ABSTRACT
Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.
Subject(s)
Exosomes/physiology , Muscle, Skeletal/metabolism , Cell Communication , HomeostasisABSTRACT
Objective The expression and neuroprotective effect of meteorin in neurons and astrocytes after cerebral infarc-tion have yet to be clarified.This study was to investigate the expression and location of meteorin in the rat model of middle cerebral ar -tery occlusion (MCAO) and its neuroprotective effect against oxygen -glucose deprivation (OGD)-induced injury in cultured neurons or astrocytes. Methods Forty-two healthy adult male SD rats were randomly divided into 6 groups of equal number:sham operation and 6 h, 12 h, 24 h, 3 d, and 7 d MCAO.The cortical tissue was harvested for determination of the expression and location of meteorin by Western blot and immunohistochemistry as well as the meteorin expression in the neurons and astrocytes subjected to OGD. The neuroprotective effect of meteorin on the neurons and astrocytes was e-valuated by CCK8 and PI/Hoechst33342 staining. Results Com-pared with the sham operation group, the expression of meteorin was decreased after MCAO and reached the lowest level at 3 days ( P (0.78), and OGD+PBS (0.60) as compared with the sham control ( 1.51) (P0.05).Concerning the effect of meteorin intervention on the OGD-induced injury of the astrocytes, the A value was significantly reduced in OGD (1.24 ±0.17), OGD+meteorin (1.51 ±0.30), and OGD+PBS (1.23 ±0.16) in comparison with the sham control (2.43 ±0.12) (P<0.01), lower in the OGD and OGD+PBS groups than in the OGD+meteorin group ( P<0.05) . Conclusion Meteorin is mainly expressed in the neurons and astrocytes after MCAO and it promotes the survival of the astrocytes with OGD-induced injury.
ABSTRACT
Objective To study the effect of intranasal nerve growth factor (NGF) on the expression of amyloid-β,peptide (Aβ) in the central nervous system in rats with traumatic brain injury (TBI).Methods Eighty rats were randomly divided into sham(n =26),control(n =27) and treatment group (n =27 ).They were subjected to the modified Feeney' s weight-drop model.The treatment group was treated with NGF administered by nasal route,and the control group was given phosphate-buffered saline (PBS).Beam walking and Morris water maze test were performed in the three groups.The concentration of Aβ40 and Aβ42 in the injured ipsilateral hippocampus was elevated by ELISA measurement.Immunohistochemistry was used to detect the amyloid precursor protein (APP) positive cells near the region of injury in the hippocampus in rats after TBI.Results NGF group traversed the beam significantly quicker (s) than control group ( 19.00 + 6.99 vs 27.33 ± 7.39 respectively,F2,15 =12.87,P =0.028 ).Morris water maze performance revealed that mean time of latency in the NGF group was significant shorter than vehicle group,and significant memory retention in NGF group as evidenced by a greater percentage of the 60 s allotted time spent in the target quadrant (45.82％ ± 11.15％ vs 33.99％ ± 3.46％,F2,15 =6.814,P=0.037),as well as the number crossing of the former site of the removed platform in NGF group was significant more than control group (8.60 ±2.73 vs 3.60 ±2.06,F2,15 =5.346,P =0.04).The Aβ42 level in control group was increased significantly higher than NGF group as indicated by ELISA measurements.While the Aβ40 level did not have similar shown.Immunohistochemical staining showed that APP level had significant differences among three groups ( F2,15 =8.672,P =0.003).The APP level in NGF group did not alter with control group.Conclusion Intranasal administration of NGF can regulate Aβ42 overproduction,improve the motor and cognitive function after brain injury in rats.
ABSTRACT
Vascular endothelial growth factor (VEGF) is a powerful angiogeuetic factor. In recent years, it has been found that it has a powerful capacity to promote nerve regeneration, and has potential value in the treatment of ischemic cerebrovascular disease. Newborn endothelial celts can form "vascular niche", and promote neurogenesis by releasing an array of neurotrophic factors. Also, newborn neuronal cells can enhance angiogenesis. There is a "cross-talk" between angiogenesis and neurogenesis, and VEGF plays a very important intermediary role in it. This article reviews the studies of VEGF in promoting angiogenesis and neurogenesis after cerebral ischemia.