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Bone Jun 2024Recent research has revealed several important pathways of epigenetic regulation leading to transcriptional changes in bone cells. Rest Corepressor 2 (Rcor2) is a...
Recent research has revealed several important pathways of epigenetic regulation leading to transcriptional changes in bone cells. Rest Corepressor 2 (Rcor2) is a coregulator of Lysine-specific histone demethylase 1 (Lsd1), a demethylase linked to osteoblast activity, hematopoietic stem cell differentiation and malignancy of different neoplasms. However, the role of Rcor2 in osteoblast differentiation has not yet been examined in detail. We have previously shown that Rcor2 is highly expressed in mesenchymal stromal cells (MSC) and particularly in the osteoblastic lineage. The role of Rcor2 in osteoblastic differentiation in vitro was further characterized and we demonstrate here that lentiviral silencing of Rcor2 in MC3T3-E1 cells led to a decrease in osteoblast differentiation. This was indicated by decreased alkaline phosphatase and von Kossa stainings as well as by decreased expression of several osteoblast-related marker genes. RNA-sequencing of the Rcor2-downregulated MC3T3-E1 cells showed decreased repression of Rcor2 target genes, as well as significant upregulation of majority of the differentially expressed genes. While the heterozygous, global loss of Rcor2 in vivo did not lead to a detectable bone phenotype, conditional deletion of Rcor2 in limb-bud mesenchymal cells led to a moderate decrease in cortical bone volume. These findings were not accentuated by challenging bone formation by ovariectomy or tibial fracture. Furthermore, a global deletion of Rcor2 led to decreased white adipose tissue in vivo and decreased the capacity of primary cells to differentiate into adipocytes in vitro. The conditional deletion of Rcor2 led to decreased adiposity in fracture callus. Taken together, these results suggest that epigenetic regulation of mesenchymal stromal cell differentiation is mediated by Rcor2, which could thus play an important role in defining the MSC fate.
PubMed: 38944098
DOI: 10.1016/j.bone.2024.117180 -
Alternative Therapies in Health and... Jun 2024Osteoporosis (OP) is a chronic skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue, resulting in increased bone...
Study on the Mechanism of Xianling Gubao Capsule Regulating Runt-Related Transcription Factor 2 (RUNX2) and Promoting Osteoblast Differentiation by N6-Methyladenosine (m6A) Methyltransferase-Like 3 (METTL3).
BACKGROUND
Osteoporosis (OP) is a chronic skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue, resulting in increased bone fragility and a higher risk of fractures. It is a significant public health concern, particularly among postmenopausal women and older adults. The imbalance between bone formation and resorption is the fundamental cause of OP. Current clinical drugs for OP have limited efficacy and can cause side effects. Therefore, there is a need to explore alternative treatments and investigate their mechanisms to improve OP management. The Xianling Gubao capsule, a traditional Chinese medicine, is commonly used to treat OP by tonifying the kidney. However, the specific mechanism of action of the Xianling Gubao capsule in improving OP remains unclear, necessitating further research in this area.
METHODS
The N6-methyladenosine (m6A) content was evaluated by dot blot and m6A ribonucleic acid (RNA) methylation assay kit. The contents of methyltransferase-like 3 (METTL3), runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and bone gamma-carboxyglutamate protein (BGLAP) were appraised by quantitative Reverse Transcription polymerase chain reaction (qRT-PCR) and western blot. The bilateral ovariectomy (OVX) method was used to establish an animal model of OP. OP bone marrow mesenchymal stem cells (OP-BMSCs) were extracted from mice in the OVX group by the whole bone marrow method. METTL3 overexpression and control vectors were transfected to OP-BMSCs using X-tremeGENE HP DNA Transfection Reagent. The ALP activity in OP-BMSCs was assessed by ALP staining. The calcium nodules in OP-BMSCs were detected by Alizarin Red S (ARS) assay. The Xianling Gubao capsule solution was employed to gavage mice, and the drug-containing serum was used to treat OP-BMSCs. Dot blot allows for the assessment of relative levels of m6A modification. The m6A RNA methylation assay kit is a specialized kit designed to quantitatively measure m6A levels in RNA samples. qRT-PCR allows for the measurement of mRNA levels of target genes. Western blot is used to detect and quantify specific proteins in a sample, and provides information about protein expression levels. OVX mimics the hormonal changes occurring in postmenopausal women and leads to bone loss and osteoporotic conditions in animals. This model allows for the investigation of the effects of the Xianling Gubao capsule on OP in a controlled experimental setting.
RESULTS
The m6A modification and METTL3, RUNX2, ALP, and BGLAP levels were reduced in bone samples of patients with OP and OVX mice compared with the corresponding control groups. Upregulated METTL3 enhanced the osteogenic ability of OP-BMSCs. METTL3 overexpression obviously increased m6A modification and METTL3, RUNX2, ALP, and BGLAP levels in OP-BMSCs. Xianling Gubao capsule treatment could weaken the impact of OP in mice by regulating the m6A modification and METTL3, RUNX2, ALP, and BGLAP levels. Serum containing Xianling Gubao capsule could enhance the osteogenic capability of OP-BMSCs and boost METTL3, RUNX2, ALP, and BGLAP levels. Treatment with the Xianling Gubao capsule shows promising effects in attenuating the impact of OP. The capsule is found to regulate m6A modification and increase the levels of METTL3, RUNX2, ALP, and BGLAP in OP-BMSCs. This indicates that the Xianling Gubao capsule may rescue the diminished osteogenic capability of OP-BMSCs by modulating METTL3. These findings suggest that the Xianling Gubao capsule has the potential to be an effective drug for the treatment of OP.
CONCLUSION
Taken together, the m6A modification and contents of osteogenic-related factors were reduced in OP. Upregulated METTL3 improved the osteogenic ability, m6A modification, and osteogenic-related factor abundances in OP-BMSCs. Xianling Gubao capsule rescued the diminished osteogenic capability of OP-BMSCs by modulating METTL3 and might serve as an effective drug for OP. The Xianling Gubao capsule, as a traditional Chinese medicine, could potentially complement existing therapeutic approaches for OP. By targeting the m6A modification pathway and promoting osteogenic differentiation, the capsule may help to expedite bone formation and repair, which are critical for managing OP and reducing the risk of fractures.
PubMed: 38940781
DOI: No ID Found -
Frontiers in Pharmacology 2024Although caffeine generally offers benefits to human health, its impact on bone metabolism remains unclear. This study aimed to systematically evaluate the long-term...
Although caffeine generally offers benefits to human health, its impact on bone metabolism remains unclear. This study aimed to systematically evaluate the long-term effects of caffeine administration on osteoclasts, osteoblasts, and ovariectomy-induced postmenopausal osteoporosis (OP). Our findings revealed that 3.125 and 12.5 μg/mL caffeine inhibited RANKL-mediated osteoclastogenesis in RAW 264.7 cells through the MAPK and NF-κB pathways, accompanied by the inactivation of nuclear translocation of nuclear factor NFATc1. Similarly, 3.125 and 12.5 μg/mL of caffeine modulated MC3T3-E1 osteogenesis via the AKT, MAPK, and NF-κB pathways. However, 50 μg/mL of caffeine promoted the phosphorylation of IκBα, P65, JNK, P38, and AKT, followed by the activation of NFATc1 and the inactivation of Runx2 and Osterix, ultimately disrupting the balance between osteoblastogenesis and osteoclastogenesis. studies showed that gavage with 55.44 mg/kg caffeine inhibited osteoclastogenesis, promoted osteogenesis, and ameliorated bone loss in ovariectomized mice. Conversely, long-term intake of high-dose caffeine (110.88 mg/kg) disrupted osteogenesis activity and promoted osteoclastogenesis, thereby disturbing bone homeostasis. Collectively, these findings suggest that a moderate caffeine intake (approximately 400 mg in humans) can regulate bone homeostasis by influencing both osteoclasts and osteoblasts. However, long-term high-dose caffeine consumption (approximately 800 mg in humans) could have detrimental effects on the skeletal system.
PubMed: 38939843
DOI: 10.3389/fphar.2024.1405173 -
Amino Acids Jun 2024Exogenous polyamines, including putrescine (PUT), spermidine (SPD), and spermine (SPM), and the irreversible inhibitor of the rate-limiting enzyme ornithine...
Exogenous polyamines, including putrescine (PUT), spermidine (SPD), and spermine (SPM), and the irreversible inhibitor of the rate-limiting enzyme ornithine decarboxylase (ODC) of polyamine biosynthesis, α-difluoromethylornithine (DFMO), are implicated as stimulants for bone formation. We demonstrate in this study the osteogenic potential of exogenous polyamines and DFMO in human osteoblasts (hOBs), murine monocyte cell line RAW 264.7, and an ovariectomized rat model. The effect of polyamines and DFMO on hOBs and RAW 264.7 cells was studied by analyzing gene expression, alkaline phosphatase (ALP) activity, tartrate-resistant acid phosphatase (TRAP) activity, and matrix mineralization. Ovariectomized rats were treated with polyamines and DFMO and analyzed by micro computed tomography (micro CT). The mRNA level of the early onset genes of osteogenic differentiation, Runt-related transcription factor 2 (Runx2) and ALP, was significantly elevated in hOBs under osteogenic conditions, while both ALP activity and matrix mineralization were enhanced by exogenous polyamines and DFMO. Under osteoclastogenic conditions, the gene expression of both receptor activator of nuclear factor-κB (RANK) and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) was reduced, and TRAP activity was suppressed by exogenous polyamines and DFMO in RAW 264.7 cells. In an osteoporotic animal model of ovariectomized rats, SPM and DFMO were found to improve bone volume in rat femurs, while trabecular thickness was increased in all treatment groups. Results from this study provide in vitro and in vivo evidence indicating that polyamines and DFMO act as stimulants for bone formation, and their osteogenic effect may be associated with the suppression of osteoclastogenesis.
Topics: Animals; Mice; Osteoclasts; Osteogenesis; Rats; Humans; Cell Differentiation; Eflornithine; Female; Polyamines; Osteoblasts; RAW 264.7 Cells; Ovariectomy; Rats, Sprague-Dawley; Spermidine
PubMed: 38935136
DOI: 10.1007/s00726-024-03403-8 -
Medicina (Kaunas, Lithuania) May 2024The ongoing concern of the medical profession regarding chronic medication is related to increasing patient adherence and compliance to treatment and reducing...
The ongoing concern of the medical profession regarding chronic medication is related to increasing patient adherence and compliance to treatment and reducing medication side effects. In this respect, drugs represented by fixed-dose combinations of active substances within the same tablet have emerged. Such a principle can be extrapolated by following the potential beneficial effects that a chronic medication can have on chronic pathologies affecting different systems. The study included 48 female Albino Wistar rats, aged 16-18 months, which were divided into two groups: ovariectomized and non-ovariectomized rats. One batch of 12 non-ovariectomized rats received no treatment, becoming a control batch (NOVX-M). The ovariectomized (OVX) group was divided into 3 batches of 12 rats each: no treatment, control (OVX-M), fenofibrate-treated (OVX-F) and statin-treated (OVX-S) rats. At 12 weeks after ovariectomy, a femoral fracture occurred in the right hind limb of all animals included in the experiment To reveal the changes, at intervals of 2, 4, 6 and 8 weeks post-fracture, the proximal part of the femur was evaluated by NMR diffusiometry, which allows random motion of proton molecules expressed by self-diffusion coefficients, , thus allowing analysis of the size and complexity of microscopic order cavities within biological structures, such as pores inside bones. The effects of hypolipidemic medication in the absence of estrogen were evidenced, proving the beneficial effect that fenofibrate can have in preserving healthy tissue exposed to osteoporotic risk during the menopausal period. The effects of lipid-lowering medication are also influenced by the duration of administration. Osteoporosis and heart disease are two chronic pathologies that affect mainly female population in the second half of life, and proving the dual therapeutic potential of lipid-lowering medication may also have positive effects by increasing adherence and compliance to treatment.
Topics: Animals; Rats, Wistar; Female; Rats; Ovariectomy; Hypolipidemic Agents; Magnetic Resonance Spectroscopy; Fenofibrate; Disease Models, Animal; Femur; Bone and Bones
PubMed: 38929535
DOI: 10.3390/medicina60060918 -
Animals : An Open Access Journal From... Jun 2024The ovariectomy (OVE) procedure can trigger somatosensory and visceral peritoneal nociception. Sacrococcygeal epidural (ScE) anesthesia may complement or replace...
The ovariectomy (OVE) procedure can trigger somatosensory and visceral peritoneal nociception. Sacrococcygeal epidural (ScE) anesthesia may complement or replace systemic analgesia used for feline OVE, reducing opioid consumption and their related undesirable adverse effects and consequently reducing or completely blocking the sympathetic nervous system activation during this procedure. The present study aimed to evaluate the activation of the sympathetic nervous system resulting from adding an ScE injection of bupivacaine 0.25% (0.3 mL kg) in feline OVE and identify whether this translates to hemodynamic variables stability. A Parasympathetic Tone Activity (PTA) monitor was applied given that it performs analysis of heart rate variability (HRV) detecting changes in sympathetic and parasympathetic tone, making it a good tool for detecting activation of the sympathetic nervous system during the study. Two groups of animals were evaluated in five perioperative times, namely, the control group (CG) (n = 18) with systemic analgesia alone and the sacrococcygeal epidural group (ScEG) (n = 20) with 0.25% bupivacaine combined with systemic analgesia. Thirty-eight female cats were selected. All animals assigned to CG and ScEG were premedicated with dexmedetomidine (20 μg kg IM) and methadone (0.2 mg kg IM). General anesthesia was induced with propofol IV ad effectum and maintained with isoflurane in 100% oxygen. Heart rate, non-invasive systolic and median blood pressure, respiratory rate, and instantaneous parasympathetic tone activity were recorded. Compared to systemic analgesia alone (CG), sacrococcygeal epidural (ScEG) reduced the rise of common hemodynamic variables but did not prevent sympathetic nervous system activation.
PubMed: 38929350
DOI: 10.3390/ani14121732 -
Antioxidants (Basel, Switzerland) May 2024Menopause brings about profound physiological changes, including the acceleration of insulin resistance and other abnormalities, in which adipose tissue can play a...
Menopause brings about profound physiological changes, including the acceleration of insulin resistance and other abnormalities, in which adipose tissue can play a significant role. This study analyzed the effect of ovariectomy and estradiol substitution on the metabolic parameters and transcriptomic profile of adipose tissue in prediabetic females of hereditary hypertriglyceridemic rats (HHTgs). The HHTgs underwent ovariectomy (OVX) or sham surgery (SHAM), and half of the OVX group received 17β-estradiol (OVX+E2) post-surgery. Ovariectomy resulted in weight gain, an impaired glucose tolerance, ectopic triglyceride (TG) deposition, and insulin resistance exemplified by impaired glycogenesis and lipogenesis. Estradiol alleviated some of the disorders associated with ovariectomy; in particular, it improved insulin sensitivity and reduced TG deposition. A transcriptomic analysis of perimetrial adipose tissue revealed 809 differentially expressed transcripts in the OVX vs. SHAM groups, mostly pertaining to the regulation of lipid and glucose metabolism, and oxidative stress. Estradiol substitution affected 1049 transcripts with overrepresentation in the signaling pathways of lipid metabolism. The principal component and hierarchical clustering analyses of transcriptome shifts corroborated the metabolic data, showing a closer resemblance between the OVX+E2 and SHAM groups compared to the OVX group. Changes in the adipose tissue transcriptome may contribute to metabolic abnormalities accompanying ovariectomy-induced menopause in HHTg females. Estradiol substitution may partially mitigate some of these disorders.
PubMed: 38929066
DOI: 10.3390/antiox13060627 -
International Journal of Molecular... Jun 2024Osteoporosis, a prevalent chronic health issue among the elderly, is a global bone metabolic disease. Flavonoids, natural active compounds widely present in vegetables,...
Onion ( L.) Flavonoid Extract Ameliorates Osteoporosis in Rats Facilitating Osteoblast Proliferation and Differentiation in MG-63 Cells and Inhibiting RANKL-Induced Osteoclastogenesis in RAW 264.7 Cells.
Osteoporosis, a prevalent chronic health issue among the elderly, is a global bone metabolic disease. Flavonoids, natural active compounds widely present in vegetables, fruits, beans, and cereals, have been reported for their anti-osteoporotic properties. Onion is a commonly consumed vegetable rich in flavonoids with diverse pharmacological activities. In this study, the trabecular structure was enhanced and bone mineral density (BMD) exhibited a twofold increase following oral administration of onion flavonoid extract (OFE). The levels of estradiol (E2), calcium (Ca), and phosphorus (P) in serum were significantly increased in ovariectomized (OVX) rats, with effects equal to alendronate sodium (ALN). Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) levels in rat serum were reduced by 35.7% and 36.9%, respectively, compared to the OVX group. In addition, the effects of OFE on bone health were assessed using human osteoblast-like cells MG-63 and osteoclast precursor RAW 264.7 cells in vitro as well. Proliferation and mineralization of MG-63 cells were promoted by OFE treatment, along with increased ALP activity and mRNA expression of osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL). Additionally, RANKL-induced osteoclastogenesis and osteoclast activity were inhibited by OFE treatment through decreased TRAP activity and down-regulation of mRNA expression-related enzymes in RAW 264.7 cells. Overall findings suggest that OFE holds promise as a natural functional component for alleviating osteoporosis.
Topics: Animals; Osteoblasts; RANK Ligand; Osteoporosis; Flavonoids; Mice; Onions; Cell Differentiation; Plant Extracts; Rats; Cell Proliferation; RAW 264.7 Cells; Osteogenesis; Humans; Female; Osteoclasts; Bone Density; Ovariectomy; Rats, Sprague-Dawley; Osteoprotegerin
PubMed: 38928460
DOI: 10.3390/ijms25126754 -
The Journal of Veterinary Medical... Jun 2024Laparoscopic ovariectomy under general anesthesia was planned in a 10-year-old, 146 kg, apparently healthy female African lion (Panthera leo). The lion was immobilized...
Laparoscopic ovariectomy under general anesthesia was planned in a 10-year-old, 146 kg, apparently healthy female African lion (Panthera leo). The lion was immobilized via intramuscular darts containing midazolam (0.033 mg/kg), medetomidine (50 µg/kg) and ketamine (2.5 mg/kg), and intubated using an endotracheal tube (16 mm internal diameter). The anesthesia was maintained using sevoflurane (0.9-2.1% end-tidal concentration), in combination with remifentanil (0.1 µg/kg/min) and ketamine (11 µg/kg/min) at a constant rate infusion (CRI), with Hartmann's solution (5 mL/kg/hr). Surgery was conducted with stable vital signs, but hypotension (mean arterial blood pressure 55 mmHg) developed, requiring dobutamine treatment. The hypotension was effectively controlled by adjusting dobutamine from 5 µg/kg/min to 0.2 to 0.3 µg/kg/min. This case suggests possibilities that dosages in this range can be clinically useful for peri-anesthetic hypotension in lions.
PubMed: 38925983
DOI: 10.1292/jvms.23-0436 -
Veterinary Sciences Jun 2024Surgical neutering in pet rabbits is common practice to prevent reproduction and associated health issues. Adequate postoperative pain management is crucial for...
Surgical neutering in pet rabbits is common practice to prevent reproduction and associated health issues. Adequate postoperative pain management is crucial for recovery, yet effective methods in clinical settings remain underexplored. This study compared the analgesic effects of carprofen and meloxicam in pet rabbits undergoing surgical neutering. Fifty rabbits of varied demographics were included, with pain assessed using the Centro Animali Non Convenzionali Rabbit Scale (CANCRS). Rabbits were allocated to receive postoperative 2 mg kg carprofen or 1 mg kg meloxicam by subcutaneous injection. Anesthesia was induced with an intramuscular combination of ketamine (20 mg kg), medetomidine (0.4 mg kg), and butorphanol (0.2 mg kg), and ovariectomy or orchiectomy were performed. The CANCRS scale was used to assess pain by evaluating the rabbit preoperatively, 6 h postoperatively, and at three time points the following day. Times of return to spontaneous feeding and fecal production were also recorded. No statistically significant difference was found between treatment groups based on CANCRS scores and resumption of food intake and fecal output. No clinically detectable adverse effects were noted. While limitations include the use of a single pain assessment scale and the absence of a placebo control group, the results suggest that both carprofen and meloxicam can be viable options in clinical practice. Further research utilizing diverse pain assessment methods is warranted to enhance understanding and optimize pain management strategies for rabbits undergoing surgical procedures.
PubMed: 38922004
DOI: 10.3390/vetsci11060257