Author Correction: Complete biosynthesis of cannabinoids and their unnatural analogues in yeast.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Complete biosynthesis of cannabinoids and their unnatural analogues in yeast.

Cannabis sativa L. has been cultivated and used around the globe for its medicinal properties for millennia1. Some cannabinoids, the hallmark constituents of Cannabis, and their analogues have been investigated extensively for their potential medical applications2. Certain cannabinoid formulations have been approved as prescription drugs in several countries for the treatment of a range of human ailments3. However, the study and medicinal use of cannabinoids has been hampered by the legal scheduling of Cannabis, the low in planta abundances of nearly all of the dozens of known cannabinoids4, and their structural complexity, which limits bulk chemical synthesis. Here we report the complete biosynthesis of the major cannabinoids cannabigerolic acid, Δ9-tetrahydrocannabinolic acid, cannabidiolic acid, Δ9-tetrahydrocannabivarinic acid and cannabidivarinic acid in Saccharomyces cerevisiae, from the simple sugar galactose. To accomplish this, we engineered the native mevalonate pathway to provide a high flux of geranyl pyrophosphate and introduced a heterologous, multi-organism-derived hexanoyl-CoA biosynthetic pathway5. We also introduced the Cannabis genes that encode the enzymes involved in the biosynthesis of olivetolic acid6, as well as the gene for a previously undiscovered enzyme with geranylpyrophosphate:olivetolate geranyltransferase activity and the genes for corresponding cannabinoid synthases7,8. Furthermore, we established a biosynthetic approach that harnessed the promiscuity of several pathway genes to produce cannabinoid analogues. Feeding different fatty acids to our engineered strains yielded cannabinoid analogues with modifications in the part of the molecule that is known to alter receptor binding affinity and potency9. We also demonstrated that our biological system could be complemented by simple synthetic chemistry to further expand the accessible chemical space. Our work presents a platform for the production of natural and unnatural cannabinoids that will allow for more rigorous study of these compounds and could be used in the development of treatments for a variety of human health problems.

OralExplorer: a web server for exploring the mechanisms of oral inflammatory diseases.

BACKGROUND: Oral inflammatory diseases are localized infectious diseases primarily caused by oral pathogens with the potential for serious systemic complications. However, publicly available datasets for these diseases are underutilized. To address this issue, a web tool called OralExplorer was developed. This tool integrates the available data and provides comprehensive online bioinformatic analysis. METHODS: Human oral inflammatory disease-related datasets were obtained from the GEO database and normalized using a standardized process. Transcriptome data were then subjected to differential gene expression analysis, immune infiltration analysis, correlation analysis, pathway enrichment analysis, and visualization. The single-cell sequencing data was visualized as cluster plot, feature plot, and heatmaps. The web platform was primarily built using Shiny. The biomarkers identified in OralExplorer were validated using local clinical samples through qPCR and IHC. RESULTS: A total of 35 human oral inflammatory disease-related datasets, covering 6 main disease types and 901 samples, were included in the study to identify potential molecular signatures of the mechanisms of oral diseases. OralExplorer consists of 5 main analysis modules (differential gene expression analysis, immune infiltration analysis, correlation analysis, pathway enrichment analysis and single-cell analysis), with multiple visualization options. The platform offers a simple and intuitive interface, high-quality images for visualization, and detailed analysis results tables for easy access by users. Six markers (IL1ß, SRGN, CXCR1, FGR, ARHGEF2, and PTAFR) were identified by OralExplorer. qPCR- and IHC-based experimental validation showed significantly higher levels of these genes in the periodontitis group. CONCLUSIONS: OralExplorer is a comprehensive analytical platform for oral inflammatory diseases. It allows users to interactively explore the molecular mechanisms underlying the action and regression of these diseases. It also aids dental researchers in unlocking the potential value of transcriptomics data related to oral diseases. OralExplorer can be accessed at https://smuonco.shinyapps.io/OralExplorer/  (Alternate URL: http://robinl-lab.com/OralExplorer ).

Sirtuin 1 in osteoarthritis: Perspectives on regulating glucose metabolism.

Osteoarthritis (OA) is a degenerative disease characterised by articular cartilage destruction, and its complex aetiology contributes to suboptimal clinical treatment outcomes. A close association exists between glucose metabolism dysregulation and OA pathogenesis. Owing to the unique environment of low oxygen and glucose concentrations, chondrocytes rely heavily on their glycolytic capacity, exhibiting distinct spatiotemporal differences. However, under pathological stimulation, chondrocytes undergo excessive glycolytic activity while mitochondrial respiration and other branches of glucose metabolism are compromised. This metabolic change induces cartilage degeneration by reprogramming the inflammatory responses. Sirtuins, a highly conserved family of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, regulate glucose metabolism in response to energy fluctuations in different cellular compartments，alleviating metabolic stress. SIRT1, the most extensively studied sirtuin, participates in maintaining glucose homeostasis in almost all key metabolic tissues. While actively contributing to the OA progression and displaying diverse biological effects in cartilage protection, SIRT1's role in regulating glucose metabolism in chondrocytes has not received sufficient attention. This review focuses on discussing the beneficial role of SIRT1 in OA progression from a metabolic regulation perspective based on elucidating the primary characteristics of chondrocyte glucose metabolism. We also summarise the potential mechanisms and therapeutic strategies targeting SIRT1 in chondrocytes to guide clinical practice and explore novel therapeutic directions.

Androgen Receptor Upregulates Mucosa-Associated Lymphoid Tissue 1 to Induce NF-κB Activity via Androgen-Dependent and -Independent Pathways in Prostate Carcinoma Cells.

The androgen-dependent or -independent pathways are regarded as primary therapeutic targets for the neoplasm of the prostate. Mucosa-associated lymphoid tissue 1 (MALT1) acting as a paracaspase in the regulation of nuclear factor κB (NF-κB) signal transduction plays a central role in inflammation and oncogenesis in cancers. This study confirmed the potential linkages between androgen and NF-κB activation by inducing MALT1 in the androgen receptor-full length (ARFL)-positive LNCaP and 22Rv1 prostate cancer cells. Although androgen did not stimulate MALT1 expression in AR-null or ectopic ARFL-overexpressed PC-3 cells, the ectopic overexpression of the AR splicing variant 7 (ARv7) upregulated MALT1 to activate NF-κB activities in 22Rv1 and PC-3 cells. Since the nuclear translocation of p50 and p65 was facilitated by ARv7 to motivate NF-κB activity, the expressions of MALT1, prostate-specific antigen (PSA), and N-myc downstream regulated 1 (NDRG1) were therefore induced in ectopic ARv7-overexpressed prostate cancer cells. Ectopic ARv7 overexpression not only enhanced 22Rv1 or PC-3 cell growth and invasion in vitro but also the tumor growth of PC-3 cells in vivo. These results indicate that an androgen receptor induces MALT1 expression androgen-dependently and -independently in ARFL- or ARv7-overexpressed prostate cancer cells, suggesting a novel ARv7/MALT1/NF-κB-signaling pathway may exist in the cells of prostate cancer.

WNT1 Inducible Signaling Pathway Protein 1 Is a Stroma-Specific Secreting Protein Inducing a Fibroblast Contraction and Carcinoma Cell Growth in the Human Prostate.

The WNT1 inducible signaling pathway protein 1 (WISP1), a member of the connective tissue growth factor family, plays a crucial role in several important cellular functions in a highly tissue-specific manner. Results of a RT-qPCR indicated that WISP1 expressed only in cells of the human prostate fibroblasts, HPrF and WPMY-1, but not the prostate carcinoma cells in vitro. Two major isoforms (WISP1v1 and WISP1v2) were identified in the HPrF cells determined by RT-PCR and immunoblot assays. The knock-down of a WISP1 blocked cell proliferation and contraction, while treating respectively with the conditioned medium from the ectopic WISP1v1- and WISPv2-overexpressed 293T cells enhanced the migration of HPrF cells. The TNFα induced WISP1 secretion and cell contraction while the knock-down of WISP1 attenuated these effects, although TNFα did not affect the proliferation of the HPrF cells. The ectopic overexpression of WISP1v1 but not WISP1v2 downregulated the N-myc downstream regulated 1 (NDRG1) while upregulating N-cadherin, slug, snail, and vimentin gene expressions which induced not only the cell proliferation and invasion in vitro but also tumor growth of prostate carcinoma cells in vivo. The results confirmed that WISP1 is a stroma-specific secreting protein, enhancing the cell migration and contraction of prostate fibroblasts, as well as the proliferation, invasion, and tumor growth of prostate carcinoma cells.

Persistent chronic immune activation in HIV/HBV-coinfected patients after antiretroviral therapy.

We studied the characteristics of immune activation and investigated the underlying mechanisms in patients with human immunodeficiency virus-1/hepatitis B virus (HIV/HBV) coinfection after receiving HBV-active antiretroviral therapy. Forty patients with HIV/HBV coinfection, 38 patients with HIV monoinfection and 20 healthy controls were enrolled. CD4+ count, HIV load, HBV load, markers of immune activation and regulatory T-cell (Treg cell) frequency were assessed and compared between HIV-monoinfected and HIV/HBV-coinfected patients at week 0 (baseline), 12, 24, 36 and 48 after the onset of HBV-active antiretroviral therapy. Before antiretroviral therapy, frequencies of CD4+ HLADR+ CD38+ , CD8+ HLADR+ CD38+ , and Treg cells, and sCD163 and sCD14 levels were significantly higher in both HIV/HBV-coinfected patients and HIV-monoinfected patients, compared with healthy controls. Frequencies of CD4+ HLADR+ CD38+ and CD8+ HLADR+ CD38+ cells decreased following antiretroviral therapy in both groups. sCD163 levels did not change significantly in both groups and no significant difference was observed between the two groups at each time point during the 48-week antiretroviral therapy. In week 24, levels of sCD14 and frequencies of Treg cells appeared significantly higher in HIV/HBV-coinfected patients than in HIV-monoinfected patients, in which sCD14 levels and Treg cell frequencies declined to those in healthy controls. The Treg cell frequency was consistent with that of sCD14 levels in HIV/HBV-coinfected patients. Coinfection with HBV significantly increases sCD14 levels in HIV-infected patients during HBV-active antiretroviral therapy, which may potentially contribute to liver inflammation.

Association between detectable SARS-COV-2 RNA in anal swabs and disease severity in patients with coronavirus disease 2019.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was found in the intestines and feces, but its clinical significance is not completely clear. We aim to characterize the longitudinal test results of SARS-CoV-2 RNA in anal swabs and to explore the association with disease severity. METHODS: We included laboratory-confirmed coronavirus disease 2019 (COVID-19) patients, who were hospitalized in Guangzhou Eighth People's Hospital and excluded those who had not received anal swabs for SARS-COV-2 RNA testing. Epidemiological, clinical, and laboratory data were obtained. Throat swabs and anal swabs were collected periodically for SARS-COV-2 RNA detection. RESULTS: Two hundred and seventeen eligible patients (median aged 50 years, 50.2% were females) were analyzed. 21.2% (46/217) of the patients were detected with SARS-CoV-2 RNA in anal swabs. The duration of viral RNA was longer, but the viral load was lower in anal swabs than throat swabs in the early stage of the disease. During a median follow-up of 20 days, 30 (13.8%) patients were admitted to the intensive care unit (ICU) for high-flow nasal cannula or higher-level oxygen support measures to correct hypoxemia. Detectable viral RNA in anal swabs (adjusted hazard ratio [aHR], 2.50; 95% confidence interval [CI], 1.20-5.24), increased C-reactive protein (aHR, 3.14; 95% CI, 1.35-7.32) and lymphocytopenia (aHR, 3.12; 95% CI, 1.46-6.67) were independently associated with ICU admission. The cumulative incidence of ICU admission was higher among patients with detectable viral RNA in anal swabs (26.3% vs 10.7%, P = .006). CONCLUSION: Detectable SARS-CoV-2 RNA in the digestive tract was a potential warning indicator of severe disease.

Development and validation of a model for hepatitis B e antigen seroconversion in entecavir-treated patients with chronic hepatitis B.

Achieving hepatitis B e antigen (HBeAg) seroconversion is a satisfactory endpoint during antiviral treatment for chronic hepatitis B (CHB). This study aimed to develop and validate a novel scoring system to predict HBeAg seroconversion during entecavir (ETV) treatment. A total of 526 patients with HBeAg-positive CHB treated with ETV for at least 1 year were randomly assigned to the training and validation cohorts. Baseline parameters including hepatitis B virus DNA, hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb), and alanine aminotransferase level were quantified. Patients who achieved HBeAg seroconversion were compared with those without HBeAg seroconversion. A prediction model was established to predict HBeAg seroconversion during ETV treatment. After a median follow up of 2.67 years, 93 (36.0%) and 87 (32.5%) patients in the training and validation cohorts developed HBeAg seroconversion. A prediction score composed of age, HBsAg and HBcAb quantification was derived. Areas under receiver operating characteristic curve at 5 years of this prediction score were 0.70 and 0.72 in the training and validation cohorts. By using the dual cutoff values of 0.28 and 0.58, the model was endowed with high sensitivity and specificity to exclude or identify patients developing HBeAg seroconversion (90.3% sensitivity and 90.2% specificity in the training cohort as well as 92.8% sensitivity and 84.4% specificity in the validation cohort, respectively). A novel prediction score that uses baseline clinical variables was developed and validated. The score accurately estimates the probabilities of developing HBeAg seroconversion at 5-years ETV therapy in patients with CHB.

Hybridization Chain Reactions Targeting the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

In this work, hybridization chain reactions (HCRs) toward Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nucleocapsid phosphoproteins gene loci and human RNase P are proposed to provide an isothermal amplification screening tool. The proposed chain reactions target the complementary DNA (cDNA) of SARS-CoV-2, with loci corresponding to gold-standard polymerase chain reaction (PCR) loci. Four hybridization chain reaction reactions are demonstrated herein, targeting N1/N2/N3 loci and human RNase P. The design of the hybridization chain reaction, herein, is assisted with an algorithm. The algorithm helps to search target sequences with low local secondary structure and high hybridization efficiency. The loop domain of the fuel hairpin molecule H1 and H2, which are the tunable segments in such reactions, are used as an optimization parameter to improve the hybridization efficiency of the chain reaction. The algorithm-derived HCR reactions were validated with gel electrophoresis. All proposed reactions exhibit a hybridization complex with a molecular mass >1.5k base pairs, which is clear evidence of chain reaction. The hybridization efficiency trend revealed by gel electrophoresis corresponds nicely to the simulated data from the algorithm. The HCR reactions and the corresponding algorithm serve as a basis to further SARS-CoV-2 sensing applications and facilitate better screening strategies for the prevention of on-going pandemics.

Longitudinal Change of Body Mass Index Is Associated With Alanine Aminotransferase Elevation After Complete Viral Suppression in Chronic Hepatitis B Patients.

BACKGROUND: Little is known about cause and intervention for alanine aminotransferase (ALT) elevation after complete viral suppression in patients with chronic hepatitis B (CHB). METHODS: In this prospective cohort study, patients with CHB who were treated with nucleos(t)ide analogs and maintained undetectable levels of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) for at least 6 months were enrolled. Patients were followed up at 6-month intervals, and anthropometric, biochemical, and virological assessments were performed. RESULTS: Of 1965 patients with median follow-up of 18.36 months, one third of patients experienced ALT elevation. Baseline high body mass index ([BMI] defined as ≥25 kg/m2), younger age, and liver cirrhosis independently increased the risk of longitudinal ALT elevation. At the end of follow-up, 89 (4.8%) patients reverted to low BMI, and 92 (5.0%) developed to high BMI. Compared with persistent high BMI, reversion to low BMI reduced the risk of ALT elevation (adjusted odds ratio [aOR], 0.38; 95% confidence interval [CI], 0.19-0.77); compared with persistent low BMI, onset of high BMI increased the risk of ALT elevation (aOR, 1.78; 95% CI, 1.02-3.11). CONCLUSIONS: High BMI is an independent predictor for ALT elevation after complete HBV DNA suppression. Improvement of BMI may have a beneficial effect on ALT normalization and even long-term outcomes.

Engineering ß-oxidation in Yarrowia lipolytica for methyl ketone production.

Medium- and long-chain methyl ketones are fatty acid-derived compounds that can be used as biofuel blending agents, flavors and fragrances. However, their large-scale production from sustainable feedstocks is currently limited due to the lack of robust microbial biocatalysts. The oleaginous yeast Yarrowia lipolytica is a promising biorefinery platform strain for the production of methyl ketones from renewable lignocellulosic biomass due to its natively high flux towards fatty acid biosynthesis. In this study, we report the metabolic engineering of Y. lipolytica to produce long- and very long-chain methyl ketones. Truncation of peroxisomal ß-oxidation by chromosomal deletion of pot1 resulted in the biosynthesis of saturated, mono-, and diunsaturated methyl ketones in the C13-C23 range. Additional overexpression and peroxisomal targeting of a heterologous bacterial methyl ketone biosynthesis pathway yielded an initial titer of 151.5 mg/L of saturated methyl ketones. Dissolved oxygen concentrations in the cultures were found to substantially impact cell morphology and methyl ketone biosynthesis. Bioreactor cultivation under optimized conditions resulted in a titer of 314.8 mg/L of total methyl ketones, representing more than a 6000-fold increase over the parental strain. This work highlights the potential of Y. lipolytica to serve as chassis organism for the biosynthesis of acyl-thioester derived long- and very long-chain methyl ketones.

The tether function of the anoctamins.

The core functions of the anoctamins are Cl- channel activity and phosphatidylserine (and perhaps other lipids) scrambling. These functions have been extensively studied in various tissues and cells. However, another function of the anoctamins that is less recognized and minimally explored is as tethers at membrane contact sites. This short review aims to examine evidence supporting the localization of the anoctamins at membrane contact sites, their tether properties, and their functions as tethers.

Clinical characteristics and prognosis of Talaromycosis marneffei associated immune reconstitution inflammatory syndrome in AIDS patients.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) is an inflammatory reaction that occurs in HIV/AIDS patients after antiretroviral therapy (ART) initiation. Along with immune system recovery, IRIS can overreact to existing infections or latent pathogens, causing symptoms that mimic those infections. Few studies elucidated the clinical features and prognosis of Talaromycosis marneffei (TSM)-associated IRIS in HIV/AIDS patients. The aim of our study was to evaluate the incidence, clinical characteristics, and prognosis of TSM-associated IRIS by retrospectively analyzing the clinical data of HIV/AIDS patients with TSM. METHODOLOGY/PRINCIPAL FINDINGS: A total of 224 HIV/AIDS inpatients with TSM were enrolled, aged between 19 and 81 years. Among them, 86.6% were male and 13.4% were female, of which 24 (10.7%) patients developed IRIS. In IRIS group, the median time from ART initiation to IRIS occurrence was 9.0 days (IQR, 5.0-16.8 days), with 87.5% (21/24) occurring within 2 weeks. Primary clinical manifestations included recurrent fever and exacerbation of pulmonary infection. At the onset of IRIS, 54.2% (13/24) patients were treated with intravenous dexamethasone, and 12.5% (5/24) patients were treated with oral prednisone for 1-3 weeks. No significant differences in baseline characteristics or ART regimens were observed between IRIS and non-IRIS groups; however, patients in IRIS group had higher levels of CRP, CD4+ count, and CD4+/CD8+ ratio than non-IRIS group (equivalent time point: 1-2 weeks after ART initiation) at IRIS onset. The IRIS group exhibited longer hospital stays and higher readmission rates, but equivalent mortality rates compared with non-IRIS group. CONCLUSIONS/SIGNIFICANCE: IRIS is a common complication in HIV/AIDS patients with TSM, often occurring within 2 weeks after ART initiation and exhibiting more pronounced immune reconstitution. The occurrence of IRIS significantly extended the hospitalization duration and increased the rate of readmission but had no influence on the mortality rate.

E. Coli LPS-induced calcium signaling regulates the expression of hypoxia-inducible factor 1α in periodontal ligament fibroblasts in a non-hypoxia-dependent manner.

Periodontitis, an inflammatory disease, can cause significant damage to the oral tissues which support the teeth. During the early development of periodontitis, periodontal ligament fibroblasts (PDLFs) undergo metabolic reprogramming regulated by hypoxia-inducible factor 1α (HIF-1α), which is strongly linked to the progression of inflammation. However, the precise mechanisms by which PDLFs regulate HIF-1α and its associated metabolic reprogramming during early inflammation remain unclear. This study illustrated that brief and low-dose exposure to Escherichia coli (E. coli) lipopolysaccharide (LPS) can serve as a non-hypoxic stimulus, effectively replicating early periodontal inflammatory reactions. This is evidenced by the upregulation of HIF-1α expression and the activation of HIF-1α-mediated crucial glycolytic enzymes, namely lactate dehydrogenase a, pyruvate kinase, and hexokinase 2, concomitant with an augmentation in the inflammatory response within PDLFs. We observed that the effects mentioned and their impact on macrophage polarization were notably attenuated when intracellular and extracellular stores of Ca2+ were depleted using BAPTA-AM and Ca2+-free medium, respectively. Mechanistically, our findings demonstrated that the transcriptional process of HIF-1α is regulated by Ca2+ during E. coli LPS stimulation, mediated through the signal transducer and activator of transcription 3 (STAT3) pathway. Additionally, we observed that the stabilization of intracellular HIF-1α proteins occurs via the endothelin (ET)-1-endothelin A receptor pathway, independent of hypoxia. Taken together, our research outcomes underscore the pivotal involvement of Ca2+ in the onset of early periodontitis by modulating HIF-1α and glycolysis, thereby presenting novel avenues for early therapeutic interventions.

Activating transcription factor 3 is an antitumor gene synergizing with growth differentiation factor 15 to modulate cell growth in human bladder cancer.

BACKGROUND: The functions of activating transcription factor 3 (ATF3) within the human bladder remain unexplored. This study delves into the expressions, functions, and regulatory mechanisms of ATF3 in human bladder cancer. MATERIAL AND METHODS: Gene expressions were determined by immunoblot, RT-qPCR, and reporter assays. Assays of Ki67, colony formation, Matrigel invasion, and the xenograft animal study were used to assess the cell proliferation, invasion, and tumorigenesis in vitro and in vivo. Silico analysis from TCGA database examined the correlations between GDF15 and ATF3 expressions, clinicopathologic features, and progression-free survival rates. RESULTS: Silico analysis confirmed that ATF3 is an antitumor gene, and the expression positively correlates with GDF15 in bladder cancer tissues. Multivariate analysis revealed that low ATF3/GDF15 but not a single low expression of ATF3 is an independent prognostic factor for progression-free survival of bladder cancer patients. Ectopic overexpression of ATF3 downregulated cell proliferation and invasion in bladder cancer cells in vitro, while ATF3-knockdown reversed these results. Knockdown of ATF3 upregulated EMT markers to enhance cell invasion in vitro and downregulated GDF15, NDRG1, and KAI-1 to elevate tumor growth in vivo. The activation of metformin on ATF3 and GDF15 in bladder cancer cells was blocked by SB431542, a TGFß receptor inhibitor. ATF3 positively regulated GDF15 expression in bladder cancer cells through a feedback loop. CONCLUSIONS: Our results identify that ATF3 is a metformin-upregulated antitumor gene. Results of Silico analysis align with cell-based studies suggesting that low ATF3/GDF15 could be a negative prognostic marker for bladder cancer.

Development of a gene knockout system using mobile group II introns (Targetron) and genetic disruption of acid production pathways in Clostridium beijerinckii.

Clostridium beijerinckii is a well-known solvent-producing microorganism with great potential for biofuel and biochemical production. To better understand and improve the biochemical pathway to solvents, the development of genetic tools for engineering C. beijerinckii is highly desired. Based on mobile group II intron technology, a targetron gene knockout system was developed for C. beijerinckii in this study. This system was successfully employed to disrupt acid production pathways in C. beijerinckii, leading to pta (encoding phosphotransacetylase)- and buk (encoding butyrate kinase)-negative mutants. In addition to experimental characterization, the mutant phenotypes were analyzed in the context of our C. beijerinckii genome-scale model. Compared to those of the parental strain (C. beijerinckii 8052), acetate production in the pta mutant was substantially reduced and butyrate production was remarkably increased, while solvent production was dependent on the growth medium. The pta mutant also produced much higher levels of lactate, suggesting that disrupting pta influenced the energy generation and electron flow pathways. In contrast, acetate and butyrate production in the buk mutant was generally similar to that of the wild type, but solvent production was consistently 20 to 30% higher and glucose consumption was more rapid and complete. Our results suggest that the acid and solvent production of C. beijerinckii can be effectively altered by disrupting the acid production pathways. As the gene disruption method developed in this study does not leave any antibiotic marker in a disrupted allele, multiple and high-throughput gene disruption is feasible for elucidating genotype and phenotype relationships in C. beijerinckii.

Hydrophobic interactions within the C terminus pole helices tunnel regulate calcium-dependent inactivation of TRPC3 in a calmodulin-dependent manner.

Recent structural studies have shown that the carboxyl-terminus of many TRP channels, including TRPC3, are folded into a horizontal rib helix that is connected to the vertical pole helix, which play roles in inter-structural interactions and multimerization. In a previous work we identified I807 located in the pole helix with a role in regulation of TRPC3 by STIM1 (Lee et al., 2014, Liu et al., 2022). To further determine the role of the pole helix in TRPC3 function, here we identified key hydrophobic residues in the pole helix that form tight tunnel-like structure and used mutations to probe their role in TRPC3 regulation by Ca2+ and Calmodulin. Our findings suggest that the hydrophobic starch formed by the I807-L818 residues has several roles, it modulates gating of TRPC3 by Ca2+, affects channel selectivity and the channel Ca2+ permeability. Mutations of I807, I811, L814 and L818 all attenuated the Ca2+-dependent inactivation (CDI) of TRPC3, with I807 having the most prominent effect. The extent of modulation of the CDI depended on the degree of hydrophobicity of I807. Moreover, the TRPC3(I807S) mutant showed altered channel monovalent ion selectivity and increased Ca2+ permeability, without affecting the channel permeability to Mg2+ and Ba2+ and without changing the pore diameter. The CDI of TRPC3 was reduced by an inactive calmodulin mutant and by a pharmacological inhibitor of calmodulin, which was eliminated by the I807S mutation. Notably, deletion of STIM1 caused similar alteration of TRPC3 properties. Taken together, these findings reveal a role of the pole helix in CDI, in addition to its potential role in channel multimerization that required gating of TRPC3 by STIM1. Since all TRPC and most TRP channels have pole helix structures, our findings raise the possibility that the pole helix may have similar roles in all the TRP family.

Incidence and factors associated with hepatitis B surface antigen seroclearance in patients co-infected with HBV/HIV during antiretroviral therapy in Guangdong, China.

BACKGROUND: Hepatitis B surface antigen (HBsAg) clearance is vital for a functional cure of hepatitis B virus (HBV) infection. However, the incidence and predictors of HBsAg seroclearance in patients co-infected with HBV and human immunodeficiency virus (HIV) remain largely unknown in Guangdong, China. METHODS: Between 2009 and 2019, patients co-infected with HBV/HIV undergoing antiretroviral therapy (ART) in Guangzhou Eighth People's Hospital affiliated to Guangzhou Medical University were retrospectively reviewed with the endpoint on December 31, 2020. The incidence and risk factors for HBsAg seroclearance were evaluated using Kaplan-Meier and multivariate Cox regression analyses. RESULTS: A total of 1550 HBV/HIV co-infected patients were included in the study, with the median age of 42 years and 86.0% (1333/1550) males. Further, 98.3% (1524/1550) received ART containing tenofovir disoproxil fumarate (TDF) plus lamivudine (3TC). HBV DNA was examined in 1283 cases at the last follow-up. Over the median 4.7 years of follow-up, 8.1% (126/1550) patients achieved HBsAg seroclearance, among whom 50.8% (64/126) obtained hepatitis B surface antibody, 28.1% (137/488) acquired hepatitis B e antigen seroconversion, and 95.9% (1231/1283) undetectable HBV DNA. Compared with patients who maintained HBsAg positive, cases achieving HBsAg seroclearance showed no differences in age, gender, CD4 + T cell count, alanine aminotransferase (ALT) level, or fibrosis status; however, they presented lower HBV DNA levels, lower HBsAg levels, and higher rates of HBV genotype B at the baseline. Multivariate analysis showed that baseline HBsAg <1500 cutoff index (COI) (adjusted hazard ratio [aHR], 2.74, 95% confidence interval [95% CI]: 1.48-5.09), ALT elevation >2 × upper limit of normal during the first six months after receiving ART (aHR, 2.96, 95% CI: 1.53-5.77), and HBV genotype B (aHR, 3.73, 95% CI: 1.46-9.59) were independent predictors for HBsAg seroclearance (all P <0.01). CONCLUSIONS: Long-term TDF-containing ART has high anti-HBV efficacy including relatively high overall HBsAg seroclearance in HBV/HIV co-infected patients. Lower baseline HBsAg levels, HBV genotype B, and elevated ALT levels during the first six months of ART are potential predictors of HBsAg seroclearance.

An evaluation of Mp1p antigen screening for talaromycosis in HIV-infected antiretroviral therapy-naïve population in Guangdong, China.

BACKGROUND: Talaromycosis is one of the most common opportunistic infections in human immunodeficiency virus (HIV) infected patients. However, few researches have explored the prevalence in Southern China and fully assessed the value of the Mp1p antigen screening for the diagnosis of talaromycosis. METHODOLOGY/PRINCIPAL FINDINGS: We performed a cross-sectional study of HIV-infected antiretroviral therapy (ART)-naïve adult patients who were seen in 2018 at Guangzhou Eighth People's Hospital, Guangzhou Medical University. Serum samples collected from all the 784 enrolled patients were tested for Mp1p antigen using double-antibody sandwich enzyme-linked immunosorbent assay. A culture of pathogen was conducted in 350 clinically suspected patients to confirm talaromycosis. The overall prevalence of talaromycosis based on the Mp1p antigen detection was 11.4% (89/784) and peaked at 32.2% (75/233) in patients with CD4+ ≤50 Nr/µl. Logistic regression analysis found Mp1p antigen positive rate decreased with the increase in CD4+ counts (OR 0.982, 95% CI 0.977-0.987, P<0.01). The optimal cut-off point of the CD4+ count was 50 Nr/µl or less. Among the 350 patients received both fungal culture and Mp1p antigen detection, 95/350 (27.1%) patients were culture-positive for a Talaromyces marneffei, 75/350 (21.4%) patients were Mp1p antigen positive. The Mp1p antigen assay showed a good agreement to the culture of pathogen, and the sensitivity, specificity, positive predictive value, negative predictive value and kappa value was 71.6% (68/95), 97.3% (248/255), 90.7% (68/75), 90.2% (248/275), and 0.737, respectively. The screening accuracy of the Mp1p antigen assay in patients with CD4+ counts of ≤50 Nr/µl was superior to that in those with higher CD4+ counts. CONCLUSIONS/SIGNIFICANCE: Mp1p antigen screening can be an effective tool for more efficient diagnosis of Talaromycosis, especially in HIV/AIDS patients with low CD4+ counts. Future validation studies are needed.