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Theranostics 2024Mesenchymal stromal cells (MSCs) are considered a promising resource for cell therapy, exhibiting efficacy in ameliorating diverse bone diseases. However, most MSCs...
Mesenchymal stromal cells (MSCs) are considered a promising resource for cell therapy, exhibiting efficacy in ameliorating diverse bone diseases. However, most MSCs undergo apoptosis shortly after transplantation and produce apoptotic extracellular vesicles (ApoEVs). This study aims to clarify the potential role of ApoEVs from apoptotic MSCs in ameliorating osteoporosis and molecular mechanism. In this study, Dio-labeled bone marrow mesenchymal stem cells (BMSCs) were injected into mice to track BMSCs apoptosis and ApoEVs production. ApoEVs were isolated from BMSCs after inducing apoptosis, the morphology, size distribution, marker proteins expression of ApoEVs were characterized. Protein mass spectrometry analysis revealed functional differences in proteins between ApoEVs and BMSCs. BMSCs were adopted to test the cellular response to ApoEVs. Ovariectomy mice were used to further compare the ability of ApoEVs in promoting bone formation. SiRNA and lentivirus were used for gain and loss-of-function assay. The results showed that BMSCs underwent apoptosis within 2 days after being injected into mice and produce a substantial quantity of ApoEVs. Proteomic analysis revealed that ApoEVs carried a diverse functional array of proteins, and easily traversed the circulation to reach the bone. After being phagocytized by endogenous BMSCs, ApoEVs efficiently promoted the proliferation, migration, and osteogenic differentiation of BMSCs. In an osteoporosis mouse model, treatment of ApoEVs alleviated bone loss and promoted bone formation. Mechanistically, ApoEVs carried Ras protein and activated the Ras/Raf1/Mek/Erk pathway to promote osteogenesis and bone formation and . Given that BMSC-derived ApoEVs are high-yield and easily obtained, our data underscore the substantive role of ApoEVs from dying BMSCs to treat bone loss, presenting broad implications for cell-free therapeutic modalities.
PubMed: 38948067
DOI: 10.7150/thno.96174 -
Research Square Jun 2024: Stem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) have limited proliferation and...
: Stem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) have limited proliferation and differentiation, which may minimize the risk of tumor formation while restoring smooth muscle cell deficiencies. Up to 30 % of women who suffer from recurrence of vaginal prolapse after prolapse surgery are faced with reoperation. Therefore, there is an unmet need for therapies that can restore vaginal tissue function. We hypothesize that human pSMCs can restore vaginal function in a vaginal-injury rat model. : Female immune-compromised RNU rats were divided into 5 groups: intact controls (n=12), VSHAM (surgery + saline injection, n=33), and cell-injection group (surgery + cell injection using three patient pSMCs lines, n=14/cell line). The surgery, similar to what is done in vaginal prolapse surgery, involved ovariectomy, urethrolysis, and vagina injury. The vagina, urethra, bladder dome and trigone were harvested 10 weeks after surgery (5 weeks after injection). Organ bath myography was performed to evaluate the contractile function of vagina, and smooth muscle thickness was examined by tissue immunohistochemistry. Collagen I, collagen III, and elastin mRNA and protein expressions in tissues were assessed. : When compared to the VSHAM group, cell-injection groups showed significantly increased vaginal smooth muscle contractions induced by carbachol (groups A and C) and by KCl (group C), and significantly higher collagen I protein expression in the vagina (groups A and B). Elastin mRNA and protein expressions in the vagina did not correlate with injection group. In the urethra, mRNA expressions of collagen I, collagen III, and elastin were all significantly higher in the cell-injection groups compared to the VSHAM group. Collagen I protein expression of the urethra was also higher in the cell-injection group compared to the VSHAM group. Elastin protein expression in the urethra did not correlate with injection group. : Human iPSC-derived pSMCs improved contractile function of the post-surgery vagina. Additionally, pSMC injection modulated collagen I, collagen III and elastin mRNA and protein expressions in the vagina and urethra. These findings suggest that pSMCs may be a possible therapy for vaginal prolapse recurrence after surgical intervention.
PubMed: 38946968
DOI: 10.21203/rs.3.rs-4172308/v1 -
Journal of Nutritional Science and... 2024Osteoporosis is characterized by bone loss and deterioration in bone microstructure, leading to bone fragility. It is strongly correlated with menopause in women....
Osteoporosis is characterized by bone loss and deterioration in bone microstructure, leading to bone fragility. It is strongly correlated with menopause in women. Previously, we reported that diets supplemented with a kudzu (Pueraria lobata) vine extract suppressed bone resorption in ovariectomized (OVX) mice, a postmenopausal model. The main isoflavone in kudzu is puerarin (daidzein-8-C-glycoside). Puerarin (daidzein-8-C-glycoside), which is main isoflavone of kudzu, probably contributes to the beneficial effect. However, the underlying mechanism is unclear. Therefore, the nutrikinetics of puerarin and the comparison with the suppressive effects of kudzu isoflavones on osteoclast differentiation was examined in this study. We demonstrated that orally administered puerarin was absorbed from the gut and entered the circulation in an intact form. In addition, puerarin accumulated in RAW264.7 pre-osteoclast cells in a time-dependent manner. Tartrate-resistant acid phosphatase activity was decreased by puerarin treatment in a concentration-dependent manner in RAW264.7 cells stimulated with the receptor activator of nuclear factor kappa-B ligand. Ovariectomy-induced elevated bone resorption was suppressed, and the fragile bone strength was improved by puerarin ingestion in the diet. These findings suggested that orally administered puerarin was localized in bone tissue and suppressed bone resorption and osteoclastogenesis in ovariectomized mice.
Topics: Animals; Isoflavones; Ovariectomy; Osteoclasts; Female; Mice; Femur; Pueraria; Cell Differentiation; RAW 264.7 Cells; Bone Resorption; Plant Extracts; Osteoporosis; Tartrate-Resistant Acid Phosphatase
PubMed: 38945892
DOI: 10.3177/jnsv.70.262 -
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 -
Biochimica Et Biophysica Acta.... Jun 2024Postmenopausal women experience bone loss and weight gain. To date, crosstalk between estrogen receptor signals and nuclear factor-κB (NF-κB) has been reported, and...
Postmenopausal women experience bone loss and weight gain. To date, crosstalk between estrogen receptor signals and nuclear factor-κB (NF-κB) has been reported, and estrogen depletion enhances bone resorption by osteoclasts via NF-κB activation. However, it is unclear when and in which tissues NF-κB is activated after menopause, and how NF-κB acts as a common signaling molecule for postmenopausal weight gain and bone loss. Therefore, we examined the role of NF-κB in bone and energy metabolism following menopause. NF-κB reporter mice, which can be used to measure NF-κB activation in vivo, were ovariectomized (OVX) and the luminescence intensity after OVX increased in the metaphyses of the long bones and perigonadal white adipose tissue, but not in the other tissues. OVX was performed on wild-type (WT) and p65 mutant knock-in (S534A) mice, whose mutation enhances the transcriptional activity of NF-κB. Weight gain with worsening glucose tolerance was significant in S534A mice after OVX compared with those of WT mice. The bone density of the sham group in WT or S534A mice did not change, whereas in the S534A-OVX group it significantly decreased due to the suppression of bone formation and increase in bone marrow adipocytes. Disulfiram, an anti-alcoholic drug, suppressed OVX-induced activation of NF-κB in the metaphyses of long bones and white adipose tissue (WAT), as well as weight gain and bone loss. Overall, the activation of NF-κB in the metaphyses of long bones and WAT after OVX regulates post-OVX weight gain and bone loss.
PubMed: 38936515
DOI: 10.1016/j.bbadis.2024.167320 -
European Journal of Pharmacology Jun 2024Given estrogen's recognized regulatory influence on diverse metabolic and immune functions, this study sought to explore its potential impact on fibrosis and elucidate...
AIM
Given estrogen's recognized regulatory influence on diverse metabolic and immune functions, this study sought to explore its potential impact on fibrosis and elucidate the underlying metabolic regulations.
METHODS
Female mice underwent ovary removal surgery, followed by carbon tetrachloride (CCl) administration to induce liver injury. Biochemical index analysis and histopathological examination were then conducted. The expression levels of alpha-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), and collagen type 1 alpha 1 chain (COL1A1) were assessed using western blotting to further elucidate the extent of liver injury. Finally, metabolite extraction and metabolomic analysis were performed to evaluate metabolic changes.
RESULTS
Ovary removal exacerbated CCl-induced liver damage, while estrogen supplementation provided protection against hepatic changes resulting from OVX. Furthermore, estrogen mitigated liver injury induced by CCl treatment in vivo. Estrogen supplementation significantly restored liver damage induced by OVX and CCl. Comparative analysis revealed significant alterations in pathways including aminoacyl-tRNA biosynthesis, glycine, serine, and threonine metabolism, lysine degradation, and taurine and hypotaurine metabolism in estrogen treatment.
CONCLUSION
Estrogen supplementation alleviates liver injury induced by OVX and CCl, highlighting its protective effects against fibrosis and associated metabolic alterations.
PubMed: 38936452
DOI: 10.1016/j.ejphar.2024.176774 -
Biochemical and Biophysical Research... Jun 2024With the aging of the global demographic, the prevention and treatment of osteoporosis are becoming crucial issues. The gradual loss of self-renewal and osteogenic...
With the aging of the global demographic, the prevention and treatment of osteoporosis are becoming crucial issues. The gradual loss of self-renewal and osteogenic differentiation capabilities in bone marrow stromal cells (BMSCs) is one of the key factors contributing to osteoporosis. To explore the regulatory mechanisms of BMSCs differentiation, we collected bone marrow cells of femoral heads from patients undergoing total hip arthroplasty for single-cell RNA sequencing analysis. Single-cell RNA sequencing revealed significantly reduced CRIP1 (Cysteine-Rich Intestinal Protein 1) expression and osteogenic capacity in the BMSCs of osteoporosis patients compared to non-osteoporosis group. CRIP1 is a gene that encodes a member of the LIM/double zinc finger protein family, which is involved in the regulation of various cellular processes including cell growth, development, and differentiation. CRIP1 knockdown resulted in decreased alkaline phosphatase activity, mineralization and expression of osteogenic markers, indicating impaired osteogenic differentiation. Conversely, CRIP1 overexpression, both in vitro and in vivo, enhanced osteogenic differentiation and rescued bone mass reduction in ovariectomy-induced osteoporosis mice model. The study further established CRIP1's modulation of osteogenesis through the Wnt signaling pathway, suggesting that targeting CRIP1 could offer a novel approach for osteoporosis treatment by promoting bone formation and preventing bone loss.
PubMed: 38936225
DOI: 10.1016/j.bbrc.2024.150277 -
Journal of Biological Physics Jun 2024Bone is a complex tissue that fulfills the role of a resistance structure. This quality is most commonly assessed by bone densitometry, but bone strength may not only be...
Bone is a complex tissue that fulfills the role of a resistance structure. This quality is most commonly assessed by bone densitometry, but bone strength may not only be related to bone mineral density but also to the preservation of bone cytoarchitectonics. The study included two groups of rats, ovariectomized and non-ovariectomized. Each group was divided into three batches: control, simvastatin-treated, and fenofibrate-treated. In the ovariectomized group, hypolipidemic treatment was instituted at 12 weeks post ovariectomy. One rat from each of the 6 batches was sacrificed 8 weeks after the start of treatment in the group. The experimental study was performed using a Bruker Minispec mq 20 spectrometer operating at a frequency of 20 MHz, subsequently also performed by H T-T molecular exchange maps. The results were represented by T-T molecular exchange maps that showed, comparatively, both pore size and their interconnectivity at the level of the femoral epiphysis, being able to evaluate both the effect of estrogen on bone tissue biology and the effect of the lipid-lowering medication, simvastatin, and fenofibrate, in both the presence and absence of estrogen. T-T molecular exchange maps showed that the absence of estrogen results in an increase in bone tissue pore size and interconnectivity. In the presence of estrogen, lipid-lowering medication, both simvastatin and fenofibrate alter bone tissue cytoarchitectonics by reducing pore interconnectivity. In the absence of estrogen, fenofibrate improves bone tissue cytoarchitectonics, the T-T molecular exchange map being similar to that of non-osteoporotic bone tissue.
PubMed: 38935192
DOI: 10.1007/s10867-024-09658-2