Grape seed extract prevents oestrogen deficiency-induced bone loss by modulating the gut microbiota and metabolites.

Proanthocyanidin-rich grape seed extract (GSE) has been shown to have the potential to protect bones, although the underlying mechanism remains unknown. The current study aims to explore GSE's preventive and therapeutic impact on bone loss induced by oestrogen deficiency and the underlying mechanism through the gut microbiota (GM) and metabolomic responses. In oestrogen-deficient ovariectomized (OVX) mice, GSE ameliorated bone loss by inhibiting the expansion of bone marrow adipose tissue (BMAT), restoring BMAT lipolysis and promoting bone formation. GSE regulated OVX-induced GM dysbiosis by reducing the abundance of opportunistic pathogenic bacteria, such as Alistipes, Turicibacter and Romboutsia, while elevating the abundance of beneficial bacteria, such as Bifidobacterium. The modified GM primarily impacted lipid and amino acid metabolism. Furthermore, the serum metabolites of GSE exhibited a significant enrichment in lipid metabolism. In summary, GSE shows potential as a functional food for preventing oestrogen deficiency-induced bone loss by modulating GM and metabolite-mediated lipid metabolism.

Electroacupuncture promotes gastrointestinal function recovery in patients undergoing laparoscopic gastrectomy : a randomized controlled trial. / ç”µé’ˆä¿ƒè¿›è ¹è ”é•œèƒƒç™Œæ ¹æ²»æœ¯æ‚£è€ èƒƒè‚ åŠŸèƒ½æ¢å¤ï¼šéšæœºå¯¹ç §è¯•éªŒ.

OBJECTIVES: To explore the clinical effect of electroacupuncture (EA) on promoting gastrointestinal function recovery in patients undergoing laparoscopic gastrectomy. METHODS: One hundred and twenty patients undergoing laparoscopic gastrectomy were randomly divided into an EA group (40 cases, 1 case was eliminated), a placebo EA (PEA) group (40 cases, 1 case dropped out) and a conventional treatment group (40 cases, 1 case dropped out). The patients in the conventional treatment group received perioperative routine treatment. On the basis of routine treatment, patients in the EA group and the PEA group were given electroacupuncture or placebo electroacupuncture stimulation at 24,48 and 72 h after anesthesia recovery. Bilateral Neiguan (PC 6), Zusanli (ST 36) and Shangjuxu (ST 37) were selected, and the electrodes of SDV-Z electroacupuncture instrument were connected to Zusanli (ST 36) and Shangjuxu (ST 37) on the same side respectively. Continuous wave was selected, the frequency was 5 Hz, and the needles were retained for 30 min each time. The postoperative gastrointestinal-2 ( GI-2 ) time, the incidence of grade A/B delayed gastric emptying were compared among the three groups, and the safety of acupuncture was evaluated. RESULTS: The GI-2 time of the EA group was significantly shorter than that of the PEA group and the conventional treatment group (P<0.05). The incidence of grade A and grade B of delayed gastric emptying in the EA group was lower than that in the PEA group and the conventional treatment group (P<0.05). No acupuncture-related adverse reactions occurred. CONCLUSIONS: EA can promote the recovery of gastrointestinal function in patients undergoing laparoscopic gastrectomy, and the treatment plan is safe, which is worthy of promotion and application into the enhanced recovery surgery program.

[Impact of lithocholic acid on the osteogenic and adipogenic differentiation balance of bone marrow mesenchymal stem cells].

Objective: To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Methods: Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 µmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ). Results: Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 µmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area. Conclusion: After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.

The unique role of bone marrow adipose tissue in ovariectomy-induced bone loss in mice.

BACKGROUND: Accumulation of bone marrow adipose tissue (BMAT) is always seen in osteoporosis induced by estrogen deficiency. Herein, we aimed to investigate the mechanisms and consequences of this phenomenon by establishing a mouse model of osteoporosis caused by ovariectomy (OVX)-mimicked estrogen deficiency. METHODS: Micro-CT, osmium tetroxide staining, and histological analyses were performed to examine the changes in bone microstructure, BMAT and white adipose tissue (WAT) in OVX mice compared to sham mice. The osteogenesis and adipogenesis of primary bone marrow stromal cells (BMSCs) isolated from sham and OVX mice were compared in vitro. The molecular phenotypes of BMAT and WAT were determined and compared by quantitative PCR (qPCR). Bone marrow adipocyte-conditioned medium (BMA CM) was prepared from sham or OVX mice for coculture assays, and BMSCs or bone marrow monocytes/macrophages (BMMs) were isolated and subjected to osteoblast and osteoclast differentiation, respectively. Cell staining and qPCR were used to assess the effects of BMAT on bone metabolism. RESULTS: OVX-induced estrogen deficiency induced reductions in both cortical and trabecular bone mass along with an expansion of BMAT volume. At the cellular level, loss of estrogen inhibited BMSC osteogenesis and promoted BMSC adipogenesis, whereas addition of estradiol exerted the opposite effects. In response to estrogen deficiency, despite the common proinflammatory molecular phenotype observed in both fat depots, BMAT, unlike WAT, unexpectedly exhibited an increase in adipocyte differentiation and lipolytic activity as well as the maintenance of insulin sensitivity. Importantly, BMAT, but not WAT, presented increased mRNA levels of both BMP receptor inhibitors (Grem1, Chrdl1) and Rankl following OVX. In addition, treatment with BMA CM, especially from OVX mice, suppressed the osteoblast differentiation of BMSCs while favoring the osteoclast differentiation of BMMs. CONCLUSION: Our study illustrates that OVX-induced estrogen deficiency results in bone loss and BMAT expansion by triggering imbalance between the osteogenesis and adipogenesis of BMSCs. Furthermore, expanded BMAT, unlike typical WAT, may negatively regulate bone homeostasis through paracrine inhibition of osteoblast-mediated bone formation and promotion of osteoclast-mediated bone resorption.

Postmenopausal osteoporosis coexisting with sarcopenia: the role and mechanisms of estrogen.

Estrogens (estradiol, estriol, and estrone) are important hormones that directly and indirectly regulate the metabolism and function of bone and skeletal muscle via estrogen receptors. Menopause causes a dramatic reduction in the concentration of estrogen in the body. This contributes to a decline in bone and skeletal muscle function, thereby resulting in osteoporosis and sarcopenia. Menopausal women often experience osteoporosis and muscle wasting, and clinicians recognize estrogen as playing an important role in these conditions, particularly in women. Bone and muscle are closely related endocrine tissues that synthesize and produce various cytokines. These bone- and muscle-derived cytokines, including interleukin-6, irisin, ß-aminoisobutyric acid, osteocalcin, fibroblast growth factor-23, and sclerostin, regulate both local and distant tissues, and they mediate the crosstalk between bone and skeletal muscle. This review examines the metabolic effects of estrogen on bone and skeletal muscle and describes cytokine-mediated bone-muscle crosstalk in conditions of estrogen deficiency.

The role and mechanism of tumor necrosis factor-alpha in alcohol-induced bone loss.

AIM: It is well known that alcohol can cause bone loss and that bone mineral density has an inverse relationship with bone marrow adipocyte (BMA). However, little is known about the mechanisms that link alcohol and bone loss, and existing studies lack data on BMA in alcohol-induced bone loss. Here, wild-type (WT) and tumor necrosis factor-alpha knockout (TNF-α KO) mice were used to examine the effects of alcohol on bone metabolism. METHODS: The effects of alcohol on bone metabolism were demonstrated in vivo by feeding WT and TNF-α KO mice with alcohol. The osteogenesis and adipogenesis of primary bone marrow stromal cells (BMSCs) derived from WT and TNF-α KO mice under alcohol intervention were compared in vitro. Tissue staining, cell staining, micro-CT, and quantitative RT-PCR were used to explore the potential mechanism. RESULTS: Alcohol induced trabecular bone loss, increased BMA, and promoted the mRNA expression of Adipoq, Fabp4, visfatin， Pparg, TNF-α, IL-1ß, and IL-6 in BMA in WT mice, but not in TNF-α KO mice. In addition, alcohol promoted BMSC adipogenesis and inhibited BMSC osteogenesis, while TNF-α knockout could restrain this situation. CONCLUSION: Our study demonstrated that alcohol may reduce bone mass by disrupting the balance of osteogenesis and adipogenesis in bone marrow, and TNF-α plays an important role in this process.

Bone Marrow Stromal Stem Cell Fate Decision: A Potential Mechanism For Bone Marrow Adipose Increase with Aging-related Osteoporosis.

OBJECTIVE: Osteoporosis is a systemic bone disease that seriously threatens the health and quality of life in middle-aged and older adults. In this review, we describe the relationship between bone marrow adipose tissue and aging osteoporosis and mainly focus on bone marrow mesenchymal stem cell osteogenic-adipose differentiation fate with aging along with the relevant mechanisms responsible for these changes. METHODS: We summarized recent advances in regulating the bone marrow mesenchymal stem cell differentiation due to aging in this review. RESULTS: Aging-related bone mass loss is accompanied by expanding bone marrow adipose because of an imbalance of bone marrow mesenchymal stem cell differentiation, resulting in adipogenesis. Ectopic adipocytes in the bone marrow increase with age and are a key factor responsible for the aging-related bone mass decrease. Transcription factors and classical regulating pathways are involved in this process during aging. CONCLUSION: As the global aging population increases, not only older women but also older men face a great fracture risk. Therefore, finding molecular mechanisms controlling the stimulating adipogenesis in BMSC during aging is important for providing the new cue for prevention and therapeutics for aging-related bone loss. Furthermore, upon physical examination of older people, except for the bone mineral density and bone turnover biochemical marker, the bone marrow adipose measurement should be taken into account when assessing the fracture risk and treatment plan that will be beneficial in clinical practice.

Moxibustion as adjuvant therapy for preventing bone loss in postmenopausal women: protocol for a randomised controlled trial.

INTRODUCTION: Postmenopausal osteoporosis, caused by ageing and oestrogen deficiency, seriously threatens women's physical and mental health. Postmenopausal osteopenia is the transition from healthy bone to osteoporosis, and it may be the key period for preventing bone loss. Moxibustion, a physical therapy of Traditional Chinese Medicine, has potential benefits for osteoporosis treatment and prevention, but it has not been adequately studied. This study aims to explore the clinical effects and safety of moxibustion in delaying bone loss in postmenopausal women. METHODS AND ANALYSIS: In this parallel-design, randomised, patient-blind and assessor-blind, controlled clinical study, 150 women with osteopenia at low fracture risk will be randomly assigned to a moxibustion treatment (MT) group or a placebo-moxibustion control (PMC) group in a 1:1 ratio. In addition to the fundamental measures (vitamin D3 and calcium) as recommended by the guidelines, participants of the two groups will receive MT or PMC treatment for 42 sessions over 12 months. The primary outcome will be the bone mineral density (BMD) of the lumbar spine at the end of the 12-month treatment, and secondary outcomes will be the BMD of the femoral neck and total hip, T-scores, bone turnover markers, serum calcium levels, serum magnesium levels, serum phosphorus levels, serum parathyroid hormone levels and 25-hydroxyvitamin D levels, intensity of bone pain, quality of life, incidence of osteoporosis and fractures, usage of emergency drugs or surgery, participant self-evaluation of therapeutic effects and the rate of adverse events. All statistical analyses will be performed based on the intention-to-treat and per-protocol principle. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University (permission number: 2021-1243). The results are expected to be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2100053953.

Transcutaneous electrical acupoint stimulation combined with electroacupuncture promotes rapid recovery after abdominal surgery: Study protocol for a randomized controlled trial.

Introduction: The most frequent complications after abdominal surgery include a decrease or loss of appetite, abdominal distension, abdominal pain caused by reduced gastrointestinal motility, anal arrest with intestinal distension and defecation, and nausea and vomiting due to anesthetic and opioid analgesic administration. These complications severely affect postoperative recovery, prolong hospital stay, and increase the financial burden. The objective of this study is to investigate the efficacy and safety of three acupoint stimulation modalities (electroacupuncture [EA], transcutaneous electrical acupoint stimulation [TEAS], and transcutaneous acupoint electrical stimulation combined with EA [TEAS+EA]), and two EA instrument waveforms (continuous wave and dilatational wave) for rapid recovery after abdominal surgery. Methods and analysis: A total of 560 patients will be recruited and randomly allocated to receive one of the following seven interventions: continuous wave EA, continuous wave TEAS, continuous wave TEAS + EA, dilatational wave EA, dilatational wave TEAS, dilatational wave TEAS + EA, and a control. For this study, continuous waves at 2 Hz, and dilatational waves at 2/50 Hz would be selected. The points to be stimulated by EA are the bilateral Neiguan (PC6), Hegu (LI6), Zusanli (ST36), Shangjuxu (ST37), and Xiajuxu (ST39), and TEAS would stimulate the bilateral Liangmen (ST21) and Daheng (SP15). The control group will neither receive EA nor TEAS. All patients will undergo an enhanced recovery plan after surgery and be provided with standardized perioperative management. Treatment will start on the first postoperative day and be administered once daily in the morning until the patient regains spontaneous bowel movements and can tolerate oral intake of solid food. The primary outcome is a composite of time to first defecation and time to tolerance of a solid diet. Secondary outcomes include time to first exhaustion; time of first defecation; time of tolerance of a solid diet; time to the first ambulation; length of hospital stay from surgery to discharge; visual analog scale score for postoperative daily pain, nausea, and vomiting; incidence of postoperative complications; and treatment acceptability. Discussion: This study will compare the efficacy and safety of three acupoint stimulation methods and two EA instrument waveforms for rapid recovery after abdominal surgery. Trial Registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn), ChiCTR2100043883.

Inpatient Quality-of-Care Measures for Heart Failure: Treatment Gaps and Opportunities in the Contemporary Era.

BACKGROUND: Quality of care measures are vital tools to assess processes of care within and between health care systems. The 2020 American College of Cardiology/AHA performance measures for heart failure provide a new set of such measures. We evaluated the achievement of these and other performance measures within the Veterans Affairs hospital system in a contemporary cohort of patients hospitalized for heart failure. METHODS: Hospital discharges from January 2010 to February 2021 with a primary diagnosis of heart failure (n=289 810) were evaluated. Adherence to each measure was determined using the measure's stated definition and by site. RESULTS: Among patients with reduced ejection fraction (53.0%), beta blocker use was high (89.0%), ACE (angiotensin-converting enzyme) inhibitor, angiotensin receptor blocker, or angiotensin receptor-neprilysin inhibitor (ARNI) use decreased over time (75.3% in 2010, 55.8% in 2020), and hydralazine/nitrate use in eligible Black patients (19.3%) was low. While 68.1% were eligible for ARNI, only 6.0% received them, reaching 17.2% by 2020. Mineralocorticoid receptor antagonists were used in 49.3% of those eligible; laboratory testing 7 days after their initiation was 73.0%, detecting hyperkalemia in 2.2%, although it occurred in 13.7% by 90 days. Achievement of ≥50% target dose was low (beta blocker 45.9%, ACE inhibitor/angiotensin receptor blocker 31.6%, ARNI 19.0%) and for ACE inhibitor/angiotensin receptor blocker/ARNI, decreased over time. Discharge appointments were 56.2% at 7 days and 78.8% at 14 days. Cardiac rehabilitation referral was low (10.5%) but increased. There were significant site-level differences, particularly for hydralazine, ARNI, devices, and cardiac rehabilitation. CONCLUSIONS: Important inpatient quality of care measures can be readily measured across the Veterans Administration health care system from electronic health records. Treatment gaps and site-level differences persisted into the contemporary era and will likely be exacerbated as newer treatments are added to this complex baseline. These measures and methods also offer the opportunity to target global, local, and individual processes of care for innovative quality improvement initiatives.

[Postoperative ileus after laparotomy for gastrointestinal cancer treated with electroacupuncture: a randomized controlled trial].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on postoperative ileus after laparotomy for gastrointestinal cancer. METHODS: A total of 90 patients with postoperative ileus after laparotomy for gastrointestinal cancer were randomized into an EA group and a conventional treatment group, 45 cases in each one. In the conventional treatment group, the postoperative fast track surgical regimen was accepted. In the EA group, on the base of the treatment as the conventional treatment group, acupuncture was applied to Zusanli (ST 36), Shangjuxu (ST 37), Yinlingquan (SP 9) and Taichong (LR 3) and electric stimulation was attached on Zusanli (ST 36) and Yinlingquan (SP 9), with continuous wave, 2 Hz in frequency and 3-5 mA in intensity. Acupuncture was provided once daily till the onset of postoperative exhaust and defecation. The first postoperative exhaust time, the first postoperative defecation time, the postoperative hospital stay and the wound pain under standing on the next morning after entering group were compared in the patients between the two groups. The impact of the EA expectation was analyzed on the first postoperative exhaust time, the first postoperative defecation time and the postoperative hospital stay separately. RESULTS: The first postoperative exhaust time and the first postoperative defecation time in the EA group were earlier than the conventional treatment group (P<0.05), the postoperative hospital stay was shorter than the conventional treatment group (P<0.05), and the rate of wound pain in the postoperative standing was lower than the conventional treatment group (P<0.05). EA expectation had no obvious correlation with the clinical therapeutic effect (P>0.05). CONCLUSION: EA can relieve postoperative ileus symptoms, alleviate pain and shorten hospital stay in the patients after laparotomy for gastrointestinal cancer.

Bone marrow adiposity during pathologic bone loss: molecular mechanisms underlying the cellular events.

Bone marrow (BM) is a heterogeneous niche where bone marrow stromal cells (BMSCs), osteoblasts, osteoclasts, adipocytes, hematopoietic cells, and immune cells coexist. The cellular composition of BM changes with various pathophysiological states. A reduction in osteoblast number and a concomitant increase in adipocyte number in aging and pathological conditions put bone marrow adipose tissue (BMAT) into spotlight. Accumulating evidence strongly supports that an overwhelming production of BMAT is a major contributor to bone loss disorders. Therefore, BMAT-targeted therapy can be an efficient and feasible intervention for osteoporosis. However, compared to blocking bone-destroying molecules produced by BMAT, suppressing BMAT formation is theoretically a more effective and fundamental approach in treating osteoporotic bone diseases. Thus, a deep insight into the molecular basis underlying increased BM adiposity during pathologic bone loss is critical to formulate strategies for therapeutically manipulating BMAT. In this review, we comprehensively summarize the molecular mechanisms involved in adipocyte differentiation of BMSCs as well as the interaction between bone marrow adipocytes and osteoclasts. More importantly, we further discuss the potential clinical implications of therapeutically targeting the upstream of BMAT formation in bone loss diseases.

Transcutaneous electrical acupoint stimulation combined with electroacupuncture for rapid recovery of patients after laparotomy for gastrointestinal surgery: a study protocol for a randomised controlled trial.

INTRODUCTION: Abdominal surgery is associated with common complications, including decreased or poor appetite, abdominal distension, abdominal pain caused by decreased or absent gastrointestinal motility, anal arrest with flatus and defecation, and nausea and vomiting resulting from the use of anaesthetics and opioid analgesics. These complications seriously affect postoperative recovery, prolong hospital stay and aggravate patient burden. This study aims to investigate for the first time the efficacy of transcutaneous electrical acupoint stimulation (TEAS) combined with electroacupuncture (EA) therapy for rapid recovery after laparotomy for gastrointestinal surgery. There have been no clinical studies of this combination therapy. METHODS AND ANALYSIS: This will be a prospective, single-centre, three-arm, randomised controlled trial. A total of 480 patients undergoing abdominal surgery will be stratified according to surgery type (ie, gastric or colorectal procedure) and randomised into three groups; namely, the EA, TEAS +EA and control groups. The control group will receive enhanced recovery after surgery (ERAS)-standardised perioperative management, including preoperative education, optimising the anaesthesia scheme, avoiding intraoperative hypothermia, restrictive fluid infusion and reducing surgical trauma. The EA group will receive EA stimulation at LI4, PC6, ST36, ST37 and ST39 based on the ERAS-standardised perioperative management. Moreover, the TEAS +EA group will receive ERAS-standardised perioperative management; EA stimulation at the LI4, PC6, ST36, ST37 and ST39; and TEAS stimulation at ST21 and SP15. The primary outcome will be the GI-2 (composite outcome of time to first defaecation and time to tolerance of a solid diet). Secondary outcomes will include the time of first passage of flatus, time to first defaecation, time to tolerance of a solid diet, time to first ambulation, hospital duration from operation to discharge, pain and nausea vomiting scores on the Visual Analogue Scale, medication use, incidence of postoperative complications and evaluation of treatment modality acceptability. All statistical analyses will be performed based on the intention-to-treat principle. ETHICS AND DISSEMINATION: Ethics approval has been granted by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University (approval number: 2021; number 52). The results are expected to be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2100045646.

[Research progress of cellular senescence in the pathogenesis of osteoarthritis].

OBJECTIVE: To review the pathological effects of cellular senescence in the occurrence and development of osteoarthritis (OA) and potential therapeutic targets. METHODS: The role of chondrocyte senescence, synovial cell senescence, mesenchymal stem cells senescence in OA, and the biological mechanism and progress of chondrocyte senescence were summarized by consulting relevant domestic and abroad literature. RESULTS: The existing evidence has basically made clear that chondrocyte senescence, mesenchymal stem cells senescence, and cartilage repair abnormalities, and the occurrence and development of OA have a certain causal relationship, and the role of the senescence of synovial cells, especially synovial macrophages in OA is still unclear. Transcription factors and epigenetics are the main mechanisms that regulate the upstream pathways of cellular senescence. Signal communication between cells can promote the appearance of senescent phenotypes in healthy cells. Targeted elimination of senescent cells and promotion of mesenchymal stem cells rejuvenation can effectively delay the progress of OA. CONCLUSION: Cellular senescence is an important biological phenomenon and potential therapeutic target in the occurrence and development of OA. In-depth study of its biological mechanism is helpful to the early prevention and treatment of OA.

Estrogen-induced circRNA, circPGR, functions as a ceRNA to promote estrogen receptor-positive breast cancer cell growth by regulating cell cycle-related genes.

Estrogen and estrogen receptor (ER)-regulated gene transcriptional events have been well known to be involved in ER-positive breast carcinogenesis. Meanwhile, circular RNAs (circRNAs) are emerging as a new family of functional non-coding RNAs (ncRNAs) with implications in a variety of pathological processes, such as cancer. However, the estrogen-regulated circRNA program and the function of such program remain uncharacterized. Methods: CircRNA sequencing (circRNA-seq) was performed to identify circRNAs induced by estrogen, and cell proliferation, colony formation, wound healing, transwell and tumor xenograft experiments were applied to examine the function of estrogen-induced circRNA, circPGR. RNA sequencing (RNA-seq) and ceRNA network analysis wereperformed to identify circPGR's target genes and the microRNA (miRNA) bound to circPGR. Anti-sense oligonucleotide (ASO) was used to assess circPGR's effects on ER-positive breast cancer cell growth. Results: Genome-wide circRNA profiling by circRNA sequencing (circRNA-seq) revealed that a large number of circRNAs were induced by estrogen, and further functional screening for the several circRNAs originated from PGR revealed that one of them, which we named as circPGR, was required for ER-positive breast cancer cell growth and tumorigenesis. CircPGR was found to be localized in the cytosol of cells and functioned as a competing endogenous RNA (ceRNA) to sponge miR-301a-5p to regulate the expression of multiple cell cycle genes. The clinical relevance of circPGR was underscored by its high and specific expression in ER-positive breast cancer cell lines and clinical breast cancer tissue samples. Accordingly, anti-sense oligonucleotide (ASO) targeting circPGR was proven to be effective in suppressing ER-positive breast cancer cell growth. Conclusions: These findings reveled that, besides the well-known messenger RNA (mRNA), microRNA (miRNA), long non-coding RNA (lncRNA) and enhancer RNA (eRNA) programs, estrogen also induced a circRNA program, and exemplified by circPGR, these estrogen-induced circRNAs were required for ER-positive breast cancer cell growth, providing a new class of therapeutic targets for ER-positive breast cancer.

Bone marrow adipocytes enhance osteolytic bone destruction by activating 1q21.3(S100A7/8/9-IL6R)-TLR4 pathway in lung cancer.

PURPOSE: Bone metastasis is the result of complex crosstalk between tumor cells and bone marrow cells. Bone marrow adipocytes (BMAs) are the most abundant cell type in adult bone marrow. Therefore, we explore the effects of BMAs on bone metastasis in lung cancer. METHODS: RNA-seq was used to compare the mRNA expression level of bone metastatic SBC5 cells and non-bone metastatic SBC3 cells. Rosiglitazone-induced marrow adiposity and intra-femoral injection of SBC5 cells were used to demonstrate the relationship between BMAs and SBC5 cells in vivo. Co-culture system, gene co-expression, gene ontology (GO) enrichment analysis and protein-protein interaction (PPI) network were used to explore the potential mechanism. RESULTS: BMAs specially enhance the invasion of bone metastatic SBC5 instead of non-bone metastatic SBC3 in vitro. SBC5 instead of SBC3 promoted osteoblast and osteoclast differentiation as well as de-differentiation of mature BMAs. Rosiglitazone-induced marrow adiposity significantly enhanced osteolytic lesion induced by SBC5 in vivo. RNA-seq revealed that compared with SBC3, S100A9 and S100A8 genes were the most prominent genes up-regulated in SBC5 cells. High expression of S100A8/9 in SBC5 could be responsible for the crosstalk between lung cancer cells and BMAs. More importantly, interleukin 6 receptor (IL6R), which is adjacent to S100A8/A9 in 1q21.3, was significantly up-regulated by BMAs in vitro. S100A8/A9 (1 µg/ml) could obviously enhance the osteoblastic differentiation and inhibit adipogenic differentiation, whereas TLR4 inhibitor TAK242 (10 µmol/l) significantly attenuated this effect. CONCLUSIONS: Our study suggested that bone marrow adipocyte may communicate with lung cancer cells via 1q21.3 (S100A8/A9-IL6R)-TLR4 pathway to promote osteolytic bone destruction. 1q21.3 (S100A8/A9-IL6R) is a potential target for the treatment of lung cancer bone metastasis.

The relationship between bone marrow adipose tissue and bone metabolism in postmenopausal osteoporosis.

Postmenopausal osteoporosis (PMOP) is a prevalent skeletal disorder associated with menopause-related estrogen withdrawal. PMOP is characterized by low bone mass, deterioration of the skeletal microarchitecture, and subsequent increased susceptibility to fragility fractures, thus contributing to disability and mortality. Accumulating evidence indicates that abnormal expansion of marrow adipose tissue (MAT) plays a crucial role in the onset and progression of PMOP, in part because both bone marrow adipocytes and osteoblasts share a common ancestor lineage. The cohabitation of MAT adipocytes, mesenchymal stromal cells, hematopoietic cells, osteoblasts and osteoclasts in the bone marrow creates a microenvironment that permits adipocytes to act directly on other cell types in the marrow. Furthermore, MAT, which is recognized as an endocrine organ, regulates bone remodeling through the secretion of adipokines and cytokines. Although an enhanced MAT volume is linked to low bone mass and fractures in PMOP, the detailed interactions between MAT and bone metabolism remain largely unknown. In this review, we examine the possible mechanisms of MAT expansion under estrogen withdrawal and further summarize emerging findings regarding the pathological roles of MAT in bone remodeling. We also discuss the current therapies targeting MAT in osteoporosis. A comprehensive understanding of the relationship between MAT expansion and bone metabolism in estrogen deficiency conditions will provide new insights into potential therapeutic targets for PMOP.

Interleukin-6 Knockout Inhibits Senescence of Bone Mesenchymal Stem Cells in High-Fat Diet-Induced Bone Loss.

Obesity, a chronic low-grade inflammatory state, not only promotes bone loss, but also accelerates cell senescence. However, little is known about the mechanisms that link obesity, bone loss, and cell senescence. Interleukin-6 (IL-6), a pivotal inflammatory mediator increased during obesity, is a candidate for promoting cell senescence and an important part of senescence-associated secretory phenotype (SASP). Here, wild type (WT) and (IL-6 KO) mice were fed with high-fat diet (HFD) for 12 weeks. The results showed IL-6 KO mice gain less weight on HFD than WT mice. HFD induced trabecular bone loss, enhanced expansion of bone marrow adipose tissue (BMAT), increased adipogenesis in bone marrow (BM), and reduced the bone formation in WT mice, but it failed to do so in IL-6 KO mice. Furthermore, IL-6 KO inhibited HFD-induced clone formation of bone marrow cells (BMCs), and expression of senescence markers (p53 and p21). IL-6 antibody inhibited the activation of STAT3 and the senescence of bone mesenchymal stem cells (BMSCs) from WT mice in vitro, while rescued IL-6 induced senescence of BMSCs from IL-6 KO mice through the STAT3/p53/p21 pathway. In summary, our data demonstrated that IL-6 KO may maintain the balance between osteogenesis and adipogenesis in BM, and restrain senescence of BMSCs in HFD-induced bone loss.

Interleukin-17A Interweaves the Skeletal and Immune Systems.

The complex crosstalk between the immune and the skeletal systems plays an indispensable role in the maintenance of skeletal homeostasis. Various cytokines are involved, including interleukin (IL)-17A. A variety of immune and inflammatory cells produces IL-17A, especially Th17 cells, a subtype of CD4+ T cells. IL-17A orchestrates diverse inflammatory and immune processes. IL-17A induces direct and indirect effects on osteoclasts. The dual role of IL-17A on osteoclasts partly depends on its concentrations and interactions with other factors. Interestingly, IL-17A exerts a dual role in osteoblasts in vitro. IL-17A is a bone-destroying cytokine in numerous immune-mediated bone diseases including postmenopausal osteoporosis (PMOP), rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondylarthritis (axSpA). This review will summarize and discuss the pathophysiological roles of IL-17A on the skeletal system and its potential strategies for application in immune-mediated bone diseases.