Abstract:Objective To investigate the effect of high fat diet feeding on mitochondrial structure and function. Methods Male C57BL/6J mice at the age of 4 weeks were used in this study. After 6 weeks of regular diet (RD) or high-fat diet (HF) feeding, the high fat-induced obesity phenotype was confirmed by body weight measurement and liver histopathology. RNA was isolated from the liver tissue of RD and HF mice and the expression profiles were detected using RNA-seq. Differentially expressed genes between RD and HF mice were analyzed using BRB-ArrayTools. DAVID online tools were applied to analyze the GO and KEGG pathways. Transmission electron microscopy and western blotting were performed to observe the mitochondrial ultrastructure and quantified the expression of function-related proteins. Results Compared with the RD mice, the body weight gain was faster in the HF mice. The size of the lipid droplets was bigger in the HF-fed mouse liver tissue. Multiple pathway analysis all identified that these major gene changes were related to mitochondria. The mitochondrial deformation, enlarged or even destruction was observed in the high fat diet group observed by transmission electron microscopy. This observation was further confirmed by detecting of the expression of genes in the HF liver mitochondria. The levels of MFN1 and PHB1 were significantly increased, while the level of FKBP51 was significantly decreased. Conclusions FKBP 51 is involved in the high-fat-induced mitochondrial damage via morphological and structural damages of mitochondria.

Abstract:Objective To compare the transparency efficiency of six different optical clearing method on the rat brain tissues. Methods Brain tissue blocks of 14 SD rats were processed with iDISCO, SeeDB, CUBIC, SCALEVIEW-A2, CLARITY-CUBIC, Passive-CLARITY clearing method, respectively. Results The gray value of PBS group was 13.031 ±0.586, that of iDISCO, SeeDB, CUBIC, SCALEVIEW-A2, CLARITY-CUBIC, passive-CLARITY clearing were 6.447 ±0.574, 11.690 ±0.909, 2.318 ±0.986, 8.118 ±1.026, 8.591 ±0.384, 4.198 ±0.182, respectively. Except the SeeDB group ( P =0.185), the rest groups showed significant differences compared with the PBS group ( P < 0.01), and there were significant differences between CUBIC and other groups ( P < 0.01). After the clearing treatment, the changes of tissue area ratio in the iDISCO, SeeDB, CUBIC, SCALEVIEW-A2, CLARITY-CUBIC, Passive-CLARITY method were( -30.02 ±2.39)%,(19.74 ±4.09)%,(14.7 ± 3.92)%,(10.7 ± 5.55)%,(23.01 ± 4.19)%,(66.51±5.68)%, respectively. Each group showed a significant difference compared with the groups iDISCO and the Passive-CLARITY, P < 0.01. Conclusions Except the SeeDB method, all the clearing methods can achieve a transparent effect, while CUBIC is better than the other groups applied for rat brain tissues. The tissue block volume is shrunken after iDISCO clearing, and expanded after Passive-CLARITY processing.

Abstract:Objective To study the effect of atrial natriuretic peptide (ANP) deletion on melanoma growth. Methods A subcutaneous xenotransplanted melanoma model was established in ANP knockout mice and C57BL/6J mice. The tumor volume was measured at the sixth day after establishment of the subcutaneous transplantation. Tumor cell proliferation and tumor-induced angiogenesis were detected by immunohistochemical staining. Results The volume and weight of xenotransplanted melanoma were significantly decreased in the ANP knockout mice compared with those in the C57BL/6J mice. The proliferative tumor cells and microvessel density were significantly decreased in the tumor tissues of ANP knockout mice compared with those in the C57BL/6J mice. Conclusions ANP deletion significantly suppresses xenotransplanted melanoma growth through inhibiting the tumor cell proliferation and angiogenesis.

Abstract:Objective To study the differences of symptoms and pathological features of Wistar and Lewis rat models of collagen-induced rheumatoid arthritis. Methods Wistar and Lewis rats were injected with intermixture of bovine TypeⅡ collage and complete Freund’s adjuvant(CFA) for first immunization, then strengthen it after 14 days and observed the incidence of Wistar-RA group and Lewis-RA group. The degree of paws swelling and the titer of serum anti CII antibody were determined. The pathological changes in toe and joint tissues were examined at 12 weeks, and the expressions of VEGF, IL-6, IL-10 and IL-17A in the synovial membrane of ankle joint were detected. Results After collagen induction, the Wistar and Lewis rats showed paw swelling after 10 d and 14 d, and peaked at 21 d and 24 d, the titer of serum anti CII antibody was significantly increased at third week ( P < 0.01), and arthritis index (AI) was also significantly increased ( P < 0.01). In the Wistar-RA rat group, the rate of molding was 80%, and at fifth weeks, the swelling of the paws subsided and went into a flat level. The molding rate of the Lewis-RA group was 100%, at the seventh week, the swelling of paws subsided and went into a flat level. At 12 weeks, the two model groups showed severe articular cartilage erosion, synovial hyperplasia and inflammatory cell infiltration, neovascularization and pannus formation in the joint synovium, and the bone mineral density of the femur and tibia of the hind limbs was significantly decreased ( P < 0.01). The expression of VEGF, IL-6 and IL-17A in synovium was significantly increased ( P < 0.05, P < 0.01). The expression of IL-10 was obviously decreased ( P < 0.01). Compared with the Wistar-RA group, the paw volume and paw thickness were increased for a longer time in the Lewis-RA group, AI was higher than that of the Wistar-RA group, synovial angiogenesis and pannus formation were more distinct, the expression of VEGF in synovium was significantly higher than that of Wistar-RA group ( P < 0.05), while the expression of IL-17A was significantly lower than that in the Wistar-RA group ( P < 0.05). Conclusions Both the Wistar-RA rat model and Lewis-RA rat model show joint swelling, deformation and decreased activity. AI is increased, the expression of VEGF, IL-6 and IL-17A increased, and the expression of IL-10 decreased, which are consistent with the clinical manifestation. The Wistar-RA rat model has a short duration of swelling, while the Lewis-RA rat model has a longer swelling duration and more severe joint damages. The neovascularization and pannus formation are more obvious. The expression of IL-17A in the Wistar-RA rat model is higher, while the Lewis-RA model has a highly expressed VEGF, which may be related to its pathological characteristics.

Abstract:Objective To study the radiation-protective effect of diallyl disulfide (DADS) in germ cells of male mice. Methods Male mice were whole-body exposured to 4 Gy X-ray irradiation to establish a animal radiation damage model. Testicular histology, sperm motility and sperm deformity rate were observed, protein carbonyl content, malondialdehyde (MDA) and 8-hydroxy deoxyguanosine (8-OHdG) content were tested to assess the degrees of radiation damages of sperm cells and protective effect of DADS. Testicular tissue antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-px) activity and glutathione (GSH) content were examined. The expression of Nrf2 signal protein was detected to explore the radiation-protective mechanism of DADS. Results Compared with the pure exposure group, the testicular tissue damages in the DADS pretreatment group were milder, sperm motility increased significantly ( P < 0.05) and sperm deformity rate decreased ( P < 0.05), and the protein carbonyl content, MDA and 8-OHdG levels significantly reduced ( P < .05). The antioxidant indexes of SOD, CAT, GSH-px and GSH were markedly improved ( P < 0.05), and the expression of Nrf2 was dramatically enhanced. Conclusions DADS has a protective effect on acute radiation injury in germ cells of male mice by means of anti-oxidative ability.

Abstract:Objective To establish a BALB/ c mouse model of total hysterectomy and to investigate and analyze its characteristics and formation mechanism. Methods The control group was fed conventionally without any treatment. The mice in the model group were anesthetized and performed hysterectomy. The animals in the sham-operated group had abdominal cavity opened and only exposing the uterus. The changes of body weight were observed dynamically, and at the end of the fourth weeks. The concentration of serum estradiol was determined and histological structure of the ovaries was examined. Results The general status of all the mice after operation was good without obvious inflammation, and the incision healed completely. There was no significant difference in the body weight before operation among the mice, whereas the weight of model group mice was higher than the control group and sham-operation group at the end of the second, third and forth weeks ( P < 0.05). The estradiol contents of the model group was significantly lower than that in control group and sham operation group ( P < 0.01). The histological structure of ovaries in the control group and sham-operation group was normal, however the model group showed differences, such as irregular shape of the ovaries, changed number of mature follicles, loosely distributed granulosa cells, and apoptosis. Conclusions The mouse model of total hysterectomy established in our study can well simulate the clinical manifestations of ovarian dysfunction after operation, and is an ideal model for the study of complications after ovariectomy and screening of drugs.

Abstract:Objective To explore the immune mechanism in the systemic lupus erythematosus MRL/ lpr mice at different months of age, and to provide the basis for research of its pathogenesis. Methods 3-, 4-, 5- and 6-month old female MRL/ lpr mice, and wild type C57 female mice were used in this study, 10 mice per each group. Their organ coefficients were determined. ELISA was performed to detect the serum levels of double stranded DNA ( ds-DNA) antibody. The interleukins IL-2, IL-4, IL-17 and tumor necrosis factor-α (TNF-α) in spleen tissue were detected. Flow cytometry was used to assess the content of spleen lymphocyte CD3 cells and CD4/ CD8 cell ratio. Results Compared with the 3-month old wild-type C57 mice, the spleen coefficient, the blood concentration of ds-DNA antibody, IL-2 and TNF-α in the 3- to 6-month old MRL/ lpr mice were significantly increased ( P < 0.05). There was no significant difference between the concentrations of interleukin IL-4 ( P > 0.05). The blood concentration of IL-17 in the 5- and 6-month old MRL/ lpr mice was significantly lower ( P < 0.05 or P < 0.01) than that in the 3-month old MRL/ lpr mice. The rest indexes of MRL/ lpr mice showed no obvious changes or significant difference in the mice at different ages. Compared with the 3-month old C57 mice, the spleen CD3 lymphocyte concentration in the MRL/ lpr mice was significantly decreased ( P < 0.01). With the increasing age, the CD3 lymphocyte concentration and D4 + / CD8 + cell ratio in the MRL/ lpr mice were decreased, however, showing a non-significant difference ( P ﹥ 0.05). Conclusions The data obtained in this study indicate that 3-month old lupus MRL/ lpr mice have already immune injury, increasing with the increase of age of the mice.

Abstract:Objective To develop a computer-aided-controlling and analysis system for light/ dark box in mice and rats with a high degree of automation and intelligence. Methods Video recording and image processing were applied to develop the computer-aided-controlling and image analysis system for light/ dark box test in mice and rats. The artificial environment was developed. The stability and reliability of the system was validated by male rats. Results The percentage of time spent in the lit chamber in total time was above 79.40%. The data showed that the artificial environment was successful. When the threshold was set at 18 cm/ s, the data showed a high correlation coefficient of movement time between the computer and manual recordings (r > 0.99). Classical indexes including transition and time spent in both the lit and dark chambers also showed a high correlation. The model group showed a significantly decrease in the transitions and time spent in the lit chamber compared with the control group, indicating a high stability and reliability of the light/dark box test. Conclusions A stable and highly intelligent computer-aided-controlling and image analysis system for light/dark box test of mice and rats has been developed, and it could be used for pathological mechanism studies of anxiolytics.

Abstract:Objective To study the immune intervention effect and mechanism of blockage of macrophage-mediated PD1 / PD-L1 pathways with functional PD-L1(programmed cell death ligand-1,PD-L1)monoclonal antibody upon tuberculosis (TB) relapse in mice. Methods Female C57BL/6 mice were infected by tail vein injection of 106 CFU M. tuberculosis H37Rv to obtain active TB infection. Two weeks postinfection, the mice in different groups were administered isoniazid (10 mg/ kg) (group ISO) and isoniazid combined with PD-L1 monoclonal antibody (50 μg/ each) (group ISO +PD-L1) respectively, continued for four weeks to obtain latent infection. The subsequent relapse was monitored. Among the treatment groups, the TB relapse was induced by TNF-α antibody (50 ug/ each) for four weeks from the beginning of latent stage. At each scheduled time point, bacterial loads and pathological changes in the lung, spleen and liver were quantitatively analyzed, thereby, the in vivo intervention effect of PD-L1 monoclonal antibody on tuberculosis recurrence in mice was revealed. The in vitro experiment was further explored whether knock-down the expression of PD-L1 on the infected macrophages could accerlate the macrophage apoptosis. Results The bacterial burden reached 3 -4 Lg (CFU/mL), and granuloma lesions were extensive in the lung, spleen and liver in the all infected groups, which appeared as active TB stage at 2nd week postinfection. After treated, the bacterial burden of the lung, spleen and liver was decreased, and the pathological lesions alleviated in the group ISO and group ISO + PD-L1, compared with the model control group, showing significant differences, but there was no significant difference between the two treatment groups. However, compared with the group ISO, the group ISO + PD-L1 had a significantly lower bacterial load and milder pathological lesions during the relapse period. Futhermore, knock-down the expression of PD-L1 on macrophages with anti-PD-L1 or PD-L1-siRNA promoted apoptosis in macrophages. Conclusions Blockade of the PD1/ PD-L1 pathway by PD-L1 functional antibody can inhibit TB relapse in mice, and knock-down the expression of PD-L1 on macrophages or PD1/ PD-L1 pathway with functional antibody can promote apoptosis in macrophages, which together indicate that PD-L1 blockage can effectively promote isoniazid treatment of TB and remarkably inhibit the recurrence of TB in mice.

Abstract:Objective To Study the depression-like behavior and impairment of learning and memory induced by chronic injection of corticosterone in mice. Methods Forty male C57BL/6J mice were divided into four groups, the control group, and the corticosterone groups (20, 40, 80 mg/ kg). The mice received subcutaneous injection of corticosterone once a day for 21 days. The depression-like behaviors were detected by open field test ( OFT), tail suspension test (TST) and forced swimming test (FST). To select the most effective dose of corticosterone, TST, FST, object location recognition test, and Morris water maze (MWM) test were used to study the corticosterone-induced depression-like behaviors and impairment of learning and memory in the mice. Results Compared with the control group, the movement distance and duration were significantly decreased in the corticosterone injection groups (40, 80 mg/ kg) ( P < 0.01 or P < 0.05). In the TST group, the immobilization time was significantly increased in the corticosterone injection group (40, 80 mg/ kg) ( P < 0.05). The TST and FST showed that the immobilization time of the corticosterone injection group (40 mg/ kg) was significantly increased ( P < 0.05). The object recognition test showed that the discrimination indexes of the object location recognition were decreased in the corticosterone injection group (40 mg/ kg). The MWM test showed that the escape latency was increased ( P <0 . 05), and the number of crossing in target quadrant and the velocity in target quadrant were decreased ( P < 0.05) in the corticosterone injection group (40 mg/ kg). Conclusions Chronic injection of corticosterone can induce depression accompanied with learning and memory impairment in mice.

Abstract:Objective To provide reference values for bone mineral density (BMD) in different skeletal regions of female Wistar rats at different ages. Methods Thirty SPF female Wistar rats were selected. The BMD of different skeletal regions (skull, upper limbs, thighs, trunk, ribs, pelvis, spine and the whole body) was measured by dual energy X-ray absorptiometry (DXA) at 6, 10, 12, 24 and 30 months of age. The bone mineral densities between different age groups and that of different skeletal regions in the same age groups were compared. Results The BMD of the skull, upper limbs, thighs, trunk, ribs, pelvis, spine and the whole body was increased rapidly with age, and reached a peak at 10 months of age. The BMD of the skull, upper limbs, thighs, trunk, ribs were significantly higher than the whole body BMD in the same month-age group ( P < 0.05 or P < 0.01). However, there was no significant difference between the pelvic, spine and the whole body BMD ( P > 0.05). There was a significant positive correlation among the three correlations ( P <0.01). Conclusions Some background data are provided for the bone biology studies of female Wistar rats, and provide useful supplementary reference for the studies of bone metabolism in rats and their application in biomedicine.

Abstract:Objective To investigate and analyze the characteristics of blood physiological and biochemical parameters of Tibetan chickens bred in Guangzhou. Methods Blood samples of Tibetan chickens bred in Guangzhou were collected, and the physiological and biochemical parameters were measured. Results (1) The blood RBC, PLT, PDW, RDW-SD and P-LCR were not significantly different in the males than females ( P > 0.05). (2) HCT ( P < 0.05), MCHC ( P < 0.05), MPV ( P < 0.05), HGB ( P < 0.01), MCV ( P < 0.01) and MCH ( P < 0.01) were significantly higher between the males and females. (3) RDW-CV was significantly lower in the blood physiological parameters of males than females. (4) AST, TRIG, ALKP, ALT, Ca, CHOL, CREA, GLU, PHOS and TBIL were not remarkably different in the blood of males than females ( P > 0.05). (5) The blood AMYL ( P < 0.05) and TP ( P < 0.01) were significantly higher in the males than females. (6) The blood ALB ( P < 0.01), UREA ( P < 0.05), and GLOB ( P <0.01) were significantly lower in the males than females. Conclusions The essential data of blood physiological and biochemical indexes of Tibetan chickens bred in Guangzhou are obtained.

Abstract:Objective To investigate the changes of content or activity of Nrf2 and anti-oxidative stress-related factors in rat models of traumatic brain injury, and explore the mechanisms of protective effect of curcumin on brain damage and oxidative stress in rats. Methods Twenty healthy SPF male SD rats were divided into 4 groups: the control group, brain injury model group (TBI group), brain injury and solvent-treated group (TBI + S group), brain injury and curcumin-treated group (TBI + C group), 5 rats ineach group. The control group received only saline and anesthesia. The TBI, TBI + S and TBI + C groups were given free falling body brain injury modeling device to establish the models and then received curcumin (5 mg/ kg), an equal amount of DMSO solvent (0.05%) and an equal amount of physiological saline, respectively. The rats were sacrificed at the next day and the RNA and proteins of brain tissues were extracted. qRT-PCR and Western blot were used to detect the mRNA and protein expression of Nrf2. Chemocolorimetry was used to detect the content or activity of MDA, GSH, CAT and SOD in the brain tissues of rats. ELISA was used to detect the contents of iNOS and HO-1. Results Compared with the control group,the mRNA and protein expressions of Nrf2, the content of MDA,the activity of HO-1 and iNOS were significantly increased, the content of GSH, the activity of SOD and CAT were significantly decreased in the TBI group and TBI + S group, with a significant difference ( P < 0.05). Compared with the TBI and TBI + S groups, the mRNA and protein expressions of Nrf2, the content of MDA, the activities of HO-1 and iNOS were significantly decreased, the content of GSH, the activity of SOD and CAT were significantly increased in the TBI + C group, showing a sigfnificant difference ( P < 0.05), but there were no significant differences between the TBI group and TBI + S group ( P < 0.05). Conclusions Curcumin has an anti?oxidative stress effect on rats with brain injury. It can reduce the expression of Nrf2, change the anti?oxidant stress?related indicators, therefore to protect the TBI?impaired brain tissues.

Abstract:Objective To obtain the basic data of Bama minipigs and provide basic reference for embryo-fetal developmental toxicity study. Methods Pregnant minipigs were sacrificed at different days during the gestation period respectively. The examinations included necropsy, count of corporea lutea, live and dead implantations, fetal body weight, and external, visceral, and skeletal examination of fetuses. Results The basic data of Bama minipigs, such as body weight, fetal development, and fetal malformation/ variation were obtained. Conclusions We obtained the basic reproductive parameters of pregnant Bama minipigs and the indexes of fetal development, which can provide valuable reference data for embryo-fetal developmental toxicity tests of Bama minipigs.

Abstract:Objective To investigate the effect of interfering with E2F3 gene expression on the invasion and migration of prostate cancer cells and its mechanism. Methods The expression of E2F3 gene in human prostate cancer Du145 cells was knocked down by siRNA. The cells were divided into three groups: control group, Du145 NC group (siRNA?NC) and Du145?siRNA group (siRNA?E2F3). Cell migration and invasion were detected by Transwell invasion and wound healing assay. The expressions of E2F3, E?cadherin and MMP?9 proteins were detected by western blotting. Results After transfection, the expression of E2F3 protein in the Du145?siRNA group was significantly lower than the control group ( P < 0.01). The number of invasive cells and wound healing rate of Du145 cells in the Du145?siRNA group were significantly lower than the control group ( P < 0.01). Furthermore, the protein expression of E?cadherin was significantly increased ( P < 0.01) while MMP?9 decreased ( P < 0.01) in the Du145?siRNA group. Conclusions E2F3 silencing can inhibit the invasion and migration ability of prostate cancer Du145 cells, and this might be accomplished by regulating E?cadherin and MMP?9 protein.

Abstract:Objective To explore the effect of miR-126 on proliferation and apoptosis in colon cancer cells via targeting regulation of SOX2 expression. Methods miR-126 mimics and miR-126 NC were transfected into SW480 cells by liposome LipofectamineTM2000. The expression of miR-126 was detected by RT-PCR. Cell viability was determined by MTT staining. Cell apoptosis and cell cycle were detected by flow cytometry. The expression of SOX2 protein and mRNA was measured by western blot and RT-PCR. Luciferase reporter analysis was performed. Results Compared with miR-126 NC, the expression of miR-126 was upregulated ( P < 0.01), cell viability was reduced ( P < 0.01), early cell apoptosis rate and late apoptosis rate were increased ( P < 0.01), cell cycle was arrested at G1 phase ( P < 0.01), meanwhile, miR-126 mimics targeted downregulation of the expression of SOX2 protein and mRNA ( P < 0.01). Conclusions miR-126 mimics can inhibit SW480 cell proliferation and induce cell apoptosis by targeting downregulation of expression of SOX2.

Abstract:Objective To analyze the effect of transport and storage conditions on the detection of pathogenic nucleic acid MHV, Reo-3, MNV in laboratory mouse cecal contents samples. Methods MHV, Reo-3 and MNV were mixed with mouse cecal contents and used as reference samples, respectively. They were placed in the lysis buffer of RNA extraction reagent (buffer AVL) or normal saline, and stored at 4℃ and room temperature (22℃-25℃). RNA of these samples was extracted at 1, 2, 3, 7, and 14 days. Then the amount of nucleic acid in samples was detected by real-time fluorescence quantitative PCR. Results A greater decrease of the amount of nucleic acid was observed when the samples were placed in normal saline than that kept in buffer AVL. The amount of nucleic acid in samples stored at 4℃ was found to be higher than that stored at 25℃ room temperature. The amount of nucleic acid in the samples which were kept in buffer AVL at 4℃ for 3 days was higher than 50%, still detectable in the samples kept for 7 days, and undetectable at 14 days. Conclusions Mouse cecal content samples are preferably stored in the lysis buffer of RNA extraction reagent and transported at 4℃ for the detection of MHV, Reo-3, and MNV nucleic acid. It is better to complete the detection test within 3 days.

Abstract:Objective To analyze the result of proficiency testing (PT) of detection activities for Laboratory animal pathogenic bacteria in 2011 and 2013 -2017. To further improve the detection capacity of laboratory animal testing agency, and promote PT to be carried out in future. Methods During the six years (2011 and 2013 - 2017), the National Institutes for Food and Drug Control conducted a total of six (seven projects) PT activities of laboratory animal pathogen bacteria. We analyzed the overall trend and the exposed problems by summarizing the result data of the PT in 6 years. Results A total of 45 laboratories in the country including 20 provinces and cities participated in the PT. The PT projects included Mycoplasma pulmonis, Clostridium piliformis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella spp. , Klebsiella pneumoniae and Bordetella bronchiseptica. The satisfaction rates were 75%, 87.5%, 80.0%,78.6%, 93.3, 96.2% and 88.0%, respectively. The main reasons of unsatisfactory results were for lack of incubation time, select errors of suspicious bacteria, biochemical identification errors, report writing errors and not timely feedback results. Conclusions The level of domestic laboratory animal pathogenic bacteria detection is gradually increased to achieve the desired goal through continuous proficiency testing activities.

Abstract:Objective To study the influencing factors and quality control of chromosome preparation during chromosome aberration test in vitro, and to summarize and analyze the method and key points of successful preparation of chromosome specimens in vitro. Methods Chinese hamster lung cells (CHL) were used for cell culture and chromosome preparation. Mitomycin and cyclophosphamide were used as positive mutagens. After routine hypotonic treatment, fixation, and squash preparation, finally, to read the film under the microscope. Results The CHL chromosome aberration test showed that both the chromosome aberration rates of mitomycin- and cyclophosphamide-treated cells were significantly increased ( >20%), while the aberration rates in the negative control group were less than 5%, either with and without metabolic activation. The success rate was high and the prepared chromosomes were well dispersed with a moderate length. Conclusions Many factors can affect the specimen preparation in chromosome aberration test. Every step is very important, and it should be strictly following the operating procedures. It is of importance to grasp the principle of each step and to operate carefully, patiently and scientifically in order to prepare good specimens.

Abstract:Objective To explore a rapid, convenient and non-polluting method of collecting cerebrospinal fluid (CSF) in Sprague Dawley (SD) rats for beginners. Methods Forty-five SD rats were divided into three groups — group 1 (collecting CSF through neck muscles), group 2 (collecting CSF through skin directly), and group 3 (collecting CSF through endorhachis). Results The successful rate of the CSF collection in the group 1 was 86.7%, group 2 was 46.7%, and group 3 is 33.3%. Conclusions The modified collection method of CSF by cisterna puncture through neck muscles in SD rats is simple, convenient, efficient and non-polluting, and is especially suitable for beginners.

Abstract:Histone acetylation is one of the most important reactions of post?translational modification of histones, which plays an important role in the regulation of epigenetic processes. Histone deacetylase 2 as a member of type I histone deacetylases, involved in the catalytic regulation of histone and a variety of non-histone deacetylation, regulates a variety of life processes. This paper summarizes the basic structure of histone deacetylase 2 and the role of histone deacetylase 2 in various diseases, and provides a theoretical basis for conducting related studies.

Abstract:Microglia, a type of neuroglia, has a variety of functions such as phagocytosis, clearance, antigen presentation, promotion of repairment of injury and secretion of extracellular signaling molecules, in which phagocytosis of microglia plays a crucial role in maintaining brain tissue, remodeling synapses, clearance of several aberrant proteins such as amyloid β in neurodegenerative diseases, and in neurodevelopment. This review briefly summarizes the phagocytic function of microglia with underlying regulatory mechanism in neurodevelopment and neurodegenerative diseases, aiming to provide a new thought for the therapy of neurodegenerative diseases.

Abstract:Cardiovascular disease is still the world’s first cause of death, its morbidity and mortality rates are still increasing. Recent studies have shown that circular RNA is involved in the regulation of gene expression and plays a significant role in the pathogenesis of cardiovascular diseases. Circular RNA is a kind of special non-coding RNA, which can regulate the expression of genes at the level of post-transcription or transcription, then regulate various life activities as well as cardiovascular system diseases, becoming a latest research hot spot in the field of RNA. Nowadays, more and more attention is paid to the role of cyclic RNA in the development, early diagnosis, disease monitoring and other aspects of cardiovascular diseases. In this paper, we make an overview of the latest research on circRNAs from the aspects of genesis, function, and the relationship with cardiovas cular diseases, and so on.