[Mechanism of miR-221-3p inhibiting cadmium-induced apoptosis of TM3 cells through DDIT4].

OBJECTIVE: To investigate the mechanism of DNA-damage-inducible transcript 4(DDIT4)targeting miR-221-3p in microRNA(miRNA) on cadmium-induced apoptosis of mouse testicular stromal cells. METHODS: The activity of mouse testicular interstitial cells(TM3) was detected by CCK-8 after exposure to different concentrations of cadmium(0, 10, 20, 30, 40 µmol/L). Total RNA was extracted from cadmium-treated TM3 cells, and the significantly differentially expressed miRNA was screened with fold change(FC)>1.2 and P<0.05 as the criterion. TM3 cells were divided into blank control group, negative control group, cadmium exposure group(CdCl_2, 20 µmol/L), and cadmium+miR-221-3p mimic group. miR-221-3p mimic group was transfected into TM3 cells first, combined with cadmium exposure for 24 hours. The cell morphology was detected by Hoechst staining, and the apoptosis rate was analyzed by flow cytometry. Quantitative real-time PCR(qRT-PCR) and Western blot were used to detect DDIT4 expression. Dual luciferase reporter gene assay verified the binding of miR-221-3p to DDIT4. The function of DDIT4 and its relationship with apoptosis were analyzed by bioinformatics. The expression levels of B-cell lymphoma-2(Bcl-2) and Bcl-2 associated X protein(BAX) were observed after overexpression of miR-221-3p. RESULTS: Cadmium treatment of TM3 cells could reduce cell activity and there was a dose-effect relationship. The cell morphology showed that compared with the control group, the cells were wrinkled and the nuclei were heavily stained, and the apoptosis rate increased to 19.66%±0.45%(P<0.01). Compared with the cadmium exposure group, the normal morphologic cells increased in the cadmium exposure +miR-221-3p mimic group, and the apoptosis rate decreased to 13.76%±0.37%(P<0.05). The expression level of miR-221-3p was down-regulated(P<0.01), and the expression level of DDIT4 was up-regulated(P<0.05). Bioinformatics analysis and dual luciferase report analysis showed that DDIT4 was one of the target genes of miR-221-3p. Compared with the cadmium exposure group, the expression level of DDIT4 in the cadmium+miR-221-3p mimic group was down-regulated(P<0.05), and the ratio of Bcl-2/BAX was increased from 0.54±0.03 to 0.71±0.04. CONCLUSION: miR-221-3p inhibits cadmium-induced apoptosis of TM3 cells by targeting DDIT4.

Astellolides R-W, Drimane-Type Sesquiterpenoids from an Aspergillus parasiticus Strain Associated with an Isopod.

Sesquiterpenoids with a cage-like multiring frame are rarely found in nature. Mining of the isopod-derived fungus Aspergillus parasiticus SDU001 by the one strain-many compounds (OSMAC) strategy unexpectedly led to the discovery of fungal drimane-type sesquiterpenoids astellolide R (1), featuring an unusual cage-like 6/6/5/6/5 pentacyclic ring system, astellolide S (2), possessing a rare nicotinic acid building block, and astellolides T-W (3-6). Their structures were comprehensively assigned by spectroscopic data analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Furthermore, compounds 3 and 5 exhibited anti-inflammatory activity by inhibiting the lipopolyssacharide-induced NO production in RAW264.7 macrophages with IC50 values of 6.1 ± 0.8 and 6.8 ± 0.8 µM, respectively. A putative biosynthetic pathway for 1 is proposed. Our results enlarge the chemical space of the drimane-type sesquiterpenoids generated from endophytic fungi.

[Analysis the mechanism of cadmium-induced cytotoxicity in mouse testicular mesenchymal cells with miRNA transcriptomic].

OBJECTIVE: To analyze the mechanism of cadmium-induced cytotoxicity in mouse testicular mesenchymal cells(TM3) with transcriptome sequencing and bioinformatics techniques. METHODS: TM3 cells were selected as the cell model and divided into control group(no cadmium treatment) and cadmium-treated group(20 µmol/L CdCl_2). After 24 hours of administration, cells were harvested to extract total RNA, and then miRNA expression profiles were obtained by sequencing program after RNA quality detection. The fold change(FC) >2, P<0.05 was used as the standard to screen for differentially expressed miRNAs. The quantitative real-time polymerase chain reaction(qRT-PCR) was used to verify the differentially expressed miRNAs. Then, their target genes were predicted by miRanda software to construct miRNA-target gene interaction network, and their target genes were enriched by gene ontology(GO) and Kyoto encyclopedia of genes and genomes(KEGG) pathway function. RESULTS: A total of 26 differentially expressed miRNAs were identified which may be related to cadmium-induced TM3 cytotoxicity, including 19 up-regulated and 7 down-regulated miRNAs. The result of qRT-PCR were consistent with the miRNA sequencing result. Meanwhile, bioinformatics analysis result showed that the 26 differentially expressed miRNAs predicted 657 target genes. GO enrichment was mainly classified into biological regulation, metabolic process, protein binding and catalytic activity. KEGG pathway analysis showed that target genes were significantly involved in mitogen-activated protein kinase(MAPK) and tumor necrosis factor(TNF) signal pathways closely related to inflammatory response and apoptosis. CONCLUSION: Cadmium can lead to the differential expression of miRNAs in TM3 cells, and its target genes may be involved in Cd-induced TM3 cytotoxicity through signaling pathways such as MAPK and TNF.

[N-acetylcysteine alleviates cadmium-induced testicular interstitial cell apoptosis by activating protein kinase B pathway].

OBJECTIVE: To investigate the regulation mechanism of N-acetylcysteine(NAC) on cadmium-induced apoptosis of mouse testicular interstitial cells based on protein kinase B pathway(AKT pathway). METHODS: Mouse testicular mesenchymal cells(TM3) were divided into fourgroups according to different treatment, control group, cadmium group(Cd, 5, 10, 20, 30, 40 and 50 µmol/L), NAC group(NAC, 500 µmol/L) and NAC+Cd group(500 µmol/L NAC+20 µmol/L Cd). Cells of NAC+Cd group were pretreated with NAC for 30 min, and then combined with cadmium for 24 h. Cell viability was determined by CCK8. Hoechst staining was used to determine cell morphology. Cell apoptosis rate was analyzed by flow cytometry. Malondialdehyde(MDA) and glutathione(GSH) were measured simultaneously. Western blot was used to detect the expression levels of AKT protein, B-cell lymphoma-2(Bcl-2) and Bcl-2 associated X protein(Bax). RESULTS: Cadmium inhibited the proliferation of TM3 cells in a dose-effect relationship. Cell morphology observation showed that with the increase of cadmium concentration, the cells shrank, became round and even fell off, and appeared dense nuclear staining. The MDA level in Cd group was(1.56±0.11) µmol/mg prot, which was significantly higher than that in control group(P<0.01). Compared to the control group, the level of GSH was significantly decreased to(1.28±0.25) µmol/mg prot(P<0.01). NAC pretreatment could reduce the MDA content and increase the GSH level, and the difference was statistically significant compared with the Cd group(P<0.01). Western blot result showed that NAC pretreatment significantly increased levels of phosphorylated AKT and Bcl-2, the levels were 0.65±0.05 and 0.45±0.03, respectively(P<0.01). The Bax/Bcl-2 ratio was 1.54±0.15, which was significantly lower than that of the Cd group(P<0.01). CONCLUSION: NAC can inhibit cadmium-mediated TM3 cell damage and apoptosis, which may be related to the improvement of oxidative stress state, activation of TM3 AKT pathway and reduction of Bax/Bcl-2 ratio.

Saccharochelins A-H, Cytotoxic Amphiphilic Siderophores from the Rare Marine Actinomycete Saccharothrix sp. D09.

Siderophores are secreted by microorganisms to survive in iron-depleted conditions, and they also possess tremendous therapeutic potential. Genomic-inspired isolation facilitated the identification of eight amphiphilic siderophores, saccharochelins A-H (1-8), from a rare marine-derived Saccharothrix species. Saccharochelins feature a series of fatty acyl groups appended to the same tetrapeptide skeleton. With the help of gene disruption and heterologous expression, we identified the saccharochelin biosynthetic pathway. The diversity of saccharochelins originates from the flexible specificity of the starter condensation (CS) domain at the beginning of the nonribosomal peptide synthetase (NRPS) toward various fatty acyl substrates. Saccharochelins showed cytotoxicity against several human tumor cell lines, with IC50 values ranging from 2.3 to 17 µM. Additionally, the fatty acid side chains of the saccharochelins remarkably affected the cytotoxicity, suggesting changing the N-terminal acyl groups of lipopeptides may be a promising approach to produce more potent derivatives.

Genome-Guided Discovery of Highly Oxygenated Aromatic Polyketides, Saccharothrixins D-M, from the Rare Marine Actinomycete Saccharothrix sp. D09.

Angucyclines and angucyclinones are aromatic polyketides with intriguing structures and therapeutic value. Genome mining of the rare marine actinomycete Saccharothrix sp. D09 led to the identification of a type II polyketide synthase biosynthetic gene cluster, sxn, which encodes several distinct subclasses of oxidoreductases, implying that this strain has the potential to produce novel polycyclic aromatic polyketides with unusual redox modifications. The "one strain-many compounds" (OSMAC) strategy and comparative metabolite analysis facilitated the discovery of 20 angucycline derivatives from the D09 strain, including six new highly oxygenated saccharothrixins D-I (1-6), four new glycosylated saccharothrixins J-M (7-10), and 10 known analogues (11-20). Their structures were elucidated based on detailed HRESIMS, NMR spectroscopic, and X-ray crystallographic analysis. With the help of gene disruption and heterologous expression, we proposed their plausible biosynthetic pathways. In addition, compounds 3, 4, and 8 showed antibacterial activity against Helicobacter pylori with MIC values ranging from 16 to 32 µg/mL. Compound 3 also revealed anti-inflammatory activity by inhibiting the production of NO with an IC50 value of 28 µM.

Anthocyanin from purple sweet potato attenuates lead-induced reproductive toxicity mediated by JNK signaling pathway in male mice.

The present work aimed to explore the protective effect of APSP on Pb-induced reproductive toxicity and possible mechanism. APSP (100 mg/kg) was administered to Pb-intoxicated (0.2% lead acetate) male Kunming mice once daily by oral gavage for 6 weeks. Our results showed that APSP exerted male reproductive protection effects as showed by attenuated Pb-induced testicular injury, improved sperm count and motility, and reduced sperm abnormality rate. APSP also restored Pb-induced decrease in both enzymatic and non-enzymatic antioxidants, and GSH/GSSG ratio, but inhibited lipid peroxidation in serum and testes. Moreover, APSP downregulated Pb-induced Bax mRNA and protein expressions, suppressed activation of caspase-3, upregulated Bcl-2 protein expression, and prevented Pb-induced DNA damage. APSP treatment also interfered with Pb-induced testicular JNK signaling through inhibition of JNK mRNA expression and phosphorylation, resulting in inhibition of c-Jun expression. These effects of APSP were abolished by Pb. In conclusion, APSP represents a potential therapeutic agent for preventing Pb-caused reproductive toxicity, which is attributed to its antioxidant and anti-apoptotic properties, as well as, modulation of JNK signaling pathway.

Lead acetate induces apoptosis in Leydig cells by activating PPARγ/caspase-3/PARP pathway.

This study was designed to investigate the cytotoxicity of lead acetate (Pb(AC)2, a representative air pollutant) by focusing on PPARγ/caspase-3/PARP apoptotic signaling pathway and to explore the inhibitory effect of PPARγ antagonist on apoptosis of TM3 Leydig cells. MTT assay was utilized to examine cell viability. Cell apoptosis was analyzed using a flow cytometry by staining with Annexin V-PE/7AAD staining and a fluorescence microscope by staining with Hoechst 33,258. The levels of apoptosis-related proteins were examined using western blot. From the results, Pb reduced significantly TM3 cell proliferation in concentration- and time-dependent manner. It increased significantly apoptosis; increased the PPARγ, Bax, procaspase-3, cleaved caspase-3, proPARP, cleaved PARP levels; and decreased Bcl-2 level in Pb-treated TM3 cells as compared to control cells. Furthermore, pretreatment with PPARγ antagonist significantly attenuated the apoptosis and cleavage of caspase-3 and PARP induced by Pb. Our results suggested that Pb induced cytotoxicity on TM3 Leydig cells, at least in part, by increasing PPARγ expression, stimulating cleavage of caspase-3 and PARP, and then induced cell apoptosis.

Selenium ameliorates cadmium-induced mouse leydig TM3 cell apoptosis via inhibiting the ROS/JNK /c-jun signaling pathway.

Despite the well-known acknowledgement of both the toxicity of cadmium (Cd) and the ameliorative effect of selenium (Se), the mechanism of the protective effect of selenium on cadmium-induced Mouse Leydig (TM3) cell apoptosis remains unknown. In this study, we hypothesized that the reactive oxygen species (ROS)-mediated c-jun N-terminal kinase (JNK) signaling pathway is involved in anti-apoptosis of selenium against cadmium in TM3 cells. We found that exposure to cadmium caused evident cytotoxicity, in which cell viability was inhibited, followed by inducement of apoptosis. Moreover, the level of ROS generation was elevated, leading to the phosphorylation of JNK. In addition, following cadmium exposure, the nuclear transcription factor c-jun was significantly activated, which led to increased expression of downstream gene c-jun, resulting in downstream activation of the apoptosis-related protein Caspase3 and upregulation of Cleaved-PARP, as well as inhibition of the anti-apoptosis protein Bcl-2. However, pretreatment with selenium remarkably suppressed cadmium-induced TM3 cell apoptosis. Furthermore, the level of ROS declined, and the JNK signaling pathway was blocked. Following this, the gene expression of c-jun decreased while Bcl-2 increased, which was consistent with the effects on proteins, that Caspase3 activity and Cleaved-PARP were inhibited while Bcl-2 level was restored. In order to explain the relationship between molecules of the signaling pathway, N-acetyl-L-cysteine (NAC), the ROS inhibitor, and JNK1/2 siRNA were administered, which further indicated the mediatory role of the ROS/JNK/c-jun signaling pathway in regulating anti-apoptosis of selenium against cadmium-induced TM3 cell apoptosis.

Cadmium-induced apoptosis through reactive oxygen species-mediated mitochondrial oxidative stress and the JNK signaling pathway in TM3 cells, a model of mouse Leydig cells.

Cadmium (Cd) is a heavy metal that widely exists in the environment and industry, and which causes serious damages to reproductive system. Recent studies have reported that cadmium induces apoptosis of various germ cells in testes, resulting in male infertility. However, the exact mechanism of cadmium-induced apoptosis remains unclear. In this study, we hypothesized that reactive oxygen species (ROS)-mediated c-jun N-terminal kinase (JNK) signaling pathway was involved in cadmium-induced apoptosis in TM3 cells, a model of mouse Leydig cells. TM3 cells were exposed for various times to a range of cadmium concentrations. We found that cadmium reduced TM3 cell viability and increased apoptosis in a time- and dose- dependent manner. Moreover, the levels of ROS generation and the phosphorylation of JNK were elevated by cadmium treatment. In addition, the nuclear transcription factor c-jun was significantly activated, which led to increased expression of downstream c-jun targets and Bcl-2 was decreased, accompanied with downstream activation of apoptosis-related proteins such as Cleaved-Caspase3 and Cleaved-PARP. However, pretreatment with the ROS inhibitor N-acetyl-L-cysteine (NAC) and JNK inhibitor JNK-IN-8, ROS, JNK and cadmium-induced TM3 cell apoptosis were remarkably suppressed. Based on above-mentioned results, this study provides a mechanistic understanding of cadmium induced TM3 cell apoptosis through the ROS/JNK signaling pathways.

[Role of DNA methyltransferase 1 in mouse skin aging].

OBJECTIVE: To explore the role ofDNA methyltransferase 1 (DNMT1) in mouse skin aging.
 Methods: Epidermal conditional K14 Cre-mediated DNA methyltransferase 1 (DNMT1) knockout mice (Mut group, n=4) and the littermate normal mice with the same age (WT group) n=4) were used in this study. HE staining was used to detect the pathological changes of skin; the changes of number in the dermal elastic fibers were detected by Gomori aldehyde fuchsin staining, the number of 5-bromo-2-deoxyuridine (BrdU)-labeled transit amplifying cells (TAC) in epidermis were detected by immunohistochemical staining; the number of chlorodeoxyuridine (CldU)-label-retaining cells (LRC) in epidermis were detected by immunofluorescent staining.
 Results: Compared with the WT group, the skin showed premature aging symptoms in the Mut group concomitant with the decreased epidermal thickness as well as the number of dermal collagen fibers, while the increased dermal elastic fiber fracture. Compared with the WT group, the number of TAC in the epidermis was significantly increased (P<0.05), and the number of LRC was significantly decreased (P<0.05) in the Mut group.
 Conclusion: The phenotype of skin premature aging in epidermal stem cell conditional DNMT1-knockout mice suggests an important role of DNMT1 in skin aging.

Chemical composition and antioxidant activity of phenolic compounds from Dioscorea (Yam) leaves.

This study was aimed to assess the potential of Dioscorea (yam) leaves as a source of antioxidants. Microwave-assisted extraction (MAE) process was used to prepare the extracts. The phenolic compounds in Dioscorea leaves extracts were analyzed by HPLC-DAD-ESI-MS/MS method and the contents of major compounds were determined. Results indicated that a total of 17 phenolic compounds were separated identified by means of UV and mass spectra compared with authentic reference substances and/or reported values in the literature. The main phenolic compound was rosmarinic acid and its highest amount was found in Dioscorea glabra Roxb. leaves (22.31±1.33 mg/g DW). Rutin was the dominant flavonoid followed by quercetin which highest amount was found in Dioscorea alata leaves (8.66±0.29 mg/g DW). Antioxidant activity of the extracts was estimated by the use of DPPH and ABTS assays. Both kinds of leaves exhibited satisfied antioxidant capacity which was correlated with phenolic contents. In the cytoprotective effect on HUVECs viability assay, Dioscorea glabra Roxb. leaves extract was found to be more active than that of Dioscorea alata against H2O2-induced oxidative stress. Our findings support the promising role of Dioscorea leaves that can be used as an interesting source of phenolic antioxidants.

Higher serum ascorbic acid levels are associated with lower depression prevalence in US adults: a case-control study.

Background: Recent studies have shown that a higher intake of ascorbic acid was associated with a lower prevalence of depression. Nevertheless, the recall bias was common in dietary surveys in these studies, and it was ignored that there were differences in the absorption and utilization of ascorbic acid in the body. Hence, we aim to investigate the association between serum ascorbic acid levels and the prevalence of depression in US adults. Methods: A total of 3,404 participants from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) that underwent measurement of the Patient Health Questionnaire-9 (PHQ-9) scores and serum levels of ascorbic acid. Propensity Score Matching (PSM) successfully established a case-control study, comprising 299 participants diagnosed with depression and 1,107 as controls. We used binary logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to explore associated risk factors for depression. Restricted cubic splines (RCS) were used to show the nonlinear relationship between serum ascorbic acid levels and the prevalence of depression. Results: The prevalence of depression was approximately 8.8%, with a median serum ascorbic acid level of 49.9 (36.0, 67.0) µmol/L. Results revealed that the serum ascorbic acid levels of depressed patients were significantly lower than those of non-depressed individuals (42.97 VS 52.97 µmol/L). The baseline data indicated that as serum ascorbic acid levels increased from Quartile 1 (Q1) to Quartile 4 (Q4), the depression prevalence decreased from 12.0 to 5.4% (p < 0.05). The results of the chi-square test after PSM showed that serum ascorbic acid was still statistically significant (p < 0.001) with the prevalence of depression. Forest plot showed that compared with the Q1 of serum ascorbic acid level, the OR and 95%CI of depression prevalence in Q4 was 0.42 (0.30 ~ 0.61), and the adjusted OR and 95%CI of depressive prevalence was 0.49 (0.33 ~ 0.73). RCS models showed an L-shaped nonlinear relationship (P for nonlinearity <0.05) between serum ascorbic acid and depression. Conclusion: Our results suggested that higher serum ascorbic acid levels are associated with a reduced prevalence of depression.

Association of systemic immune-inflammation index with malnutrition among Chinese hospitalized patients: a nationwide, multicenter, cross-sectional study.

Background: Systemic immune-inflammation index (SII) is associated with increased risk in a wide range of illnesses. However, few studies have explored the associations between SII and the risk of malnutrition. Therefore, this study aimed to investigate the association between SII and malnutrition in a nationwide, multicenter, cross-sectional study involving Chinese hospitalized patients. Design: From August 2020 to August 2021, a total of 40,379 hospitalized patients met the inclusion and exclusion criteria. Detailed demographic data, diagnoses, as well as physical and laboratory examination results were recorded. The diagnosis of malnutrition was used with two distinct methods: the Malnutrition Screening Tool 2002 (NRS 2002) + Global Leaders Initiative on Malnutrition (GLIM) criteria and the controlling nutritional status (CONUT) score. The risk factors for malnutrition were analyzed using binary logistic regression and multiple logistic regression to obtain odds ratios (OR) and 95% confidence intervals (CI). Restricted cubic spline (RCS), linear spline, and receiver operating characteristic (ROC) analysis were also used. Results: The prevalence of malnutrition diagnosed by the two methods was 13.4% and 14.9%, respectively. In the NRS 2002 + GLIM diagnostic model, lnSII showed statistical significance between the malnutrition and non-malnutrition group (6.28 ± 0.78 vs. 6.63 ± 0.97, p < 0.001). A positive association was observed between higher SII and the risk of malnutrition in both before and after adjustment models compared to the first quartile (Q3 vs. Q1, OR = 1.27, 95%CI: 1.15-1.40; Q4 vs. Q1, OR = 1.83, 95%CI: 1.67-2.00). However, a significant reduction in prevalence was observed when SII was in the second quartile (Q2 vs. Q1, OR < 1), as indicated by a restricted cubic spline with a U trend (p for nonlinear <0.001). According to the CONUT score, the prevalence of individuals with normal nutritional status decreased with increasing SII, while the occurrence of three different degrees of malnutrition generally increased. The Kappa value between the two diagnostic methods was 0.23, and the merged data observed an area under the ROC curve of 0.73 (95%CI: 0.714-0.742). Conclusion: The U-shaped association between SII and the prevalence of malnutrition was observed. Both lower and higher SII levels (either continuous or categorical variable) were significantly associated with an increased risk of malnutrition.

Corrigendum: Association of systemic immune-inflammation index with malnutrition among Chinese hospitalized patients: a nationwide, multicenter, cross-sectional study.

[This corrects the article DOI: 10.3389/fnut.2024.1375053.].

Nano-selenium Alleviates Cadmium-Induced Mouse Leydig Cell Injury, via the Inhibition of Reactive Oxygen Species and the Restoration of Autophagic Flux.

Cadmium (Cd) is a well-known environmental pollutant that can contribute to male reproductive toxicity through oxidative stress. Nano-selenium (Nano-se) is an active single body of selenium with strong antioxidant properties and low toxicity. Some studies have addressed the potential ameliorative effect of Nano-se against Cd-induced testicular toxicity; however, the underlying mechanisms remain to be investigated. This study aimed to explore the protective effect of Nano-se on Cd-induced mouse testicular TM3 cell toxicity by regulating autophagy process. We showed that cadmium exposure to TM3 cells inhibited cell viability and elevated the level of reactive oxygen species (ROS) generation. Morphology observation by transmission electron microscope and the presence of mRFP-GFP-LC3 fluorescence puncta demonstrated that cadmium increased autophagosome formation and accumulation in TM3 cells, resulting in blocking the autophagic flux of TM3 cells. Meanwhile, cadmium remarkably increased the ratio of LC3-II to LC3-I protein expression (2.07 ± 0.31) and the Beclin-1 protein expression (1.97 ± 0.40) in TM3 cells (P < 0.01). Pretreatment with Nano-se significantly reduced Cd-induced TM3 cell toxicity (P < 0.01). Furthermore, Nano-se treatment reversed Cd-induced ROS production and autophagosome accumulation, and autophagy as evidenced by the ratio of LC3-II to LC3-I and Beclin-1 expression. In addition, ROS scavenger, N-acetyl-L-cysteine (NAC) or autophagy inhibitor, 3-methyladenine (3-MA) reversed cadmium-induced ROS generation, autophagosome accumulation, and autophagy-related protein expression levels, which confirmed that cadmium induced TM3 cell injury via ROS signal pathway and blockage of autophagic flux. Collectively, our results reveal that Nano-se attenuates Cd-induced TM3 cell toxicity through the inhibition of ROS production and the amelioration of autophagy disruption.

BMI growth trajectory from birth to 5 years and its sex-specific association with prepregnant BMI and gestational weight gain.

Objective: The purpose of the study was to identify the latent body mass index (BMI) z-score trajectories of children from birth to 5 years of age and evaluate their sex-specific association with prepregnant BMI and gestational weight gain (GWG). Methods: This was a retrospective longitudinal cohort study performed in China. In total, three distinct BMI-z trajectories from birth to 5 years of age were determined for both genders using the latent class growth modeling. The logistic regression model was used to assess the associations of maternal prepregnant BMI and GWG with childhood BMI-z growth trajectories. Results: Excessive GWG increased the risks of children falling into high-BMI-z trajectory relative to adequate GWG (OR = 2.04, 95% CI: 1.29, 3.20) in boys; girls born to mothers with prepregnancy underweight had a higher risk of low-BMI-z trajectory than girls born to mothers with prepregnancy adequate weight (OR = 1.85, 95% CI: 1.22, 2.79). Conclusion: BMI-z growth trajectories of children from 0 to 5 years of age have population heterogeneity. Prepregnant BMI and GWG are associated with child BMI-z trajectories. It is necessary to monitor weight status before and during pregnancy to promote maternal and child health.

Heterologous Biosynthesis of Complex Bacterial Natural Products in Burkholderia gladioli.

Bacterial natural products (NPs) are an indispensable source of drugs and biopesticides. Heterologous expression is an essential method for discovering bacterial NPs and the efficient biosynthesis of valuable NPs, but the chassis for Gram-negative bacterial NPs remains inadequate. In this study, we built a Burkholderiales mutant Burkholderia gladioli Δgbn::attB by introducing an integrated site (attB) to inactivate the native gladiolin (gbn) biosynthetic gene cluster, which stabilizes large foreign gene clusters and reduces the native metabolite profile. The growth and successful heterologous production of high-value NPs such as phylogenetically close Burkholderiales-derived antitumor polyketides (PKs) rhizoxins, phylogenetically distant Gammaproteobacteria-derived anti-MRSA (methicillin-resistant Staphylococcus aureus) antibiotics WAP-8294As, and Deltaproteobacteria-derived antitumor PKs disorazols demonstrate that this strain is a potential chassis for Gram-negative bacterial NPs. We further improved the yields of WAP-8294As through promoter insertions and precursor pathway overexpression based on heterologous expression in this strain. This study provides a robust bacterial chassis for genome mining, efficient production, and molecular engineering of bacterial NPs.

Biosynthesis of trans-AT PKS-Derived Shuangdaolides Featuring a trans-acting Enzyme for Online Epoxidation.

Bacterial trans-acyltransferase polyketide synthases (trans-AT PKSs) synthesize natural products with intricate structures and potent biological activities. They generally contain various unusual modules or trans-acting enzymes. Herein, we report the trans-AT PKS-derived biosynthetic pathway of the shuangdaolide with a rare internal 2-hydroxycyclopentenone moiety. The multidomain protein SdlR catalyzes the synthesis of 16,17-epoxide during polyketide chain elongation. The SdlR contains a ketoreductase, an acyl carrier protein, a flavoprotein monooxygenase, and a serine hydrolase domain. This online epoxidation occurs at unusual positions away from the thioester. Then, two tailoring enzymes, SdlB and SdlQ, convert a methylene to a carbonyl group and oxidize a hydroxyl group to a carbonyl group, respectively. The following spontaneous opening of 16,17-epoxide induces the formation of a new C-C bond to generate the 2-hydroxycyclopentenone moiety. The characterization of the shuangdaolide pathway extends the understanding of the trans-AT PKSs, facilitating the mining and identification of this class of natural products.

Exploring the association and causal effect between white blood cells and psoriasis using large-scale population data.

Introduction: Psoriasis is a chronic inflammatory disease of the skin. A few studies have shown that psoriasis is an immune-mediated disease in which multiple immune cells play crucial roles. However, the association between circulating immune cells and psoriasis remains elusive. Methods: To explore the role of circulating immune cells in psoriasis, 361,322 individuals from the UK Biobank (UKB) and 3,971 patients with psoriasis from China were included to investigate the association between white blood cells and psoriasis via an observational study. Genome-wide association studies (GWAS) and Mendelian randomization (MR) were used to evaluate the causal relationship between circulating leukocytes and psoriasis. Results: The risk of psoriasis increased with high levels of monocytes, neutrophils, and eosinophils (relative risks and 95% confidence intervals, respectively: 1.430 (1.291-1.584) for monocytes, 1.527 (1.379-1.692) for neutrophils, and 1.417 (1.294-1.551) for eosinophils). Upon further MR analysis, eosinophils showed a definite causal relationship with psoriasis (odds ratio of inverse-variance weighted: 1.386, 95% confidence intervals: 1.092-1.759) and a positive correlation with the psoriasis area and severity index (PASI) score (P = 6.6 × 10-5). The roles of the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR) in psoriasis were also assessed. More than 20,000 genetic variations associated with NLR, PLR, and LMR were discovered in a GWAS analysis using the UKB data. Following adjustment for covariates in the observational study, NLR and PLR were shown to be risk factors for psoriasis, whereas LMR was a protective factor. MR results indicated that there was no causal relationship between these three indicators and psoriasis; however, NLR, PLR, and LMR correlated with the PASI score (NLR: rho = 0.244, P = 2.1 × 10-21; PLR: rho = 0.113, P = 1.4 × 10-5; LMR: rho = -0.242, P = 3.5×10-21). Discussion: Our findings revealed an important association between circulating leukocytes and psoriasis, which is instructive for the clinical practice of psoriasis treatment.