Resveratrol can enhance osteogenic differentiation and mitochondrial biogenesis from human periosteum-derived mesenchymal stem cells

Role of oxidative stress in the concurrent development of osteoporosis and tendinopathy: Emerging challenges and prospects for treatment modalities

Both osteoporosis and tendinopathy are widely prevalent disorders, encountered in diverse medical contexts. Whilst each condition has distinct pathophysiological characteristics, they share several risk factors and underlying causes. Notably, oxidative stress emerges as a crucial intersecting factor, playing a pivotal role in the onset and progression of both diseases. This imbalance arises from a dysregulation in generating and neutralising reactive oxygen species (ROS), leading to an abnormal oxidative environment. Elevated levels of ROS can induce multiple cellular disruptions, such as cytotoxicity, apoptosis activation and reduced cell function, contributing to tissue deterioration and weakening the structural integrity of bones and tendons. Antioxidants are substances that can prevent or slow down the oxidation process, including Vitamin C, melatonin, resveratrol, anthocyanins and so on, demonstrating potential in treating these overlapping disorders. This comprehensive review aims to elucidate the complex role of oxidative stress within the interlinked pathways of these comorbid conditions. By integrating contemporary research and empirical findings, our objective is to outline new conceptual models and innovative treatment strategies for effectively managing these prevalent diseases. This review underscores the importance of further in-depth research to validate the efficacy of antioxidants and traditional Chinese medicine in treatment plans, as well as to explore targeted interventions focused on oxidative stress as promising areas for future medical advancements.

METTL3 promotes the osteogenic differentiation of periosteum-derived MSCs via regulation of the HOXD8/ITGA5 axis in congenital pseudarthrosis

Background

Congenital pseudarthrosis of the tibia (CPT) is a dominant health challenge in pediatric orthopedics. The essential process in the development of CPT is the limited capacity of mesenchymal stem cells (MSCs) derived from CPT to undergo osteogenic differentiation. Our research aimed to elucidate the role and mechanism of methyltransferase-like 3 (METTL3) in the osteogenic differentiation process of CPT MSCs.

Methods

The osteogenic differentiation medium was used to culture MSCs, and the detection of osteogenic differentiation was performed using Alizarin Red S and alkaline phosphatase (ALP) assays. Gene or protein expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, or immunofluorescence (IF) staining. The m6A modification of Homeobox D8 (HOXD8) was verified by methylated RNA immunoprecipitation (MeRIP) assay. Interactions between METTL3 and HOXD8 or HOXD8 and integrin alpha 5 (ITGA5) promoter were validated by the luciferase reporter gene, RIP, and chromatin immunoprecipitation (ChIP) assays.

Results

METTL3 overexpression enhanced CPT MSCs' osteogenic differentiation. METTL3 stabilized the HOXD8 in an m6A-dependent manner. Moreover, the overexpressed ITGA5 up-regulated the CPT MSCs' osteogenic differentiation. Further, HOXD8 could transcriptionally activate ITGA5. METTL3 increased the transcription of ITGA5 via HOXD8 to enhance the osteogenic differentiation of CPT MSCs.

Conclusion

METTL3 promoted osteogenic differentiation via modulating the HOXD8/ITGA5 axis in CPT MSCs.

Equine Musculoskeletal Pathologies: Clinical Approaches and Therapeutical Perspectives-A Review

Musculoskeletal injuries such as equine osteoarthritis, osteoarticular defects, tendonitis/desmitis, and muscular disorders are prevalent among sport horses, with a fair prognosis for returning to exercise or previous performance levels. The field of equine medicine has witnessed rapid and fruitful development, resulting in a diverse range of therapeutic options for musculoskeletal problems. Staying abreast of these advancements can be challenging, prompting the need for a comprehensive review of commonly used and recent treatments. The aim is to compile current therapeutic options for managing these injuries, spanning from simple to complex physiotherapy techniques, conservative treatments including steroidal and non-steroidal anti-inflammatory drugs, hyaluronic acid, polysulfated glycosaminoglycans, pentosan polysulfate, and polyacrylamides, to promising regenerative therapies such as hemoderivatives and stem cell-based therapies. Each therapeutic modality is scrutinized for its benefits, limitations, and potential synergistic actions to facilitate their most effective application for the intended healing/regeneration of the injured tissue/organ and subsequent patient recovery. While stem cell-based therapies have emerged as particularly promising for equine musculoskeletal injuries, a multidisciplinary approach is underscored throughout the discussion, emphasizing the importance of considering various therapeutic modalities in tandem.

Mitochondria in Mesenchymal Stem Cells: Key to Fate Determination and Therapeutic Potential

Mesenchymal stem cells (MSCs) have become popular tool cells in the field of transformation and regenerative medicine due to their function of cell rescue and cell replacement. The dynamically changing mitochondria serve as an energy metabolism factory and signal transduction platform, adapting to different cell states and maintaining normal cell activities. Therefore, a clear understanding of the regulatory mechanism of mitochondria in MSCs is profit for more efficient clinical transformation of stem cells. This review highlights the cutting-edge knowledge regarding mitochondrial biology from the following aspects: mitochondrial morphological dynamics, energy metabolism and signal transduction. The manuscript mainly focuses on mitochondrial mechanistic insights in the whole life course of MSCs, as well as the potential roles played by mitochondria in MSCs treatment of transplantation, for seeking pivotal targets of stem cell fate regulation and stem cell therapy.

Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

Prevention and Co-Management of Breast Cancer-Related Osteoporosis Using Resveratrol

Breast cancer (BC) is currently one of the most common cancers in women worldwide with a rising tendency. Epigenetics, generally inherited variations in gene expression that occur independently of changes in DNA sequence, and their disruption could be one of the main causes of BC due to inflammatory processes often associated with different lifestyle habits. In particular, hormone therapies are often indicated for hormone-positive BC, which accounts for more than 50-80% of all BC subtypes. Although the cure rate in the early stage is more than 70%, serious negative side effects such as secondary osteoporosis (OP) due to induced estrogen deficiency and chemotherapy are increasingly reported. Approaches to the management of secondary OP in BC patients comprise adjunctive therapy with bisphosphonates, non-steroidal anti-inflammatory drugs (NSAIDs), and cortisone, which partially reduce bone resorption and musculoskeletal pain but which are not capable of stimulating the necessary intrinsic bone regeneration. Therefore, there is a great therapeutic need for novel multitarget treatment strategies for BC which hold back the risk of secondary OP. In this review, resveratrol, a multitargeting polyphenol that has been discussed as a phytoestrogen with anti-inflammatory and anti-tumor effects at the epigenetic level, is presented as a potential adjunct to both support BC therapy and prevent osteoporotic risks by positively promoting intrinsic regeneration. In this context, resveratrol is also known for its unique role as an epigenetic modifier in the regulation of essential signaling processes-both due to its catabolic effect on BC and its anabolic effect on bone tissue.

The Potential Influence of Uremic Toxins on the Homeostasis of Bones and Muscles in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) often experience a high accumulation of protein-bound uremic toxins (PBUTs), specifically indoxyl sulfate (IS) and p-cresyl sulfate (pCS). In the early stages of CKD, the buildup of PBUTs inhibits bone and muscle function. As CKD progresses, elevated PBUT levels further hinder bone turnover and exacerbate muscle wasting. In the late stage of CKD, hyperparathyroidism worsens PBUT-induced muscle damage but can improve low bone turnover. PBUTs play a significant role in reducing both the quantity and quality of bone by affecting osteoblast and osteoclast lineage. IS, in particular, interferes with osteoblastogenesis by activating aryl hydrocarbon receptor (AhR) signaling, which reduces the expression of Runx2 and impedes osteoblast differentiation. High PBUT levels can also reduce calcitriol production, increase the expression of Wnt antagonists (SOST, DKK1), and decrease klotho expression, all of which contribute to low bone turnover disorders. Furthermore, PBUT accumulation leads to continuous muscle protein breakdown through the excessive production of reactive oxygen species (ROS) and inflammatory cytokines. Interactions between muscles and bones, mediated by various factors released from individual tissues, play a crucial role in the mutual modulation of bone and muscle in CKD. Exercise and nutritional therapy have the potential to yield favorable outcomes. Understanding the underlying mechanisms of bone and muscle loss in CKD can aid in developing new therapies for musculoskeletal diseases, particularly those related to bone loss and muscle wasting.

Chlorogenic Acid Induced Neuroblastoma Cells Differentiation via the ACAT1-TPK1-PDH Pathway

BACKGROUND

Chlorogenic acid (CHA) has been shown to have substantial biological activities, including anti-inflammatory, antioxidant, and antitumor effects. However, the pharmacological role of CHA in neuroblastoma has not yet been assessed. Neuroblastoma is a type of cancer that develops in undifferentiated sympathetic ganglion cells. This study aims to assess the antitumor activity of CHA against neuroblastoma and reveal its mechanism of action in cell differentiation.

METHODS

Be(2)-M17 and SH-SY5Y neuroblastoma cells were used to confirm the differentiation phenotype. Subcutaneous and orthotopic xenograft mouse models were also used to evaluate the antitumor activity of CHA. Seahorse assays and metabolomic analyses were further performed to investigate the roles of CHA and its target ACAT1 in mitochondrial metabolism.

RESULTS

CHA induced the differentiation of Be(2)-M17 and SH-SY5Y neuroblastoma cells in vivo and in vitro. The knockdown of mitochondrial ACAT1, which was inhibited by CHA, also resulted in differentiation characteristics in vivo and in vitro. A metabolomic analysis revealed that thiamine metabolism was involved in the differentiation of neuroblastoma cells.

CONCLUSIONS

These results provide evidence that CHA shows good antitumor activity against neuroblastoma via the induction of differentiation, by which the ACAT1-TPK1-PDH pathway is involved. CHA is a potential drug candidate for neuroblastoma therapy.

Revisiting Resveratrol as an Osteoprotective Agent: Molecular Evidence from In Vivo and In Vitro Studies

Resveratrol (RSV) (3,5,4'-trihydroxystilbene) is a stilbene found in abundance in berry fruits, peanuts, and some medicinal plants. It has a diverse range of pharmacological activities, underlining the significance of illness prevention and health promotion. The purpose of this review was to delve deeper into RSV's bone-protective properties as well as its molecular mechanisms. Several in vivo studies have found the bone-protective effects of RSV in postmenopausal, senile, and disuse osteoporosis rat models. RSV has been shown to inhibit NF-κB and RANKL-mediated osteoclastogenesis, oxidative stress, and inflammation while increasing osteogenesis and boosting differentiation of mesenchymal stem cells to osteoblasts. Wnt/β-catenin, MAPKs/JNK/ERK, PI3K/AKT, FoxOs, microRNAs, and BMP2 are among the possible kinases and proteins involved in the underlying mechanisms. RSV has also been shown to be the most potent SIRT1 activator to cause stimulatory effects on osteoblasts and inhibitory effects on osteoclasts. RSV may, thus, represent a novel therapeutic strategy for increasing bone growth and reducing bone loss in the elderly and postmenopausal population.

Reciprocal Effect of Environmental Stimuli to Regulate the Adipogenesis and Osteogenesis Fate Decision in Bone Marrow-Derived Mesenchymal Stem Cells (BM-MSCs)

Mesenchymal stem cells derived from bone marrow (BM-MSCs) can differentiate into adipocytes and osteoblasts. Various external stimuli, including environmental contaminants, heavy metals, dietary, and physical factors, are shown to influence the fate decision of BM-MSCs toward adipogenesis or osteogenesis. The balance of osteogenesis and adipogenesis is critical for the maintenance of bone homeostasis, and the interruption of BM-MSCs lineage commitment is associated with human health issues, such as fracture, osteoporosis, osteopenia, and osteonecrosis. This review focuses on how external stimuli shift the fate of BM-MSCs towards adipogenesis or osteogenesis. Future studies are needed to understand the impact of these external stimuli on bone health and elucidate the underlying mechanisms of BM-MSCs differentiation. This knowledge will inform efforts to prevent bone-related diseases and develop therapeutic approaches to treat bone disorders associated with various pathological conditions.

Enhancers of mesenchymal stem cell stemness and therapeutic potency

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a range of cell types, including osteoblasts, chondrocytes, myocytes, and adipocytes. Multiple preclinical investigations and clinical trials employed enhanced MSCs-dependent therapies in treatment of inflammatory and degenerative diseases. They have demonstrated considerable and prospective therapeutic potentials even though the large-scale use remains a problem. Several strategies have been used to improve the therapeutic potency of MSCs in cellular therapy. Treatment of MSCs utilizing pharmaceutical compounds, cytokines, growth factors, hormones, and vitamins have shown potential outcomes in boosting MSCs' stemness. In this study, we reviewed the current advances in enhancing techniques that attempt to promote MSCs' therapeutic effectiveness in cellular therapy and stemness in vivo with potential mechanisms and applications.

Emerging Effects of Resveratrol Derivatives in Cells Involved in Oral Wound Healing: A Preliminary Study

Recently, there has been an increasing interest in finding new approaches to manage oral wound healing. Although resveratrol (RSV) exhibited many biological properties, such as antioxidant and anti-inflammatory activities, its use as a drug is limited by unfavorable bioavailability. This study aimed to investigate a series of RSV derivatives (1a-j) with better pharmacokinetic profiles. At first, their cytocompatibility at different concentrations was tested on gingival fibroblasts (HGFs). Among them, derivatives 1d and 1h significantly increased cell viability compared to the reference compound RSV. Thus, 1d and 1h were investigated for cytotoxicity, proliferation, and gene expression in HGFs, endothelial cells (HUVECs), and oral osteoblasts (HOBs), which are the main cells involved in oral wound healing. For HUVECs and HGFs, the morphology was also evaluated, while for HOBs ALP and mineralization were observed. The results showed that both 1d and 1h did not exert negative effects on cell viability, and at a lower concentration (5 µM) both even significantly enhanced the proliferative rate, compared to RSV. The morphology observations pointed out that the density of HUVECs and HGFs was promoted by 1d and 1h (5 µM) and mineralization was promoted in HOBs. Moreover, 1d and 1h (5 µM) induced a higher eNOS mRNA level in HUVECs, higher COL1 mRNA in HGFs, and higher OCN in HOBs, compared to RSV. The appreciable physicochemical properties and good enzymatic and chemical stability of 1d and 1h, along with their promising biological properties, provide the scientific basis for further studies leading to the development of RSV-based agents useful in oral tissue repair.

Resveratrol suppresses lipopolysaccharide-mediated activation of osteoclast precursor RAW 264.7 cells by increasing miR-181a-5p expression

Resveratrol (Res) has anti-inflammation and antiosteoporosis functions. We evaluated the effect of Res on osteoclast differentiation by releasing inflammatory cytokines from osteoclast precursor RAW 264.7 cells stimulated by lipopolysaccharide (LPS). In the study, LPS (1 ng/L) was used to induce the Raw 264.7 inflammatory injury model in vitro. A total of 25 ng/mL M-CSF + 30 ng/mL RANKL or plus 1 μg/L LPS was used to induce osteoclastogenesis in the experiments. We utilized the Cell Counting Kit-8 assay to measure the relative cell survival of RAW 264.7 cells. Then, enzyme-linked immunosorbent assays were utilized to measure the abundance of inflammatory markers, such as interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and IL-6. Subsequently, Western blot analysis was applied to assess the abundance of phosphorylated transforming growth factor beta-activated kinase 1 (P-TAK1) protein, TNF receptor-associated factor 6 (TRAF6), nuclear factor-κB inhibitor protein (IκB), phosphorylated IκB-α (P-IκB-α), and nuclear factor κB65 (NF-κB65). mRNA expression levels of miR-181a-5p, TRAF6, specific gene calcitonin receptor (CTR), activated T nuclear factor 1 (NFATC1), cathepsin K (CTSK), and matrix metalloproteinase (MMP)-9 were determined via a real-time polymerase chain reaction. Osteoclast bone resorption function was determined. Finally, tartrate-resistant acid phosphatase (TRAP) staining was performed.The results found that Compared with the model group, the degrees of expressions of supernatant inflammatory factors TNF-α, IL-1β, and IL-6 were substantially attenuated in the Res treatment group (p < 0.05). Furthermore, the extent of miR-181a-5p expression in the RAW 264.7 cells significantly increased, whereas P-IκB-α, P-TAK1, NF-κB65, and TRAF6 expressions significantly decreased in the Res treatment group as opposed to the model group (p < 0.05). The CTR, NFATC1, MMP-9, CTSK, and TRAP mRNA expression levels were substantially reduced during osteoclast differentiation and bone resorption in the Res treatment group.The results suggest that Res can reduce the RAW 264.7 cell differentiation into osteoclasts and relieve LPS-stimulated osteoporosis, and the underlying mechanism may be associated with the Res-inhibited activity of the TRAF6/TAK1 pathway through the increased miR-181a-5p expression.

Mitochondrial quality control and its role in osteoporosis

Mitochondria are important organelles that provide cellular energy and play a vital role in cell differentiation and apoptosis. Osteoporosis is a chronic metabolic bone disease mainly caused by an imbalance in osteoblast and osteoclast activity. Under physiological conditions, mitochondria regulate the balance between osteogenesis and osteoclast activity and maintain bone homeostasis. Under pathological conditions, mitochondrial dysfunction alters this balance; this disruption is important in the pathogenesis of osteoporosis. Because of the role of mitochondrial dysfunction in osteoporosis, mitochondrial function can be targeted therapeutically in osteoporosis-related diseases. This article reviews different aspects of the pathological mechanism of mitochondrial dysfunction in osteoporosis, including mitochondrial fusion and fission, mitochondrial biogenesis, and mitophagy, and highlights targeted therapy of mitochondria in osteoporosis (diabetes induced osteoporosis and postmenopausal osteoporosis) to provide novel targets and prevention strategies for the prevention and treatment of osteoporosis and other chronic bone diseases.

M13, an anthraquinone compound isolated from Morinda officinalis promotes the osteogenic differentiation of MSCs by targeting Wnt/β-catenin signaling

BACKGROUND

Morinda officinalis (MO) is a herb used in Traditional Chinese Medicine (TCM) for the treatment of osteoporosis. M13, a MO-based anthraquinone compound is known to suppress osteoclast activity. However, whether M13 promotes MSCs osteogenic differentiation and its potential mechanism remains unknown.

PURPOSE

To examine the influence of M13 on MSCs proliferation and osteogenic differentiation and elucidate the underlying mechanism.

METHODS/STUDY DESIGNS

The effect of M13 exposure on MSCs proliferation was assessed via CCK8 assay, clone formation assay, immunofluorescence, RT-qPCR, and Western blot. The M13-mediated osteogenesis in vitro and ex vivo were evaluated via ALP and Alizarin red S staining, osteogenesis-associated gene (Runx2, Col1a1 and Opn) expression, and fetal limb explants culture. Molecular docking was employed for target signal pathway screening. The potential signaling mechanisms of M13-promoted MSCs osteogenic differentiation were analyzed by introducing XAV939 (Wnt/β-catenin signaling inhibitor).

RESULTS

M13 induced certain obvious positive effects on MSCs proliferation and osteogenic differentiation. Treatment with M13 enhanced MSCs viability and clone numbers. Meanwhile, M13 promoted osteogenic gene expression, enhanced ALP intensity and Alizarin red S staining in MSCs. In terms of mechanism, M13 strongly interacted with the docking site of the WNT signaling complex, thereby activating the Wnt/β-catenin pathway. Furthermore, the M13-mediated osteogenic effect was partially inhibited by XAV939 both in vitro and ex vivo, which confirmed that the Wnt/β-catenin axis is a critical regulator of M13-induced osteogenic differentiation of MSCs.

CONCLUSION

Our study elucidated for the first time that M13 significantly promoted osteogenic differentiation of MSCs via stimulation of the Wnt/β-catenin pathway in vitro and ex vivo.Our findings offered new additional evidence to support the MO or M13-based therapy of osteoporosis.

Design and development of biomimetic electrospun sulphonated polyether ether ketone nanofibrous scaffold for bone tissue regeneration applications: in vitro and in vivo study

Bone defect restoration remains challenging in orthopedic medical practices. In this study an attempt is carried out to probe the use of new biomimetic SPEEK (sulfonated polyether ether ketone) based nanofibrous scaffold to deliver amine functionalized hydroxyapatite nanoparticles loaded resveratrol for its potent functionality in osteogenic differentiation. SPEEK polymer with reactive functional group SO₃H was synthesized through process of sulphonation reaction. Amine functionalized nanoparticles with protonated amino groups revamp the molecular interaction by the formation of hydrogen bonds that in turn intensify the bioactivity of the nanofibrous scaffold. Osteoconductive functionalized nanohydroxyapatite enhances the cell proliferation and osteogenicity with improved cell attachment and spreading. The results of FT-IR, XRD, Carbon-Silica NMR and EDX analysis confirmed the amine functionalization of the hydroxyapatite nanoparticles. Surface morphological analysis of the fabricated nanofibers through SEM and AFM analysis shows vastly interconnected porous structure that mimics the bone extracellular matrix, which enhances the cell compatibility. Cell adhesion and live dead assay of the nanoscaffolds express less cytotoxicity. Mineralization and alkaline phosphatase assay establish the osteogenic differentiation of the nanofibrous scaffold. The in vitro biocompatibility studies reveal that the fabricated scaffold was osteo-compatible with MG63 cell lines. Hemocompatibility study further proved that the designed biomimetic nanofibrous scaffold was highly suitable for bone tissue engineering. The results of in vivo analysis in zebrafish model for the fabricated nanofibers demonstrated significant increase in the caudal fin regeneration indicating mineralization of osteoblast. Thus, the commending results obtained instigate the potentiality of the composite nanofibrous scaffold as an effective biomimetic substrate for bone tissue regeneration.

The combined therapy of mesenchymal stem cell transplantation and resveratrol for diabetes: Future applications and challenges

Diabetes mellitus (DM) is a worldwide chronic epidemic disease of impaired glucose metabolism. Transplantation of mesenchymal stem cells (MSCs) is considered a promising emerging treatment strategy for diabetes. However, the harsh internal environment of DM patients can inhibit the treatment effects of transplanted MSCs. Fortunately, this adverse effect can be reversed by resveratrol (Res). Therefore, we investigated and summarized relevant studies on the combined treatment of diabetes with MSCs and resveratrol. This review presents the therapeutic effects of this combination therapy strategy on DM in glycemic control, anti-inflammatory, anti-oxidative stress and anti-fibrotic. Moreover, this review explained the mechanisms of MSCs and resveratrol in diabetes treatment from 3 aspects, including promoting cell survival and inhibiting apoptosis, inhibiting histiocyte fibrosis, and improving glucose metabolism. These findings help to understand in-depth mechanisms of the treatment of DM and help to propose a potential treatment strategy for DM and its complications.

Osteoinductive activity of bisdemethoxycurcumin and its synergistic protective effect with human amniotic mesenchymal stem cells against ovariectomy-induced osteoporosis mouse model

Osteoporosis is a common disease characterized by skeletal fragility and microarchitectural deterioration. However, existing conventional drugs exhibit limited efficacy and can elicit severe adverse effects; moreover, and novel stem cell-based therapies have not exhibited sufficient therapeutic efficacy. Our hypothesis is that an appropriate osteogenic inducer may improve their therapeutic efficacy. In this study, we found that bisdemethoxycurcumin (BDMC) stimulates the differentiation of human amniotic mesenchymal stem cells (hAMSCs) into osteoblasts without inducing cytotoxicity. Here BDMC enhances calcium deposition in hAMSCs, while promoting the expression of early and late markers of osteoblast differentiation, including ALP, runt-related transcription factor 2, osterix, COL1-α1, osteocalcin, and osteopontin at the transcriptional and translational levels. Mechanistically, BDMC was found to activate the JAK2/STAT3 pathway; whereas AG490 (JAK2/STAT3 pathway inhibitor) inhibited BDMC functioning. Subsequently, we found that the combinatorial therapy of BDMC and hAMSC had a positive synergistic effect on osteoporotic mouse model induced by bilateral ovariectomy, including inhibiting bone loss and bone resorption and improving bone micro-architecture. Moreover, BDMC inhibited production of the bone resorption markers C-terminal telopeptide of type I collagen, and tartrate resistant acid phosphatase, while promoting serum levels of bone formation markers OCN, and procollagen I N-terminal propeptide. BDMC also improved liver and kidney function in osteoporotic mouse model. Collectively, BDMC improved osteoporosis by enhancing hAMSC osteogenesis and exhibited a protective effect on liver and kidney function in an osteoporotic mouse model. Hence, BDMC may serve as an effective adjuvant, and combined therapy with hAMSCs is a promising new approach toward osteoporosis treatment.

Mechanical and chemical cues synergistically promote human venous smooth muscle cell osteogenesis through integrin β1-ERK1/2 signaling: A cell model of hemodialysis fistula calcification

Arteriovenous fistula (AVF) is the vascular access of choice for renal replacement therapy. However, AVF is susceptible to calcification with a high prevalence of 40%-65% in chronic hemodialysis patients. Repeated needle puncture for hemodialysis cannulation results in intimal denudation of AVF. We hypothesized that exposure to blood shear stress in the medial layer promotes venous smooth muscle cell (SMC) osteogenesis. While previous studies of shear stress focused on arterial-type SMCs, SMCs isolated from the vein had not been investigated. This study established a venous cell model of AVF using the fluid shear device, combined with a high phosphate medium to mimic the uremic milieu. Osteogenic gene expression of venous SMCs upon mechanical and chemical cues was analyzed in addition to the activated cell signaling pathways. Our findings indicated that upon shear stress and high phosphate environment, mechanical stimulation (shear stress) had an additive effect in up-regulation of an early osteogenic marker, Runx2. We further identified that the integrin β1-ERK1/2 signaling pathway was responsible for the molecular basis of venous SMC osteogenesis upon shear stress exposure. Mitochondrial biogenesis also took part in the early stage of this venopathy pathogenesis, evident by the up-regulated mitochondrial transcription factor A and mitochondrial DNA polymerase γ in venous SMCs. In conclusion, synergistic effects of fluid shear stress and high phosphate induce venous SMC osteogenesis via the ERK1/2 pathway through activating the mechanosensing integrin β1 signaling. The present study identified a promising druggable target for reducing AVF calcification, which deserves further in vivo investigations.

Non-flavonoid polyphenols in osteoporosis: preclinical evidence

The development of progressive osteopenia and osteoporosis (OP) is due to the imbalance between bone resorption and bone formation, determining a lower bone resistance, major risks of fractures, with consequent pain and functional limitations. Flavonoids, a class of polyphenols, have been extensively studied for their therapeutic activities against bone resorption, but less attention has been given to a whole series of molecules belonging to the polyphenolic compounds. However, these classes have begun to be studied for the treatment of OP. In this systematic review, comprehensive information is provided on non-flavonoid polyphenolic compounds, and we highlight pathways implicated in the action of these molecules that act often epigenetically, and their possible use for OP treatment and prevention.

Mesenchymal stem cell energy deficit and oxidative stress contribute to osteopenia in the Pahenu2 classical PKU mouse

Osteopenia occurs in a subset of phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) patients. While osteopenia is not fully penetrant in patients, the Pah^enu2 classical PKU mouse is universally osteopenic, making it an ideal model of the phenotype. Pah^enu2 Phe management, with a Phe-fee amino acid defined diet, does not improve bone density as histomorphometry metrics remain indistinguishable from untreated animals. Previously, we demonstrated Pah^enu2 mesenchymal stem cells (MSCs) display impaired osteoblast differentiation. Oxidative stress is recognized in PKU patients and PKU animal models. Pah^enu2 MSCs experience oxidative stress determined by intracellular superoxide over-representation. The deleterious impact of oxidative stress on mitochondria is recognized. Oximetry applied to Pah^enu2 MSCs identified mitochondrial stress by increased basal respiration with concurrently reduced maximal respiration and respiratory reserve. Proton leak secondary to mitochondrial complex 1 dysfunction is a recognized superoxide source. Respirometry applied to Pah^enu2 MSCs, in the course of osteoblast differentiation, identified a partial complex 1 deficit. Pah^enu2 MSCs treated with the antioxidant resveratrol demonstrated increased mitochondrial mass by MitoTracker green labeling. In hyperphenylalaninemic conditions, resveratrol increased in situ alkaline phosphatase activity suggesting partial recovery of Pah^enu2 MSCs osteoblast differentiation. Up-regulation of oxidative energy production is required for osteoblasts differentiation. Our data suggests impaired Pah^enu2 MSC developmental competence involves an energy deficit. We posit energy support and oxidative stress reduction will enable Pah^enu2 MSC differentiation in the osteoblast lineage to subsequently increase bone density.