Higher frequency electrical stimulation enhanced myloglossus satellite cell differentiation by upregulating expression of Pax7 mRNA, MyoD, myogenin and MyHC protein.

OBJECTIVE: We investigated the effect of electrical stimulation (ES) of varying pulse frequency on differentiation and proliferation of canine myloglossus satellite cells in vitro. MATERIALS AND METHODS: Cellular viability and proliferation were assayed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay and flow cytometry fluorescence-activated cell sorting analysis. Cellular differentiation and expression of mark molecule were assayed by Real Time-PCR and Western blot. RESULTS: With increasing frequency ES, we found a significant increase in Myod (r=0.988, p<0.0001), myogenin (r=0.988, p<0.0001), MyHC-slow (r=0.988, p<0.0001), MyHC-fast (r=0.875, p<0.0001) protein expression, and Pax7 mRNA expression (r=0.712, p=0.001). CONCLUSIONS: Pax7 mRNA expression and MyoD, myogenin, and MyHC protein expression were increased with increment of electrical stimulation frequency in myloglossus muscle satellite. Higher frequency ES enhanced myloglossus satellite cell differentiation, not proliferation and viability.

LncRNA SNHG6 can regulate the proliferation and apoptosis of rat degenerate nucleus pulposus cells via regulating the expression of miR-101-3p.

OBJECTIVE: Intervertebral disc (IVD) degeneration (IDD) is a well-known consequence of low back pain, as characterized by aberrant cell proliferation and apoptosis of nucleus pulposus (NP) cells. In the present study, we aimed to investigate the effect of lncRNA small nucleolar RNA host gene 6 (SNHG6) on deregulated functions of degenerative NP cells. MATERIALS AND METHODS: After the establishment of rat IDD models, the mRNA and protein levels of collagen-I (Col-I) and collagen II (Col-II), and mRNA level of SNHG6 were detected by using reverse transcription quantitative Real Time-PCR (RT-qPCR) and Western blot. We further investigated the role and molecular mechanisms of SNHG6 by overexpressing or silencing it in degenerative NP cells. Cell proliferation was measured by MTT assay and EdU staning, and apoptosis was measured by flow cytometry. The target of SNHG6 was identified by starBase and Dual-Luciferase reporter assay. RESULTS: Upregulation of SNHG6 was found in IDD NP cells than in normal cells, associated with higher level of Col-I and lower level of Col-II. Overexpression of SNHG6 inhibited cell proliferation and enhanced apoptosis, accompanied by increased expression of Bax, caspase-3, and p21, as well as decreased expression of Bcl-2, which was in reverse to the treatment of SNHG6 silencing. Moreover, miR-101-3p was indicated as a target of SNHG6, and inhibition of miR-101-3p reversed the effects on proliferation and apoptosis induced by SNHG6. CONCLUSIONS: SNHG6 suppressed cell proliferation and induced apoptosis by increasing expression of Bax, caspase-3, p21 and decreasing Bcl-2 through targeting miR-101-3p, which suggested that SNHG6 could be a potential target in the treatment of IDD.

[Long term result of arytenoidectomy with CO2 laser for dyspnoea in iatrogenic bilateral vocal fold paralysis patients].

Objective:To investigate the optimal time of tracheotomy/arytenoidectomy and the improvement of dyspnoea, dysphonia and dysphagia after arytenoidectomy with CO2 laser in iatrogenic bilateral vocal folds paralysis patients. Method:Thirty patients [29 females, 56 (49-60) years, one male, 49 years] with bilateral vocal cords paralysis resulted from neck surgery were retrospectively analyzed by case archived information and following-up questionnaire. The data included patients' dysponea time, degree and duration from tracheotomy/arytenoidectomy to neck surgery. Twenty sixty patients required unilateral partial/total arytenoidectomy. The results of treatment were evaluated by questionnaire including dyspnoea, dysphonia and dysphagia. Result:All patients whose bilateral vocal paralysis were resulted from thyroid gland surgery. Dysponea occurred immediately after thyroidectomy surgery in 14 cases (46.7%), and 2 years later after thyroidectomy in 13 cases (43.3%), 8 years later in 3 cases (10.0%). There was one (3.3%) patient without tracheotomy. The duration of tracheotomy/arytenoidectomy to neck surgery was significantly correlated with duration of tracheotomy/arytenoidectomy to dyspnoea appearance (r=0.879, P<0.05), not correlated with duration of thyroid surgery to dyspnoea appearance. There is significantly negative correlation between degree of dyspnoea and duration of tracheotomy/arytenoidectomy to neck surgery (r=0.452, P<0.05). Twenty six patients appeared dyspnoea and underwent CO2 laser arytenoidectomy after thyoidectomy 0.5-23 years. Five patients did unilateral total arytenoidectomy and 21 patients did unilateral partial arytenoidectomy. After 12-96 months following up, dyspnoea improved in 24 patients, no improved in 2 patients. Dysphonia improved and remained in 17 patients, being worse mildly in 8 patients and obviously in one patient. Dysphagia improved and remained in 24 patients, being worse in 2 patients. There was no difference between total and partial arytenoidectomy in dyspnoea, dysphonia and dysphagia. Conclusion:The morbidity of dyspnoea was correlated with time after neck surgery. It was rarely necessary to take tracheotomy immediately in bilateral vocal fords paralysis patients after neck surgery. The severer degree of dyspnoea led to shorter duration between neck surgery and tracheotomy/arytenoidectomy. There was obvious improvement after arytenoidectomy in dyspnoea, no significant change in dysphonia and dysphagia. The effect of total arytenoidectomy on bilateral vocal paralysis was similar to partial arytenoidectomy.

Effect of loading conditions on the dissociation behaviour of catch bond clusters.

Under increasing tensile load, the lifetime of a single catch bond counterintuitively increases up to a maximum and then decreases exponentially like a slip bond. So far, the characteristics of single catch bond dissociation have been extensively studied. However, it remains unclear how a cluster of catch bonds behaves under tensile load. We perform computational analysis on the following models to examine the characteristics of clustered catch bonds: (i) clusters of catch bonds with equal load sharing, (ii) clusters of catch bonds with linear load sharing, and (iii) clusters of catch bonds in micropipette-manipulated cell detachment. We focus on the differences between the slip and catch bond clusters, identifying the critical factors for exhibiting the characteristics of catch bond mechanism for the multiple-bond system. Our computation reveals that for a multiple-bond cluster, the catch bond behaviour could only manifest itself under relatively uniform loading conditions and at certain stages of decohesion, explaining the difficulties in observing the catch bond mechanism under real biological conditions.

Sliding-induced non-uniform pre-tension governs robust and reversible adhesion: a revisit of adhesion mechanisms of geckos.

Several mechanisms have been proposed in the literature to explain the robust attachment and rapid, controllable detachment of geckos' feet on vertical walls or ceilings, yet, it is still debatable, which one is ultimately responsible for geckos' extraordinary capabilities for robust and reversible adhesion. In this paper, we re-examine some of the key movements of geckos' spatula pads and seta hairs during attachment and detachment, and propose a sequence of simple mechanical steps that would lead to the extraordinary properties of geckos observed in experiments. The central subject under study here is a linear distribution of pre-tension along the spatula pad induced by its sliding motion with respect to a surface. The resulting pre-tension, together with a control of setae's pulling force and angle, not only allows for robust and strong attachment, but also enables rapid and controllable detachment. We perform computational modelling and simulations to validate the following key steps of geckos' adhesion: (i) creation of a linear distribution of pre-tension in spatula through sliding, (ii) operation of an instability envelope controlled by setae's pulling force and angle, (iii) triggering of an adhesion instability leading to partial decohesion along the interface, and (iv) complete detachment of spatula through post-instability peeling. The present work not only reveals novel insights into the adhesion mechanism of geckos, but also develops a powerful numerical simulation approach as well as additional guidelines for bioinspired materials and devices.