Physical Activity Prevents Cartilage Degradation: A Metabolomics Study Pinpoints the Involvement of Vitamin B6

The impact of acute and chronic aerobic and resistance exercise on stem cell mobilization: A review of effects in healthy and diseased individuals across different age groups

Stem cells (SCs) play a crucial role in tissue repair, regeneration, and maintaining physiological homeostasis. Exercise mobilizes and enhances the function of SCs. This review examines the effects of acute and chronic aerobic and resistance exercise on the population of SCs in healthy and diseased individuals across different age groups. Both acute intense exercise and moderate regular training increase circulating precursor cells CD34+ and, in particular, the subset of angiogenic progenitor cells (APCs) CD34+/KDR+. Conversely, chronic exercise training has conflicting effects on circulating CD34+ cells and their function, which are likely influenced by exercise dosage, the health status of the participants, and the methodologies employed. While acute activity promotes transient mobilization, regular exercise often leads to an increased number of progenitors and more sustainable functionality. Short interventions lasting 10-21 days mobilize CD34+/KDR + APCs in sedentary elderly individuals, indicating the inherent capacity of the body to rapidly activate tissue-reparative SCs during activity. However, further investigation is needed to determine the optimal exercise regimens for enhancing SC mobilization, elucidating the underlying mechanisms, and establishing functional benefits for health and disease prevention. Current evidence supports the integration of intense exercise with chronic training in exercise protocols aimed at activating the inherent regenerative potential through SC mobilization. The physical activity promotes endogenous repair processes, and research on exercise protocols that effectively mobilize SCs can provide innovative guidelines designed for lifelong tissue regeneration. An artificial neural network (ANN) was developed to estimate the effects of modifying elderly individuals and implementing chronic resistance exercise on stem cell mobilization and its impact on individuals and exercise. The network's predictions were validated using linear regression and found to be acceptable compared to experimental results.

Effects of mineral trioxide aggregate and methyl sulfonyl methane on pulp exposure via RUNX2 and RANKL pathways

The aim of this study was to determine the therapeutic effects of mineral trioxide aggregate (MTA) and methyl sulfonyl methane (MSM) on pulp damage due to pulp exposure through the RUNX2 and RANKL pathways. Seventy-two male Sprague-Dawley rats aged 4-6 months and weighing 250-300 g were divided into healthy, control, MTA, and MSM groups. After experimental applications, all rats at 2, 4, and 8 weeks were killed anesthetically with xylazine hydrochloride (Rompun, Bayer) 30 mg/kg and ketamine hydrochloride (Ketalar, Pfizer) 50 mg/kg injections (i.p.). We observed that necrotic odontoblasts, edema, inflammation, and vascular congestion findings were reduced from week 2 to week 8 in the MSM treatment group after pulp capping compared to the control group and MTA group. Similarly, we found a decrease in RUNX2 and RANKL levels in the MSM application group compared to the control and MTA groups (p < 0.05). MSM material has shown therapeutic effects on pulp capping treatment-induced pulp injury via increased RUNX2 ve RANKL expression.

Vitamin B6 alleviates osteoarthritis by suppressing inflammation and apoptosis

BACKGROUND

Although various anti-inflammatory medicines are widely recommended for osteoarthritis (OA) treatment, no significantly clinical effect has been observed. This study aims to examine the effects of vitamin B6, a component that has been reported to be capable of alleviating inflammation and cell death in various diseases, on cartilage degeneration in OA.

METHODS

Collagen-induced arthritis (CIA) mice model were established and the severity of OA in cartilage was determined using the Osteoarthritis Research Society International (OARSI) scoring system. The mRNA and protein levels of indicators associated with extracellular matrix (ECM) metabolism, apoptosis and inflammation were detected. The effect of vitamin B6 (VB6) on the mice were assessed using HE staining and masson staining. The apoptosis rate of cells was assessed using TdT-mediated dUTP nick end labeling.

RESULTS

Our results showed a trend of improved OARSI score in mice treated with VB6, which remarkably inhibited the hyaline cartilage thickness, chondrocyte disordering, and knees hypertrophy. Moreover, the VB6 supplementation reduced the protein expression of pro-apoptosis indicators, including Bax and cleaved caspase-3 and raised the expression level of anti-apoptosis marker Bcl-2. Importantly, VB6 improved ECM metabolism in both in vivo and in vitro experiments.

CONCLUSIONS

This study demonstrated that VB6 alleviates OA through regulating ECM metabolism, inflammation and apoptosis in chondrocytes and CIA mice. The findings in this study provide a theoretical basis for targeted therapy of OA, and further lay the theoretical foundation for studies of mechanisms of VB6 in treating OA.

The influence of different sports on cartilage adaptations: A systematic review

Molecular composition and structural adaptation are changes in the cartilage tissue after different stimuli. Sports activities with different loads at different angles, speeds, and intensities can modify the molecular composition of the articular cartilage, hence it is crucial to understand the molecular adaptations and structural modifications generated by sports practice and this review aims to synthesize the current evidence on this topic. A systematic search until July 2022 was performed on the database Medline, Pubmed, Scopus, and Web of Science with a collection of 62,198. After the screening process, the included articles were analyzed narratively. Thirty-one studies have been included in the analysis. From the results emerged that running, swimming, ballet and handball were not correlated with detrimental structural or molecular cartilage adaptation; instead, soccer, volleyball, basketball, weightlifting, climbing, and rowing showed signs of cartilage alteration and molecular adaptation that could be early predictive degeneration's signs. From the included studies it came to light that the regions more interested in morphological cartilage changes were the knee in athletes from different disciplines. In conclusion, different sports induce different cartilage modifications both at a molecular and structural level and it is important to know the risks correlated to sports to implement preventive strategies.

Matrix from urine stem cells boosts tissue-specific stem cell mediated functional cartilage reconstruction

Articular cartilage has a limited capacity to self-heal once damaged. Tissue-specific stem cells are a solution for cartilage regeneration; however, ex vivo expansion resulting in cell senescence remains a challenge as a large quantity of high-quality tissue-specific stem cells are needed for cartilage regeneration. Our previous report demonstrated that decellularized extracellular matrix (dECM) deposited by human synovium-derived stem cells (SDSCs), adipose-derived stem cells (ADSCs), urine-derived stem cells (UDSCs), or dermal fibroblasts (DFs) provided an ex vivo solution to rejuvenate human SDSCs in proliferation and chondrogenic potential, particularly for dECM deposited by UDSCs. To make the cell-derived dECM (C-dECM) approach applicable clinically, in this study, we evaluated ex vivo rejuvenation of rabbit infrapatellar fat pad-derived stem cells (IPFSCs), an easily accessible alternative for SDSCs, by the abovementioned C-dECMs, in vivo application for functional cartilage repair in a rabbit osteochondral defect model, and potential cellular and molecular mechanisms underlying this rejuvenation. We found that C-dECM rejuvenation promoted rabbit IPFSCs' cartilage engineering and functional regeneration in both ex vivo and in vivo models, particularly for the dECM deposited by UDSCs, which was further confirmed by proteomics data. RNA-Seq analysis indicated that both mesenchymal-epithelial transition (MET) and inflammation-mediated macrophage activation and polarization are potentially involved in the C-dECM-mediated promotion of IPFSCs' chondrogenic capacity, which needs further investigation.

The different effects of intramuscularly-injected lactate on white and brown adipose tissue in vivo

BACKGROUND

Lactate is an important product of glycolysis metabolism during exercise and has long been recognized as an important metabolic signaling molecule involved in inhibiting lipolysis and promoting lipogenesis, which consequently leads to regulated adipose tissue metabolism. However, recent studies have shown that lactate promotes the browning of white adipose tissue (WAT), which induces heat production and energy expenditure and ultimately causes weight loss. These studies assessing the effects of lactate on lipid metabolism in adipose tissue have revealed conflicting data, making it an important area worthy of further research.

METHODS

In this study, using intramuscular injection of lactate to the gastrocnemius, we identified the role of lactate treatment on lipid metabolism and mitochondrial biogenesis of white adipose tissue and brown adipose tissue (BAT).

RESULTS

Our results showed that lactate treatment activated the cAMP/PKA signaling pathway and promoted the expression of lipolysis-related proteins (AMPK, HSL, ATGL) and mitochondrial biomarkers (PGC-1α, COXIV) of WAT, while BAT showed an opposite trend after lactate treatment. Further studies showed that lactate treatment significantly increased serum epinephrine and promoted β3-AR protein expression in WAT and significantly decreased in BAT.

CONCLUSION

Our study shows that lactate seems to regulate β3-adrenergic receptors differently in WAT and BAT, thereby eliciting disparate responses in adipose tissue.

Fisetin: An Integrated Approach to Identify a Strategy Promoting Osteogenesis

Flavonoids may modulate the bone formation process. Among flavonoids, fisetin is known to counteract tumor growth, osteoarthritis, and rheumatoid arthritis. In addition, fisetin prevents inflammation-induced bone loss. In order to evaluate its favorable use in osteogenesis, we assayed fisetin supplementation in both in vitro and in vivo models and gathered information on nanoparticle-mediated delivery of fisetin in vitro and in a microfluidic system. Real-time RT-PCR, Western blotting, and nanoparticle synthesis were performed to evaluate the effects of fisetin in vitro, in the zebrafish model, and in ex vivo samples. Our results demonstrated that fisetin at 2.5 µM concentration promotes bone formation in vitro and mineralization in the zebrafish model. In addition, we found that fisetin stimulates osteoblast maturation in cell cultures obtained from cleidocranial dysplasia patients. Remarkably, PLGA nanoparticles increased fisetin stability and, consequently, its stimulating effects on RUNX2 and its downstream gene SP7 expression. Therefore, our findings demonstrated the positive effects of fisetin on osteogenesis and suggest that patients affected by skeletal diseases, both of genetic and metabolic origins, may actually benefit from fisetin supplementation.

Methylsulfonylmethane enhances MSC chondrogenic commitment and promotes pre-osteoblasts formation

BACKGROUND

Methylsulfonylmethane (MSM) is a nutraceutical compound which has been indicated to counteract osteoarthritis, a cartilage degenerative disorder. In addition, MSM has also been shown to increase osteoblast differentiation. So far, few studies have investigated MSM role in the differentiation of mesenchymal stem cells (MSCs), and no study has been performed to evaluate its overall effects on both osteogenic and chondrogenic differentiation. These two mutually regulated processes share the same progenitor cells.

METHODS

Therefore, with the aim to evaluate the effects of MSM on chondrogenesis and osteogenesis, we analyzed the expression of SOX9, RUNX2, and SP7 transcription factors in vitro (mesenchymal stem cells and chondrocytes cell lines) and in vivo (zebrafish model). Real-time PCR as well Western blotting, immunofluorescence, and specific in vitro and in vivo staining have been performed. Student's paired t test was used to compare the variation between the groups.

RESULTS

Our data demonstrated that MSM modulates the expression of differentiation-related genes both in vitro and in vivo. The increased SOX9 expression suggests that MSM promotes chondrogenesis in treated samples. In addition, RUNX2 expression was not particularly affected by MSM while SP7 expression increased in all MSM samples/model analyzed. As SP7 is required for the final commitment of progenitors to preosteoblasts, our data suggest a role of MSM in promoting preosteoblast formation. In addition, we observed a reduced expression of the osteoclast-surface receptor RANK in larvae and in scales as well as a reduced pERK/ERK ratio in fin and scale of MSM treated zebrafish.

CONCLUSIONS

In conclusion, our study provides new insights into MSM mode of action and suggests that MSM is a useful tool to counteract skeletal degenerative diseases by targeting MSC commitment and differentiation.

Mechanism of Cyclic Tensile Stress in Osteogenic Differentiation of Human Periodontal Ligament Stem Cells

Human periodontal ligament stem cells (hPDLSCs) can undergo osteogenic differentiation under induction conditions. Cyclic tensile stress (CTS) can stimulate stem cell osteogenic differentiation. The present study explored the mechanism of CTS in hPDLSC osteogenic differentiation. The hPDLSCs of the 4th passage were selected. hPDLSCs were subjected to CTS with deformation of 10% elongation at 0.5 Hz for 1, 4, 8, 12 and 24 h. ALP activity and staining, ARS staining and detection of expressions of osteogenesis-related genes (RUNX2, OPN, Sp7 and OCN) were used to assess hPDLSC osteogenic differentiation ability. microRNA (miR)-129-5p and BMP2 expression and p-Smad1/5 level were detected under CTS stimulation. The binding relationship between miR-129-5p and BMP2 was predicted and verified. The osteogenic differentiation ability of CTS-treated hPDLSCs was evaluated after intervention of miR-129-5p and BMP2. CTS induced hPDLSC osteogenic differentiation, as manifested by increased ALP activities, osteogenesis-related gene expressions and mineralized nodules, together with positive ALP staining. CTS inhibited miR-129-5p expression, and promoted BMP2 expression and p-Smad1/5 level in hPDLSCs. miR-129-5p targeted BMP2. Overexpressed miR-129-5p or silenced BMP2 prevented hPDLSC osteogenic differentiation ability. We demonstrated that CTS inhibited miR-129-5p expression, and then activated the BMP2/Smad pathway, thereby showing stimulative effects on hPDLSC osteogenic differentiation.

Comparison between Acupuncture and Nutraceutical Treatment with Migratens® in Patients with Fibromyalgia Syndrome: A Prospective Randomized Clinical Trial

OBJECTIVES

Fibromyalgia syndrome (FMS) is a chronic clinical condition characterized by pain, fatigue, altered sleep, and cognitive disturbances. The purpose of this study was to compare two alternative treatments (nutraceutical and acupuncture) in FMS patients through a randomized clinical trial.

RESEARCH METHODS

A total of 60 FMS female patients were randomized for treatment with a nutritional combination containing coenzyme Q10, vitamin D, alpha-lipoic acid, magnesium, and tryptophan (Migratens® Group) or acupuncture treatment (Acupuncture Group) performed according the principles of traditional Chinese medicine (TCM), both for 3 months. Changes in pain and in quality of life (QoL) measured with a Fibromyalgia Impact Questionnaire Score-Revised (FIQ-R) and the Fibromyalgia Severity Scale (FSS) were performed at 1, 3, and 6 months after the start of treatments.

RESULTS

A total of 55 patient completed the study (21 in the Migratens® Group and 34 in the Acupuncture Group). Migratens® treatment shows a statistically significant reduction of pain 1 month after the start of therapy (T1, p = 0.025), strengthened after 3 months with maintenance of treatment (p = 0.012). The efficacy in reducing pain was apparent in the Acupuncture Group at all post-treatment determinations and at follow-up (T1 and T2 p = <0.001). Regarding QoL, improvement in FIQ-R and FSS values was revealed in both groups.

CONCLUSION

The nutraceutical approach with Migratens® seems to be an effective option to for patients with FMS. Our experience confirmed also the validity of acupuncture in these patients. Considering the complexity of the management of FMS patients, our results suggest a cyclical and sequential, or even concurrent treatment with different approaches, to improve the efficacy and the compliance of patients to long-term treatment.

Molecular and Lifestyle Factors Modulating Obesity Disease

Obesity adversely affects bone health by means of multiple mechanisms, e.g., alterations in bone-regulating hormones, inflammation, and oxidative stress. Substantial evidence supports the relationship between adiposity and bone disorders in overweight/obese individuals. It is well known that the balance between mutually exclusive differentiation of progenitor cells into osteoblasts or adipocytes is controlled by different agents, including growth factors, hormones, genetic and epigenetic factors. Furthermore, an association between vitamin D deficiency and obesity has been reported. On the other hand, regular physical activity plays a key role in weight control, in the reduction of obesity-associated risks and promotes osteogenesis. The aim of this review is to highlight relevant cellular and molecular aspects for over-weight containment. In this context, the modulation of progenitor cells during differentiation as well as the role of epigenetics and microbiota in obesity disease will be discussed. Furthermore, lifestyle changes including an optimized diet as well as targeted physical activity will be suggested as strategies for the treatment of obesity disease.

Cytokine Directed Chondroblast Trans-Differentiation: JAK Inhibition Facilitates Direct Reprogramming of Fibroblasts to Chondroblasts

Osteoarthritis (OA) is a degenerative disease of the hyaline articular cartilage. This disease is progressive and may lead to disability. Researchers proposed many regenerative approaches to treat osteoarthritis, including stem cells. Trans-differentiation of a fully differentiated cell state directly into another different differentiated cell state avoids the disadvantages of fully reprogramming cells to induced pluripotent stem cells (iPSCs) in terms of faster reprogramming of the needed cells. Trans-differentiation also reduces the risk of tumor formation by avoiding the iPSC state. OSKM factors (Oct4, Sox2, Klf4, and cMyc) accompanied by the JAK-STAT pathway inhibition, followed by the introduction of specific differentiation factors, directly reprogrammed mouse embryonic fibroblasts to chondroblasts. Our results showed the absence of intermediate induced pluripotent stem cell formation. The resulting aggregates showed clear hyaline and hypertrophic cartilage. Tumor formation was absent in sub-cutaneous capsules transplanted in SCID mice.