Magnesium Ascorbyl Phosphate Promotes Bone Formation Via CaMKII Signaling.

Dysregulation of bone homeostasis is closely related to the pathogenesis of osteoporosis. Suppressing bone resorption by osteoclasts to attenuate bone loss has been widely investigated, but far less effort has been poured toward promoting bone formation by osteoblasts. Here, we aimed to explore magnesium ascorbyl phosphate (MAP), a hydrophilic and stable ascorbic acid derivative, as a potential treatment option for bone loss disorder by boosting osteoblastogenesis and bone formation. We found that MAP could promote the proliferation and osteoblastic differentiation of human skeletal stem and progenitor cells (SSPCs) in vitro. Moreover, MAP supplementation by gavage could alleviate bone loss and accelerate bone defect healing through promoting bone formation. Mechanistically, we identified calcium/calmodulin-dependent serine/threonine kinase IIα (CaMKIIα) as the target of MAP, which was found to be directly bound and activated by MAP, then with a concomitant activation in the phosphorylation of ERK1/2 (extracellular regulated kinase 1/2) and CREB (cAMP-response element binding protein) as well as an elevation of C-FOS expression. Further, blocking CaMKII signaling notably abolished these effects of MAP on SSPCs and bone remodeling. Taken together, our data indicated that MAP played an important role in enhancing bone formation through the activation of CaMKII/ERK1/2/CREB/C-FOS signaling pathway and may be used as a novel therapeutic option for bone loss disorders such as osteoporosis. © 2023 American Society for Bone and Mineral Research (ASBMR).

Magnesium supplementation enhances mTOR signalling to facilitate myogenic differentiation and improve aged muscle performance.

Magnesium (Mg2+), as an essential mineral, supports and sustains the health and activity of the organs of the human body. Despite some clinical evidence on the association of Mg2+ deficiency with muscle regeneration dysfunction and sarcopenia in older-aged individuals, there is no consensus on the action mode and molecular mechanism by which Mg2+ influences aged muscle size and function. Here, we identified the appropriate Mg2+ environment that promotes the myogenic differentiation and myotube hypertrophy in both C2C12 myoblast and primary aged muscle stem cell (MuSC). Through animal experiments, we demonstrated that Mg2+ supplementation in aged mice significantly promotes muscle regeneration and conserves muscle mass and strength. Mechanistically, Mg2+ stimulation activated the mammalian target of rapamycin (mTOR) signalling, inducing the myogenic differentiation and protein synthesis, which consequently offers protections against the age-related decline in muscle regenerative potential and muscle mass. These findings collectively provide a promising therapeutic strategy for MuSC dysfunction and sarcopenia through Mg2+ supplementation in the elderly.

Multifunctional Nanoengineered Hydrogels Consisting of Black Phosphorus Nanosheets Upregulate Bone Formation.

Tissue-engineered hydrogels have received extensive attention as their mechanical properties, chemical compositions, and biological signals can be dynamically modified for mimicking extracellular matrices (ECM). Herein, the synthesis of novel double network (DN) hydrogels with tunable mechanical properties using combinatorial screening methods is reported. Furthermore, nanoengineered (NE) hydrogels are constructed by addition of ultrathin 2D black phosphorus (BP) nanosheets to the DN hydrogels with multiple functions for mimicking the ECM microenvironment to induce tissue regeneration. Notably, it is found that the BP nanosheets exhibit intrinsic properties for induced CaP crystal particle formation and therefore improve the mineralization ability of NE hydrogels. Finally, in vitro and in vivo data demonstrate that the BP nanosheets, mineralized CaP crystal nanoparticles, and excellent mechanical properties provide a favorable ECM microenvironment to mediate greater osteogenic cell differentiation and bone regeneration. Consequently, the combination of bioactive chemical materials and excellent mechanical stimuli of NE hydrogels inspire novel engineering strategies for bone-tissue regeneration.

Metabolomics and Its Application in the Development of Discovering Biomarkers for Osteoporosis Research.

Osteoporosis is a progressive skeletal disorder characterized by low bone mass and increased risk of fracture in later life. The incidence and costs associated with treating osteoporosis cause heavy socio-economic burden. Currently, the diagnosis of osteoporosis mainly depends on bone mineral density and bone turnover markers. However, these indexes are not sensitive and accurate enough to reflect the osteoporosis progression. Metabolomics offers the potential for a holistic approach for clinical diagnoses and treatment, as well as understanding of the pathological mechanism of osteoporosis. In this review, we firstly describe the study subjects of osteoporosis and bio-sample preparation procedures for different analytic purposes, followed by illustrating the biomarkers with potentially predictive, diagnosis and pharmaceutical values when applied in osteoporosis research. Then, we summarize the published metabolic pathways related to osteoporosis. Furthermore, we discuss the importance of chronological data and combination of multi-omics in fully understanding osteoporosis. The application of metabolomics in osteoporosis could provide researchers the opportunity to gain new insight into the metabolic profiling and pathophysiological mechanisms. However, there is still much to be done to validate the potential biomarkers responsible for the progression of osteoporosis and there are still many details needed to be further elucidated.

An updated meta-analysis of randomized controlled trials assessing the effect of sorafenib in advanced hepatocellular carcinoma.

BACKGROUND: The efficacy of sorafenib in the treatment of advanced hepatocellular carcinoma (HCC) remains controversial. Therefore, we conducted a meta-analysis to evaluate the efficacy and safety of sorafenib for treating patients with advanced HCC. METHODS: The PubMed, Embase, and Web of Science databases were searched. Eligible studies were randomized controlled trials (RCTs) that assessed sorafenib therapy in patients with advanced HCC. The outcomes included overall survival (OS), time to progression (TTP), overall response rate (ORR), and toxicities. Hazard ratio (HR) and risk ratio (RR) were used for the meta-analysis and were expressed with 95% confidence intervals (CIs). RESULTS: Seven RCTs, with a total of 3807 patients, were included in this meta-analysis. All patients received sorafenib alone, or with other chemotherapeutic regimens. Pooled estimates showed that sorafenib improved the OS (HR = 0.74, 95% CI: 0.61, 0.90; P = 0.002), or TTP outcomes (HR = 0.69, 95% CI: 0.55, 0.86; P = 0.001). Subgroup analysis revealed that sorafenib was more effective in the patients with an Eastern Cooperative Oncology Group performance status (ECOG PS) of 1-2 (HR = 0.77, 95% CI: 0.60, 1.0; P = 0.05), or macroscopic vascular invasion (MVI), and/or extrahepatic spread (EHS) (H  = 0.65, 95% CI: 0.46, 0.93; P = 0.02), in terms of OS. Patients who received sorafenib did not have a higher ORR (RR = 0.85, 95% CI: 0.65, 1.11; P = 0.10). In addition, there was a slight increase in toxicity in the sorafenib group. CONCLUSION: Treatment with sorafenib significantly improved OS and TTP in patients with advanced HCC. Additional large-scale, well-designed RCTs are needed to evaluate the efficacy of sorafenib-based therapy in the treatment of advanced HCC.

Effect of epimedium-derived phytoestrogen on bone turnover and bone microarchitecture in OVX-induced osteoporotic rats.

To investigate the preventive effect of epimedium-derived phytoestrogen (PE) on osteoporosis induced by ovariectomy (OVX) in rats, 11-month-old female Wistar rats were randomly divided into Sham, OVX and PE groups. One week after OVX, daily oral administration of PE (0.4 g.kg(-1).day(-1)) started in PE group, and rats in Sham and OVX groups were given vehicle accordingly. The administrations lasted for 12 weeks. The biological markers including serum osteocalcin (OC) and urinary deoxypyridinoline (DPD) for bone turnover were evaluated at the end of the 12th week. On the 13th week, all the rats were sacrificed. The right proximal tibiae were removed, subjected to micro CT for determination of trabecular bone structure and then bone histomorphometry was performed to assess bone remodeling. The OVX rats were in a high bone turnover status as evidenced by increased bone formation markers and bone resorption markers. Treatment with PE could suppress the high bone turnover rate in OVX rats. Micro CT data revealed that PE treatment could ameliorate the deterioration of the micro-architecture of proximal tibiae induced by OVX, as demonstrated by greater bone volume, increased trabecular thickness and less trabecular separation in PE group in comparison with OVX group. The static and dynamic parameters of bone histomorphometry indicated that there were significant increases in bone formation variables and significant decreases in bone resorption variables between PE and OVX groups. The findings suggest that PE has a beneficial effect on trabecular bone in OVX rat model and this effect is possibly associated with stimulation of bone formation as well as inhibition of bone resorption.

[Effects of Shenfu injection on prostacyclin, thromboxane A2 and activities of ATPases in rats exposed to hepatic ischemia-reperfusion injury].

OBJECTIVE: To explore the effects of Shenfu Injection on prostacyclin, thromboxane A2 and the activities of ATPases in rats exposed to hepatic ischemia-reperfusion injury. METHODS: Twenty-four male Wistar rats weighing 200-250 g were randomly divided into two groups: Shenfu Injection (SF)-treated group (rats were treated with Shenfu Injection of 10 ml/kg through intraperitoneal injection) and untreated group (rats were administered with normal saline at the same dose and served as a control group). Hepatic ischemia was caused by Pringle's maneuver and lasted for fifteen minutes, and then one-hour or three-hour reperfusion was performed. Venous blood samples for the measurement of thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F(1 alpha)(6-keto-PGF(1 alpha)) were collected three hours after reperfusion. Liver tissue samples were collected one hour or three hours after reperfusion for the measurement of Na(+)-K(+)-ATPase and Ca(+)-Mg(+)-ATPase and for morphological studies. RESULTS: Plasma TXB(2) was lower in the SF-treated group than that in the untreated group after three-hour reperfusion (P>0.05), while 6-keto-PGF(1 alpha) was higher in the SF-treated group than that in the untreated group (P>0.05). The ratio of TXB(2) and 6-keto-PGF(1 alpha) was significantly lower in the SF-treated group than that in the untreated group (P<0.05). The activities of Na(+)-K(+)-ATPase and Ca(+)-Mg(+)-ATPase in the SF-treated group were improved obviously. A three-hour reperfusion after fifteen-minute ischemia caused important hepatic histological alterations. Marked structural abnormalities were observed in the untreated group, such as massive hepatocyte swelling, necrosis, mitochondria edema and vacuolar changes. In the SF-treated group, hepatic tissue injury was reduced significantly. CONCLUSION: Shenfu Injection protects hepatic tissue from ischemia-reperfusion injury, and such protective effects are achieved by decreasing the ratio of thromboxane A(2) and prostacyclin, and increasing the activities of Na(+)-K(+)-ATPase and Ca(+)-Mg(+)- ATPase.