Novel Function of Osteocalcin in Chondrocyte Differentiation and Endochondral Ossification Revealed on a CRISPR/Cas9 bglap-bglap2 Deficiency Mouse Model.

Endochondral ossification is the process by which cartilage is mineralized into bone, and is essential for the development of long bones. Osteocalcin (OCN), a protein abundant in bone matrix, also exhibits high expression in chondrocytes, especially hypertrophic chondrocytes, while its role in endochondral ossification remains unclear. Utilizing a new CRISPR/Cas9-mediated bglap-bglap2 deficiency (OCNem) mouse model generated in our laboratory, we provide the first evidence of OCN's regulatory function in chondrocyte differentiation and endochondral ossification. The OCNem mice exhibited significant delays in primary and secondary ossification centers compared to wild-type mice, along with increased cartilage length in growth plates and hypertrophic zones during neonatal and adolescent stages. These anomalies indicated that OCN deficiency disturbed endochondral ossification during embryonic and postnatal periods. Mechanism wise, OCN deficiency was found to increase chondrocyte differentiation and postpone vascularization process. Furthermore, bone marrow mesenchymal stromal cells (BMSCs) from OCNem mice demonstrated an increased capacity for chondrogenic differentiation. Transcriptional network analysis implicated that BMP and TGF-ß signaling pathways were highly affected in OCNem BMSCs, which is closely associated with cartilage development and maintenance. This elucidation of OCN's function in chondrocyte differentiation and endochondral ossification contributes to a more comprehensive understanding of its impact on skeletal development and homeostasis.

Newly identified peptide hormone inhibits intestinal fat absorption and improves NAFLD through its receptor GPRC6A.

BACKGROUND & AIMS: Circulating peptides and G protein-coupled receptors (GPCRs) have gained much attention because of their biofunctions in metabolic disorders including obesity and non-alcoholic fatty liver disease (NAFLD). Herein, we aimed to characterize the role and therapeutic potential of a newly identified peptide hormone in NAFLD. METHODS: Using bioinformatics, we identified a murine circulating pentadecapeptide flanked by potential convertase cleavage sites of osteocalcin (OCN), which we named 'metabolitin (MTL)'. We used ligand-receptor binding, receptor internalization, bioluminescence resonance energy transfer and Nano isothermal titration calorimetry assays to study the binding relationship between MTL and GPRC6A. For in vivo biological studies, wild-type mice kept on a high-fat diet (HFD) were injected or gavaged with MTL to study its function in NAFLD. RESULTS: We confirmed that MTL binds to GPRC6A and OCN interacts with GPRC6A using in vitro biological studies. Both intraperitoneal and oral administration of MTL greatly improved NAFLD and insulin resistance in a mouse model. Interacting with GPRC6A expressed in intestines, MTL can significantly inhibit intestinal neurotensin secretion, which in turn inhibits triglyceride but not cholesterol gut absorption, mediated by the 5'AMP-activated protein kinase pathway. In addition, glucagon like peptide-1 secretion was induced by MTL treatment. CONCLUSIONS: Oral or intraperitoneal MTL significantly improves the symptoms of NAFLD by inhibiting lipid absorption and insulin resistance. MTL could be a potential therapeutic candidate for the treatment of NAFLD. LAY SUMMARY: A novel murine peptide hormone, herein named 'metabolitin', inhibits fatty acid absorption and improves systemic insulin resistance in a murine model of obesity and non-alcoholic fatty liver disease. Thus, metabolitin has therapeutic potential for the treatment of patients with non-alcoholic fatty liver disease.

Chemokine-like receptor 1 deficiency leads to lower bone mass in male mice.

The adipokine Chemerin and its receptor, chemokine-like receptor 1 (CMKLR1), are associated with osteoblastogenic differentiation of mesenchymal stem cells (MSCs) and osteoclastogenic differentiation of osteoclast precursors in vitro, suggesting that CMKLR1 would affect the bone mineral density (BMD). However, the role of CMKLR1 on BMD in vivo remains unknown. Here, using CMKLR1 knockout mouse model, we unveiled that CMKLR1 effected the amount of Leydig cells in testis and regulated androgen-dependent bone maintenance in male mice, which exhibited lower serum testosterone levels, thereby reducing the trabecular bone mass. Correspondingly, the mRNA expression of testosterone synthesis enzymes in testis decreased. The bone tissue also showed decreased mRNAs expression of osteogenic markers and increased mRNA levels for osteoclast markers. Furthermore, by in vitro differentiation models, we found CMKLR1-deficiency could break the balance between osteoblastogenesis and osteoclastogenesis that caused a shift from osteogenic to adipogenic differentiation in MSCs and enhanced osteoclast formation. In addition, bone mass increase in CMKLR1 KO male mice can be promoted by treatment with 5α-dihydrotestosterone (DHT), and the inactivation of CMKLR1 in male wild-type (WT) mice with antagonist treatment can lead to low bone mass. Taken together, these data indicate that CMKLR1 positively regulates bone metabolism through mediating testosterone production and the balance between osteoblast and osteoclast formation.

Deficiency of Gpr1 improves steroid hormone abnormality in hyperandrogenized mice.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a complex genetic disease with multifarious phenotypes. Many researches use dehydroepiandrosterone (DHEA) to induce PCOS in pubertal mouse models. The aim of this study was to investigate the role of GPR1 in dehydroepiandrosterone (DHEA)-induced hyperandrogenized mice. METHODS: Prepubertal C57BL/6 mice (25 days of age) and Gpr1-deficient mice were each divided into two groups and injected daily with sesame oil with or without DHEA (6 mg/100 g) for 21 consecutive days. Hematoxylin and eosin (H&E) staining was performed to determine the characteristics of the DHEA-treated ovaries. Real-time PCR was used to examine steroid synthesis enzymes gene expression. Granulosa cell was cultured to explore the mechanism of DHEA-induced, GPR1-mediated estradiol secretion. RESULTS: DHEA treatment induced some aspects of PCOS in wild-type mice, such as increased body weight, elevated serum testosterone, increased number of small, cystic, atretic follicles, and absence of corpus luteum in ovaries. However, Gpr1 deficiency significantly attenuated the DHEA-induced weight gain and ovarian phenotype, improving steroidogenesis in ovaries and estradiol synthesis in cultured granulosa cells, partially through mTOR signaling. CONCLUSIONS: In conclusion, Gpr1 deficiency leads to the improvement of steroid synthesis in mice hyperandrogenized with DHEA, indicating that GPR1 may be a therapeutic target for DHEA-induced hyperandrogenism.

Greater alteration of gut microbiota occurs in childhood obesity than in adulthood obesity.

The children's gut microbiota, associated with the development of obesity, is in maturation. The impact of obesity on the gut microbiota in childhood could have a more significant effect than on adulthood and eventually be lifelong lasting, but it has been rarely studied. Aimed to discover the difference in gut microbiota between children and adults with obesity, we collected published amplicon sequencing data from National Center for Biotechnology Information (NCBI) and re-analyzed them using a uniform bioinformatic pipeline, as well as predicted the obesity using gut microbiota based on the random forest model. Summarizing common points among these cohorts, we found that the gut microbiota had a significant difference between children with and without obesity, but this difference was not observed in adult cohorts. Based on the random forest model, it was more challenging to predict childhood obesity using gut microbiota than adulthood obesity. Our results suggest that gut microbiota in childhood is more easily affected than in adulthood. Early intervention for childhood obesity is essential to improve children's health and lifelong gut microbiota-related health.

Small intestinal microbiota composition altered in obesity-T2DM mice with high salt fed.

Obesity has become a global concern because of increasing the risk of many diseases. Alterations in human gut microbiota have been proven to be associated with obesity, yet the mechanism of how the microbiota are altered by high salt diet (HSD) remains obscure. In this study, the changes of Small Intestinal Microbiota (SIM) in obesity-T2DM mice were investigated. High-throughput sequencing was applied for the jejunum microbiota analysis. Results revealed that high salt intake (HS) could suppress the body weight (B.W.) in some extent. In addition, significant T2DM pathological features were revealed in high salt-high food diet (HS-HFD) group, despite of relatively lower food intake. High-throughput sequencing analysis indicated that the F/B ratio in HS intake groups increased significantly (P < 0.001), whereas beneficial bacteria, such as lactic acid or short chain fatty acid producing bacteria, were significantly decreased in HS-HFD group (P < 0.01 or P < 0.05). Furthermore, Halorubrum luteum were observed in small intestine for the first time. Above results preliminary suggested that in obesity-T2DM mice, high dietary salt could aggravate the imbalance of composition of SIM to unhealthy direction.

Orphan receptor GPR50 attenuates inflammation and insulin signaling in 3T3-L1 preadipocytes.

Type 2 diabetes (T2DM) is characterized by insulin secretion deficiencies and systemic insulin resistance (IR) in adipose tissue, skeletal muscle, and the liver. Although the mechanism of T2DM is not yet fully known, inflammation and insulin resistance play a central role in the pathogenesis of T2DM. G protein-coupled receptors (GPCRs) are involved in endocrine and metabolic processes as well as many other physiological processes. GPR50 (G protein-coupled receptor 50) is an orphan GPCR that shares the highest sequence homology with melatonin receptors. The aim of this study was to investigate the effect of GPR50 on inflammation and insulin resistance in 3T3-L1 preadipocytes. GPR50 expression was observed to be significantly increased in the adipose tissue of obese T2DM mice, while GPR50 deficiency increased inflammation in 3T3-L1 cells and induced the phosphorylation of AKT and insulin receptor substrate (IRS) 1. Furthermore, GPR50 knockout in the 3T3-L1 cell line suppressed PPAR-γ expression. These data suggest that GPR50 can attenuate inflammatory levels and regulate insulin signaling in adipocytes. Furthermore, the effects are mediated through the regulation of the IRS1/AKT signaling pathway and PPAR-γ expression.

Cervical vertebrae for early bone loss evaluation in osteoporosis mouse models.

Background: Osteoporosis (OP), a systemic skeletal disease common in aged population, is an important public health problem worldwide. Animal models are important tools for understanding OP. In ovariectomy (OVX) or orchiectomy (ORX) OP models, lumbar vertebrae are often used for evaluating of the OP progression. However, unlike the bipeds, the lumbar vertebrae are not weight loading bones in quadruped animal, but the head-bearing cervical vertebrae take much higher stress. So, we compared the murine cervical vertebrae with lumbar vertebrae for OP assessment. Methods: OVX and ORX mouse models were established on C57BL/6J mice. Serum estradiol, testosterone and bone related biomarkers were verified. Bone quantity and quality were determined using micro computed tomography (micro-CT) analysis. Hard tissue sections were prepared, stained for histomorphological analyzing, and micro-indentation measured for bone mechanical property evaluation. Results: In OVX and ORX mice, serum estradiol or testosterone levels reduced, bone resorption level and related biomarkers elevated, indicated the successful generation of the OP models. In the early stage, the trabecular bone mineral density (BMD) of cervical vertebrae was already reduced 16.1% (OVX) and 21.7% (ORX) one-month post-gonadectomy, respectively; while this decline in the fifth lumbar vertebra were only 5% and 7.4%, respectively. Six months post-gonadectomy, the reduction of BMD in cervical vertebrae and the fifth lumbar vertebra were 31.2% & 36.1% and 28.5% & 30.7% respectively. In biomechanical aspects, cervical spines showed worse Vickers hardness (HV) and elastic modulus than lumbar spine in six-month OVX and ORX mice. Conclusions: We provide a new OP early-stage evaluation mouse model based on the cervical spine. Through the radiographic, biological and biomechanical assessments, the mouse cervical spine is more suitable for bone remodeling evaluation in OP models than the conventional lumbar vertebrae, especially for early-stage OP study.

Perturbation on gut microbiota impedes the onset of obesity in high fat diet-induced mice.

High-calorie intake has become one of the most common causes of dietary obesity, which eventually develops into type 2 diabetes mellitus (T2DM). Microbiota, along with the length of the gastrointestinal tract, is related to metabolic disorders, but its shifts and following impact on metabolic disorders due to external perturbation are still unclear. To evaluate shifts of microbiota from the proximal to the distal intestine and their impact on metabolic disorders, we profiled jejunal and colonic microbiota with the perturbation using high salt (HS) and antibiotic-induced microbiota depletion (AIMD) in diet-induced obesity (DIO) mice and analyzed the association with parameters of both obesity and blood glucose. After ten weeks of feeding DIO mice with HS intake and AIMD, they failed to develop obesity. The DIO mice with HS intake had T2DM symptoms, whereas the AIMD DIO mice showed no significant difference in blood glucose parameters. We observed that the jejunal and colonic microbiota had shifted due to settled perturbation, and jejunal microbiota within a group were more dispersed than colonic microbiota. After further analyzing jejunal microbiota using quantified amplicon sequencing, we found that the absolute abundance of Colidextribacter (R = 0.695, p = 0.001) and Faecalibaculum (R = 0.631, p = 0.005) in the jejunum was positively correlated with the changes in BW and FBG levels. The predicted pathway of glucose and metabolism of other substances significantly changed between groups (p <0.05). We demonstrated that the onset of obesity and T2DM in DIO mice is impeded when the gut microbiota is perturbed; thus, this pathogenesis depends on the gut microbiota.

An Improved Genetically Encoded Fluorescent cAMP Indicator for Sensitive cAMP Imaging and Fast Drug Screening.

Cyclic adenosine 3',5'-monophosphate (cAMP) is an important intracellular second messenger molecule downstream of many G protein-coupled receptors (GPCRs). Fluorescence imaging with bright and sensitive cAMP indicators allows not only dissecting the spatiotemporal dynamics of intracellular cAMP, but also high-content screening of compounds against GPCRs. We previously reported the high-performance circularly permuted GFP (cpGFP)-based cAMP indicator G-Flamp1. Here, we developed improved G-Flamp1 variants G-Flamp2 and G-Flamp2b. Compared to G-Flamp1, G-Flamp2 exhibited increased baseline fluorescence (1.6-fold) and larger fluorescence change (ΔF/F0) (1,300% vs. 1,100%) in HEK293T cells, while G-Flamp2b showed increased baseline fluorescence (3.1-fold) and smaller ΔF/F0 (400% vs. 1,100%). Furthermore, live cell imaging of mitochondrial matrix-targeted G-Flamp2 confirmed cytosolic cAMP was able to enter the mitochondrial matrix. G-Flamp2 imaging also showed that adipose tissue extract activated the Gi protein-coupled orphan GPCR GPR50 in HEK293T cells. Taken together, our results showed that the high-performance of G-Flamp2 would facilitate sensitive intracellular cAMP imaging and activity measurement of compounds targeting GPCR-cAMP signaling pathway during early drug development.

Enhancing Drug Utilization Efficiency via Dish-Structured Triboelectric Nanogenerator.

Due to the finding of severe side effects and low therapeutic efficacy with cancer chemotherapy, there still remains a great challenge to benefit patients with curative effect. In this work, we designed a self-powered drug delivery system comprising a current source derived from the disk TENG (D-TENG) and a pair of Au electrodes. Thus, cells seeded within the electrode gap could be stimulated by the current followed by D-TENG`s work. Under the rotation frequency of about 7.4 Hz, the peak output current and voltage of the D-TENG reached 3.7 µA and 135 V and achieved an average of 2.8 µA of output current. Furthermore, the D-TENG also showed its good stability to output steady current in a long-term condition. When applying the electric stimulation by this self-powered drug delivery system, a chemotherapy drug, doxorubicin (DOX), had significant uptake by cancer cells. Therefore, utilizing a novel TENG device as a part of chemotherapy would provide a new opportunity in future disease treatment.

A high-performance genetically encoded fluorescent indicator for in vivo cAMP imaging.

cAMP is a key second messenger that regulates diverse cellular functions including neural plasticity. However, the spatiotemporal dynamics of intracellular cAMP in intact organisms are largely unknown due to low sensitivity and/or brightness of current genetically encoded fluorescent cAMP indicators. Here, we report the development of the new circularly permuted GFP (cpGFP)-based cAMP indicator G-Flamp1, which exhibits a large fluorescence increase (a maximum ΔF/F0 of 1100% in HEK293T cells), decent brightness, appropriate affinity (a Kd of 2.17 µM) and fast response kinetics (an association and dissociation half-time of 0.20 and 0.087 s, respectively). Furthermore, the crystal structure of the cAMP-bound G-Flamp1 reveals one linker connecting the cAMP-binding domain to cpGFP adopts a distorted ß-strand conformation that may serve as a fluorescence modulation switch. We demonstrate that G-Flamp1 enables sensitive monitoring of endogenous cAMP signals in brain regions that are implicated in learning and motor control in living organisms such as fruit flies and mice.

Continuous infusion of UHMWPE particles induces increased bone macrophages and osteolysis.

BACKGROUND: Aseptic loosening and periprosthetic osteolysis resulting from wear debris are major complications of total joint arthroplasty. Monocyte/macrophages are the key cells related to osteolysis at the bone-implant interface of joint arthroplasties. Whether the monocyte/macrophages found at the implant interface in the presence of polyethylene particles are locally or systemically derived is unknown. QUESTIONS/PURPOSES: We therefore asked (1) whether macrophages associated with polyethylene particle-induced chronic inflammation are recruited locally or systemically and (2) whether the recruited macrophages are associated with enhanced osteolysis locally. METHODS: Noninvasive in vivo imaging techniques (bioluminescence and microCT) were used to investigate initial macrophage migration systemically from a remote injection site to polyethylene wear particles continuously infused into the femoral canal. We used histologic and immunohistologic staining to confirm localization of migrated macrophages to the polyethylene particle-treated femoral canals and monitor cellular markers of bone remodeling. RESULTS: The values for bioluminescence were increased for animals receiving UHMWPE particles compared with the group in which the carrier saline was infused. At Day 8, the ratio of bioluminescence (operated femur divided by nonoperated contralateral femur of each animal) for the UHMWPE group was 13.95 ± 5.65, whereas the ratio for the saline group was 2.60 ± 1.14. Immunohistologic analysis demonstrated the presence of reporter macrophages in the UHMWPE particle-implanted femora only. MicroCT scans showed the bone mineral density for the group with both UHMWPE particles and macrophage was lower than the control groups. CONCLUSIONS: Infusion of clinically relevant polyethylene particles, similar to the human scenario, stimulated systemic migration of remotely injected macrophages and local net bone resorption.

Cartilage tissue engineering for obesity-induced osteoarthritis: Physiology, challenges, and future prospects.

Osteoarthritis (OA) is a multifactorial joint disease with pathological changes that affect whole joint tissue. Obesity is acknowledged as the most influential risk factor for both the initiation and progression of OA in weight-bearing and non-weight-bearing joints. Obesity-induced OA is a newly defined phenotypic group in which chronic low-grade inflammation has a central role. Aside from persistent chronic inflammation, abnormal mechanical loading due to increased body weight on weight-bearing joints is accountable for the initiation and progression of obesity-induced OA. The current therapeutic approaches for OA are still evolving. Tissue-engineering-based strategy for cartilage regeneration is one of the most promising treatment breakthroughs in recent years. However, patients with obesity-induced OA are often excluded from cartilage repair attempts due to the abnormal mechanical demands, altered biomechanical and biochemical activities of cells, persistent chronic inflammation, and other obesity-associated factors. With the alarming increase in the number of obese populations globally, the need for an innovative therapeutic approach that could effectively repair and restore the damaged synovial joints is of significant importance for this sub-population of patients. In this review, we discuss the involvement of the systemic and localized inflammatory response in obesity-induced OA and the impact of altered mechanical loading on pathological changes in the synovial joint. Moreover, we examine the current strategies in cartilage tissue engineering and address the critical challenges of cell-based therapies for OA. Besides, we provide examples of innovative ways and potential strategies to overcome the obstacles in the treatment of obesity-induced OA. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Altogether, this review delivers insight into obesity-induced OA and offers future research direction on the creation of tissue engineering-based therapies for obesity-induced OA.

High accumulation of Mx2 renders limited multiplication of oncolytic herpes simplex virus-1 in human tumor cells.

Increasing studies demonstrated that oncolytic activities of oHSV-1 are limited to the capacity of virus replicating in tumors. In order to potentiate the oHSV-1 oncolytic activity and expand the application of oHSV-1 treatment in multiple types of tumors, it is critical to explore the potential factors or mechanisms mediating tumor resistance to oHSV-1 infection. Here we evaluated the levels of oHSV-1 multiplication in various tumor cell lines and showed that glioblastoma cell line A172 had the lowest virus yields but intrinsically accumulated the highest levels of Mx2 protein. Subsequently we demonstrated that genetic depletion of Mx2 specifically enhanced oHSV-1 productive replication in A172 cells through promoting the nuclear translocation of uncoated viral genomic DNA and down-regulating innate antiviral response. In the further investigation, we found that Mx2 knockdown could alter the intrinsic mRNA accumulation of diverse sets innate immune genes in A172 cells, in particular DHX36 and MyD88. Mx2 depletion led to a decrease in mRNA levels of MyD88 and DHX36 in A172 cells and MyD88/DHX36 knockdown increased virus yield in A172 cells and decreased the production of IFNα, activation of IRF3 activity and NF-κB signaling in A172 cells. This shed new lights on understanding the roles of some intrinsic antiviral genes in oHSV-1 resistance, facilitating to offer potential targets to improve oHSV-1 oncolytic efficacy and develop candidates of biomarkers to predict the efficiency of oHSV-1 multiplication in tumors.

Emergence of Klebsiella pneumoniae ST307 Co-Producing CTX-M with SHV and KPC from Paediatric Patients at Shenzhen Children's Hospital, China.

AIM: We investigated the clonal diversity of carbapenemase-producing Klebsiella pneumoniae isolates from the Shenzhen Children's Hospital, China, and drew conclusions on the clinical and public health impact of these isolates as multidrug-resistant. METHODS: From January 2014 to December 2018, a total number of 36 unique carbapenemase-producing clinical isolates of Klebsiella pneumoniae were collected out of 900 clinical isolates in paediatric patients from the Shenzhen Children's Hospital, China. After carbapenemase production confirmation, antimicrobial susceptibility, resistance determinants and phylogenetic relationship were determined. RESULTS: The isolates showed resistance to ceftazidime, ertapenem, ampicillin, cefazolin, ceftriaxone, cefotetan, ticarcillin, cefaclor, cefpodoxime, azlocillin, cefcapene, mezlocillin and ampicillin-sulbactam. Of the 36 Klebsiella pneumoniae carbapenemase genes coding isolates, bla NDM was the mostly detected 50% (n=18) followed by bla KPC and bla IMP 19% (n=7), bla VIM 17% (n=6), bla OXA-48-like 8% (n=3) and bla SME 5% (n=2), whereas extended-spectrum ß-lactamase (bla SHV) was predominantly detected 92% (n=33) followed by bla CTX-M 53% (n=19) and bla CMY 28% (n=10). Pulsed-field gel electrophoresis typing showed eight different patterns, and twenty-five distinct sequences types were observed with ST307 being predominantly identified 11% (n=4), followed by ST2407 8% (n=3). Plasmid replicon typing results indicated that IncFIS, IncHI2, IncFIC and IncFIA plasmids carry bla CTX-M, bla SHV and bla NDM genes. CONCLUSION: This study reports on the occurrence and spread of carbapenemase and extended-spectrum ß-lactamase encoding genes co-existence in sporadic Klebsiella pneumoniae ST307 in paediatric patients from the Shenzhen Children's Hospital, China.

Inhibition of Col6a5 Improve Lipid Metabolism Disorder in Dihydrotestosterone-Induced Hyperandrogenic Mice.

Hyperandrogenism is a key pathological feature of polycystic ovarian syndrome (PCOS). Excess androgen can lead to PCOS-like cell hypertrophy in the ovaries and adipose tissue of rodents. Here, we established a dihydrotestosterone (DHT)-induced hyperandrogenic mouse model to analyze the differences in gene expression and signaling pathways of the ovaries and gonad fat pads of mice treated with or without DHT by RNA microarray analysis. From the results, we focused on the overlapping differentially expressed gene-Col6a5-and the major differentially enriched signaling pathway-lipid metabolism. We employed DHT-induced mouse ovarian stromal cell, adipogenic 3T3-L1 cell and hepatic cell line NCTC1469 models to investigate whether androgens directly mediate lipid accumulation and hypertrophy. We found that DHT increased lipid droplet accumulation in ovarian stromal cells and adipogenic 3T3-L1 cells but not NCTC1469 cells. DHT significantly altered stromal cell cholesterol metabolism and steroidogenesis, as indicated by changes in cholesterol levels and the expression of related genes, but these effects were not observed in 3T3-L1 cells. Moreover, Col6a5 expression was significantly increased in ovaries and gonadal fat pads of DHT-treated mice, and Col6a5 inhibition alleviated DHT-induced excess lipid accumulation and hypertrophy of ovarian stromal cells and adipogenic 3T3-L1 cells, even improved lipid metabolism in overnourished NCTC1469 cells. Our results indicate that Col6a5 plays important roles in the pathogenesis of DHT-induced lipid metabolism disorder and the hypertrophy of ovarian stromal cells and adipocytes.

Modulating osteogenesis of mesenchymal stem cells by modifying growth factor availability.

Growth factors control the proliferation and differentiation of osteoprogenitor cells. This study explores the effects of modulating growth factors (VEGF, IGF-1, FGF-2 and BMP-2) on osteogenesis of mesenchymal stem cells (MSCs) in vitro. Constant and profiled delivery protocols, in accordance with protein expression in vitro, were applied to deliver or neutralize growth factors. Cell number, alkaline phosphatase (ALP-2) and osteocalcin (OC) expression, and mineralization were measured as outcome variables. Profiled addition of VEGF increased MSC proliferation. Constant and profiled application of FGF-2 and neutralization of IGF-1 and BMP-2 decreased ALP-2 levels. Profiled addition of BMP-2 vastly increased OC release from MSCs, but constant addition of IGF-1, constant and profiled neutralization of IGF-1 and FGF-2 reduced OC levels. Constant addition of IGF-1 and FGF-2, as well as profiled loading of FGF-2 decreased mineralization of MSCs. This study indicated that endogenous IGF-1 and FGF-2 are essential to osteogenesis; excess IGF-1 and FGF-2 were inhibitory to bone formation. Selective, temporally specific addition of growth factors, such as BMP-2 and VEGF appears to be an important strategy to enhance osteogenesis.

Antimicrobial Resistance and Resistance Determinant Insights into Multi-Drug Resistant Gram-Negative Bacteria Isolates from Paediatric Patients in China.

INTRODUCTION: The emergence of multi-drug-resistant Gram-negative bacteria (GNB) is a concern in China and globally. This study investigated antimicrobial resistance traits and resistance determinant detection in GNB isolates from paediatric patients in China. METHODS: In the present study, a total of 170 isolates of GNB including the most prevalent Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii were collected from Shenzhen Children's Hospital, China. ESBLs production was confirmed by using the combination disc diffusion method, and carbapenemase production was confirmed by using a carbapenem inactivation method followed by antimicrobial susceptibility. In addition, ß-lactamase-encoding genes and co-existence of plasmid-borne colistin resistance mcr-1 gene were determined by PCR and sequencing. RESULTS: Overall, 170 etiological agents (GNB) were recovered from 158 paediatric patients. The most prevalent species was E. coli 40% (n=68), followed by K. pneumoniae 17.64% (n=30), and Enterobacter cloacae 14.11% (n=24). Of 170 GNB, 71.76% (n=122) were multi-drug-resistant, 12.35% (n=21) extreme-drug resistant, and 7.64% (n=13) single-drug-resistant, while 8.23% (n=14) were sensitive to all of the studied antibiotics. The prevalence of ESBLs and carbapenemase producers were 60% and 17%, respectively. bla CTX-M was the most prevalent resistance gene (59.42%), followed by bla TEM (41.17%), bla SHV (34.270%), bla KPC (34.11%), bla OXA-48 (18.82%) and bla NDM-1 (17.64%). CONCLUSION: The present study provides insights into the linkage between the resistance patterns of GNB to commonly used antibiotics and their uses in China. The findings are useful for understanding the genetics of resistance traits and difficulty in tackling of GNB in paediatric patients.

Effect of High-Fat Diet on Immature Female Mice and Messenger and Noncoding RNA Expression Profiling in Ovary and White Adipose Tissue.

Obesity is a chronic multifactorial disease prevalent in many areas of the world and is a major cause of morbidity and mortality. In women, obesity increases the risks of both metabolic and reproductive diseases, such as diabetes and infertility. The mechanisms underlying these effects, especially in young women, are largely unknown. To explore these mechanisms, we established a high-fat diet (HFD) model of obesity in immature female mice. Microarray analysis of gene expression in ovaries and white adipose tissue identified a large number of differentially expressed genes (>1.3-fold change) in both tissues. In ovaries of the HFD group, there were 208 differentially expressed messenger RNAs (mRNAs), including 98 upregulated and 110 downregulated, and 295 differentially expressed lncRNAs (long non coding RNAs), including 63 upregulated and 232 downregulated. In white adipose tissue, there were 625 differentially expressed mRNAs, including 220 upregulated and 605 downregulated in the HFD group, and 1595 differentially expressed lncRNAs, including 1320 and 275 downregulated in the HFD group. Our results reveal significant differences between the transcriptomes of the HFD and control groups in both ovaries and white adipose tissue that provide clues to the molecular mechanisms of diet-induced female reproductive dysfunction and metabolic disorders, as well as biomarkers of risk for these disorders.