Construction of Stable MCT1-Knockout RKO Cell Line Based on CRISPR/Cas9 Technology and Its Biological Function Detection / 华中科技大学学报(医学版)

@#Objective To precisely knock out MCT1in humancolorectalcancercellline RKO by using CRISPR/Cas9 gene editingtechnique,and to detect its biological function. Methods CRISPRv2-MCT1-KO # 1 and CRISPRv2-MCT1-KO # 2 plasmids weretransfected into RKO cells. The monoclonal cells were selected by the medium containing puromycin after 48 h. The expression of MCT1 was detected by Western blotting and DNA sequencing. The change of expression and distribution of MCT1 protein were detected by immunofluorescence.Intracellular lactic acid level was detected by lactic acid detection kits. Colonyformation assayand CCK-8 assay were performed to detect cell proliferation ability. The potential signaling pathways of MCT1 in colorectal cancer were explored by GSEA software. Results CRISPRv2-MCT1-KO plasmid was well constructed. Western blottingand DNAsequencingresults showedthat MCT1 was successfully knocked outinthe humancolorectal cancer RKOcells. Compared withthecontrol group, MCT1 protein was notobserved onthecell membraneof MCT1-nockoutcells,andtheintracellularlactatelevel was significantlyreduced(P <0.05). The proliferation ability of RKO cells was significantly decreased after MCT1 knockout(P <0.05). GSEA analysis showedthat MCT1 may promotethe occurrence and development ofcolorectal cancerthrough oxidative phosphorylation and MYC signaling pathway. Conclusion The stable MCT1-knockout human colorectal cancer RKO cell line was successfully constructed by applying CRISPR/Cas9 technology, which might become an ffectivetoolforstudyingtherole of MCT1 inthe occurrence and development ofcolorectal cancer.

Pyruvate Supplementation Can Prevent HIIE-induced Metabolic Acidosis and Increase the Expression of MCT1/MCT4 in Skeletal Muscles of Rats / 中国生物化学与分子生物学报

As one of the causes of exercise-induced fatigue, exercise-induced metabolic acidosis has attracted much attention. The effect of pyruvate supplementation on exercise-induced metabolic acidosis is rarely reported, and its mechanism has not been fully elucidated. Monocarboxylate transporters (MCTs) play an important role in the maintenance of the acid-base balance, but it is not clear whether pyruvate can alleviate acidosis by increasing the expression of MCTs. In this study, pyruvate (616 mg/kg/day) was supplemented to rats for one week, and then acute HIIE was performed. The HIIE protocol comprised 13 repeats of a 60 s sprint session at 110% VO

Explore Mechanism of Modified Si Junzitang in Improving Acidic Microenvironment and Reversing Gastric Precancerous Lesions Based on MCT4/CD147 / 中国实验方剂学杂志

Objective:To observe the effect of modified Si Junzitang on the level of lactic acid in gastric mucosa and the expression of Carboxylic acid transporter 1（MCT1）， monocarboxylic acid transporter 4（MCT4）， and extracellular matrix metalloproteinase inducer （CD147）in rats with gastric precancerous lesions（GPL）. Method:Seventy-four SD male rats were randomly divided into normal group （12 rats） and model group （62 rats）. <italic>N</italic>-methyl-<italic>N'</italic>-nitro-<italic>N</italic>-nitrosoguanidine（MNNG）-ammonia compound method was used to establish GPL rat models， and at the 9^th week， the model rats were randomly divided into model group， folic acid group（2.7 mg·kg^-1）， modified Si Junzitang high， medium and low dose groups（12.6， 6.3， 3.15 g·kg^-1）， with 12 rats in each group. After intragastric administration for 12 weeks， the general conditions of the rats were observed. Hematoxylin-eosin（HE）staining was used to observe the histopathological changes of gastric mucosa in rats， chemical colorimetry was used to detect the content of lactic acid in gastric mucosa； immunohistochemistry and real-time polymerase chain reaction（Real-time PCR）were used to detect MCT1， MCT4， CD147 protein and mRNA expression in gastric mucosal tissues. Result:Modified Si Junzitang significantly improved the pathological manifestations in GPL rats such as gastric mucosal epithelial gland structure， disorder of arrangement and cell atypia. Compared with the normal group， the lactic acid content of the gastric mucosa tissue in the model group increased significantly（<italic>P</italic><0.01）， and the protein and mRNA expressions of MCT1， MCT4， CD147 significantly increased（<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with the model group， the lactic acid content in each dose group of modified Si Junzitang was significantly reduced（<italic>P</italic><0.05， <italic>P</italic><0.01）， and the protein expression levels of MCT4 and CD147 were also significantly reduced in each dose group of modified Si Junzitang（<italic>P</italic><0.05， <italic>P</italic><0.01）. The mRNA expression of MCT4 was significantly reduced in the middle and high dose groups（<italic>P</italic><0.05， <italic>P</italic><0.01）， and the mRNA expression of CD147 was significantly reduced in the high dose group（<italic>P</italic><0.05）. Modified Si Junzitang showed no significant regulatory effect on MCT1. Conclusion:Modified Si Junzitang can significantly improve the abnormal histopathology of gastric mucosal epithelium in GPL model rats. Its mechanism may be related to down-regulating the overexpression of MCT4 and CD147， inhibiting lactic acid outflow， and improving the acidic microenvironment of gastric mucosal epithelium.

The effect of downregulation of MCT1 on the proliferation of glioma cells / 中华肿瘤杂志

Objective@#To investigate the molecular mechanism of down-regulation of monocarboxylic acid transporter 1 (MCT1) on the proliferation inhibition of glioma cell.@*Methods@#siMCT1, siMCT4 and negative control siRNA were transfected into glioma cell lines including U-251 and U-87. The proliferation activities of U-251 and U-87 cells were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay and clonogenic assay. Glucose consumption and lactic acid efflux of U-251 and U-87 cells were determined by spectrophotometry.Western blot was used to detect the expressions of MCT1, MCT4, human glucose transporter 1 (GLUT1), GLUT4, tuberous sclerosis associated protein (TSC2), p-TSC2, 4E binding protein 1 (4EBP1), p-4EBP1, ribosomal S6 protein kinase (S6) and p-S6 protein in U-251 and U-87 cells.@*Results@#Compared with negative control group, siMCT1 and siMCT4 significantly inhibited the expressions of MCT1 and MCT4 protein in U-251 and U-87 cells (both P<0.05). However, only knockdown of MCT1, the proliferation activities of U-251 and U-87 cells significantly decreased (P<0.05). The clone formation rates of U-251 and U-87 cells decreased to (55.20±3.27)% and (68.33±4.58) %, respectively (P<0.05). The glucose consumption of U-251 and U-87 cells in the negative control group at 72 hours were (82.65±6.66) pmol/L and (63.33±5.27) pmol/L, respectively, significantly higher than (31.70±3.17) pmol/L and (26.41±3.19) pmol/L of the siMCT1 transfected group (P<0.05). The extracellular lactate flow of U-251 and U-87 cells in negative control group at 72 h were (155.49±8.15) mmol/L and (135.37±8.21) mmol/L, respectively, significantly higher than (42.69±4.66) mmol/L and (38.91±4.83) mmol/L of the siMCT1 transfected group (P<0.05). Western blot analysis showed that knockdown of MCT1 significantly decreased the protein levels of GLUT1 p-TSC2, p-4EBP1 and p-S6 in U-251 and U-87 cells.@*Conclusions@#Downregulation of MCT1 expression can inhibit the proliferation of glioma cells. Deletion of MCT1 inhibits the glycolysis and metabolism of glioma cells through regulating the mTOR signaling pathway.

Study of acupuncture combined with rat nerve growth factor on neurobehavioral ability of cerebral palsy infant rats and its brain tissue growth and metabolism associated proteins / 中国针灸

<p><b>OBJECTIVE</b>To study the effects of acupuncture combined with rat nerve growth factor (NGF) on the cerebral palsy infant rats and the proteins which associated with growth, apoptosis and metabolism.</p><p><b>METHODS</b>Seventy infant rats were selected, Fifty infant rats of which were made the cerebral palsy infant model by the ligation of unilateral carotid artery for cerebral ischemia and oxygen-deficient environment, then the 30 model rats were randomly divided into a model group, a NGF group and a combined group, 10 rats in each group. Twenty infant rats were used in the sham-operated group and the blank control group, 10 rats in each group. The treatment was not given in the blank control group. The rats in the sham-operated group were cut the neck skin and separated the left carotid artery, and then sutured and disinfected the wound. The intraperitoneal injection of NGF (2000 U•kg•d) was used in the NGF group. Based on the injection in the NGF group, acupuncture was used in the combined group, once a day, and the acupoints were "Baihui" (GV 20), left "nieⅠ" (extra), "Dazhui" (GV 14), "Jizhong" (extra), "Quchi" (LI 11), "Yongquan" (KI 1), "Hegu" (LI 4), "Zhoujie" (extra) and "Xiqianxue" (extra). The same volume of saline was intraperitoneally injected in the model group for continuous 14 days. Neurobehavioral ability score was evaluated after treatment. TUNEL were conducted to detect the brain cell apoptosis rate and the expressions of apoptosis associated gene Bax, Bcl-2 and Casp3 were detected by PCR. The level of nerve growth associated protein (GAP-43) and energy metabolism-related protein monocarboxylate transporter protien 1(MCT 1) were detected by Western blot.</p><p><b>RESULTS</b>After intervention, the neurobehavioral ability of baby rats in the blank control and sham-operated group was normal, but there was various degrees of abnormity in the model group, NGF group and combined group. The scores of neurobehavioral ability of the combined group and NGF group were better than those of the model control (all <0.05), and the scores in the combined group was better than those in the NGF group (all <0.05). The left brain cell apoptosis rate, expressions of Bax and Casp3 in the combined group and NGF group were lower and the expressions of Bcl-2 were higher than those of the model group (all <0.05), with more obvious results of Bax and Gasp3 in the combined group than those in the NGF group (all <0.05). The protein levels of GAP-43 and MCT 1 in the combined group and NGF group were higher than those in the model group (all <0.05), with higher expressions in the combined group compared with those in the NGF group (both <0.05).</p><p><b>CONCLUSION</b>Acupuncture combined with NGF could improve the neurobehavioral ability of cerebral palsy infant rats, inhibit the nerve cell apoptosis and improve the brain tissue injure and energy metabolism by up-regulating the expressions of GAP-43 and MCT 1.</p>

Exercise training and selenium or a combined treatment ameliorates aberrant expression of glucose and lactate metabolic proteins in skeletal muscle in a rodent model of diabetes

Exercise training (ET) and selenium (SEL) were evaluated either individually or in combination (COMBI) for their effects on expression of glucose (AMPK, PGC-1alpha, GLUT-4) and lactate metabolic proteins (LDH, MCT-1, MCT-4, COX-IV) in heart and skeletal muscles in a rodent model (Goto-Kakisaki, GK) of diabetes. Forty GK rats either remained sedentary (SED), performed ET, received SEL, (5 micromol/kg body wt(-1)/day(-1)) or underwent both ET and SEL treatment for 6 wk. ET alone, SEL alone, or COMBI resulted in a significant lowering of lactate, glucose, and insulin levels as well as a reduction in HOMA-IR and AUC for glucose relative to SED. Additionally, ET alone, SEL alone, or COMBI increased glycogen content and citrate synthase (CS) activities in liver and muscles. However, their effects on glycogen content and CS activity were tissue-specific. In particular, ET alone, SEL alone, or COMBI induced upregulation of glucose (AMPK, PGC-1alpha, GLUT-4) and lactate (LDH, MCT-1, MCT-4, COX-IV) metabolic proteins relative to SED. However, their effects on glucose and lactate metabolic proteins also appeared to be tissue-specific. It seemed that glucose and lactate metabolic protein expression was not further enhanced with COMBI compared to that of ET alone or SEL alone. These data suggest that ET alone or SEL alone or COMBI represent a practical strategy for ameliorating aberrant expression of glucose and lactate metabolic proteins in diabetic GK rats.