 179 severe, and 16 fatal cases. Overall, 8234 specimens were collected from 7829 HFMD patients for EV detection during 2008-2013. Enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) were the dominant serotypes during 2008-2012, and they were replaced by CV-A6 as the major causative agent in 2013. Phylogenetic analysis based on complete VP1 nucleotide sequences revealed that multiple CV-A6 lineages co-circulated in Tianjin, which grouped together with strains from China and other countries and split into two distinct clusters (clusters 1 and 2). Most Tianjin strains grouped in cluster 1 and were closely related to strains from several eastern and southern provinces of China during 2012 and 2013. Estimates from Bayesian MCMC analysis suggested that multiple lineages had been transmitted silently before the outbreaks at an estimated evolutionary rate of 4.10 × 10(-3) substitutions per site per year without a specific distribution of rate variances among lineages. The sudden outbreak of CV-A6 in Tianjin during 2013 is attributed to indigenous CV-A6 lineages, which were linked to the wide spread of endemic strains around eastern and southern China.

A social emotional learning intervention to reduce psychosocial difficulties among rural children in central China.

Programmes based on social emotional learning (SEL) have been effective in reducing psychosocial difficulties in a number of countries. In Mainland China, there has been no empirical research on the prevention of children's psychosocial difficulties using the SEL approach. This study aimed to assess whether an adapted version of the SEL programme can reduce psychosocial difficulties of primary school children in rural China. The intervention consisted of 16 weekly 90-min class sessions, conducted among 206 children aged 8-12 years (with 290 controls) in a poor rural area of Central China. Self-report questionnaires were administered at baseline, post-intervention and 5-month follow-up. The results suggested that the programme (1) can reduce children's total difficulties (measured using the Strength and Difficulties Questionnaire) at post-intervention (d = -0.18) and 5-month follow-up (d = -0.19), (2) was more effective among children experiencing verbal abuse (d = -0.21) or physical abuse (d = -0.24) from caregivers and (3) was popular among more than 90% of the participants. The programme is cheap, easy to implement and can be delivered in school hours. Therefore, it has clear potential for replicability and sustainability.

A school-based intervention programme to prevent anxiety and depression among Chinese children during the COVID-19 pandemic.

BACKGROUND: Child and adolescent mental health is a major public health concern worldwide. The development of children's social and emotional skills helps to improve mental health and wellbeing, and prevent anxiety and depression. The school-based social emotional learning (SEL) programmes have proved effective in a number of countries. But in Mainland China, there has been no empirical research of the effectiveness on children's mental health. The study conducted a SEL programme in China during the COVID-19 pandemic and aimed to determine whether: (1) a SEL programme can reduce anxiety and depression, (2) the intervention effect is influenced by sociodemographic characteristics, (3) the programme effects change children's emotion management and communication. METHODS: Participants were 230 children aged 8-12 years in the intervention school and 325 in the control school in two poor villages in central China. The study was a quasi-experimental trial, comprising 16 weekly 90-minute sessions. It used a mixed-methods design, with a quantitative survey administered at baseline, post-intervention, and 5-month follow-up, and qualitative interviews. Linear mixed effects regression modeling was used to analyse the intervention effectiveness, linear models were conducted to examine the moderation effect of sociodemographic variables, and the inductive thematic analysis approach was used for interview data. RESULTS: The intervention had no significant effect on anxiety or depression, except that intervention school children who lived with neither parent (left behind children) reported lower depression scores than control school at post-intervention and 5-month follow-up. Qualitative interviews showed after intervention children were more able to control tempers and better communicated their thoughts and feelings, improving their relationships with family and friends. CONCLUSIONS: The programme was cheap, easy to implement, and warmly welcomed by children, schools and caregivers, suggesting it was feasible and potentially sustainable. More research is needed on the adaptation of the SEL programme in the Chinese context.

HMGB1: A New Target for Ischemic Stroke and Hemorrhagic Transformation.

Stroke in China is distinguished by its high rates of morbidity, recurrence, disability, and mortality. The ultra-early administration of rtPA is essential for restoring perfusion in acute ischemic stroke, though it concurrently elevates the risk of hemorrhagic transformation. High-mobility group box 1 (HMGB1) emerges as a pivotal player in neuroinflammation after brain ischemia and ischemia-reperfusion. Released passively by necrotic cells and actively secreted, including direct secretion of HMGB1 into the extracellular space and packaging of HMGB1 into intracellular vesicles by immune cells, glial cells, platelets, and endothelial cells, HMGB1 represents a prototypical damage-associated molecular pattern (DAMP). It is intricately involved in the pathogenesis of atherosclerosis, thromboembolism, and detrimental inflammation during the early phases of ischemic stroke. Moreover, HMGB1 significantly contributes to neurovascular remodeling and functional recovery in later stages. Significantly, HMGB1 mediates hemorrhagic transformation by facilitating neuroinflammation, directly compromising the integrity of the blood-brain barrier, and enhancing MMP9 secretion through its interaction with rtPA. As a systemic inflammatory factor, HMGB1 is also implicated in post-stroke depression and an elevated risk of stroke-associated pneumonia. The role of HMGB1 extends to influencing the pathogenesis of ischemia by polarizing various subtypes of immune and glial cells. This includes mediating excitotoxicity due to excitatory amino acids, autophagy, MMP9 release, NET formation, and autocrine trophic pathways. Given its multifaceted role, HMGB1 is recognized as a crucial therapeutic target and prognostic marker for ischemic stroke and hemorrhagic transformation. In this review, we summarize the structure and redox properties, secretion and pathways, regulation of immune cell activity, the role of pathophysiological mechanisms in stroke, and hemorrhage transformation for HMGB1, which will pave the way for developing new neuroprotective drugs, reduction of post-stroke neuroinflammation, and expansion of thrombolysis time window.

SENP1 facilitates OM-MSC differentiation through activating OPTN-mediated mitophagy to mitigate the neurologic impairment following ICH.

Previous studies have indicated the neuroprotective effect of olfactory mucosa mesenchymal stem cells (OM-MSCs) on brain injury. Intracerebral hemorrhage (ICH) models were established in rats by injecting autologous blood. SENP1 expression was enhanced in neurons but decreased in astrocytes compared to that in OM-MSCs. Overexpression of SENP1 promoted the proliferation and neuronal differentiation, while inhibiting the astrocytic differentiation of OM-MSCs. Conversely, its knockdown had the opposite effect. Moreover, OM-MSCs reduced neurological dysfunction in rats after ICH, and the neuroprotective effect of OM-MSCs could be further enhanced by SENP1 overexpression. In addition, SENP1 promoted mitophagy, which might be related to SENP1-mediated OPTN deSUMOylation. Furthermore, SENP1 promoted neuronal differentiation of OM-MSCs through mitophagy mediated by OPTN. Similar to SENP1, OPTN transfection further enhanced the remission effect of OM-MSC on ICH rats. SENP1 promoted neuronal differentiation of OM-MSCs through OPTN-mediated mitophagy to improve neurological deficits in ICH rats.

Unraveling the catalytic mechanism of SARS-CoV-2 papain-like protease with allosteric modulation of C270 mutation using multiscale computational approaches.

Papain-like protease (PLpro) is a promising therapeutic target against SARS-CoV-2, but its restricted S1/S2 subsites pose an obstacle in developing active site-directed inhibitors. We have recently identified C270 as a novel covalent allosteric site for SARS-CoV-2 PLpro inhibitors. Here we present a theoretical investigation of the proteolysis reaction catalyzed by the wild-type SARS-CoV-2 PLpro as well as the C270R mutant. Enhanced sampling MD simulations were first performed to explore the influence of C270R mutation on the protease dynamics, and sampled thermodynamically favorable conformations were then submitted to MM/PBSA and QM/MM MD simulations for thorough characterization of the protease-substrate binding and covalent reactions. The disclosed proteolysis mechanism of PLpro, as characterized by the occurrence of proton transfer from the catalytic C111 to H272 prior to the substrate binding and with deacylation being the rate-determining step of the whole proteolysis process, is not completely identical to that of the 3C-like protease, another key cysteine protease of coronaviruses. The C270R mutation alters the structural dynamics of the BL2 loop that indirectly impairs the catalytic function of H272 and reduces the binding of the substrate with the protease, ultimately showing an inhibitory effect on PLpro. Together, these results provide a comprehensive understanding at the atomic level of the key aspects of SARS-CoV-2 PLpro proteolysis, including the catalytic activity allosterically regulated by C270 modification, which is crucial to the follow-up inhibitor design and development.

Fully printed and self-compensated bioresorbable electrochemical devices based on galvanic coupling for continuous glucose monitoring.

Real-time glucose monitoring conventionally involves non-bioresorbable semi-implantable glucose sensors, causing infection and pain during removal. Despite bioresorbable electronics serves as excellent alternatives, the bioresorbable sensor dissolves in aqueous environments with interferential biomolecules. Here, the theories to achieve stable electrode potential and accurate electrochemical detection using bioresorbable materials have been proposed, resulting in a fully printed bioresorbable electrochemical device. The adverse effect caused by material degradation has been overcome by a molybdenum-tungsten reference electrode that offers stable potential through galvanic-coupling and self-compensation modules. In vitro and in vivo glucose monitoring has been conducted for 7 and 5 days, respectively, followed by full degradation within 2 months. The device offers a glucose detection range of 0 to 25 millimolars and a sensitivity of 0.2458 microamperes per millimolar with anti-interference capability and biocompatibility, indicating the possibility of mass manufacturing high-performance bioresorbable electrochemical devices using printing and low-temperature water-sintering techniques. The mechanisms may be implemented developing more comprehensive bioresorbable sensors for chronic diseases.