Oyster Peptides Ameliorate Dextran Sulfate Sodium-Induced Ulcerative Colitis via Modulating the Gut Microbiota and Inhibiting the TLR4/NF-κB Pathway.

Ulcerative colitis (UC) is an inflammatory bowel disease with an increasing prevalence year over year, and the medications used to treat patients with UC clinically have severe side effects. Oyster peptides (OPs) have anti-inflammatory and antioxidant properties as functional foods that can alleviate a wide range of inflammatory conditions. However, the application of oyster peptides in ulcerative colitis is not well studied. In this work, an animal model of acute colitis was established using 3% dextran sulfate sodium (DSS), and the impact of OP therapy on colitis in mice was examined. Supplementing with OPs prevented DSS-induced colitis from worsening, reduced the expression of oxidative stress and inflammatory markers, and restored the intestinal barrier damage caused by DSS-induced colitis in mice. The 16S rDNA results showed that the OP treatment improved the gut microbiota structure of the UC mice, including increasing microbial diversity, increasing beneficial bacteria, and decreasing harmful bacteria. In the UC mice, the OP therapy decreased the relative abundance of Family_XIII_AD3011_group and Prevotella_9 and increased the relative abundance of Alistipes. In conclusion, OP treatment can inhibit the TLR4/NF-κB pathway and improve the intestinal microbiota in UC mice, which in turn alleviates DSS-induced colitis, providing a reference for the treatment of clinical UC patients.

KLF4 promotes milk fat synthesis by regulating the PI3K-AKT-mTOR pathway and targeting FASN activation in bovine mammary epithelial cells.

Milk fat is an important indicator for evaluating the quality of cow's milk. In this study, we used bovine mammary epithelial cells (BMECs) to investigate the role and molecular mechanism of KLF4 in the regulation of milk fat synthesis. The results showed that KLF4 was more highly expressed in mammary tissues of high-fat cows compared with low-fat cows. KLF4 positively regulated the expression of genes related to milk fat synthesis in BMECs, increasing intracellular triglycerides content, and KLF4 promoted milk fat synthesis by activating the PI3K-AKT-mTOR signaling pathway. Furthermore, the results of animal experiments also confirmed that knockdown of KLF4 inhibited milk fat synthesis. In addition, yeast one-hybrid assays and dual-luciferase reporter gene assays confirmed that KLF4 directly targets and binds to the fatty acid synthase (FASN) promoter region to promote FASN transcription. These results demonstrate that KLF4 is a key transcription factor for milk fat synthesis in BMECs.

GnRH-driven FTO-mediated RNA m6A modification promotes gonadotropin synthesis and secretion.

BACKGROUND: Gonadotropin precisely controls mammalian reproductive activities. Systematic analysis of the mechanisms by which epigenetic modifications regulate the synthesis and secretion of gonadotropin can be useful for more precise regulation of the animal reproductive process. Previous studies have identified many differential m6A modifications in the GnRH-treated adenohypophysis. However, the molecular mechanism by which m6A modification regulates gonadotropin synthesis and secretion remains unclear. RESULTS: Herein, it was found that GnRH can promote gonadotropin synthesis and secretion by promoting the expression of FTO. Highly expressed FTO binds to Foxp2 mRNA in the nucleus, exerting a demethylation function and reducing m6A modification. After Foxp2 mRNA exits the nucleus, the lack of m6A modification prevents YTHDF3 from binding to it, resulting in increased stability and upregulation of Foxp2 mRNA expression, which activates the cAMP/PKA signaling pathway to promote gonadotropin synthesis and secretion. CONCLUSIONS: Overall, the study reveals the molecular mechanism of GnRH regulating the gonadotropin synthesis and secretion through FTO-mediated m6A modification. The results of this study allow systematic interpretation of the regulatory mechanism of gonadotropin synthesis and secretion in the pituitary at the epigenetic level and provide a theoretical basis for the application of reproductive hormones in the regulation of animal artificial reproduction.

Wheat peptide alleviates DSS-induced colitis by activating the Keap1-Nrf2 signaling pathway and maintaining the integrity of the gut barrier.

Inflammatory bowel disease (IBD) is difficult to cure, and formulating a dietary plan is an effective means to prevent and treat this disease. Wheat peptide contains a variety of bioactive peptides with anti-inflammatory and antioxidant functions. The results of this study showed that preventive supplementation with wheat peptide (WP) can significantly alleviate the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice. WP can increase body weight, alleviate colon shortening, and reduce disease activity index (DAI) scores. In addition, WP improved intestinal microbial disorders in mice with colitis. Based on LC-MS, a total of 313 peptides were identified in WP, 4 of which were predicted to be bioactive peptides. The regulatory effects of WP and four bioactive peptides on the Keap1-Nrf2 signaling pathway were verified in Caco-2 cells. In conclusion, this study demonstrated that WP alleviates DSS-induced colitis by helping maintain gut barrier integrity and targeting the Keap1-Nrf2 axis; these results provided a rationale for adding WP to dietary strategies to prevent IBD.

Agaricus blazei Polysaccharide Alleviates DSS-Induced Colitis in Mice by Modulating Intestinal Barrier and Remodeling Metabolism.

Ulcerative colitis (UC) is a chronic noninfectious intestinal disease that severely affects patients' quality of life. Agaricus blazei Murrill polysaccharide (ABP) is an effective active ingredient extracted from Agaricus blazei Murrill (ABM). It has good efficacy in inhibiting tumor cell growth, lowering blood pressure, and improving atherosclerosis. However, its effect on colitis is unclear. The aim of this study was to analyze the protective effects and potential mechanisms of ABP against dextran sulfate sodium (DSS)-induced acute colitis in mice. The results showed that dietary supplementation with ABP significantly alleviated DSS-induced colitis symptoms, inflammatory responses, and oxidative stress. Meanwhile, ABP intervention was able to maintain the integrity of the intestinal mechanical barrier by promoting the expression of ZO-1 and Occludin tight junction proteins and facilitating mucus secretion. Moreover, 16S rRNA sequencing results suggested that ABP intervention was able to alleviate DSS-induced gut microbiota disruption, and nontargeted metabolomics results indicated that ABP was able to remodel metabolism. In conclusion, these results demonstrate that dietary supplementation with ABP alleviated DSS-induced acute colitis by maintaining intestinal barrier integrity and remodeling metabolism. These results improve our understanding of ABP function and provide a theoretical basis for the use of dietary supplementation with ABP for the prevention of ulcerative colitis.

Oat Peptides Alleviate Dextran Sulfate Sodium Salt-Induced Colitis by Maintaining the Intestinal Barrier and Modulating the Keap1-Nrf2 Axis.

The prevalence of inflammatory bowel disease (IBD) is progressively rising each year, emphasizing the significance of implementing rational dietary interventions for disease prevention. Oats, being a staple agricultural product, are abundant in protein content. This study aimed to investigate the protective effects and underlying mechanisms of oat peptides (OPs) in a mouse model of acute colitis induced by dextran sulfate sodium salt (DSS) and a Caco-2 cell model. The findings demonstrated that intervention with OPs effectively mitigated the symptoms associated with DSS-induced colitis. The physicochemical characterization analysis demonstrated that the molecular weight of the OPs was predominantly below 5 kDa, with a predominant composition of 266 peptides. This study provides further evidence of the regulatory impact of OPs on the Keap1-Nrf2 signaling axis and elucidates the potential role of WGVGVRAERDA as the primary bioactive peptide responsible for the functional effects of OPs. Ultimately, the results of this investigation demonstrate that OPs effectively mitigate DSS-induced colitis by preserving the integrity of the intestinal barrier and modulating the Keap1-Nrf2 axis. Consequently, these findings establish a theoretical foundation for the utilization of OPs as dietary supplements to prevent the onset of IBD.

Sea Cucumber Peptides Ameliorate DSS-Induced Ulcerative Colitis: The Role of the Gut Microbiota, the Intestinal Barrier, and Macrophage Polarization.

The incidence of ulcerative colitis (UC) is increasing annually. There are few treatments for UC patients, and some drugs have serious side effects. Sea cucumber peptide (SCP) has anti-inflammatory, antioxidant and other biological activities, and various sea cucumber species are in pharmaceutical development. However, relevant studies on the effects of SCP on UC progression are still lacking. In this study, a mouse model of acute colitis was induced by 3% dextran sulfate (DSS), and the effect of 500 mg/kg SCP on colitis was investigated. The results showed that SCP can alleviate DSS-induced colon damage and intestinal barrier damage. SCP significantly inhibited the expression of inflammatory factors and oxidative stress in UC mice. SCP reversed the intestinal microbiota dysregulation induced by DSS, inhibited the growth of Sutterella, Prevotella_9 and Escherichia-Shigella harmful bacteria, and increased the abundance of Lachnospiraceae_NK4A136_group. At the same time, SCP treatment significantly inhibited the LPS-induced polarization of M1 macrophages, which may be mediated by two monopeptides, IPGAPGVP and TGPIGPPGSP, via FPR2. In conclusion, SCP can protect against colitis by modulating the intestinal microbiota composition and the intestinal barrier and inhibiting the polarization of M1 macrophages.

A missense mutation in Lama3 causes androgen alopecia.

Hair loss disorders such as androgenetic alopecia have caused serious disturbances to normal human life. Animal models play an important role in exploring pathogenesis of disease and evaluating new therapies. NIH hairless mice are a spontaneous hairless mouse discovered and bred in our laboratory. In this study, we resequenced the genomes of NIH normal mice and NIH hairless mice and obtained 3,575,560 high-quality, plausible SNP loci and 995,475 InDels. The Euclidean distance algorithm was used to assess the association of SNP loci with the hairless phenotype, at a threshold of 0.62. Two regions of chromosome 18 having the highest association with the phenotype contained 345 genes with a total length of 13.98 Mb. The same algorithm was used to assess the association of InDels with the hairless phenotype at a threshold of 0.54 and revealed a region of 25.45 Mb in length, containing 518 genes. The mutation candidate gene Lama3 (NM_010680.2: c.652C>T; NP_034810.1: p. Arg217Cys) was selected based on the results of functional gene analysis and mutation prediction screening. Lama3 (R217C) mutant mice were further constructed using CRISPR/Cas9 technology, and the relationship between Lama3 point mutations and the hairless phenotype were clarified by phenotypic observation. The results showed that male Lama3 point mutation mice started to lose hair on the 80th day after birth, and the hair loss area gradually expanded over time. H&E staining of skin sections showed that the point mutation mice had increased sebaceous glands in the dermis and missing hair follicle structure (i.e., typical symptoms of androgenetic alopecia). This study is a good extension of the current body of knowledge about the function of Lama3, and the constructed Lama3 (R217C) mutant mice may be a good animal model for studying androgenetic alopecia.

Investigation of LGALS2 expression in the TCGA database reveals its clinical relevance in breast cancer immunotherapy and drug resistance.

Breast cancer (BRCA) is known as the leading cause of death in women worldwide and has a poor prognosis. Traditional therapeutic strategies such as surgical resection, radiotherapy and chemotherapy can cause adverse reactions such as drug resistance. Immunotherapy, a new treatment approach with fewer side effects and stronger universality, can prolong the survival of BRCA patients and even achieve clinical cure. However, due to population heterogeneity and other reasons, there are still certain factors that limit the efficacy of immunotherapy. Therefore, the importance of finding new tumor immune biomarker cannot be emphasized enough. Studies have reported that LGALS2 was closely related to immunotherapy efficacy, however, it is unclear whether it can act as an immune checkpoint for BRCA immunotherapy. In the current study, changes in LGALS2 expression were analyzed in public datasets such as TCGA-BRCA. We found that LGALS2 expression was associated with immune infiltration, drug resistance and other characteristics of BRCA. Moreover, high LGALS2 expression was closely related to immunotherapy response, and was associated with methylation modifications and clinical resistance for the first time. These findings may help to elucidate the role of LGALS2 in BRCA for the development and clinical application of future immunotherapy strategies against BRCA.

Mammary Epithelial Cell-Derived Exosomal miR-221-3p Regulates Macrophage Polarization by Targeting Igf2bp2 during Mastitis.

Mastitis affects the milk quality and yield and is the most expensive disease in dairy cows. Elucidation of the pathogenesis of mastitis is of great importance for disease control. As a medium of intercellular communication, exosomes play key roles in various inflammatory diseases by regulating macrophage polarization. However, the molecular factors in exosomes that mediate the intercellular communication between mammary epithelial cells and macrophages during mastitis remain to be further explored. In this study, we isolated and identified mammary epithelial cell-derived exosomes from a lipopolysaccharide (LPS)/lipoteichoic acid (LTA)-induced mastitis cell model, and we demonstrated that exosomes from LPS/LTA-stimulated mammary epithelial cells promote M1-type macrophage polarization in vivo and in vitro. Based on the results of high-throughput sequencing, we constructed a differential miRNA (microRNA) expression profile of exosomes and demonstrated that miR-221-3p was highly expressed. Furthermore, in vivo and in vitro experiments, combined with coculture experiments and fluorescence tracing, showed that high miR-221-3p expression promoted M1-type macrophage polarization, demonstrating the transcellular role of miR-221-3p. Mechanistically, dual luciferase reporter gene assays and rescue assays showed that miR-221-3p regulated macrophage polarization by targeting Igf2bp2. The results of this study will deepen our understanding of the pathogenesis of mastitis, and the molecular regulatory axis that was established in this study is expected to be a target for mastitis treatment.

Lipid-based nanoparticles as drug delivery systems for cancer immunotherapy.

Immune checkpoint inhibitors (ICIs) have shown remarkable success in cancer treatment. However, in cancer patients without sufficient antitumor immunity, numerous data indicate that blocking the negative signals elicited by immune checkpoints is ineffective. Drugs that stimulate immune activation-related pathways are emerging as another route for improving immunotherapy. In addition, the development of nanotechnology presents a promising platform for tissue and cell type-specific delivery and improved uptake of immunomodulatory agents, ultimately leading to enhanced cancer immunotherapy and reduced side effects. In this review, we summarize and discuss the latest developments in nanoparticles (NPs) for cancer immuno-oncology therapy with a focus on lipid-based NPs (lipid-NPs), including the characteristics and advantages of various types. Using the agonists targeting stimulation of the interferon genes (STING) transmembrane protein as an exemplar, we review the potential of various lipid-NPs to augment STING agonist therapy. Furthermore, we present recent findings and underlying mechanisms on how STING pathway activation fosters antitumor immunity and regulates the tumor microenvironment and provide a summary of the distinct STING agonists in preclinical studies and clinical trials. Ultimately, we conduct a critical assessment of the obstacles and future directions in the utilization of lipid-NPs to enhance cancer immunotherapy.

HOPX is a tumor-suppressive biomarker that corresponds to T cell infiltration in skin cutaneous melanoma.

BACKGROUND: Skin cutaneous melanoma (SKCM) is the most threatening type of skin cancer. Approximately 55,000 people lose their lives every year due to SKCM, illustrating that it seriously threatens human life and health. Homeodomain-only protein homeobox (HOPX) is the smallest member of the homeodomain family and is widely expressed in a variety of tissues. HOPX is involved in regulating the homeostasis of hematopoietic stem cells and is closely related to the development of tumors such as breast cancer, nasopharyngeal carcinoma, and head and neck squamous cell carcinoma. However, its function in SKCM is unclear, and further studies are needed. METHODS: We used the R language to construct ROC (Receiver-Operating Characteristic) curves, KM (Kaplan‒Meier) curves and nomograms based on databases such as the TCGA and GEO to analyze the diagnostic and prognostic value of HOPX in SKCM patients. Enrichment analysis, immune scoring, GSVA (Gene Set Variation Analysis), and single-cell sequencing were used to verify the association between HOPX expression and immune infiltration. In vitro experiments were performed using A375 cells for phenotypic validation. Transcriptome sequencing was performed to further analyze HOPX gene-related genes and their signaling pathways. RESULTS: Compared to normal cells, SKCM cells had low HOPX expression (p < 0.001). Patients with high HOPX expression had a better prognosis (p < 0.01), and the marker had good diagnostic efficacy (AUC = 0.744). GO/KEGG (Gene Ontology/ Kyoto Encyclopedia of Genes and Genomes) analysis, GSVA and single-cell sequencing analysis showed that HOPX expression is associated with immune processes and high enrichment of T cells and could serve as an immune checkpoint in SKCM. Furthermore, cellular assays verified that HOPX inhibits the proliferation, migration and invasion of A375 cells and promotes apoptosis and S-phase arrest. Interestingly, tumor drug sensitivity analysis revealed that HOPX also plays an important role in reducing clinical drug resistance. CONCLUSION: These findings suggest that HOPX is a blocker of SKCM progression that inhibits the proliferation of SKCM cells and promotes apoptosis. Furthermore, it may be a new diagnostic and prognostic indicator and a novel target for immunotherapy in SKCM patients.

WITHDRAWN: RNA binding protein Musashi2 regulates dairy cows' mastitis by activating the TGFß signaling pathway.

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TRH Regulates the Synthesis and Secretion of Prolactin in Rats with Adenohypophysis through the Differential Expression of miR-126a-5p.

Prolactin (PRL) is an important hormone that is secreted by the pituitary gland and plays an important role in the growth, development and reproduction of organisms. Thyrotropin-releasing hormone (TRH) is a common prolactin-releasing factor that regulates the synthesis and secretion of prolactin. In recent studies, microRNAs (miRNAs) have been found to play a key role in the regulation of pituitary hormones. However, there is a lack of systematic studies on the regulatory role that TRH plays on the pituitary transcriptome, and the role of miRNAs in the regulation of PRL synthesis and secretion by TRH lacks experimental evidence. In this study, we first investigated the changes in PRL synthesis and secretion in the rat pituitary gland after TRH administration. The results of transcriptomic analysis after TRH treatment showed that 102 genes, including those that encode Nppc, Fgf1, PRL, Cd63, Npw, and Il23a, were upregulated, and 488 genes, including those that encode Lats1, Cacna2d1, Top2a, and Tfap2a, were downregulated. These genes are all involved in the regulation of prolactin expression. The gene expression of miR-126a-5p, which regulates the level of PRL in the pituitary gland, was screened by analysis prediction software and by a dual luciferase reporter system. The data presented in this study demonstrate that TRH can regulate prolactin synthesis and secretion through miR-126a-5p, thereby improving our understanding of the molecular mechanism of TRH-mediated PRL secretion and providing a theoretical basis for the role of miRNAs in regulating the secretion of pituitary hormones.

Exosomes in Mastitis-Research Status, Opportunities, and Challenges.

Mastitis, which affects milk quality and yield, is one of the most common diseases in dairy cows, causing large economic losses. Cow mastitis is classified into clinical and subclinical types. Subclinical mastitis presents without obvious lesions in the udder or noticeable change in milk samples, indicating persistent chronic infection that is difficult to detect and treat. Therefore, finding specific biomarkers is of great significance for the early diagnosis and treatment of subclinical mastitis. As mediators of intercellular communication, exosomes have been shown to be extensively involved in various physiological and pathological processes in the body. Exosomes in milk, blood, and cell supernatant can carry stable cell source-specific nucleic acids, proteins, and metabolites. Hence, exosomes show great application prospects for early diagnosis, targeted therapy, and disease mechanism analysis. In this review, we summarize the biogenesis, biological functions, and methods of isolating and identifying exosomes and review the current status of exosome research related to mastitis. Finally, in view of the application of exosomes to diagnose, treat, and perform disease mechanism analysis in mastitis, deficiencies in recent research on mastitis exosomes are described, and the direction of future exosome research efforts in mastitis is proposed.

Molecular Subtyping Based on Cuproptosis-Related Genes and Characterization of Tumor Microenvironment Infiltration in Kidney Renal Clear Cell Carcinoma.

The incidence of kidney renal clear cell carcinoma (KIRC) is rising worldwide, and the prognosis is poor. Cuproptosis is a new form of cell death that is dependent on and regulated by copper ions. The relationship between cuproptosis and KIRC remains unclear. In the current study, changes in cuproptosis-related genes (CRGs) in TCGA-KIRC transcriptional datasets were characterized, and the expression patterns of these genes were analyzed. We identified three main molecular subtypes and discovered that multilayer CRG changes were associated with patient clinicopathological traits, prognosis, elesclomol sensitivity, and tumor microenvironment (TME) cell infiltration characteristics. Then, a CRG score was created to predict overall survival (OS). The CRG score was found to be strongly linked to the TME. These findings may help elucidate the roles of CRGs in KIRC, potentially enhancing understanding of cuproptosis and supporting the development of more effective immunotherapy strategies.

LncRNA-m18as1 competitively binds with miR-18a-5p to regulate follicle-stimulating hormone secretion through the Smad2/3 pathway in rat primary pituitary cells.

Long noncoding RNAs (lncRNAs) are expressed in different species and different tissues, and perform different functions, but little is known about their involvement in the synthesis or secretion of follicle-stimulating hormone (FSH). In general, we have revealed lncRNA|‒|microRNA (miRNA)|‒||messenger RNA (mRNA) interactions that may play important roles in rat primary pituitary cells. In this study, a new lncRNA was identified for the first time. First, we analyzed the gene expression of lncRNA-m18as1 in different tissues and different stages by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and observed the localization of lncRNA-m18as1 with fluorescence in situ hybridization, which indicated that this lncRNA was distributed mainly in the cytoplasm. Next, we used RT-qPCR and enzyme-linked immunosorbent assay (ELISA) to analyze the regulation of FSH synthesis and secretion after overexpression or knockdown of lncRNA-m18as1 and found that lncRNA-m18as1 was positively correlated with FSH synthesis and secretion. In addition, mothers against decapentaplegic homolog 2 (Smad2) was highly expressed in our sequencing results. We also screened miR-18a-5p from our sequencing results as a miRNA that may bind to lncRNA-m18as1 and Smad2. We used RNA immunoprecipitation-qPCR (RIP-qPCR) and/or dual luciferase assays to confirm that lncRNA-m18as1 interacted with miR-18a-5p and miR-18a-5p interacted with Smad2. Fluorescence in situ hybridization (FISH) showed that lncRNA-m18as1 and miR-18a-5p were localized mainly in the cytoplasm. Finally, we determined the relationship among lncRNA-m18as1, miR-18a-5p, and the Smad2/3 pathway. Overall, we found that lncRNA-m18as1 acts as a molecular sponge of miR-18a-5p to regulate the synthesis and secretion of FSH through the Smad2/3 pathway.

Identification of immune-related biomarkers associated with tumorigenesis and prognosis in skin cutaneous melanoma.

Skin cutaneous melanoma (SKCM) is one of the most malignant and aggressive forms of cancer. Investigating the mechanisms of carcinogenesis further could lead to the discovery of prognostic biomarkers that could be used to guide cancer treatment. In this study, we conducted integrative bioinformatics analyses of TCGA database, STRING, cBioPortal, TRRUST, The Human Protein Atlas, and DGIdb to determine which hub genes contributed to tumor progression and the cancer-associated immunology of SKCM. The results show that immune-related 873 differential genes grouped SKCM samples into subtypes. The initial results showed that the optimal number of clusters was two subgroups. Further analysis showed that there were significant differences in survival rate and immune infiltration level between the two subgroups. Subsequently, obtaining the different genes between groups, construct PPI to screen 6 hub genes (HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DRA, HLA-DRB1, HLA-DRB5). In total, 6 MHC class II molecules were significantly related to overall survival. We then analyzed the expression of these genes along with their mutation landscapes, transcription factor regulation, and drug regulatory networks. In summary, our study identified 6 MHC class II molecules (HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DRA, HLA-DRB1, HLA-DRB5) as important biomarkers in the occurrence and progression of SKCM tumors. Their expression levels are closely related to prognosis and immune infiltration and can help us better understand the tumorigenesis of SKCM.

GeneChip analysis of resistant Mycobacterium tuberculosis with previously treated tuberculosis in Changchun.

BACKGROUND: With the widespread use of rifampicin and isoniazid, bacterial resistance has become a growing problem. Additionally, the lack of relevant baseline information for the frequency of drug-resistant tuberculosis (TB) gene mutations is a critical issue, and the incidence of this infection in the city of Changchun has not investigated to date. However, compared with the slow traditional methods of drug susceptibility testing, recently developed detection methods, such as rifampicin and isoniazid resistance-related gene chip techniques, allow for rapid, easy detection and simultaneous testing for mutation frequency and drug resistance. METHODS: In this study, the rifampicin and isoniazid resistance-related gene mutation chip method was employed for an epidemiological investigation. To assess the gene mutation characteristics of drug-resistant TB and evaluate the chip method, we tested 2143 clinical specimens from patients from the infectious diseases hospital of Changchun city from January to December 2016. The drug sensitivity test method was used as the reference standard. RESULTS: The following mutation frequencies of sites in the rifampicin resistance gene rpoB were found: Ser531Leu (52.6%), His526Tyr (12.3%), and Leu511Pro (8.8%). The multidrug-resistance (MDR)-TB mutation frequency was 34.7% for rpoB Ser531Leu and katG Ser315Thr, 26.4% for rpoB Ser531Leu and inhA promoter - 15 (C → T), and 10.7% for rpoB His526Tyr and katG Ser315Thr. In addition, drug susceptibility testing served as a reference standard. In previously treated clinical cases, the sensitivity and specificity of GeneChip were 83.1 and 98.7% for rifampicin resistance, 79.9 and 99.6% for isoniazid resistance, and 74.1 and 99.8% for MDR-TB. CONCLUSIONS: Our experimental results show that the chip method is accurate and reliable; it can be used to detect the type of drug-resistant gene mutation in clinical specimens. Moreover, this study can be used as a reference for future research on TB resistance baselines.

Arachidonic acid induces macrophage cell cycle arrest through the JNK signaling pathway.

BACKGROUND: Arachidonic acid (AA) has potent pro-apoptotic effects on cancer cells at a low concentration and on macrophages at a very high concentration. However, the effects of AA on the macrophage cell cycle and related signaling pathways have not been fully investigated. Herein we aim to observe the effect of AA on macrophages cell cycle. RESULTS: AA exposure reduced the viability and number of macrophages in a dose- and time-dependent manner. The reduction in RAW264.7 cell viability was not caused by apoptosis, as indicated by caspase-3 and activated caspase-3 detection. Further research illustrated that AA exposure induced RAW264.7 cell cycle arrested at S phase, and some cell cycle-regulated proteins were altered accordingly. Moreover, JNK signaling was stimulated by AA, and the stimulation was partially reversed by a JNK signaling inhibitor in accordance with cell cycle-related factors. In addition, nuclear and total Foxo1/3a and phosphorylated Foxo1/3a were elevated by AA in a dose- and time-dependent manner, and this elevation was suppressed by the JNK signaling inhibitor. CONCLUSION: Our study demonstrated that AA inhibits macrophage viability by inducing S phase cell cycle arrest. The JNK signaling pathway and the downstream FoxO transcription factors are involved in AA-induced RAW264.7 cell cycle arrest.