Multi-omics research in sarcopenia: Current progress and future prospects.

Sarcopenia is a systemic disease with progressive and generalized skeletal muscle dysfunction defined by age-related low muscle mass, high content of muscle slow fibers, and low muscle function. Muscle phenotypes and sarcopenia risk are heritable; however, the genetic architecture and molecular mechanisms underlying sarcopenia remain largely unclear. In recent years, significant progress has been made in determining susceptibility loci using genome-wide association studies. In addition, recent advances in omics techniques, including genomics, epigenomics, transcriptomics, proteomics, and metabolomics, offer new opportunities to identify novel targets to help us understand the pathophysiology of sarcopenia. However, each individual technology cannot capture the entire view of the biological complexity of this disorder, while integrative multi-omics analyses may be able to reveal new insights. Here, we review the latest findings of multi-omics studies for sarcopenia and provide an in-depth summary of our current understanding of sarcopenia pathogenesis. Leveraging multi-omics data could give us a holistic understanding of sarcopenia etiology that may lead to new clinical applications. This review offers guidance and recommendations for fundamental research, innovative perspectives, and preventative and therapeutic interventions for sarcopenia.

Young people's esthetic perception of dental midline deviation.

OBJECTIVE: To test the hypothesis that young people's esthetic perception of dentition midline deviation or the threshold below which they find the deviation "acceptable" depends on the gender and face type of the person with the deviation and the gender of the evaluator. MATERIALS AND METHODS: Facial images of six young subjects with three different face types were captured, and their dentition midlines were altered digitally. The images were evaluated by young people with no dental training. Statistical analysis was carried out to determine the threshold for acceptable dentition midline deviation and factors influencing perception. RESULTS: The mean value for the threshold below which a deviation was judged "acceptable" was 2.403 mm (95% confidence interval, 2.315-2.491). The preferences of evaluators did not significantly depend on the direction of the deviation. Both male and female evaluators were significantly less tolerant of deviation in female subjects than in male subjects. However, female evaluators were significantly more tolerant of midline deviations in male subjects than were male evaluators. In addition, the same degree of deviation was most noticeable in male subjects with a tapered face type and least noticeable in female subjects with a square face type. CONCLUSIONS: The gender and face type of an individual with dentition midline deviation and the gender of the evaluator do affect young people's esthetic perception of a dentition midline deviation and the threshold below which they find the deviation "acceptable."

The treatment of spinal cord injury in rats using bone marrow-derived neural-like cells induced by cerebrospinal fluid.

This study aimed to evaluate the effect of bone mesenchymal stem cells (BMSCs) and BMSC neural-like cells (BMSC-Ns) on the spinal cord injury (SCI) in the rat model of SCI. BMSC-Ns were prepared from the third passage of BMSCs by induction of healthy cerebrospinal fluid (CSF) of an adult human. The SCI rat model was established through a surgical procedure, and after 7 days the rats were randomly divided into 3 (A, B and C) groups. Groups A (BMSC-Ns) and B (BMSCs) were treated with 1 × 106/20 µl cells, while group C (saline) was treated with saline, all via intracerebroventricular injection. After transplantation, the BBB score of group A was significantly higher than that of group B, which in turn was significantly higher than that of group C (P < .05). The levels of Bdnf, Ngf, Ntf3 were statistically significantly higher in group A than those in groups B and C (P < .05). The levels of 5-HT, NA, Ach, DA, GABA in group A were significantly higher than those in groups B and C, whereas the level of Glu was significantly lower in group A than that in groups B and C (P < .05). The histopathological data showed remarkably less necrosis of the spinal cord in group A, compared to that in groups B and C. Transplanting BMSC-Ns or BMSCs into the lateral ventricles improved the neurological function of rats with SCI. Moreover, BMSC-Ns were significantly more effective than BMSCs, which provides a possible approach for the treatment of SCI.

In Vitro Differentiation of Bone Marrow Mesenchymal Stem Cells into Neuron-Like Cells by Cerebrospinal Fluid Improves Motor Function of Middle Cerebral Artery Occlusion Rats.

Bone marrow mesenchymal stem cells (BMSCs) represent a promising tool for stem cell-based therapies. However, the majority of BMSC transplants only allow for limited recovery of the lost functions. We previously found that human cerebrospinal fluid (hCSF) is more potent than growth factors in differentiating human BMSCs into neuron-like cells in vitro. In this study, we studied the effect of transplantation of rat BMSC-derived neuron-like cells (BMSC-Ns) induced by hCSF into rat brain with middle cerebral artery occlusion (MCAO). The survival and differentiation of the transplanted cells were determined using immunofluorescence staining of bromodeoxyuridine. The recovery of neurological function were observed by the modified neurological severity score (modified NSS) at 4, 15, and 32 days after cell transplantation, HE staining for determination of the infarct volume at day 32 after cell transplantation. Transplantation of BMSC-Ns or BMSCs significantly improved indexes of neurological function and reduced infarct size in rats previously subjected to MCAO compared with those in the control group. Remarkably, 32 days after transplantation, rats treated with BMSC-Ns presented a smaller infarct size, higher number of neuron-specific, enolase-positive, and BrdU-positive cells, and improved neurological function compared with BMSC group. Our results demonstrate that transplantation of hCSF-treated BMSC-Ns significantly improves neurological function and reduces infarct size in rats subjected to MCAO. This study may pave a new avenue for the treatment of MCAO.

Spatial signalling mediated by the transforming growth factor-ß signalling pathway during tooth formation.

Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day (E) 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factor-ß signalling pathway might play a role in this process.