An early Cambrian euarthropod with radiodont-like raptorial appendages.

Resolving the early evolution of euarthropods is one of the most challenging problems in metazoan evolution1,2. Exceptionally preserved fossils from the Cambrian period have contributed important palaeontological data to deciphering this evolutionary process3,4. Phylogenetic studies have resolved Radiodonta (also known as anomalocaridids) as the closest group to all euarthropods that have frontalmost appendages on the second head segment (Deuteropoda)5-9. However, the interrelationships among major Cambrian euarthropod groups remain disputed1,2,4,7, which impedes our understanding of the evolutionary gap between Radiodonta and Deuteropoda. Here we describe Kylinxia zhangi gen. et. sp. nov., a euarthropod from the early Cambrian Chengjiang biota of China. Kylinxia possesses not only deuteropod characteristics such as a fused head shield, a fully arthrodized trunk and jointed endopodites, but also five eyes (as in Opabinia) as well as radiodont-like raptorial frontalmost appendages. Our phylogenetic reconstruction recovers Kylinxia as a transitional taxon that bridges Radiodonta and Deuteropoda. The most basal deuteropods are retrieved as a paraphyletic lineage that features plesiomorphic raptorial frontalmost appendages and includes Kylinxia, megacheirans, panchelicerates, 'great-appendage' bivalved euarthropods and isoxyids. This phylogenetic topology supports the idea that the radiodont and megacheiran frontalmost appendages are homologous, that the chelicerae of Chelicerata originated from megacheiran great appendages and that the sensorial antennae in Mandibulata derived from ancestral raptorial forms. Kylinxia thus provides important insights into the phylogenetic relationships among early euarthropods, the evolutionary transformations and disparity of frontalmost appendages, and the origin of crucial evolutionary innovations in this clade.

Integrative score based on CDK6, PD-L1 and TMB predicts response to platinum-based chemotherapy and PD-1/PD-L1 blockade in muscle-invasive bladder cancer.

BACKGROUND: Cyclin-dependent kinase 6 (CDK6) was proved to be an important regulator in the progression of cell cycle and has been a promising therapeutic target in cancer treatment. However, the clinical significance of CDK6 in muscle-invasive bladder cancer (MIBC) remains obscure. Herein, we attempt to explore the clinical relevance of CDK6 and assess the feasibility of the integrative model to predict immune checkpoint blockade (ICB) response. METHODS: This study enrolled 933 patients with muscle-invasive bladder cancer (MIBC) from Zhongshan Hospital (ZSHS), The Cancer Genome Atlas (TCGA), Chemo, IMvigor210 and UC-GENOME cohorts. Kaplan-Meier survival and Cox regression analyses were performed to assess clinical outcomes based on CDK6 expression. RESULTS: High CDK6 expression conferred poor prognosis and superior response to platinum-based chemotherapy but inferior response to ICB in MIBC. Furthermore, the integrative model named response score based on CDK6, PD-L1 and TMB could better predict the response to ICB and chemotherapy. Patients with higher response scores were characterised by inflamed immune microenvironment and genomic instability. CONCLUSIONS: CDK6 expression was correlated with prognosis and therapy response in MIBC. Integration of CDK6, PD-L1 and TMB could better identify patients who were most likely to benefit from ICB and chemotherapy.

Mentalis Muscle Reconstruction: An Innovative Technique.

BACKGROUND: The mentalis muscle is a significant component of the lower lip; its injury could impair appearance and function. This study presents a surgical strategy for treating mentalis muscle rupture to restore muscle tension and improve function. METHODS: Medical records and photographs of 2 patients with mentalis muscle rupture were reviewed. After physical examinations, 3-dimensional computed topographies were conducted to evaluate chin appearance further. The surgical strategy was designed according to individual malformations and requests. RESULTS: Both patients injured their mentalis muscles in childhood and presented to our clinic with a concave deformity at the center of the chin and impaired mentalis muscle function. The surgical procedure involved the reconstruction of the mentalis muscle by reassembling the muscle flaps and releasing the scarred soft tissue. Both patients were satisfied with the outcome. CONCLUSIONS: Mentalis muscle rupture requires surgical correction. The study proposes an innovative approach that enables patients to achieve a more harmonious appearance and improve function.

M2 Macrophage Polarization and Tissue Remodeling in Autologous Fat Grafting for Diabetic Skin Defects.

Autologous adipose tissue was recognized as a promising therapeutic option for soft tissue defects owing to its regenerative potential and ability to facilitate tissue reconstruction. However, the mechanisms by which autologous fat grafting (AFG) promotes healing remain unclear, hindering its potential applications. This study aimed to investigate the distribution and phenotypic transition of infiltrating macrophages in transplanted adipose tissue, as well as their correlation with diabetic skin defect remodeling. Streptozotocin-induced diabetic rats with full-thickness dorsal skin defects were included in this study. The transplanted adipose tissue at the skin defects was collected and analyzed using flow cytometry to determine macrophage proportion and phenotype. The healing of skin defects was evaluated, and treatment was continued until day 14 as the designated endpoint of healing, followed by histopathologic examinations. Immunostaining with CD31 and lymphatic vessel endothelial receptor-1 was performed on wound tissues to analyze angiogenesis and lymphangiogenesis, respectively. Western blot and quantitative polymerase chain reaction analyses were used to assess the expression of the representative genes involved in the healing process. The results showed early polarization of M2 macrophages in the transplanted adipose tissue, concomitant with the upregulation of growth factors and downregulation of inflammatory factors. In vivo experiments revealed that AFG significantly promoted macrophage infiltration and M2 transformation in diabetic skin defects compared to the control groups, thereby promoting tissue extracellular matrix remodeling and lymphatic and vascular regeneration. However, the beneficial effects of AFG were inhibited by macrophage depletion. This study further demonstrated the potential of AFG for treating diabetic skin defects.

[Extracorporeal Membrane Oxygenation Combined With Interventional Thrombectomy for Treating High-Risk Pulmonary Embolism Caused by Protein C Deficiency:Report of One Case].

Hereditary protein C deficiency is a chromosomal genetic disease caused by mutations in the protein C gene,which can lead to venous thrombosis and is mostly related to mutations in exons 4-9 and intron 8.Fatal pulmonary embolism caused by mutations in the protein C gene is rare,and the treatment faces great challenges.This article reports a case of fatal pulmonary embolism caused by a frameshift mutation in exon 8 of the protein C gene and summarizes the treatment experience of combining extracorporeal membrane oxygenation (for respiratory and circulatory support) with interventional thrombectomy,providing a basis for the diagnosis and treatment of this disease.

Immune inactivation by VISTA predicts clinical outcome and therapeutic benefit in muscle-invasive bladder cancer.

BACKGROUND: V domain Immunoglobulin suppressor of T cell activation (VISTA) has been proved to be a novel immune checkpoint molecule that positively regulates T cell infiltration in several malignancies. However, the clinical impact of VISTA on muscle-invasive bladder cancer (MIBC) patients remains relatively obscure. METHODS: This study enrolled 135 MIBC patients from Zhongshan Hospital (ZSHS) and 391 patients from The Cancer Genome Atlas (TCGA) to examine the VISTA expression and immune contexture based on immunohistochemistry (IHC) staining and CIBERSORT algorithm. Additionally, IMvigor210 Cohort included 195 bladder-derived urothelial carcinoma patients to evaluate the efficacy of immunotherapy. Kaplan-Meier curve and Cox regression analyses were conducted to assess clinical outcomes. RESULTS: MIBC patients with high VISTA+ immune cells (ICs) possessed poor overall survival and inferior therapeutic responsiveness to adjuvant chemotherapy (ACT), but superior responsiveness to PD-L1 inhibitor. VISTA+ ICs infiltration shaped an immunoevasive context featured by regulatory T cells (Tregs), M2 macrophages, mast cells and exhausted CD8+ T cells infiltration, with increased interleukin 10 (IL-10), transforming growth factor-ß (TGF-ß) and interferon-γ (IFN-γ), but also elevated T-cell immunoglobulin mucin-3 (TIM-3), lymphocyte activation gene 3 (LAG-3) and T-cell immunoglobulin and ITIM domain (TIGIT), which was also mainly presented in basal-squamous and luminal-infiltrated subtypes of MIBC. CONCLUSION: VISTA+ ICs infiltration could be an independent predictor to identify poor prognosis and therapeutic responses (PD-L1 blockade and ACT) in MIBC patients, which was associated with immunoevasive contexture. The novel immune checkpoint VISTA might be utilized as a candidate treatment biomarker in MIBC patients.

HIF-2α-induced upregulation of CD36 promotes the development of ccRCC.

Clear cell renal cell carcinoma (ccRCC) is characterized by the abundance of lipid droplets and the activation of the hypoxia-inducible factor (HIF) signaling pathway. However, the lipid reprogramming induced by HIF signaling in ccRCC is not fully understood. In this study, we found that the fatty acid receptor CD36 was highly expressed in human ccRCC tissues and ccRCC cell lines. CD36 overexpression increased fatty acid uptake and lipid droplet formation, and enhanced the proliferation and migration of ccRCC cells in a DGAT1-dependent manner. In contrast, the disruption of endogenous CD36 showed the opposite effects. The upregulated expression of CD36 in ccRCC was associated with hypoxia and HIF-2α activation. Furthermore, we identified CD36 as a new target of the transcription factor HIF-2α. The knockdown of CD36 in ccRCC cells reduced lipid accumulation and also blocked the tumor-promoting effects induced by HIF-2α under hypoxia. Our findings suggest that hypoxia-dependent HIF-2α promotes the remodeling of lipid metabolism and the malignant phenotype of ccRCC via CD36, providing a certain theoretical basis for clarifying the mechanism of ccRCC.

Methionine alleviates heat stress-induced ferroptosis in bovine mammary epithelial cells through the Nrf2 pathway.

Heat stress (HS) triggers mammary gland degradation, accompanied by apoptosis and autophagy in bovine mammary epithelial cells, negatively affecting milk performance and mammary gland health. Ferroptosis is iron-mediated regulated cell death caused by over production of lipid peroxides, however, the relationship between ferroptosis and HS in bovine mammary epithelial cells has not been clarified. Methionine (Met) plays a notable role in alleviating HS affecting the mammary glands in dairy cows, but the underlying mechanisms require further exploration. Therefore, we evaluated the regulatory effect and mechanism of Met in alleviating HS-induced ferroptosis by using bovine mammary epithelial cell line (MAC-T) as an in vitro model. The results showed that Met improved cell vitality, restored mitochondrial function; reduced the content of various reactive oxygen species (ROS), especially hydrogen peroxide (H2O2) and superoxide anion (O2·-); had positive effects on antioxidant enzyme activity, namely glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). More importantly, Met reduced labile iron protein (LIP) levels; increased iron storage and simultaneously decreased the levels of lipid reactive oxygen species (lipid ROS) and malondialdehyde (MDA), which all caused by HS in MAC-T. Mechanistically, Met increased the protein expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7, member 11 (SLC7A11) and ferritin heavy chain 1 (FTH1) by activating nuclear factor E2-related factor 2 (Nrf2) expression. Additionally, the protection effect of Met was cut off in MAC-T cells after interference with Nrf2, manifesting in decresing the protein expression levels of GPX4, SLC7A11 and FTH1,and increasing the levels of LIP and lipid ROS. Our findings indicate that Met eases HS-induced ferroptosis in MAC-T through the Nrf2 pathway, revealing that Met produces a marked effect on easing HS-induced bovine mammary gland injury in dairy cows.

Integrative tumour mutation burden with CD39 and PD-L1 for the prediction of response to PD-L1 blockade and adjuvant chemotherapy in muscle-invasive bladder cancer patients.

BACKGROUND: CD39, a rate-limiting enzyme to convert extracellular ATP (eATP) to adenosine, has been reported to be a key modulator of immune response, but its correlation with therapeutic sensitivity remains obscure. We conducted this study to determine whether the integration of CD39 and traditional biomarkers could improve the prediction of responsiveness to PD-L1 blockade and platinum-based chemotherapy. METHODS: We retrospectively enrolled a total of 760 patients from IMvigor210 trial, TCGA database and Zhongshan Hospital in this study. We constructed the CPT scoring system based on CD39, PD-L1 and tumour mutation burden (TMB) and validated its efficacy in predicting therapeutic responsiveness in MIBC patients. Kaplan-Meier survival and Cox regression analyses were applied to assess clinical outcomes of patients. RESULTS: The CPT scoring system could predict the response to PD-L1 blockade and platinum-based chemotherapy. The CPT score was positively correlated with APOBEC mutational signature and SNV neoantigens enrichment, antigen presentation, and TCR signalling. High CPT score also indicated the inflamed immune phenotype and basal/squamous molecular subtype. CONCLUSIONS: CD39 expression is closely correlated with the immunogenic contexture of MIBC. Integrating CD39 with PD-L1 and TMB could stratify the sensitivity of patients with MIBC to PD-L1 blockade and platinum-based chemotherapy.

CD103+CD8+ tissue-resident memory T cell infiltration predicts clinical outcome and adjuvant therapeutic benefit in muscle-invasive bladder cancer.

BACKGROUND: CD103+CD8+ tissue-resident memory T (TRM) cells, associated with better overall survival among various malignancies, are thought to activate anti-tumour immune response and affect therapeutic sensitivity including both immunotherapy and adjuvant chemotherapy (ACT). METHODS: Totally 650 muscle-invasive bladder cancer (MIBC) patients from three independent cohorts were included in this study for survival and cisplatin-based ACT response analysis. Another public data set consisting of 195 patients from IMvigor210 trial receiving PD-L1 blockade were involved in the assessment of immunotherapeutic response. Fifty-nine fresh tumour tissues were used to evaluate immune infiltration of CD103+CD8+ TRM cells. RESULTS: Patients with high CD103+CD8+ TRM cells infiltration, but not CD8+ T cells, are more likely to benefit from immunotherapy and ACT. The presence of TRM cells is highly associated with an enhanced IFNγ-enriched and T cell-inflamed anti-tumour microenvironment. Elevated CD103+CD8+ TRM cells infiltration correlated with superior ACT response in mismatch repair (MMR), homologous recombination (HR), PIK3CA/AKT and RAS/RAF pathway proficient or histone modification and cell cycle pathway deficient patients. CONCLUSIONS: CD103+CD8+ TRM cells played a crucial role in anti-tumour immunity and served as an ideal prognostic biomarker. It could be treated as a superior companion predictor for treatment response to PD-L1 inhibitor and ACT within MIBC patients.

TIGIT and PD-1 expression atlas predicts response to adjuvant chemotherapy and PD-L1 blockade in muscle-invasive bladder cancer.

BACKGROUND: TIGIT and PD-1 are checkpoint receptors that could regulate the functional status of immune cells through independent pathways. However, the clinical significance of immune classification based on TIGIT and PD-1 expression remains unclear in muscle-invasive bladder cancer (MIBC). METHODS: Patients with MIBC from four independent cohorts were categorised into three clusters. Survival analysis conducted through Kaplan-Meier curves and Cox regression model. Immune contexture was measured by immunohistochemistry and CIBERSORT algorithm. Twenty-five fresh tumour tissue samples were utilised to evaluate functional state of CD8+ T cells by flow cytometry. RESULTS: Cluster I (TIGITlowPD-1low) contained widely poor immune infiltrates with higher FGFR3 mutation, Cluster II (TIGITlowPD-1high) exhibited a highly infiltrated contexture with increased cytolytic CD8+ T cells and had the best prognosis, Cluster III (TIGIThigh) presented a suppressive tumour microenvironment (TME) featured by exhausted CD8+ T cells and basal molecular subtype. Patients of Cluster III had the worst survival but could benefit more from adjuvant chemotherapy and anti-PD-L1 immunotherapy, and also presented limited FGFR3 signalling signature but activated immunotherapeutic and EGFR-associated pathway. CONCLUSIONS: TIGIT/PD-1-based risk stratification with distinct immune and molecular features could be served as a predictor for systematic therapeutic response including adjuvant chemotherapy and immunotherapy in MIBC patients.

Identification and bioinformatics analysis of differentially expressed milk exosomal microRNAs in milk exosomes of heat-stressed Holstein cows.

In summer, heat stress is one of the primary reasons for the compromised health and low milk productivity of dairy cows. Hyperthermia affects milk synthesis and secretion in the mammary glands of dairy cows. As molecules for intercellular communication, milk-derived exosomes carry genetic material, proteins, and lipids, playing a crucial role in mammary tissue growth and milk synthesis in dairy cows. The aim of this study was to explore the milk exosomal miRNA profile of heat-stressed and normal Holstein cows. We isolated and identified milk exosomes to screening for differentially expressed miRNAs using small RNA sequencing. Then, TargetScan and miRanda algorithms were used to predict the putative targets of the differentially expressed miRNAs, whereas GO and KEGG pathway enrichment analyses were performed for the differentially expressed miRNA-target genes. Our results showed that 215 miRNAs were significantly differentially expressed in heat-stressed milk exosomes, of which one was upregulated and 214 were significantly downregulated. GO and KEGG enrichment analyses indicated that differentially expressed miRNAs might play a role in apoptosis, autophagy, and the p38 MAPK pathway. qRT-PCR assay verified that the expression of miRNAs was consistent with the sequencing results, warranting further verification of their specific targets of action. In conclusion, changes in the miRNA expression profile of milk exosomes indicated the role of exosomal miRNAs in regulating heat stress resistance and apoptosis in dairy cows. Our results suggested that milk-derived exosomal miRNAs could increase mammary gland resistance to heat stress, thereby enhancing milk synthesis in dairy cows.

Infiltration and Polarization of Tumor-associated Macrophages Predict Prognosis and Therapeutic Benefit in Muscle-Invasive Bladder Cancer.

BACKGROUND: Muscle-invasive bladder cancer (MIBC) is an aggressive and heterogeneous malignancy. Tumor-associated macrophages (TAMs) are key infiltrating cell populations in the inflammatory microenvironment of malignant tumors including MIBC. It intrigues us to explore the clinical significance and immunoregulatory role of TAMs infiltration and polarization in MIBC. METHODS: A total of 141 patients with MIBC from Zhongshan Hospital and 391 patients with MIBC from The Cancer Genome Atlas (TCGA) database were included in this study. Moreover, 195 patients who received anti-PD-L1 therapy from the IMvigor210 trial were enrolled. Patients were categorized into three subtypes considering the infiltration level and polarization status of TAMs, denoted as TAMlow (Subtype I), TAMhigh&M2/M1low (Subtype II), and TAMhigh&M2/M1high (Subtype III). RESULTS: Subtype III suffered inferior prognosis, and Subtype II could benefit more from adjuvant chemotherapy (ACT). Subtype III was featured with increased pro-tumor cells and immunosuppressive cytokines, while Subtype II possessed more immunogenic cells infiltration with activated and tumoricidal properties. Subtype II and Subtype III presented basal/squamous-like characterization and showed additional prognostic merit beyond molecular classification. Subtype I exhibited elevated level of FGFR3 signature, while Subtype II had EGFR signaling activation and immunotherapeutic indication. Additionally, Subtype II patients were indeed highly sensitive to PD-L1 blockade therapy in IMvigor210 trial. CONCLUSION: The infiltration and polarization status of TAMs shaped distinct immune microenvironment with predictive significance for survival outcome, ACT benefit, and PD-L1 blockade therapy sensitivity in MIBC. Immune classification based on TAMs polarization and infiltration might provide tools to tailor chemotherapy and immunotherapy.

Latency-associated peptide identifies therapeutically resistant muscle-invasive bladder cancer with poor prognosis.

BACKGROUND: Latency-associated peptide (LAP) was identified as crucial immune regulator in tumor microenvironment (TME) in recent researches. In this study, we aimed to estimate the predictive value of LAP expression for clinical survival and therapeutic response in muscle-invasive bladder cancer (MIBC). METHODS: Our study encompassed 140 MIBC patients from Zhongshan Hospital (ZSHS cohort), 401 patients from The Cancer Genome Atlas (TCGA cohort) and 195 patients received PDL1 blockade from IMvigor210 trial. Survival analyses were conducted through Kaplan-Meier curve and Cox regression model. LAP expression and its association with immune contexture were evaluated in ZSHS and TCGA cohort. RESULTS: We found that high intratumoral LAP+ cells infiltration anticipated inferior survival and adjuvant chemotherapy (ACT) response, and was closely related to an immunoevasive contexture with increased M2 macrophages, neutrophils and conspicuously a cluster of highly exhausted CD8+ T cells. The combinational analysis of LAP+ cells and CD8+ T cells infiltration stratified patients into distinct risk groups with implications for therapeutic sensitivity to PDL1 blockade and refinement of molecular classification in MIBC. CONCLUSIONS: LAP expression was correlated with patients' inferior prognosis, ACT-tolerance and an immunoevasive TME with exhausted CD8+ T cell infiltration, suggesting that LAP could serve as a promising therapeutic target in MIBC. Simultaneously, our novel TME classification based on LAP+ cells and CD8+ T cells infiltration and its potential in appraising PDL1 blockade application for MIBC patients deserved further validation.

Immune inactivation by neuropilin-1 predicts clinical outcome and therapeutic benefit in muscle-invasive bladder cancer.

BACKGROUND: Immune checkpoint blockade (ICB) and adjuvant chemotherapy (ACT) have shown clinical benefit in muscle-invasive bladder cancer (MIBC) with only a few predictive biomarkers identified so far. Neuropilin-1 (NRP1) has been identified as a key immune checkpoint and a novel immunotherapeutic target but the clinical significance of NRP1 remains unclear in MIBC. METHODS: Three independent cohorts were involved in our study: IMvigor210 Cohort (n = 348), The Cancer Genome Atlas Cohort (TCGA, n = 391), and Zhongshan Hospital Cohort (ZSHS, n = 130). Parallel detection and validation of risk stratification based on NRP1 expression were executed in patients treated with anti-PD-L1 agent and adjuvant chemotherapy (ACT). RESULTS: NRP1 expression conferred poor survival and predicted response to both PD-L1 blockade and cisplatin-based ACT in MIBC. Further exploration revealed high-level NRP1 was extremely associated with infiltration of exhausted CD8+ T cells, immature NK cells and M2 polarized tumor-associated macrophages in MIBC patients. Moreover, elevated NRP1 expression was also correlated with low mutation burden and reduced mutation in cell cycle pathway. CONCLUSIONS: Our study firstly identified and validated the clinical implications of NRP1 expression for prognosis and systematic therapeutic responses (PD-L1 blockade and ACT) in MIBC. NRP1 expression was associated with an immunosuppressive microenvironment with dysfunctional effector immune cells. Prospective investigations of its roles in the therapeutic landscape of MIBC warrant more consideration.

Stromal Tumor-Associated Macrophage Infiltration Predicts Poor Clinical Outcomes in Muscle-Invasive Bladder Cancer Patients.

BACKGROUND: This study aims to reveal the clinical significance of stromal-infiltrating tumor-associated macrophages (TAMs) in muscle-invasive bladder cancer (MIBC). PATIENTS AND METHODS: This study included 288 patients from the TCGA database and 118 patients from Fudan University Shanghai Cancer Center with MIBC. The CIBERSORT model and immunohistochemistry were used to evaluate TAM infiltration. Cox regression analyses were employed to calculate their prognostic value. RESULTS: Among all 23 immune phenotypes analyzed in the TCGA cohort, pan-macrophage infiltration was significantly associated with poor prognosis (p = 0.001). Further analyses found that stromal TAM infiltration could be an independent prognostic predictor for recurrence-free survival (RFS; HR: 1.019, 95% CI: 1.006-1.033, p = 0.004). High stromal infiltration was related to unfavorable RFS. After stratification by adjuvant chemotherapy (ACT), patients without ACT could be differentiated by TAM infiltration (p = 0.036), while patients with ACT could not. Moreover, TAM infiltration was negatively associated with IFN-γ-related mRNA panel, which was shown to have strong predictive value for clinical response to programmed death-1 (PD-1) inhibition. CONCLUSIONS: Stromal TAM infiltration could be an independent prognosticator for MIBC patients. This might have potential to guide precise treatments such as ACT and immune checkpoint blockade in MIBC.

Nicotinamide mononucleotide alleviates heat stress-induced oxidative stress and apoptosis in BMECs through reducing mitochondrial damage and endoplasmic reticulum stress.

Heat stress is directly correlated to mammary gland dysfunction in dairy cows, especially in summer. Abnormally high environmental temperature induces oxidative stress and apoptosis in bovine mammary epithelial cells (BMECs). Nicotinamide mononucleotide (NMN) has beneficial effects in maintaining the cellular physiological functions. In this study, we evaluate the protective effect of NMN on heat stress-induced apoptosis of BMECs and explore the potential underlying mechanisms. Our results showed that heat stress considerably decreased cell viability in BMECs, whereas pretreatment of BMECs with NMN (150 µM) for 24 h significantly alleviated the negative effects of heat stress on cells. NMN protected BMECs from heat stress-induced oxidative stress by inhibiting the excessive accumulation of reactive oxygen species (ROS) and increasing the activity of antioxidant enzymes. It also inhibited apoptosis by reducing the ratio of Bax/Bcl2 and blocking proteolytic the cleavage of Caspase-3 in heat stressed-BMECs. Importantly, NMN treatment could reduce mitochondrial damage through mediating the expression of mitochondrial fission and fusion-related genes, including Dynamin related protein 1 (Drp1), Mitochondrial fission 1 protein (Fis1), and Mitofusin1, 2 (MFN1, 2); and suppress endoplasmic reticulum stress through unfolded protein response regulator Glucose regulated protein 78 (GRP78), and downstream elements Recombinant activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP). Above all, our results demonstrate that NMN supplemention attenuates heat stress-induced oxidative stress and apoptosis in BMECs by maintaining mitochondrial fission and fusion, and regulating endoplasmic reticulum stress, which provides the convincing evidence that NMN has valuable potential in alleviating mammary gland injury of dairy cows caused by environmental heat stress.

Loss of CD36 impairs hepatic insulin signaling by enhancing the interaction of PTP1B with IR.

A contradictory role of CD36 in insulin resistance was found to be related to the nutrient state. Here, we examined that the physiological functions of CD36 in insulin signal transduction in mice fed a low-fat diet. CD36 deficiency led to hepatic insulin resistance and decreased insulin-stimulated tyrosine phosphorylation of insulin receptor ß (IRß) in mice fed a low-fat diet. The ability of insulin to bind with IR did not differ between WT and CD36-deficient hepatocytes. CD36 formed a complex with IRß and dissociation of CD36/Fyn complex or inhibition of Fyn only partially reversed the effects of CD36 on hepatic insulin signaling. Furthermore, we found that CD36 deficiency led to abnormally increased hepatic protein-tyrosine phosphatase 1B (PTP1B) expression and enhanced PTP1B and IR interactions, which contributed to the decreased insulin signaling and disordered glucose metabolism. In addition, increased endoplasmic reticulum (ER) stress was found in the livers of the CD36-deficient mice, while inhibited ER stress normalized the PTP1B expression and restored insulin signaling in the CD36-deficient mice. Our findings suggest that the loss of CD36 impairs hepatic insulin signaling by enhancing the PTP1B/IR interaction that is induced by ER stress, indicating a possible critical step in the progression of hepatic insulin resistance.

USF2 reduces BMP3 expression via transcriptional activation of miR-34a, thus promoting osteogenic differentiation of BMSCs.

INTRODUCTION: Osteoporosis is the most susceptible disease for people over 60. The main cause of osteoporosis is the decreased osteogenic differentiation of mesenchymal stem cells (MSCs). Here we showed that upstream stimulatory factor 2 (USF2)/microRNA-34a (miR-34a)/bone morphogenetic protein 3 (BMP3) axis regulated osteogenic differentiation of BMSCs. MATERIALS AND METHODS: USF2 and miR-34a expression were examined using qPCR. Protein levels of BMP3 and osteogenic markers expression were evaluated using both western blot and qPCR. Activity of ALP was determined by ALP assay kit. Mineralization capacity of hBMSCs was assessed using ARS. Besides, CHIP assay was employed to verify whether USF2 could bind to miR-34a promoter. Finally, RIP assay and dual-luciferase reporter assay were employed to verify whether miR-34a directly bound to BMP3. RESULTS: Our results suggested that miR-34a was upregulated during osteogenic differentiation of BMSCs, and miR-34a overexpression could enhance osteogenic differentiation of BMSCs. USF2 could positively regulate miR-34a expression by interacting with its promoter. USF2 overexpression enhanced osteogenic differentiation of BMSCs, while miR-34a inhibition reversed the effect. Besides, BMP3 was the target of miR-34a. MiR-34a overexpression enhanced osteogenic differentiation of BMSCs, which was abolished by BMP3 overexpression. CONCLUSION: Taken together, USF2 enhanced osteogenic differentiation of BMSCs via downregulating BMP3 by interacting with miR-34a promoter.

[Deletion of CD36 gene ameliorates glucose metabolism abnormality induced by high-fat diet and promotes liver lipid accumulation].

This study aimed to investigate the effects and the underlying mechanism of CD36 gene on glucose and lipid metabolism disorder induced by high-fat diet in mice. Wild type (WT) mice and systemic CD36 knockout (CD36-/-) mice were fed with high-fat diet for 14 weeks (n = 12). Mice were intraperitoneally injected with glucose (1 g/kg) or insulin (5 units/kg) to perform glucose tolerance test (GTT) or insulin tolerance test (ITT). Liver lipid deposition was observed by HE staining, and the contents of total triglyceride (TG), free fatty acid (FFA), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum were determined by automatic biochemical analyzer. Real-time PCR and Western blot were used to detect insulin signaling pathways in liver and muscle tissues of mice. The mRNA levels of genes encoding phosphoenolpyruvate carboxykinase (PEPCK) in primary hepatocytes of mice were detected by real-time PCR, and glucose detection kit was used to detect gluconeogenesis. Co-immunoprecipitation (Co-IP) and ELISA were used to detect insulin receptor ß (IRß) tyrosine phosphorylation in mouse muscle. Real-time PCR and immunofluorescence staining (IF) were used to detect the expression and location of glucose transporter 4 (GLUT4) in muscle of mice. After high-fat diet feeding, serum FFA, TG, AST and ALT levels of CD36-/- mice were significantly higher than WT mice (P < 0.05). The appearance of CD36-/- mouse liver presented fatty degeneration, and HE staining results showed increased lipid accumulation in the liver, suggesting that CD36 knockout promoted the occurrence of fatty liver. However, CD36-/- mice showed decreased fasting glucose levels, increased glucose tolerance, and decreased insulin tolerance compared with WT mice (P < 0.05), suggesting that CD36 knockout protects against the abnormal glucose metabolism induced by high-fat diet. Compared with WT mice, there was no significant difference in insulin signaling pathway in CD36-/- mouse liver, and there were no significant differences in PEPCK expression and gluconeogenesis between the two groups of primary hepatocytes. In muscle tissue, Co-IP and ELISA experiments showed that the phosphorylation level of IRß tyrosine was significantly increased in CD36-/- mice compared with that in WT mice. Besides, the levels of p-AKT in CD36-/- mouse muscle were significantly increased (P < 0.05). At the same time, IF experiment indicated that GLUT4 localization in cell membrane was enhanced in the muscle of CD36-/- mice, indicating that insulin sensitivity and glucose utilization ability were enhanced in CD36-/- mouse muscle. The results suggested that deletion of CD36 gene increased lipid accumulation in liver of mice with high-fat diet, but had no significant effect on liver gluconeogenesis. CD36 deficiency improves the abnormal glucose metabolism in mice with high-fat diet mainly through improving insulin sensitivity of muscle tissue and promoting GLUT4-mediated glucose utilization.