Spatiotemporal changes of NGF, BDNF and NT-3 in the developing spinal cords of embryonic chicken

Neural Stem Cell Transplantation Promotes Functional Recovery from Traumatic Brain Injury via Brain Derived Neurotrophic Factor-Mediated Neuroplasticity

Traumatic brain injury (TBI) induces cognitive impairments, motor and behavioral deficits. Previous evidences have suggested that neural stem cell (NSC) transplantation could facilitate functional recovery from brain insults, but their underlying mechanisms remains to be elucidated. Here, we established TBI model by an electromagnetic-controlled cortical impact device in the rats. Then, 5 μl NSCs (5.0 × 10⁵/μl), derived from green fluorescent protein (GFP) transgenic mouse, was transplanted into the traumatic brain regions of rats at 24 h after injury. After differentiation of the NSCs was determined using immunohistochemistry, neurological severity scores (NSS) and rotarod test were conducted to detect the neurological behavior. Western blot and RT-PCR as well as ELASA were used to evaluate the expression of synaptophysin and brain-derived neurotrophic factor (BDNF). In order to elucidate the role of BDNF on the neural recovery after NSC transplantation, BDNF knockdown in NSC was performed and transplanted into the rats with TBI, and potential mechanism for BDNF knockdown in the NSC was analyzed using microassay analysis. Meanwhile, BDNF antibody blockade was conducted to further confirm the effect of BDNF on neural activity. As a result, an increasing neurological function improvement was seen in NSC transplanted rats, which was associated with the upregulation of synaptophysin and BDNF expression. Moreover, transplantation of BDNF knockdown NSCs and BDNF antibody block reduced not only the level of synaptophysin but also exacerbated neurological function deficits. Microassay analysis showed that 14 genes such as Wnt and Gsk3-β were downregulated after BDNF knockdown. The present data therefore showed that BDNF-mediated neuroplasticity underlie the mechanism of NSC transplantation for the treatment of TBI in adult rats.

Stable transfection into rat bone marrow mesenchymal stem cells by lentivirus-mediated NT-3

Transplantation of bone marrow mesenchymal stem cells (BMSCs) is the most promising therapeutic strategy in the treatment of spinal cord injuries. BMSCs have a wide variety of sources and are characterized by being exempt from immune rejection, marked secretory functions and neuronal plasticity during differentiation. The lentiviral vector, namely PLV.Ex3d.P/neo-EF1A-NT3-internal ribosome entry site-enhanced green fluorescent protein, was constructed and subsequently transfected into Sprague Dawley (SD) rat BMSCs. The gene and protein expression levels of the nucleic acid neurotrophin-3 (NT-3) were then detected. The results demonstrated that the constructed NT-3 gene lentiviral expression vector matched the expected design and that the NT-3 gene was transfected into the BMSCs via the lentivirus‑mediated method at a transfection efficiency of 60‑70%. NT-3 gene expression was detected within the stably transfected positive cells at the nucleic acid and protein levels. The cell morphology and biological activity of BMSCs did not alter significantly following transfection with NT-3. NT-3-transfected SD BMSCs were successfully constructed and served as effective vector seed cells with stable expression. These results can be used as a reference for subsequent studies on the transplantation therapy of rat spinal cord injuries using lentivirus-mediated NT-3-transfected SD BMSCs.

Temporal profile of nerve growth factor expression in the partial central nervous system of the Yangtze alligator Alligator sinensis (Reptilia,Crocodylia) during early postnatal growth

Expression of nerve growth factor (NGF) in structures of the partial central nervous system of the Yangtze alligator, Alligator sinensis (Reptilia, Crocodylia) was examined during early postnatal growth using immunohistochemistry and Western blot assays. In animals 0-2 years of age NGF-positive cells in the cerebral cortex increased gradually in number and size, and were predominantly distributed in the molecular layer. NGF-positive cells in the midbrain showed similar increases but with predominant distribution in the ependymal layer. NGF-positive cells increased in the cerebellum between 0 and 1 years of age, with increased NGF expression being seen during the first 2 years of life mostly in the ependymal layer. NGF-positive cells were mainly found in the gray matter of the spinal cord with decreasing cell numbers, NGF expression levels being seen from 0 to 2 years and small processes without synaptic connection from 1 to 2 years. These results suggest that NGF is involved in the early postnatal growth of several structures of Yangtze alligator partial central nervous system, suggesting a possible role of NGF in the Yangtze alligator partial central nervous system.

Effects of exogenous agents on brain development: stress, abuse and therapeutic compounds

The range of exogenous agents likely to affect, generally detrimentally, the normal development of the brain and central nervous system defies estimation although the amount of accumulated evidence is enormous. The present review is limited to certain types of chemotherapeutic and "use-and-abuse" compounds and environmental agents, exemplified by anesthetic, antiepileptic, sleep-inducing and anxiolytic compounds, nicotine and alcohol, and stress as well as agents of infection; each of these agents have been investigated quite extensively and have been shown to contribute to the etiopathogenesis of serious neuropsychiatric disorders. To greater or lesser extent, all of the exogenous agents discussed in the present treatise have been investigated for their influence upon neurodevelopmental processes during the period of the brain growth spurt and during other phases uptill adulthood, thereby maintaining the notion of critical phases for the outcome of treatment whether prenatal, postnatal, or adolescent. Several of these agents have contributed to the developmental disruptions underlying structural and functional brain abnormalities that are observed in the symptom and biomarker profiles of the schizophrenia spectrum disorders and the fetal alcohol spectrum disorders. In each case, the effects of the exogenous agents upon the status of the affected brain, within defined parameters and conditions, is generally permanent and irreversible.