Analysis of 16s rRNA Gene Sequencing in Feces: The Impact of Bariatric Surgery on the Gut Microbiota in Patients with Obesity.

PURPOSE: Obesity is a risk factor for many chronic diseases. This study aimed to investigate the effect of bariatric surgery on the gut microbiota from patients with obesity. MATERIALS AND METHODS: The microbiota composition from stool samples before and after bariatric surgery were identified using bacterial 16S rRNA gene sequencing. Based on the speed of weight loss, patients were classified as the slow-loss group and fast-loss group. The ɑ- and ß-diversity analysis was done to compare the species richness, evenness, and overall structure of the microbiota between different groups. Next, linear discriminant analysis effect size (LEfSe) and receiver operating characteristic (ROC) analysis were implemented to identify high-dimensional biomarkers and significantly different species of microbial taxa between different groups. Finally, the pathway analysis was inferred using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) to predict the functional profiling of microbial communities. RESULTS: ß-diversity analysis suggested that species diversity of preoperative samples of slow-loss group was significantly higher than the fast-loss group. High levels of Oscillospira and Abiotrophia in the preoperative gut microbiota may lead to poor postoperative weight loss. For patients with poor postoperative weight loss due to changes in gut microbiota, the gut microbiota is mainly composed of Lactobacillus. For patients with good postoperative results, the gut microbiota is mainly composed of Escherichia, Robinsonella, and Dialister. In addition, multiple metabolic-related pathways were significantly different between the four groups. CONCLUSION: This comparative study revealed biomarker species based on microfloral composition in patients with obesity before and after bariatric surgery.

Mesoporous carbon spheres with programmable interiors as efficient nanoreactors for H2O2 electrosynthesis.

The nanoreactor holds great promise as it emulates the natural processes of living organisms to facilitate chemical reactions, offering immense potential in catalytic energy conversion owing to its unique structural functionality. Here, we propose the utilization of precisely engineered carbon spheres as building blocks, integrating micromechanics and controllable synthesis to explore their catalytic functionalities in two-electron oxygen reduction reactions. After conducting rigorous experiments and simulations, we present compelling evidence for the enhanced mass transfer and microenvironment modulation effects offered by these mesoporous hollow carbon spheres, particularly when possessing a suitably sized hollow architecture. Impressively, the pivotal achievement lies in the successful screening of a potent, selective, and durable two-electron oxygen reduction reaction catalyst for the direct synthesis of medical-grade hydrogen peroxide disinfectant. Serving as an exemplary demonstration of nanoreactor engineering in catalyst screening, this work highlights the immense potential of various well-designed carbon-based nanoreactors in extensive applications.

Nanoengineering of Porous 2D Structures with Tunable Fluid Transport Behavior for Exceptional H2O2 Electrosynthesis.

Precision nanoengineering of porous two-dimensional structures has emerged as a promising avenue for finely tuning catalytic reactions. However, understanding the pore-structure-dependent catalytic performance remains challenging, given the lack of comprehensive guidelines, appropriate material models, and precise synthesis strategies. Here, we propose the optimization of two-dimensional carbon materials through the utilization of mesopores with 5-10 nm diameter to facilitate fluid acceleration, guided by finite element simulations. As proof of concept, the optimized mesoporous carbon nanosheet sample exhibited exceptional electrocatalytic performance, demonstrating high selectivity (>95%) and a notable diffusion-limiting disk current density of -3.1 mA cm-2 for H2O2 production. Impressively, the electrolysis process in the flow cell achieved a production rate of 14.39 mol gcatalyst-1 h-1 to yield a medical-grade disinfectant-worthy H2O2 solution. Our pore engineering research focuses on modulating oxygen reduction reaction activity and selectivity by affecting local fluid transport behavior, providing insights into the mesoscale catalytic mechanism.

Correction: Mitochondria-targeting nanozyme alleviating temporomandibular joint pain by inhibiting the TNFα/NF-κB/NEAT1 pathway.

Correction for 'Mitochondria-targeting nanozyme alleviating temporomandibular joint pain by inhibiting the TNFα/NF-κB/NEAT1 pathway' by Qian Bai et al., J. Mater. Chem. B, 2023, https://doi.org/10.1039/d3tb00929g.

Impact of combining photodynamic diagnosis with reflectance confocal microscopy, on tumor margin detection and surgical outcomes in patients with extramammary Paget disease.

Background The recurrence rate of extramammary Paget disease after surgical resection is high due to the lesions' poorly delineated and unclear margins. Aims To evaluate the impact of non-invasive tumour margin detection via photodynamic diagnosis plus reflectance confocal microscopy on the surgical outcomes of patients with extramammary Paget disease. Methods Thirty-six patients with histopathologically confirmed primary extramammary Paget disease between January 2017 and June 2018 were included in this study. The skin lesion margins were preoperatively observed using the naked eye, photodynamic diagnosis, and reflectance confocal microscopy. An incision was made 0.5-2 cm from the outermost non-invasive detection marker line. The incision depth was more significant than the follicle level or the deepest level affected by the tumour in the biopsy specimens. After the skin lesions were removed, a pathological examination of the specimens was conducted to ensure clear margins to prevent tumour recurrence and metastases. Results A total of 166 good-quality tissue sections were selected from 36 patients. The tumour surfaces and deep margins were within the scope of resection. Six patients (6/36, 15.4%) experienced local recurrence 2-12 months postoperatively. One patient (1/36, 2.8%) had lymph node metastasis without local recurrence 36 months postoperatively and died 50 months postoperatively (1/36, 2.8%). Limitations This study is limited by the small patient population, especially the number of patients with mucous membrane involvement. Conclusion Using photodynamic diagnosis plus reflectance confocal microscopy to detect the margins of extramammary Paget disease lesions non-invasively reduces the postoperative tumour recurrence rate and is a valuable guide for tumour treatment.

DNMT1 determines osteosarcoma cell resistance to apoptosis by associatively modulating DNA and mRNA cytosine-5 methylation.

Cellular apoptosis is a central mechanism leveraged by chemotherapy to treat human cancers. 5-Methylcytosine (m5C) modifications installed on both DNA and mRNA are documented to regulate apoptosis independently. However, the interplay or crosstalk between them in cellular apoptosis has not yet been explored. Here, we reported that promoter methylation by DNMT1 coordinated with mRNA methylation by NSun2 to regulate osteosarcoma cell apoptosis. DNMT1 was induced during osteosarcoma cell apoptosis triggered by chemotherapeutic drugs, whereas NSun2 expression was suppressed. DNMT1 was found to repress NSun2 expression by methylating the NSun2 promoter. Moreover, DNMT1 and NSun2 regulate the anti-apoptotic genes AXL, NOTCH2, and YAP1 through DNA and mRNA methylation, respectively. Upon exposure to cisplatin or doxorubicin, DNMT1 elevation drastically reduced the expression of these anti-apoptotic genes via enhanced promoter methylation coupled with NSun2 ablation-mediated attenuation of mRNA methylation, thus rendering osteosarcoma cells to apoptosis. Collectively, our findings establish crosstalk of importance between DNA and RNA cytosine methylations in determining osteosarcoma resistance to apoptosis during chemotherapy, shedding new light on future treatment of osteosarcoma, and adding additional layers to the control of gene expression at different epigenetic levels.

Mitochondria-targeting nanozyme alleviating temporomandibular joint pain by inhibiting the TNFα/NF-κB/NEAT1 pathway.

Inflammatory cytokines that are secreted into the spinal trigeminal nucleus caudalis (Sp5C) may augment inflammation and cause pain associated with temporomandibular joint disorders (TMD). In a two-step process, we attached triphenylphosphonium (TPP) to the surface of a cubic liposome metal-organic framework (MOF) loaded with ruthenium (Ru) nanozyme. The design targeted mitochondria and was designated Mito-Ru MOF. This structure scavenges free radicals and reactive oxygen species (ROS) and alleviates oxidative stress. The present study aimed to investigate the effects and mechanisms by which Mito-Ru MOF ameliorates TMD pain. Intra-temporomandibular joint (TMJ) injections of complete Freund's adjuvant (CFA) induced inflammatory pain for ≥10 d in the skin areas innervated by the trigeminal nerve. Tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), long non-coding RNA nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1), and ROS also have been proved to be significantly upregulated in the Sp5C of TMD mice. Moreover, a single Mito-Ru MOF treatment alleviated TMD pain for 3 d and downregulated TNF-α, NF-κB, lncRNA NEAT1, and ROS. NF-κB knockdown downregulated NEAT1 in the TMD mice. Hence, Mito-Ru MOF inhibited the production of ROS and alleviated CFA-induced TMD pain via the TNF-α/NF-κB/NEAT1 pathway. Therefore, Mito-Ru MOF could effectively treat the pain related to TMD and other conditions associated with severe acute inflammatory activation.

Validation and benchmarking of targeted panel sequencing for cancer genomic profiling.

OBJECTIVES: To validate a large next-generation sequencing (NGS) panel for comprehensive genomic profiling and improve patient access to more effective precision oncology treatment strategies. METHODS: OncoPanScan was designed by targeting 825 cancer-related genes to detect a broad range of genomic alterations. A practical validation strategy was used to evaluate the assay's analytical performance, involving 97 tumor specimens with 25 paired blood specimens, 10 engineered cell lines, and 121 artificial reference DNA samples. RESULTS: Overall, 1107 libraries were prepared and the sequencing failure rate was 0.18%. Across alteration classes, sensitivity ranged from 0.938 to more than 0.999, specificity ranged from 0.889 to more than 0.999, positive predictive value ranged from 0.867 to more than 0.999, repeatability ranged from 0.908 to more than 0.999, and reproducibility ranged from 0.832 to more than 0.999. The limit of detection for variants was established based on variant frequency, while for tumor mutation burden and microsatellite instability, it was based on tumor content, resulting in a minimum requirement of 20% tumor content. Benchmarking variant calls against validated NGS assays revealed that variations in the dry-bench processes were the primary cause of discordances. CONCLUSIONS: This study presents a detailed validation framework and empirical recommendations for large panel validation and elucidates the sources of discordant alteration calls by comparing with "gold standard measures."

Circulating cardiac MicroRNAs safeguard against dilated cardiomyopathy.

BACKGROUND: Cardiac-resident or -enriched microRNAs (miRNAs) could be released into the bloodstream becoming circulating cardiac miRNAs, which are increasingly recognized as non-invasive and accessible biomarkers of multiple heart diseases. However, dilated cardiomyopathy (DCM)-associated circulating miRNAs (DACMs) and their roles in DCM pathogenesis remain largely unexplored. METHODS: Two human cohorts, consisting of healthy individuals and DCM patients, were enrolled for serum miRNA sequencing (10 vs. 10) and quantitative polymerase chain reaction validation (46 vs. 54), respectively. Rigorous screening strategy was enacted to define DACMs and their potentials for diagnosis. DCM mouse model, different sources of cardiomyocytes, adeno-associated virus 9 (AAV9), gene knockout, RNAscope miRNA in situ hybridization, mRFP-GFP-LC3B reporter, echocardiography and transmission electron microscopy were adopted for mechanistic explorations. RESULTS: Serum miRNA sequencing revealed a unique expression pattern for DCM circulating miRNAs. DACMs miR-26a-5p, miR-30c-5p, miR-126-5p and miR-126-3p were found to be depleted in DCM circulation as well as heart tissues. Their expressions in circulation and heart tissues were proven to be correlated significantly, and a combination of these miRNAs was suggested potential values for DCM diagnosis. FOXO3, a predicted common target, was experimentally demonstrated to be co-repressed within cardiomyocytes by these DACMs except miR-26a-5p. Delivery of a combination of miR-30c-5p, miR-126-5p and miR-126-3p into the murine myocardium via AAV9 carrying an expression cassette driven by cTnT promoter, or cardiac-specific knockout of FOXO3 (Myh6-CreERT2 , FOXO3 flox+/+ ) dramatically attenuated cardiac apoptosis and autophagy involved in DCM progression. Moreover, competitively disrupting the interplay between DACMs and FOXO3 mRNA by specifically introducing their interacting regions into murine myocardium crippled the cardioprotection of DACMs against DCM. CONCLUSIONS: Circulating cardiac miRNA-FOXO3 axis plays a pivotal role in safeguarding against myocardial apoptosis and excessive autophagy in DCM development, which may provide serological cues for DCM non-invasive diagnosis and shed light on DCM pathogenesis and therapeutic targets.

Eupatilin inhibits keratinocyte proliferation and ameliorates imiquimod-induced psoriasis-like skin lesions in mice via the p38 MAPK/NF-κB signaling pathway.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease that is currently incurable and causes long-term distress to patients. Therefore, there is an urgent need to develop safe and effective psoriatic drugs. Eupatilin is a natural flavone, that has a variety of pharmacological effects. However, the anti-psoriatic effect of eupatilin and its underlying mechanism remain unclear. METHODS: HaCaT cells were treated with 20 µg/mL LPS for 24 h to establish the proliferation model of HaCaT cells. Cell viability was measured by MTT assay. Western blotting was used to detect the expression of p-p38 MAPK, p38 MAPK, p-NF-κB p65 and NF-κB p65 in HaCaT cells. Imiquimod (IMQ) was used to induce psoriasis-like mouse model. Psoriasis Area Severity Index (PASI) score was used to evaluate the degree of skin injury, H&E staining was used to observe the pathological damage of skin tissues, and the expression levels of TNF-α, IL-6, IL-23 and IL-17 in the serum were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Eupatilin could inhibit the hyperproliferation of LPS-stimulated HaCaT cells through p38 MAPK/NF-κB signaling pathway in vitro. In psoriatic mice, eupatilin could significantly reduce skin erythema, scales and thickening scores, ameliorate skin histopathological lesions, and decrease the levels of TNF-α, IL-6, IL-23 and IL-17 in the serum. CONCLUSION: Eupatilin had a good anti-proliferative effect in LPS-stimulated HaCaT cells, and significantly alleviated IMQ-induced psoriasis-like lesions in mice. Eupatilin was a promising drug for the treatment of psoriasis.

Construction of Cupriavidus necator displayed with superoxide dismutases for enhanced growth in bioelectrochemical systems.

It is of great significance to utilize CO2 as feedstock to synthesize biobased products, particularly single cell protein (SCP) as the alternative food and feed. Bioelectrochemical system (BES) driven by clean electric energy has been regarded as a promising way for Cupriavidus necator to produce SCP from CO2 directly. At present, the key problem of culturing C. necator in BES is that reactive oxygen species (ROS) generated in cathode chamber are harmful to bacterial growth. Therefore, it is necessary to find a solution to mitigate the negative effect of ROS. In this study, we constructed a number of C. necator strains displayed with superoxide dismutase (SOD), which allowed the decomposition of superoxide anion radical. The effects of promoters and signal peptides on the cell surface displayed SOD were analyzed. The proteins displayed on the surface were further verified by the fluorescence experiment. Finally, the growth of C. necator CMS incorporating a pBAD-SOD-E-tag-IgAß plasmid could achieve 4.9 ± 1.0 of OD600 by 7 days, equivalent to 1.7 ± 0.3 g/L dry cell weight (DCW), and the production rate was 0.24 ± 0.04 g/L/d DCW, around 2.7-fold increase than the original C. necator CMS (1.8 ± 0.3 of OD600). This study can provide an effective and novel strategy of cultivating strains for the production of CO2-derived SCP or other chemicals in BES.

Effects of salinomycin and ethanamizuril on the three microbial communities in vivo and in vitro.

The fate of a drug is not only the process of drug metabolism in vivo and in vitro but also the homeostasis of drug-exposed microbial communities may be disturbed. Anticoccidial drugs are widely used to combat the detrimental effects of protozoan parasites in the poultry industry. Salinomycin and ethanamizuril belong to two different classes of anticoccidial drugs. The effect of salinomycin and ethanamizuril on the microbiota of cecal content, manure compost, and soil remains unknown. Our results showed that although both salinomycin and ethanamizuril treatments suppressed some opportunistic pathogens, they failed to repair the great changes in chicken cecal microbial compositions caused by coccidia infection. Subsequently, the metabolite5 profiling of cecal content by LC-MS/MS analyses confirmed the great impact of coccidia infection on chicken cecum and showed that histidine metabolism may be the main action pathway of salinomycin, and aminoacyl tRNA biosynthesis may be the major regulatory mechanism of ethanamizuril. The microbial community of manure compost showed a mild response to ethanamizuril treatment, but ethanamizuril in soil could promote Actinobacteria reproduction, which may inhibit other taxonomic bacteria. When the soil and manure were exposed to salinomycin, the Proteobacteria abundance of microbial communities showed a significant increase, which suggested that salinomycin may improve the ability of the microbiota to utilize carbon sources. This hypothesis was confirmed by a BIOLOG ECO microplate analysis. In the animal model of coccidia infection, the treatment of salinomycin and ethanamizuril may reconstruct a new equilibrium of the intestinal microbiota. In an in vitro environment, the effect of ethanamizuril on composting and soil microbiota seems to be slight. However, salinomycin has a great impact on the microbial communities of manure composting and soil. In particular, the promoting effect of salinomycin on Proteobacteria phylum should be further concerned. In general, salinomycin and ethanamizuril have diverse effects on various microbial communities.

Activation of TREM2 attenuates neuroinflammation via PI3K/Akt signaling pathway to improve postoperative cognitive dysfunction in mice.

Postoperative cognitive dysfunction (POCD) is a common postoperative complication involving the central nervous system, but the underlying mechanism is not well understood. Neuroinflammation secondary to surgery and anesthesia is strongly correlated with POCD. A key aspect of neuroinflammation is microglia activation. Triggering receptor expressed on myeloid cells (TREM)2, which is highly expressed in microglia, is an innate immune receptor that modulates microglia function. In this study we investigated the role of TREM2 in cognitive impairment and microglia-mediated neuroinflammation using a mouse model of POCD and in vitro systems. We found that hippocampus-dependent learning and memory were impaired in POCD mice, which was accompanied by activation of microglia and downregulation of TREM2. Pretreatment with the TREM2 agonist heat shock protein (HSP)60 inhibited surgery-induced microglia activation and alleviated postoperative cognitive impairment. In BV2 microglial cells, the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 significantly reversed the attenuation of TREM2 activation on lipopolysaccharide (LPS)-induced neuroinflammation and abrogated the protective effect of activated TREM2 against LPS-induced neuronal injury in a microglia/neuron coculture system. Accordingly, the beneficial effects of TREM2 activation on cognitive function were reversed by preoperative administration of LY294002 in the POCD mouse model. These results demonstrate that TREM2 is involved in the regulation of the inflammatory response mediated by microglia and cognitive impairment following surgery. Activation of TREM2 can attenuate neuroinflammation by modulating PI3K/protein kinase B (Akt) signaling, thereby alleviating postoperative learning and memory deficits.

CIRBP-OGFR axis safeguards against cardiomyocyte apoptosis and cardiotoxicity induced by chemotherapy.

Cold-inducible RNA-binding protein (CIRBP) is documented to be required for maintaining cardiac function, however, its role in chemotherapy-induced cardiotoxicity remains obscured. Herein, we report that CIRBP decreases cardiomyocyte apoptosis and attenuates cardiotoxicity through disrupting OGF-OGFR signal. CIRBP deficiency is involved in diverse chemotherapeutic agents induced cardiomyocyte apoptosis. Delivery of exogenous CIRBP to the mouse myocardium significantly mitigated doxorubicin-induced cardiac apoptosis and dysfunction. Specifically, OGFR was identified as a downstream core effector responsible for chemotherapy-induced cardiomyocyte apoptosis. CIRBP was shown to interact with OGFR mRNA and to repress OGFR expression by reducing mRNA stability. CIRBP-mediated cytoprotection against doxorubicin-induced cardiac apoptosis was demonstrated to largely involve OGFR repression by CIRBP. NTX as a potent antagonist of OGFR successfully rescued CIRBP ablation-rendered susceptibility to cardiac dyshomeostasis upon exposure to doxorubicin, whereas another antagonist ALV acting only on opioid receptors did not. Taken together, our results demonstrate that CIRBP confers myocardium resistance to chemotherapy-induced cardiac apoptosis and dysfunction by dampening OGF/OGFR axis, shedding new light on the mechanisms of chemo-induced cardiotoxicity and providing insights into the development of an efficacious cardioprotective strategy for cancer patients.

Algorithm of CAD Surface Generation for Complex Pipe Model in Industry 4.0 Background.

The current pipeline surface generation algorithm cannot get the angle information of the corner of complex pipeline surface, which leads to the poor accuracy of the algorithm, the slow speed of 3D point cloud intelligent mosaic, and the large number of effective points. Therefore, a CAD surface generation algorithm for complex pipeline model under the background of Industry 4.0 is designed, extracting and rendering the wireframe model and extracting background of the complex pipeline video. We obtain the angle information of the corner points of the complex pipeline surface, extract and match the feature of the dense point cloud, and construct the 3D point cloud data mosaic model. The pipe surface is generated by using double-nodal B-spline. The experimental results show that the precision and stability of the proposed method are high. In the early stage, the proposed method uses ISS feature extraction algorithm to extract feature of point cloud data, which improves the positioning accuracy effectively and enhances the 3D point cloud intelligent stitching speed.

Fusobacterium nucleatum predicts a high risk of metastasis for esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is the major type of esophageal cancer in China. The role of the bacteria present in ESCC tissue in neoplastic progression has not been fully elucidated. This study aimed to uncover different bacterial communities in ESCC tissues and examine the correlation between the abundance of the esophageal flora and clinicopathologic characteristics of ESCC. RESULTS: Microorganisms in tumors and normal tissues showed obvious clustering characteristics. The abundance of Fusobacterium (P = 0.0052) was increased in tumor tissues. The high level of Fusobacterium nucleatum was significantly associated with pT stage (P = 0.039) and clinical stage (P = 0.0039). The WES data showed that COL22A1, TRBV10-1, CSMD3, SCN7A and PSG11 were present in only the F. nucleatum-positive ESCC samples. GO and protein domain enrichment results suggested that epidermal growth factor might be involved in the regulation of cell apoptosis in F. nucleatum-positive ESCC. Both a higher mutational burden and F. nucleatum-positive was observed in tumors with metastasis than in tumors without metastasis. CONCLUSION: F. nucleatum is closely related to the pT stage and clinical stage of ESCC. The abundance of F. nucleatum and tumor mutation burden may be used in combination as a potential method to predict metastasis in ESCC.

HuB and HuD repress telomerase activity by dissociating HuR from TERC.

The ubiquitous RNA-binding protein HuR (ELAVL1) promotes telomerase activity by associating with the telomerase noncoding RNA TERC. However, the role of the neural-specific members HuB, HuC, and HuD (ELAVL2-4) in telomerase activity is unknown. Here, we report that HuB and HuD, but not HuC, repress telomerase activity in human neuroblastoma cells. By associating with AU-rich sequences in TERC, HuB and HuD repressed the assembly of the TERT-TERC core complex. Furthermore, HuB and HuD competed with HuR for binding to TERC and antagonized the function of HuR that was previously shown to enhance telomerase activity to promote cell growth. Our findings reveal a novel mechanism controlling telomerase activity in human neuroblastoma cells that involves a competition between HuR and the related, neural-specific proteins HuB and HuD.

Comparative Genomic Analysis Reveals Genetic Mechanisms of the Variety of Pathogenicity, Antibiotic Resistance, and Environmental Adaptation of Providencia Genus.

The bacterial genus Providencia is Gram-negative opportunistic pathogens, which have been isolated from a variety of environments and organisms, ranging from humans to animals. Providencia alcalifaciens, Providencia rettgeri, and Providencia stuartii are the most common clinical isolates, however, these three species differ in their pathogenicity, antibiotic resistance and environmental adaptation. Genomes of 91 isolates of the genus Providencia were investigated to clarify their genetic diversity, focusing on virulence factors, antibiotic resistance genes, and environmental adaptation genes. Our study revealed an open pan-genome for the genus Providencia containing 14,720 gene families. Species of the genus Providencia exhibited different functional constraints, with the core genes, accessory genes, and unique genes. A maximum-likelihood phylogeny reconstructed with concatenated single-copy core genes classified all Providencia isolates into 11 distant groups. Comprehensive and systematic comparative genomic analyses revealed that specific distributions of virulence genes, which were highly homologous to virulence genes of the genus Proteus, contributed to diversity in pathogenicity of Providencia alcalifaciens, Providencia rettgeri, and Providencia stuartii. Furthermore, multidrug resistance (MDR) phenotypes of isolates of Providencia rettgeri and Providencia stuartii were predominantly due to resistance genes from class 1 and 2 integrons. In addition, Providencia rettgeri and Providencia stuartii harbored more genes related to material transport and energy metabolism, which conferred a stronger ability to adapt to diverse environments. Overall, our study provided valuable insights into the genetic diversity and functional features of the genus Providencia, and revealed genetic mechanisms underlying diversity in pathogenicity, antibiotic resistance and environmental adaptation of members of this genus.

Hepatic HuR modulates lipid homeostasis in response to high-fat diet.

Lipid transport and ATP synthesis are critical for the progression of non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms are largely unknown. Here, we report that the RNA-binding protein HuR (ELAVL1) forms complexes with NAFLD-relevant transcripts. It associates with intron 24 of Apob pre-mRNA, with the 3'UTR of Uqcrb, and with the 5'UTR of Ndufb6 mRNA, thereby regulating the splicing of Apob mRNA and the translation of UQCRB and NDUFB6. Hepatocyte-specific HuR knockout reduces the expression of APOB, UQCRB, and NDUFB6 in mice, reducing liver lipid transport and ATP synthesis, and aggravating high-fat diet (HFD)-induced NAFLD. Adenovirus-mediated re-expression of HuR in hepatocytes rescues the effect of HuR knockout in HFD-induced NAFLD. Our findings highlight a critical role of HuR in regulating lipid transport and ATP synthesis.

Oligomannuronate prevents mitochondrial dysfunction induced by IAPP in RINm5F islet cells by inhibition of JNK activation and cell apoptosis.

BACKGROUND: Oligomannuronates (OM) are natural products from alginate that is frequently used as food supplement. The aim of this study was to investigate the in vitro protective effects of OM on RINm5F cells against human Islet amyloid polypeptide (IAPP) induced mitochondrial dysfunction, as well as the underlying mechanisms. METHODS: In the present study, we obtained several kinds of OM with different molecular masses, and then we used RINm5F cells as a model to elucidate the involvement of JNK signal pathway in hIAPP-induced mitochondrial dysfunction in pancreatic beta cells, and the protective effects of OM are associated with its ability to attenuate the mitochondrial dysfunction. RESULTS: Our results demonstrated that human IAPP induced mitochondrial dysfunction, as evidence by loss of ΔΨm and ATP content, and decrease in oxygen consumption and complex activities, was accompanied by JNK activation, changes in the expressions of Bcl-2 and Bax proteins, release of cytochrome c (Cyto-c) and apoptosis inducing factor (AIF) from mitochondria into cytosol. Interestingly, the human IAPP induced damage in RINm5F cells were effectively restored by co-treatment of OM. Moreover, JNK activation was required for the OM mediated changes in RINm5F cells. CONCLUSIONS: OM prevented mitochondrial dysfunction induced by human IAPP in RINm5F islet cells through JNK dependent signaling pathways.