BACKGROUND:Retinoic acid signaling pathways is very important in the formation pf nervous system, specialization of neurons and outgrowth of axons. The recent studies show that, retinoic acid plays an important role in the process of axonal regeneration, but few research reports its exact molecular mechanism.
OBJECTIVE:To analyze and summarize the mechanism underlying retinoic acid signaling pathways in the process of axonal regeneration.
METHODS:A computer-based online research was conducted among the VIP, CNKI, PubMed, BioMed Centeral, Springer, The Free Medical Journals, EBSCO and Foreign Journals Integration System between January 2000 and December 2013, with the key words of“retinoic acid, the central nervous system, nerve damage, axon regeneration, and mechanism”in Chinese and English. A total of 43 studies addressing the molecular mechanism of retinoic acid in axonal regeneration were screened. According to the supplementary documents, another five references were added. Repetitive research and atypical reports were excluded.
RESULTS AND CONCLUSION:Fol owing acute central nervous system injury, axonal regeneration and functional recovery are extremely limited. For proper functionality fol owing injury, axons must regrow, reinnervate their targets, and remyelinate their axons. When the central nervous system injuries occur, retinoic acid signaling pathways express transcription factor retinoic acid receptorβ2 to induce axonal regeneration fol owing injury;in dorsal root ganglion neurons, cAMP levels are greatly increased by lentiviral retinoic acid receptorβ2 expression and contribute to neurite outgrowth. More recently, retinoic acid-retinoic acid receptorβ2 pathways directly transcriptional y repress a member of the inhibitory Nogo receptor complex, Lingo-1, under an axonal growth inhibitory environment in vitro as wel as fol owing spinal cord injury in vivo. Through these molecular mechanisms, retinoic acid signaling pathways play its important role in the process of axonal regeneration.

Objective: To determine the effect of polygona-polysaccharose (PP) on learning and memory ability in rats with Alzheimer’s disease (AD). Methods: Forty ifve Sprague-Dawley rats were assigned into 3 groups. Rats in the sham-operated group were injected with normal saline. Rats in the Aβ group were injected with Aβ1-42. Rats in the PP group were injected with 16% PP solution for 45 days consecutively. hTe Morris water maze was used to investigate the ability of learning and memory in the rats. hTe effect of Aβ and PP on the hippocampus cells was observed by HE and Congo red staining of methanol. Results: Rats in the sham-operated group had no obvious morphological change; and morphology of rats in the PP group was basicaly normal. The layer of pyramidal cells in the Aβ group was decreased. hTe cells appeared sparse and irregular and became smaller. Karyopyknosis and vacuolardegeneration cells were also found. More positive staining materials aggradated in the Aβ group compared with the PP group by Congo red staining (P<0.05). Conclusion: Aβ infusion into the hippocampus results in the impairment of the neuronal degeneration in the rats, which shows similar characterizations of AD. PP can reduce the deposition of Aβ in the hippocampus.

Background Elevated intraocular pressure leads to the loss of retinal ganglion cells and vigorous reaction of retinal glial cells.The expression of nestin in retinal glial cells secondary to hypertention and its significance are unclear.ObjectiveThis study aim to investigate the expression of nestin in retinal glial cells (RGCs) in ocular hypertention rats.Methods The ocular hypertention models were established by cauterizing the limbus-draining veins in the right eyes of 42 SD rats,and a conjunctival incision in the left eyes of the rats served as the sham group.The intraocular pressure (IOP) was measured with the Tono-Pen XL tonometer.The number of RGCs in the rats with ocular hypertention was counted.The expression of the nestin protein in RGCs was semi-quantitatively analyzed using Western by immunochemistry.Double immunofluorescence was carried out to evaluate the the confocal laser scaning microscope.Results Significant differences were found in the IOP between the model group and the sham group at various time points (P＜0.05).In 1 week to 3 weeks after operation,the number of RGCs significantly declined in the model group compared with the sham group (P＜0.05).Immunochemistry showed that from 2 hours through 1 week after operation,the expression of nestin was gradually enhanced in the model group in comparison with the sham group.Western blot revealed that the expression of the nestin protein reflected a similar tendency to that of immunofluorescence.The increased introcular pressure as manifested by the induced expression of nestin.Immunoelectron microscopy also confirmed the induced expression of nestin especially at their end-feet suggests a potential neuroprotective mechanism in neuronal degeneration.Nestin may be a useful biomarker for retinal injury study.

Objective:To study the distribution of TCM constitutions in maintenance hemodialysis (MHD) patients.Methods:This is a multicenter cross-sectional study. The general clinical data, dialysis-related parameters and physical and chemical examination data of MHD patients from 6 dialysis centers in Sichuan were collected. At the same time, DS01-A tongue and facial pulse information collection system was used for TCM constitution discrimination.Results:A total of 232 MHD patients were enrolled , and 417 kinds of TCM constitutions were detected, including 59 patients (25.43%) with moderate constitution and 173 patients (74.57%) with biased constitution. Phlegm-dampness was the most common type of solid constitution 47 patients (20.26%). The most common deficiency constitution was qi deficiency 86 patients (37.07%). There were certain differences in the physical distribution of patients with different gender, age, dialysis age, BMI, and whether they had diabetes, hypertension or anemia.Conclusions:The TCM constitutions of MHD patients are mainly biased constitution. Gender, age, BMI, diabetes or hypertension have a certain impact on the distribution of TCM constitutions. At the same time, different constitutions may have an impact on the anemia of MHD patients. The intervention of TCM constitutions on MHD patients may be beneficial to the prognosis of MHD patients.

Objective: To investigate the correlation between Ca, Al, As, Co, Mg, P, Fe, parathyroid hormone (PTH), Ct levels and primary familial brain calcification (PFBC). Methods: We recruited 17 PFBC families from July, 2015 to October, 2016. Groups were divided according to clinical symptoms, the serum concentrations of Ca, P, Fe, Al, As, Co, PTH and Ct were compared among different family groups. Results: There was no significant difference in serum levels of Ca, P, Fe, Al, As, Co, PTH and Ct among the healthy and patient groups or the symptomatic and asymptomatic groups, symptomatic and asymptomatic groups in movement disorder families and in psychiatric families (P>0.05). Conclusions Among the 17 PFBC families, neither serum concentrations of Ca, Al, As, Co, Mg, P, and Fe nor the levels of PTH and Ct were associated with PFBC.