Abstract:Objective 　To investigate the function of Smad2/3a on vertebrate neural crest cell development.Methods　Knock-down of smad2/ 3 and overexpression of casmad2 and smad3a were achieved by microinjection of antisensemorpholino (MO) and mRNA into one-cell stage embryos, respectively. Then, the expression of snail1b, sox10, foxd3, andcrestin in MO-injected embryos and crestin in mRNA-injected embryos at the 6-somite stage were detected using whole-mountin situ hybridization. casmad2 mRNA and smad3a mRNA were used to rescue smad2 and smad3a morphants. Results　Knockdown of smad2 and smad3a resulted in a remarkable downregulation of crestin, while there were no obvious changes inthe expression of snail1b, sox10, or foxd3 in the smad2/ 3a morphants. Knockdown of smad3b did not inhibit the expression ofcrestin, snail1b, sox10, or foxd3. Overexpression of casmad2 and smad3a led to an upregulation of crestin. Overexpression ofsmad2 and smad3a restored the reduction of crestin expression caused by smad2 and smad3a depletion. Conclusions　Smad2 and Smad3a play key roles in the regulation of expression levels of crestin during neural crest cell development.

Abstract:Objective　The aim of this study was to identify the mechanism underlying skeletal muscle atrophyinduced by hypoxia exposure. To this aim, expression levels of different types of skeletal muscle protein synthesis- anddegradation-related genes were compared between rats that had experienced hypoxic exposure and normoxia in a hypoxicfeeding intervention (semi-starvation state). Methods　SD rats were divided into a normoxic normal diet group (groupC), a hypoxic normal diet group (group H; oxygen concentration of 12. 4%), or a normoxia-matched diet group (group P;the food intake was matched to that of group H). The body composition of rats was tested by DEXA after the 4-weekintervention. The soleus (SOL) and the extensor digitorum longus (EDL) muscles were collected and weighed. Musclesfiber histology was observed using HE staining, and the muscle fiber cross-sectional area (FCSA) was calculated. Theprotein contents of HIF1α, Akt, p-Akt, and skeletal muscle protein synthesis- and degradation-related genes were detectedusing Western blot. Results 　1) Body weight was lower in the group H than group C, but there was no significantdifference between the groups P and C during the intervention period. At the beginning of the intervention, the food intakeof group H (which was the same as group P) was significantly lower than that of the group C, and there was no significantdifference between the two groups. (2) After the intervention, the body weight and muscle mass were significantly lower inthe group H compared to groups C and P; the wet weights of SOL and EDL muscles in the group H were significantly lowerthan those of the group C; and the FCSA of the EDL muscle was significantly lower in the group H than in groups C and P.(3) HIF1α protein contents of the EDL muscle was significantly higher in the group H than group C; the ratio of p-Akt/Akt of the SOL muscle in the groups H and P was significantly lower than that of the group C; mTOR and 4EBP1 proteinlevels in the EDL muscle of group H was significantly lower than group C; atrogin1, MuRF1, and Beclin1 protein levelsand the ratio of LC3II/ I in EDL of the group H were significantly higher than those of the group C, and MuRF1 proteinlevel in the SOL muscle of group H was significantly higher than that of the groups C and P. Conclusions　Skeletal muscleatrophy caused by hypoxia is induced by hypoxia-specific factors, showing that decreased synthesis and decomposition ofskeletal muscle proteins, which is manifested by a decrease in skeletal muscle protein synthesis and a decrease in decomposition of fast muscle fibers, rather than a decrease in food intake under hypoxia.

Abstract:Objective　To investigate the effect and expression regulation of hypoxia-inducible factor alpha (Hif-α) for schizothoracine fish under hypoxic environment. Methods　We obtained the coding regions of Hif-1αΑ, Hif-1αB,Hif-2αΑ, and Hif-2αB genes for 13 species of schizothoracine fish, endemic to the Qinghai-Tibetan Plateau, using RTPCR,then conducted molecular evolution analysis based on the schizothoracine fish phylogeny by comparing the nonsynonymous/synonymous substitution ratios. Gymnocypris eckloni was selected to investigate the tissue expression patterns inresponse to hypoxia. Results　The coding regions of Hif-1αΑ, Hif-1αB, Hif-2αΑ, and Hif-2αB genes were 2196 bp, 2325bp, 2544 bp, and 2511 bp in length, respectively. Sequence alignment showed that the conserved proline hydroxylationmotif LxxLAP was deletion in the NODD domain of HIF-1αΑ in schizothoracine fish, and the mutation from the prolinehydroxylation motif to PxxLAP was observed in the CODD domain of HIF-1αB in the specialized and highly specializedschizothoracine fish. Under severe hypoxic conditions, the expression of Hif-α gene in the brain and heart of G. ecklonidecreased significantly compared to normoxia control. Under moderate hypoxic conditions, the expression of Hif-1αA andHif-2αA in the heart was up-regulated compared to normoxia control. Conclusions 　The Hif-α genes are identifiedpositively selected in 13 species, but which species under positively selected is not yet clear and needs further study. Theremay be two different gene expression regulations for the schizothoracine fishes to adapt to moderate hypoxic environment and severe hypoxic environment.

Abstract:Objective 　To study the effects of chronic PM2. 5 exposure on lung inflammation and NLRP3inflammasome activation in mice, and to provide a new target for prevention and treatment of lung injury caused by PM2. 5.Methods　Male C57BL/6J mice were exposed to two doses of PM2. 5 by tracheal instillation [2, 10 mg/ (kg.bw)], andthe control mice were instilled with normal saline. After mice had been instilled for 20 times (1 time every 3 days), bloodand lung tissues were collected. Blood cells were counted, and lung tissue macrophage levels were measured usingimmunofluorescence staining. Interleukin (IL)-1β and IL-18 levels and caspase-1 activity in lung tissues were determinedusing ELISA and caspase-1 activity measurement kits. The expression levels of NLRP3 inflammasome-associated mRNA inlung tissue were detected using real-time PCR. Results　The two doses of PM2. 5 significantly reduced the percentage ofmonocytes ( P < 0. 01) and induced lung inflammation. The PM2. 5-treated mice had a higher percentage of neutrophils ( P < 0. 01), a higher in caspase-1 activity ( P < 0. 01), and a higher in mRNA expression of NLRP3 and ASC ( P < 0. 01) inlung tissues compared with the control mice. IL-1β and IL-18 levels in the lung tissues of the two PM2. 5-exposed groupswere significantly higher than those seen in the control group (both P < 0. 01). Conclusion　Chronic PM2. 5 exposure may induce lung inflammation by activating the NLRP3 inflammasome in the lung tissue.

Abstract:Objective　To study the pathological changes of subchondral bone and cartilage in different osteoarthritis(OA) models. Methods　Three Sprague Dawley (SD) OA models were used and twenty-four female rats were divided into fourgroups randomly: control group (Sham, n=6), anterior cruciate ligament transection operations group (ACLT, n =6), papainjoint cavity injection group (Papain, n=6) and ovariectomy group (OVX, n=6). After 8 weeks, all knee joints were extracted.Subchondral bone specimens from tibia plateau were scanned, and trabecular parameters were obtained. Articular cartilagespecimens were stained by toluidine blue, and OA was scored according to Mankin’s histological grading system. Results　After8 weeks, the OA severity of cartilage are different for different OA models. Severe cartilage damage was observed in the ACLTand Papain groups. Only mild cartilage damage was occurred in the OVX group. Subchondral bone in all OA models also changedat week 8 post operation. Subchondral trabecular bone in the OVX group became looser than the Sham group. Subchondraltrabecular bone in the ACLT group and Papain group didn’t change significantly compared with the Sham group, but hadsignificant difference from the OVX group. Thickness of subchondral bone plate in all groups became thinner than the Shamgroup. Conclusions　Both subchondral bone and cartilage changed with OA progress for all the three OA animal models. Thosealterations in different OA models are different, which implies that subchondral bone might play different roles for different typesof OA. This study will provide us more evidences to further investigate mechanisms of different types of OA and more insight to treat subchondral bone as an OA therapeutic target.

Abstract:Objective　To get the full-length presenilin-1 (PSEN1) cDNA encoding sequence and analyze itsmolecular characteristics. Methods　Full-length PSEN1 cDNA was cloned from total RNA from brain tissue of tree shrewby RT-PCR and RACE-PCR. The molecular characteristics were compared with PSEN1 in other mammals and evaluatedusing biology softwares such as DNAMAN, MEGA and others. Quantitative reverse transcription PCR and western blotassays were used to examine the mRNA and protein expression pattern of PSEN1 in various tissues of tree shrew. ResultsThe open reading frame sequence of PSEN1 was 1128 bp and encoded 375 amino acids. We constructed a phylogeneticfamily tree and compared their PSEN1 amino acid sequences. Tree shrew PSEN1 was closer to humans and non-humanprimates than mouse and rat. The expression of PSEN1 mRNA and protein was obviously higher in the brain than that ofother organ tissues. Conclusions　We successfully cloned the PSEN1 gene in tree shrew and provided comparative analysiswith other species. These findings provide a theoretical basis for further study on the function of this gene and the establishment of animal models of Alzheimer’s disease (AD).

Abstract:Objective 　To explore the biological properties of the porous composite material HAPw/ n-ZnOimplanted into the back muscles of tree shrew. Methods　Fifteen healthy 12-month old male and female tree shrews wereselected, and each of the back muscles were implanted with porous composite materials, including HAPw/ n-Zno, bio-ossbone powder, ATLANTIK artificial bone, and domestic product Jinshi Zhiguling artificial bone. Four animals were randomlysacrificed at 4 weeks, 8 weeks, and 12 weeks after surgery, and the gross observation, histopathological examination,alkaline phosphatase activity (ALP), and calcium content were determined. Results　The pathological examination usingHE staining revealed calcification in the muscle tissues in both of HAPw/ n-ZnO and control groups. Obvious inflammatorycell infiltration in the muscle tissues was seen in the experimental group. Masson staining showed green-stained collagenfibers around the implanted material in both the experimental and control groups. There were significant differences in thealkaline phosphatase activities and calcium concentration among the experimental, Jinshi Zhiguling artificial bone, and Bio-Oss groups. The result of Jinshi Zhiguling artificial bone and Bio-Oss groups were better than the experimental group, andthere were no significant differences compared with that of ATLANTIK artificial bone group. Conclusions　The four kindsof materials have osteogenic activity in the back muscle of tree shrews, with no heterotopic osteogenesis, and induce inflammatory reaction.

Abstract:Objective　To meet the individual anesthesia requirements for different surgical procedures for nonhumanprimates that can replace or reduce the use of ketamine. To this aim, we compared the effects on body temperature,heart rate and blood oxygen saturation of ketamine, Zoletil, SumianxinII, pentobarbital, and their combination anesthesiain monkeys. Methods　Fifteen healthy female cynomolgus monkeys were divided into the following five groups: Zoletilalone, Zoletil + Sumianxin II, ketamine + Sumianxin II, pentobarbital + Sumianxin II groups, and ketamine alone as acontrol group (n = 5 per group). After the monkeys were anesthetized, the heart rate, body temperature, blood oxygensaturation, induction time, and maintenance time of anesthesia were recorded. Results 　There were no significantdifferences in heart rate, body temperature, blood oxygen saturation, or induction time between the control group andexperimental groups. The maintenance time of each group ranged from about 30 to 200 minutes. Moreover, in generalanesthesia of non-human primates, ketamine can be replaced by Zoletil; Ketamine combined with Sumianxin II can achievea longer maintenance time and a reduced dose of ketamine; Zoletil combined with Sumianxin II and pentobarbital combinedwith Sumianxin II can also replace ketamine, and the maintenance time of these combinations is longer than ketamine.Conclusions　During certain operation duration, the combined administration can reduce the dosage of ketamine, and theflexible use of different anesthesia method can meet the individualized needs of different maintenance times in general anesthesia in non-human primates.

Abstract:Objective 　To explore the feasibility of establishing an experimental model of tree shrew lungfibroblasts (TSLF) infected with CA16. Methods　TSLF were infected with enterovirus CA16, and human lung fibroblasts(KMB-17) were used as controls. The cytopathic effects ( CPE) were observed using an inverted microscope. Theexpression of viral protein and the SCARB2 receptor protein was observed by indirect immunofluorescence assay, and viralload was detected by TaqMan real-time PCR assay. Using β-actin as an internal reference, the relative expression of theSCARB2 gene was detected using SYBR Green real-time PCR, and its correlation with the infection process was analyzedalong with the gene sequence alignment. Results　CA16 infected TSLF and caused obvious CPE. The virus and SCARB2protein were observed by immunofluorescence assay. Under the infection rate of 100TCID₅₀ /10⁵ cells, the viral load washighest 48 h after infection. The SCARB2 gene had a high expression that was associated with infection, and its genesequence also has a high homology with that of humans. Conclusion　CA16 can infect TSLF and SCARB2 is related to the infection.

Abstract:Objective　To assess the relationship between peripheral TRPV1 and P2X3 in normal healthy rats toelucidate the regulation mechanism of peripheral pain sensation. Methods　Healthy male SD rats were randomly dividedinto a control group, TRPV1 agonist group, P2X3 agonist group, TRPV1 agonist + P2X3 agonist group, TPRV1 agonist +P2X3 inhibitor group, and P2X3 agonist +TRPV1 inhibitor group. Within 20 min after subcutaneous and intraplantarinjections of TRPV1 or P2X3 agonist and/ or inhibitor, the number of foot contractions and the duration of leg raising/licking in each group were measured, respectively. The expression and co-expression of positive cells of L4DRG TRPV1and P2X3 were observed using immunofluorescence. The correlation between TRPV1 and P2X3 at L4 DRG levels wasobserved using immunoprecipitation. Results　The P2X3 agonist did not alleviate pain behavior induced by the TRPV1agonist, and the P2X3 inhibitor did. The TRPV1 agonist increased pain behavior induced by P2X3 agonist, and the TRPV1inhibitor did not reduce pain behavior induced by P2X3 agonist. The P2X3 agonist increased the positive area expression ofTRPV1 in at the L4DRG level, and the TRPV1 agonist increased the positive area expression of P2X3 at the L4DRG level;TRPV1 and P2X3 were co-expressed and co-precipitated at the L4 DRG level. Conclusions 　There is an interactionbetween TRPV1 and P2X3 at the peripheral neuron level, whereby they promote each other’s expression. When one is inhibited, the other is reduced in function.

Abstract:Objective 　To obtain albino C57BL/6N mice and expand their application in research of skintransplantation and embryonic stem cells. Methods　Cas9 mRNA and a series of single guide RNAs (sgRNAs) weresynthesized in vitro and injected into the fertilized eggs of C57BL/6N mice. The gene encoding tyrosinase (TYR), anenzyme necessary for melanin production in C57BL/6N mice, was destroyed in exon 1 and exon 2, and gene mutations weregenerated to obtain albino F0 generation. Albino C57BL/6N mice were then subjected to repeated backcrossing andinbreeding to produce C57BL/6N albino mouse inbreds. Results　Two pairs of sgRNA were injected into mice, and the F0generation of albino mice was successfully obtained. Deletions in both exon 1 and exon 2 of the Tyr gene were confirmed.The albino mice transmited the mutant gene to offsprings, and homozygous white C57BL/6N mice as offspring wereconfirmed. The mutation types of albino mice were analyzed. Conclusions　The mouse Tyr gene is disrupted by CRISPRCas9technology, and the C57BL/6N albino mouse inbred line is successfully established. This mouse line provides a new research tool for future chimera preparation and tissue transplantation.

Abstract:Objective　A C57BL/6 mouse chronic unpredictable mild stress model of depression was establishedto investigate the effect of high frequency sound waves in Mozart’s K448 Sonata on depression. Methods　Establishment ofa chronic stress model: Mice were divided into a blank group (n = 10) lived with no stress and model group (n = 36)established 5 weeks of chronic mild and unpredictable stimulation (CUMS). Therapeutic intervention: The mice in themodel group were randomly divided into the model control group (n =12), fluoxetine group (n =12), and music group (n= 12) after 5 weeks. Fluoxetine hydrochloride solution (10 mg/ kg) was injected intraperitoneally every day in thefluoxetine group, and the other two groups were injected with the same amount of saline lasted 2 weeks. The music groupreceived a 2-hour high frequency music intervention every day lasted 2 weeks, while the other two groups did not. Outcomevariables: Weight was recorded 3 days before the experiment and every week during the experiment. Tail suspension test(TST) and forced swimming test (FST) were performed in weeks 1, 5, and 7. At the end of week 7, mice were sacrificedand brain homogenates were prepared. BDNF levels were determined using an enzyme-linked immunosorbent assay(ELISA). Results　At week 5, in the TST, immobility times of the model group were significantly longer than that of theblank group ( P < 0. 01). In the FST, immobility times of the model group were longer than that of the blank group ( P <0. 05). Compared with the model control group, both the fluoxetine group and music group exhibited a significantly shorterimmobility time of tail suspension ( P < 0. 01, P < 0. 05) Compared with the blank group, the model control group had asignificant lower BDNF content in brain homogenates ( P < 0. 01); compared with the model control group, the fluoxetinegroup had a significantly higher BDNF content ( P < 0. 01), and there was no significant difference in BDNF contentbetween the music group and the model control group ( P > 0. 05). Conclusion　Mozart K448 Sonata high frequency sound waves may optimise the therapeutic effect on depression mice models.

Abstract:Objective 　To explore the basic metabolic characteristics and expression of related genes in theskeletal muscle and liver of Chinese hamsters with spontaneous type 2 diabetes, including glucose and lipid metabolism,body composition, diurnal movement, metabolism, and the expression of relevant genes. Methods 　We regarded theChinese hamster with fasting blood glucose (FBG) higher than 6. 0 mmol/ L and post-prandial blood glucose (PBG) higherthan 7. 0 mmol/ L as diabetic based on the mean and 95% frequency distribution values of FBG and PBG. 12 hamsters atthe age of 48 weeks in diabetic and control groups, each group was half male and female. Animal weight, blood glucose,blood lipid, serum insulin content, and glucose tolerance were measured. Animal body composition, diurnal movement,and metabolic characteristics were analyzed by InAlyzer Dual Energy X-ray Animal Body Composition Analysis System,High-throughput Behavior Analysis System, and Open Circuit Calorimetric Metabolic System, respectively. The expressionof diabetes-related genes Glut4 and Pparg in skeletal muscle and liver were measured by Real-time PCR and Westernblotting. Results　In the diabetic group, blood glucose and lipid, serum insulin, food intake, daytime activity, and heatconsumption were significantly increased, while the percentage of body fat was significantly decreased.Compared with thecontrol group, the mRNA and protein expressions of PPARG in the liver and skeletal muscle were significantly increased,and the mRNA and protein expressions of GLUT4 in skeletal muscle were significantly decreased in diabetic hamsters.Conclusions　This type 2 diabetic Chinese hamster model exhibits non-obese, abnormal glucose and lipid metabolism, andinsulin resistance. The down-regulation of GLUT4 may be related to abnormal glucose metabolism and insulin resistance in skeletal muscle, while the up-regulated PPARG may alleviate insulin resistance in the liver.

Abstract:Objective 　An orthogonal design was used to optimize the experimental parameters for theestablishment of a rat model of conditioned fear memory and to identify the optimal experimental conditions. Methods　Themodel of conditioned fear memory in rats was established based on pavlovian conditioned fear theory. Three factors, namelysound intensity, cycle times and electric shock intensity, were adopted, and each factor was set at 3 levels. Orthogonal testwas carried out, and the freezing time ratio of rat was taken as the index to observe the changes in different parameters ofexpression of fear memory and determine the best experimental conditions. The conditioned fear memory model wasestablished again under the optimal conditions of the previous experiment, and the fear memory retention test was conducted24 h, 1 week, 2 weeks, 4 weeks and 8 weeks later. The rats without fear training were used as the control group. ResultsThe intuitive analysis results showed that the effects of various factors on the duration of fear memory of rats was soundintensity=cycle times > electric shock intensity in turn. The ANOVA test showed that the cycle times had a significantimpact on freezing time ratio ( P < 0. 05), but the sound intensity and electric shock intensity had no significant impact ( P > 0. 05). The optimal experimental conditions were as follows: 75 dB sound, 0. 8 mA electric shock, and 15 cycles. Fearmemory was maintained at 24 h and 1 week after the establishment of the model, which was significantly different from thatof the control group ( P < 0. 001 and P < 0. 05). Fear memory had faded 2 weeks later, at which point there was nosignificant difference in freezing time ratio between the model and control groups ( P > 0. 05). Conclusions 　Thisexperiment clarifies the primary and secondary factors that influence the establishment of a rat model of conditioned fearmemory The optimal experimental method for model establishment are identified. This study lays a foundation for the standardization and normalization of fear memory model.

Abstract:Objective　To establish a germ-free mouse strain to provide a new animal model for studies on therelationship between gut flora and Alzheimer’s disease and the changes of amyloid plaques in the brain, by establishing a APPswe / PS1ΔE9 (PAP) transgenic mouse model using a cesarean section decontamination technique. Methods Cesareansection was performed on pregnant PAP mice to obtain pups under a SPF barrier environment, and the pups were thentransferred to female germ-free ICR mice that served as foster mothers. Survival rates of the pups were calculated at 7 daysof age and after weaning. Pathogens were tested each month according to the national standards. The newborn PAP micewere genotyped by polymerase chain reaction (PCR). The deposition of Aβ plaques in brain tissue were observed usingimmunohistochemical staining. Result　12 cesarean sections were performed on pregnant PAP mice, and a total of 63 pupswere collected and transferred to a foster mother. The survival rate of pups after cesarean section and weaning was 95. 45%(63/66) and 95. 24% (60/63), respectively. Pathogens were tested after decontamination, and all the pups werepathogen-negative, thus met the requirement of germ-free mice. The deposition of Aβ plaques was lower in the germ-freePAP mice than in SPF mice of the same age. Conclusions　A germ-free PAP mouse model is established by cesareansection and foster mother technique. This new animal model can be used for studies on the relationship between gut flora and Alzheimer’s disease and the changes of amyloid plaques in the brain tissue.

Abstract:Objective　To study the effects of heroin on the development and brain Bax expression in embryonicrat brain tissues. Methods　Wistar rats were randomly divided into a control group or heroin administration groups (low,medium, and high dose groups). On the 7th day, 16, 32, and 64 mg/ kg of heroin were administered to the low, medium,and high dose groups, respectively, and heroin was continuously administered for 9 days. The effects of heroin onmorphological development of embryonic rats were measured, and the expression levels of Bax in embryonic brain tissueswas detected using enzyme-linked immunosorbent assay (ELISA). Results　The total numbers of living embryos in thelow, medium, and high dose heroin groups were decreased by 27. 27%, 37. 12%, and 48. 48%, respectively, comparedwith the control group ( P < 0. 01). Bax expression levels in embryonic cerebral tissues of the low, medium, and high doseheroin groups were increased by 11. 41%, 47. 06%, and 83. 74%, respectively, compared with the control group ( P <0. 05; P < 0. 01). Bax expression levels in the embryonic cerebellar tissue were increased by 17. 16%, 52. 96%, and90. 01%, respectively, compared with the control group ( P < 0. 05; P < 0. 01). Conclusions 　Heroin inhibitsmorphological development in embryonic rats, and this inhibitory effect increases with increasing doses of heroin. This effectmay be caused by the heroin-induced upregulation of Bax expression in embryonic tissues and organs.

Abstract:Objective　To explore the effect and mechanism of formula TaizishenZhikeYiqi Powder (TZY) onimproving the symptoms of bronchial asthma rats. Methods　Rats were randomly divided into 7 groups: control group,asthma model (OVA inducted), low dose group of traditional Chinese medicine, medium dose group of traditional Chinesemedicine, high dose group of traditional Chinese medicine, Pulmicort respules group, group of Pulmicort respules andtraditional Chinese medicine. HE staining was used to detect the submucocal inflammatory cell infiltration in the bronchialmucosa. Flow cytometry was used to detect the ratio of Th1 to Th2 cells in each group. The levels of IL-4, IL-5, IgE andIFN-γ in bronchoalveolar lavage fluid (BALF) of each group were detected by ELISA. The levels of SOD, MDA, GSH andT-AOC in BALF of each group were detected by biochemistry. Results　TZY reduced airway inflammation exhibiting atherapeutic effect on asthma in the rats. Compared with the asthma group, the ratio of Th1 to Th2 cells in the TZY groupand joint use group increased significantly, the levels of IL-4, IL-5 and IgE decreased significantly, but the level of IFN-γincreased significantly ( P <0. 05) in a dose-dependent manner. Compared with the asthma group, the levels of GSH, T中AOC and SOD in the TZY groups and joint drug use group were significantly increased, and the level of MDA wassignificantly decreased. The TZY and Pulmicort respules combination group exerted similar or better effects than thePulmicort respules atomization. Conclusions　TZY can alleviate the inflammatory state of bronchial mucosa in rats. Themechanism may be related to up-regulating the ratio of Th1 to Th2 cells, regulating inflammatory factors and oxidativestress.

Abstract:Spinal cord injury is an extremely complex and debilitating condition. Once spinal cord injury occurs, itis difficult to treat, and thus poses a great economic and social burden to both caregivers and healthcare resources. In recentyears, the establishment of rat spinal cord injury cell models has contributed to our understanding of the etiology andpathogenesis of spinal cord injury, in particular, the establishment of an astrocyte model has a profound significance for thetreatment of spinal cord injury. Studies have found that astrocytes, as target cells that can effectively promote tissueprotection and functional repair after spinal cord injury, directly or indirectly regulate spinal cord injury through blood-brainbarrier barrier. This paper reviews the recent studies on the preparation of astrocyte culture models to provide guidance forthe establishment of an Objective , quantitative, and simulative astrocyte model, and presents new ideas for the treatment of spinal cord injury.

Abstract:Liver is the main target organ for colorectal cancer metastasis. Liver metastasis is also the main cause of death in patients with colorectal cancer. Recent studies have shown that liver metastasis of colorectal cancer patient-derived tumor xenograft (PDTX) can better replicate the clinical characteristics of clinical tumors colon cancer. At present, the primary models used are the orthotopic tumor xenograft model and ectopic tumor xenograft model. To provide a reference for experimental modeling, this paper reviews PDTX animal models for colorectal cancer liver metastasis and their application range.