Effect of Target-directed Regulation of Uncoupling Protein-2 Gene Expression on Ischemia-reperfusion Injury of Hepatocytes

The effect of target-directed regulation of the uncoupling protein-2 （UCP-2） gene expression on the ischemia-reperfusion injury of hepatocytes under different conditions was investigated. The expression plasmid and RNAi plasmid targeting UCP-2 gene were constructed and trans- fected into normal hepatocytes and fatty liver cells, respectively. The expression of UCP-2 mRNA was detected by real time PCR. The cells were divided into normal cell group （NCG）, group of normal cells transfected with empty vector （EVNCG）, group of normal cells transfected with expression plasmid （EPNCG）, fatty liver cell group （FCG） and group of fatty liver cells transfected with RNAi plasmid （RPFCG）. The ischemia-reperfusion model in vitro was established. One, 6, 12 and 24 h after reperfusion, Annexin V/PI flow cytometry was used to measure cell necrosis rate, apoptosis rate and survival rate. Simultaneously, the intracellular ATP, ROS and MDA levels were determined. The re- sults showed that 1, 6, 12 and 24 h after ischemia-reperfusion, the intracellular ROS, MDA and ATP levels and cell survival rate in EPNCG were significantly lower, and cell necrosis rate significantly higher than in NCG and EVNCG, but there was no significant difference in apoptosis rate among NCG, EVNCG and EPNCG （P〉005）. Six, 12 and 24 h after reperfusion there was no significant dif- ference in ROS, MDA levels and apoptosis rate between FCG and RPFCG （P〉0.05）, but the ATP level and survival rate of cells in RPFCG were higher than in FCG （P〈0.05）. It was concluded that down-regulation of the UCP-2 gene expression in steatotic hepatocytes could alleviate the ische- mia-reperfusion injury of liver cells.

Effect of Berberine on Expressions of Uncoupling Protein-2 mRNA and Protein in Hepatic Tissue of Non-alcoholic Fatty Liver Disease in Rats

Objective： To observe the effect of berberine on uncoupling protein-2 （UCP2） mRNA and protein expressions in the hepatic tissue of non-alcoholic fatty liver disease （NAFLD） in rats, and to explore the molecular mechanism. Methods： To establish the NAFLD rat model; the rats were fed by high fat forage and were randomly divided into four groups： normal group, model group, berberine high-dose group （324 mg/ kg）, and berberine low-dose group （162 mg/kg）. After treatment for 12 weeks, the expression of UCP2 mRNA in the liver tissue was analyzed by semiquantitative reverse transcription polymerase chain reaction （RTPCR）. The expression level of UCP2 protein in the liver tissue was examined by immunohistochemistry. Total cholesterol （TC）, triglyceride （TG）, high-density lipoprotein cholesterol （HDL-C）, and low-density lipoprotein cholesterol （LDL-C） contents in blood serum, and TG and TC contents in the liver were detected by an automatic biochemical analyzer. The other is to observe the axungia degree of the liver. Results： The expression of UCP2 mRNA and positive cell numbers in the liver tissue were dramatically increased in the model group （P〈0.01）. Lipid in the serum and hepatic tissues increased significantly, and the liver was fatty. But in the treatment groups, the expression levels of mRNA and UCP2 proteins were significantly down-regulated （P〈0.01）. Liver steatosis was improved. Conclusions： Berberine can down-regulate the expression levels of UCP2 mRNA and UCP2 proteins of hepatic tissue in NAFLD rats. It can promote the recovery of hepatocyte steatosis and improve lipid metabolism disorder in NAFLD rats. Berberine shows a potential therapeutic effect on NAFLD.

Jueming Prescription(决明方) Reduces Body Weight by Increasing the mRNA Expressions of Beta3-Adrenergic Receptor and Uncoupling Protein-2 in Adipose Tissue of Diet-Induced Obese Rats

Objective： To investigate the antiobesity effect of Jueming Prescription （决明方, JMP）, a Chinese herbal medicine formula, and its influence on mRNA expressions of beta3 adrenergic receptor （beta3-AR） and uncoupling protein-2 （UCP-2） in adipose tissue of diet-induced obese rats. Methods： Fifty male Sprague-Dawley rats were randomly divided into the normal control group （n=8） that was on a standard chow diet, and the obese model group （n=42） that was on a diet of high fat chow. Two weeks after the high fat diet, 29 obese rats in the obese model group were further randomly divided into 3 groups： the untreated obese model group （n=9）, the met＇formin group （n=10, mefformin 300 mg-kg-1.day-1）, and the JMP group （n=10, JMP 4 g.kg-1.dayl）. After 8-week treatment, body weight, wet weight of visceral fat, and percentage of body fat （PBF） were measured. The levels of fasting blood glucose, serum lipids, and insulin were assessed, and insulin sensitivity index （ISI） was calculated. The adipose tissue section was stained with hematoxylin-Eosin, and the cellular diameter and quantity of adipocytes were evaluated by light microscopy. The mRNA expressions of beta3-AR and UCP-2 from the pet-renal fat tissue were determined by real-time reverse transcription polymerase chain reaction （RT-PCR）. Results： Compared with the obese model group, treatment with JMP resulted in significantly lower body weight, wet weight of visceral fat, PBF, and diameter of adipocytes, and significantly higher level of high-density lipoprotein cholesterol, ISI （all P〈0.01）, JMP increased the mRNA expressions of beta3-AR and UCP-2 from pedrenal fat tissue （P〈0.05, P〈0.01）. Conclusions： JMP could reduce body weight and adipocyte size; and the effect was associated with the up-regulation of beta3-AR and UCP-2 expressions in the adipose tissue and improvement of insulin sensitivity.

Kaiyuqingre formula improves insulin secretion via regulating uncoupling protein-2 and KATPchannel

Background Type 2 diabetes mellitus （T2DM） results from the complex association of insulin resistance and pancreatic β-cell failure. Recent studies have shown that patients diagnosed with T2DM present with a significant decrease in β-cell function, which can be further compromised during the progression of the disease. Several mechanisms have been shown to play a role in this process such as glucotoxicity and lipotoxicity, which contribute to accelerating insulin secretion. In this regard, Chinese medicine has a certain advantage. This experiment was performed to observe the effect of a Chinese medicine named Kaiyuqingre formula （KYQRF） on β-cell function and its mechanisms of action therein. Methods High glucose was used to set up a model of β-cell function failure. At the same time, medicated serum of KYQRF with different doses were administered to the cells. Rosiglitazone was taken as a control to observe the changes in insulin secretion, ATP-sensitive K＋ channels （KATP channel） and uncoupling protein-2 （UCP-2） in each group. Results KYQRF had some effects on the insulin secretion. In a low glucose environment, no effective change in insulin secretion was observed （P 〉0.05）. However, insulin levels increased significantly when INS-1 cells were exposed to a high glucose environment （P 〈0.05）. KYQRF could also enhance cell viability （P 〈0.05） in an effect similar to rosiglitazone. Although KYQRF had no effect on inwardly rectifying potassium channels （Kir6.2） （P 〉0.05）, it could decrease the overexpression of both UCP-2 and sulfonylurea receptor 1 （P〈0.05）. Conclusion KYQRF can protect islet function by decreasing UCP-2 and sulfonylurea receptor 1.

Evaluating new biomarkers for diabetic nephropathy:Role ofα2-macroglobulin,podocalyxin,α-L-fucosidase,retinol-binding protein-4,and cystatin C

BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the roles and diagnostic values ofα2-macroglobulin(α2-MG),podocalyxin(PCX),α-L-fucosidase(AFU),retinol-binding protein-4(RBP-4),and cystatin C(CysC)in DN.METHODS From December 2018 to December 2020,203 T2DM patients were enrolled in the study.Of these,115 were diagnosed with DN(115 patients),while the remaining 88 patients were classified as non-DN.The urinary levels ofα2-MG,PCX,and AFU and the serum concentrations RBP-4 and CysC were measured in conjunction with other relevant clinical indicators to evaluate their potential correlations and diagnostic utility.RESULTS After adjustments for age and gender,significant positive correlations were observed between the biomarkers CysC,RBP-4,α2-MG/urinary creatinine(UCr),PCX/UCr,and AFU/UCr,and clinical indicators such as urinary albumin-to-creatinine ratio(UACR),serum creatinine,urea,24-h total urine protein,and neutrophil-to-lymphocyte ratio(NLR).Conversely,these biomarkers exhibited negative correlations with the estimated glomerular filtration rate(P<0.05).Receiver operating characteristic(ROC)curve analysis further demonstrated the diagnostic performance of these biomarkers,with UACR showcasing the highest area under the ROC curve(AUC^(ROC))at 0.97.CONCLUSION This study underscores the diagnostic significance ofα2-MG,PCX,and AFU in the development of DN.The biomarkers RBP-4,CysC,PCX,AFU,andα2-MG provide promising diagnostic insights,while UACR is the most potent diagnostic biomarker in assessing DN.

Bone morphogenetic protein-6 suppresses TGF-β_(2)-induced epithelial-mesenchymal transition in retinal pigment epithelium

AIM:To evaluate the effect of bone morphogenetic protein-6(BMP-6)on transforming growth factor(TGF)-β_(2)-induced epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE).METHODS:Adult retinal pigment epithelial cell line(ARPE-19)were randomly divided into control,TGF-β_(2)(5μg/L),and BMP-6 small interfering RNA(siRNA)group.The cell morphology was observed by microscopy,and the cell migration ability were detected by Transwell chamber.The EMT-related indexes and BMP-6 protein levels were detected by Western blotting.Furthermore,a BMP-6 overexpression plasmid was constructed and RPE cells were divided into the control group,TGF-β_(2)+empty plasmid group,BMP-6 overexpression group,and TGF-β_(2)+BMP-6 overexpression group.The EMT-related indexes and extracellular regulated protein kinases(ERK)protein levels were detected.RESULTS:Compared with the control group,the migration of RPE cells in the TGF-β_(2) group was significantly enhanced.TGF-β_(2) increased the protein expression levels ofα-smooth muscle actin(α-SMA),fibronectin and vimentin but significantly decreased the protein levels of E-cadherin and BMP-6(P<0.05)in RPE.Similarly,the migration of RPE cells in the BMP-6 siRNA group was also significantly enhanced.BMP-6 siRNA increased the protein expression levels ofα-SMA,fibronectin and vimentin but significantly decreased the protein expression levels of E-cadherin(P<0.05).Overexpression of BMP-6 inhibited the migration of RPE cells induced by TGF-β_(2) and prevented TGF-β_(2) from affecting EMT-related biomarkers(P<0.05).CONCLUSION:BMP-6 prevents the EMT in RPE cells induced by TGF-β_(2),which may provide a theoretical basis for the prevention and treatment of proliferative vitreoretinopathy.

Uncoupling protein 2 deficiency of non-cancerous tissues inhibits the progression of pancreatic cancer in mice

Background: Pancreatic ductal adenocarcinoma(PDAC) is a disease of the elderly mostly because its development from preneoplastic lesions depends on the accumulation of gene mutations and epigenetic alterations over time. How aging of non-cancerous tissues of the host affects tumor progression, however, remains largely unknown. Methods: We took advantage of a model of accelerated aging, uncoupling protein 2-deficient( Ucp2 knockout, Ucp2 KO) mice, to investigate the growth of orthotopically transplanted Ucp2 wild-type(WT) PDAC cells(cell lines Panc02 and 6606PDA) in vivo and to study strain-dependent differences of the PDAC microenvironment. Results: Measurements of tumor weights and quantification of proliferating cells indicated a significant growth advantage of Panc02 and 6606PDA cells in WT mice compared to Ucp2 KO mice. In tumors in the knockout strain, higher levels of interferon-γ m RNA despite similar numbers of tumor-infiltrating T cells were observed. 6606PDA cells triggered a stronger stromal reaction in Ucp2 KO mice than in WT animals. Accordingly, pancreatic stellate cells from Ucp2 KO mice proliferated at a higher rate than cells of the WT strain when they were incubated with conditioned media from PDAC cells. Conclusions: Ucp2 modulates PDAC microenvironment in a way that favors tumor progression and implicates an altered stromal response as one of the underlying mechanisms.

急性缺血性脑卒中患者血清解偶联蛋白2水平与病情严重程度及预后的相关性

目的 探讨解偶联蛋白2(UCP2)与急性缺血性脑卒中(AIS)患者病情严重程度和预后的相关性。方法 选取2020年1月—2022年1月成都市第六人民医院收治的180例AIS患者,根据患者神经功能缺损评估情况,将其分为轻度组57例、中度组89例、重度组34例,所有患者治疗90 d后,根据Rankin量表(mRS)评分将患者评为预后良好组115例和预后不良组65例。酶联免疫吸附法(ELISA)测定所有患者血清中UCP2的含量,并使用受试者工作特征(ROC)曲线预测血清UCP2的水平对AIS患者预后不良的价值;AIS患者预后的影响因素采用Logistic回归分析。结果 轻、中、重度组患者血清UCP2水平依次升高,差异具有统计学意义(P <0.05)。不明原因及其他原因脑卒中、大动脉粥样硬化型脑卒中、心源性脑卒中和小动脉闭塞型脑卒中UCP2水平比较,差异有统计学意义(P<0.05)。AIS患者梗死面积评分为(3.76±0.75)cm^(2),梗死面积≥4 cm^(2)患者血清UCP2水平高于梗死面积<4 cm^(2)患者,差异具有统计学意义(P<0.05)。预后不良组患者血清UCP2水平高于预后良好组,差异具有统计学意义(P<0.05)。UCP2、入院时NIHSS评分、发病到住院时间均是患者发生预后不良的影响因素(P<0.05)。UCP2水平预测AIS患者预后不良的曲线下面积(AUC)为0.847,截断值为5.398 mg/mL,特异性、敏感度分别为79.1%、81.5%,约登指数为0.606。结论 AIS患者血清UCP2水平显著升高,与疾病严重程度密切相关,且对患者预后具有良好的预测价值。

VEGFR2、miR-21、UCP1及UCP3在非小细胞肺癌组织中表达及与其预后的相关性分析

目的分析血管内皮细胞生长因子受体2(VEGFR2)、微小RNA-21(miR-21)、解偶联蛋白1(UCP1)、解偶联蛋白3(UCP3)在非小细胞肺癌(NSCLC)组织内的表达及与其预后的相关性。方法选取98例NSCLC患者,术中取其癌组织与癌旁正常组织,检测VEGFR2、miR-21、UCP1及UCP3表达;分析VEGFR2、miR-21、UCP1及UCP3表达与其临床病理特征的关系;随访1年,分析VEGFR2、miR-21、UCP1及UCP3表达与患者生存率的关系。结果癌组织内的VEGFR2、UCP1阳性表达率及miR-21相对表达量高于癌旁正常组织,UCP3阳性表达率低于癌旁正常组织,差异有统计学意义(P<0.05);VEGFR2、miR-21、UCP1及UCP3表达与淋巴结转移、临床分期、分化程度有关(P<0.05);VEGFR2、UCP1阳性表达及miR-21高表达患者的1年生存率分别低于VEGFR2、UCP1阴性表达及miR-21低表达患者,UCP3阳性表达患者的1年生存率高于UCP3阴性表达者,差异有统计学意义(P<0.05)。结论VEGFR2、miR-21、UCP1及UCP3在NSCLC癌组织内呈异常表达,与患者的预后具有紧密联系。

Mitochondrial uncoupling protein 2 expression in colon cancer and its clinical significance

AIM: To detect the expression of mitochondrial uncoupling protein 2 (UCP2) in colon cancer and analyze the relation between UCP2 expression and clinical pathological features of colon cancer.METHODS: Fifteen colon tissue samples and 15 its adjacent tissue samples were obtained from colon cancer patients during surgical interventions. UCP2 expression was detected with immunohistochemical method in 10 normal controls, 10 hyperplastic polyp patients, 20 tubular adenoma patients and 78 colon cancer patients. Patients with rectal cancer were excluded. Quantitative reverse transcription polymerase chain reaction and Western blotting were used to detect UCP2 expressions in colon cancer tissue samples and its adjacent tissue samples. Relation between UCP2 expression and clinical pathological features of colon cancer was also analyzed. RESULTS: The UCP2 mRNA expression level was fourfold higher in colon cancer tissue samples than in its adjacent tissue samples. The UCP2 protein expression level was three-fold higher in colon cancer tissue samples than in its adjacent normal tissue samples. The UCP2 was mainly expressed in cytoplasm. The UCP2 was not expressed in normal colon mucosa. Strong positive staining for UCP2 with a diffuse distribution pattern was identified throughout the mucosa in colon cancer tissue samples with a positive expression rate of 85.9%. The UCP2 expression level was higher in colon cancer tissue samples at clinical stages Ⅲ and Ⅳ than in those at stageⅠ+ Ⅱ. Univariate analysis showed that the high UCP2 expression level was significantly correlated to colon cancer metastasis (hazard ratio = 4.321, confidence interval = 0.035-0.682, P = 0.046). CONCLUSION: UCP2 is highly expressed in human colon cancer tissue and may be involved in colon cancer metastasis.

Mitochondrial uncoupling protein 2 and pancreatic cancer:A new potential target therapy

Overall 5-years survival of pancreatic cancer patients is nearly 5%,making this cancer type one of the most lethal neoplasia.Furthermore,the incidence rate of pancreatic cancer has a growing trend that determines a constant increase in the number of deceases caused by this pathology.The poor prognosis of pancreatic cancer is mainly caused by delayed diagnosis,early metastasis of tumor,and resistance to almost all tested cytotoxic drugs.In this respect,the identification of novel potential targets for new and efficient therapies should be strongly encouraged in order to improve the clinical management of pancreatic cancer.Some studies have shown that the mitochondrial uncoupling protein 2(UCP2) is over-expressed in pancreatic cancer as compared to adjacent normal tissues.In addition,recent discoveries established a key role of UCP2 in protecting cancer cells from an excessive production of mitochondrial superoxide ions and in the promotion of cancer cell metabolic reprogramming,including aerobic glycolysis stimulation,promotion of cancer progression.These observations together with the demonstration that UCP2 repression can synergize with standard chemotherapy to inhibit pancreatic cancer cell growth provide the molecular rationale to consider UCP2 as a potential therapeutic target for pancreatic cancer.In this editorial,recent advances describing the relationship between cancer development and mitochondrial UCP2 activity are critically provided.

过表达解偶联蛋白2抑制氧化应激减轻糖尿病小鼠心肌缺血再灌注损伤

目的:探讨过表达解偶联蛋白2(UCP2)减轻糖尿病小鼠心肌缺血再灌注损伤(IRI)的机制。方法:60只8周龄C57BL小鼠高脂喂养6周后,注射链脲佐菌素建立小鼠糖尿病模型,采用随机数字表法分为5组,假手术组(Sham组)、缺血再灌注组(I/R组)、UCP2抑制剂组(Genipin组)、空载9型腺相关病毒(AAV9-NC)组(AN组)和携带UCP2基因的AAV9组(AU组),每组12只。Sham组仅切开皮肤后缝合,其余4组开胸结扎冠状动脉左前降支,缺血60 min后松开结扎线结,再灌注120 min建立IRI模型。酶联免疫吸附试验检测血清肌钙蛋白I(cTnI)、丙二醛(MDA)、超氧化物歧化酶(SOD)水平,流式细胞仪观察活性氧(ROS)的产生情况,透射电镜观察线粒体超微结构的变化,Western blot检测UCP2的表达水平,超声心动图评估心功能。结果:与Sham组相比,I/R组、Genipin组、AN组及AU组cTnI、MDA水平明显升高,SOD水平明显下降,ROS产生增多,线粒体结构紊乱,每搏输出量(SV)、射血分数(EF)、左室短轴缩短率(FS)明显降低(P<0.05)。与I/R组相比,Genipin组cTnI、MDA水平明显升高,SOD水平明显下降,ROS产生增多,心肌结构严重受损,线粒体明显肿胀,SV、EF、FS明显降低(P<0.05)。与I/R组相比,AU组cTnI、MDA水平明显降低,SOD水平明显升高,ROS产生减少,心肌结构明显改善,线粒体肿胀减轻,SV、EF、FS的明显升高(P<0.05);AN组与I/R组c TnI、ROS、MDA、SOD、SV、EF、FS的差异无统计学意义,心肌组织和线粒体损伤程度相似。与Sham组相比,I/R组UCP2表达水平明显增加(P<0.05)。与I/R组相比,Genipin组UCP2表达水平明显降低,AU组UCP2表达水平明显增加(P<0.05),AN组与I/R组UCP2表达水平的差异无统计学意义(P>0.05)。结论:过表达的UCP2通过抑制ROS产生,降低氧化应激水平,改善糖尿病小鼠心肌IRI。

Hypertrophic cardiomyopathy secondary to deficiency in lysosomeassociated membrane protein-2: A case report

BACKGROUND Danon disease(DD),in which mutations in the X-linked lysosome-associated membrane protein-2(LAMP-2)gene result in hypertrophic cardiomyopathy,is a rare disease,reported primarily in small samples or cases.However,with the development of cardiac magnetic resonance imaging and genetic technology in recent years,the number of reports has increased.CASE SUMMARY We report a case of DD in an adolescent male patient,confirmed by genetic testing.The patient was admitted to our hospital with complaints of a three-year history of chest tightness and shortness of breath.His preliminary clinical diagnosis is hypertrophic cardiomyopathy.Our report includes the patient’s clinical course from hospital admission to death,step-by-step diagnosis,treatment course,and noninvasive imaging features.We highlight how a noninvasive diagnostic approach,based solely on clinical and imaging“red flags”for DD,can be used to achieve a diagnosis of DD with a high degree of confidence.CONCLUSION DD is a very dangerous cardiomyopathy,and it is necessary to achieve early diagnosis and treatment.

Uncoupling protein 2 regulates glucagon-like peptide-1 secretion in L-cells

AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.

Decreased uncoupling protein 2 expression in aging retinal pigment epithelial cells

AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal pigment epithelial-19(ARPE-19) cells and the primary RPE cells at the different age(9-20 y,50-55 y, 60-70 y, >70 y) were cultured and harvested. The expression of UCP2 in these cells was detected by reverse transcription-polymerase chain reaction(RT-PCR), Western blot and confocal microscopy.RESULTS: Cells from the donors more than 60 y are larger and more fibroblastic in appearance compared to ARPE-19 cells and those primary cultures obtained from the younger individuals by using phase-contrast micrographs. Results of RT-PCR, Western blot and confocal microscopy all showed that UCP2 was highly expressed in ARPE-19 cells and in the younger primary cultured human RPE cells at the age of 9-20 y and 50-55 y, whereas lower expression of UCP2 was measured in the older primary cultured human RPE cells at the age more than 60 y.CONCLUSION: Expression of UCP2 gene is decreased in aged RPE cells, promoting the lower ability of anti-oxidation in these cells. It is indicated that UCP2 gene might be a new target for protecting the cells from oxidative stress damage.

Uncoupling protein 2 deficiency reduces proliferative capacity of murine pancreatic stellate cells

BACKGROUND： Uncoupling protein 2 （UCP2） has been suggested to inhibit mitochondrial production of reactive oxygen species （ROS） by decreasing the mitochondrial membrane potential. Experimental acute pancreatitis is associated with increased UCP2 expression, whereas UCP2 deficiency retards regeneration of aged mice from acute pancreatitis. Here, we have addressed biological and molecular functions of UCP2 in pancreatic stellate cells （PSCs）, which are involved in pancreatic wound repair and fibrogenesis. METHODS： PSCs were isolated from 12 months old （aged） UCP2^-/- mice and animals of the wild-type （WT） strain C57BL/6. Proliferation and cell death were assessed by em- ploying trypan blue staining and a 5-bromo-2＇-deoxyuridine incorporation assay. Intracellular fat droplets were visualized by oil red O staining. Levels of mRNA were determined by RT-PCR, while protein expression was analyzed by immunoblotting and immunofluorescence analysis. Intracellular ROS levels were measured with 2＇,7＇-dichlorofluorescin diacetate. Expression of senescence-associated β-galactosidase （SA β-Gal） was used as a surrogate marker of cellular senescence. RESULTS： PSCs derived from UCP2^-/- mice proliferated at a lower rate than cells from WT mice. In agreement with this observation, the UCP2 inhibitor genipin displayed dose- dependent inhibitory effects on WT PSC growth. Interestingly, ROS levels in PSCs did not differ between the two strains, and PSCs derived from UCP2^-/- mice did not senesce faster than those from corresponding WT cells. PSCs from UCP2^-/- mice and WT animals were also indistinguishable with respect to the activation-dependent loss of intracellular fat droplets, expression of the activation marker α-smooth muscle actin, type I collagen and the autocrine/paracrine mediators interleukin-6 and transforming growth factor-I~ 1. CONCLUSIONS： A reduced proliferative capacity of PSC from aged UCP2^-/- mice may contribute to the retarded regeneration after acute pancreatitis. Apart from their slower growth, PSC of UCP2^-/- mice displayed no functional abnormalities. The antifibrotic potential of UCP2 inhibitors deserves further attention.

Uncoupling protein 2 regulates myocardial apoptosis via the diabetogenic action of streptozotocin

Objective: Determine the role of uncoupling protein 2 (UCP2) in the myocardial apoptosis of diabetic mellitus(DM). Methods: DM animal models were induced by streptozotocinon (STZ) on UCP2 knock-out mice (UCP2KO) and wild-type mice (WT), which were reared for 7 and 28 days after successful modeling, respectively. The expressions of relative protein for myocardial apoptosis, pro-caspase-9, were investigated using western blot. However, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) was used to explain apoptosis at the DNA level. Results: Image analysis showed that the expression of pro-caspase-9 protein levels increased slightly in UCP-/- + DM-7-day group comparing with DM-7-day group (P > 0.05). The expression of pro-caspase-9 protein levels increased significantly (P < 0.05)in UCP-/- + DM-28-day group comparing with DM-28-day group. TUNEL analysis indicated that UCP2 reduced the number of apoptotic myocytes in the DM-28-day group by 70% in comparison to DM-7-day group by 30% (P < 0.05). Conclusion UCP2 may be one of the most important factors that contribute to the myocardial apoptosis of DM.

血清UCP2水平对脓毒症诊断和预后评估的临床价值

目的探讨血清解偶联蛋白2(UCP2)水平对脓毒症的诊断价值和预后意义。方法选取2021年1月~2022年5月在四川省人民医院诊治的脓毒症患者104例(脓毒症组),根据28 d内预后情况将脓毒症患者分为存活组(n=68)与死亡组(n=36);另选取同期收治的局部感染患者100例作为对照组;检测患者入院24 h内血清UCP2、降钙素原(PCT)、C反应蛋白(CRP)、白细胞计数(WBC)、中性粒细胞(NEU)和血乳酸(Lac)等实验室指标;采用Spearman相关性检验对脓毒症患者血清UCP2水平与PCT水平进行相关性分析;采用多因素Logsitic回归模型分析各指标与脓毒症发生以及患者28 d预后的关系;并采用受试者工作特征(ROC)曲线评价各指标对脓毒症的诊断价值及预后预测价值。结果脓毒症组血清UCP2、PCT、CRP和Lac水平均显著高于对照组(P<0.05),两组WBC、NEU对比差异无统计学意义(P>0.05)。脓毒症患者血清UCP2水平与PCT水平呈正相关(r=0.351,P<0.05)。Logisitic回归分析显示,UCP2、PCT是脓毒症发生的独立危险因素(P<0.05),且是患者28 d死亡的独立危险因素(P<0.05)。ROC曲线分析显示,UCP2诊断脓毒症发生和预测患者28 d死亡的曲线下面积(AUC)分别为0.937、0.711。结论血清UCP2是脓毒症诊断的潜在标志物,其检测对于患者预后有预测意义。

Macrophage inflammatory protein-2 as mediator of inflammation in acute liver injury

Macrophage inflammatory protein(MIP)-2 is one of the CXC chemokines and is also known as chemokine CXC ligand(CXCL2). MIP-2 affects neutrophil recruitment and activation through the p38 mitogen-activatedprotein-kinase-dependent signaling pathway, by binding to its specific receptors, CXCR1 and CXCR2. MIP-2 is produced by a variety of cell types, such as macrophages, monocytes, epithelial cells, and hepatocytes, in response to infection or injury. In liver injury, activated Kupffer cells are known as the major source of MIP-2. MIP-2-recruited and activated neutrophils can accelerate liver inflammation by releasing various inflammatory mediators. Here, we give a brief introduction to the basic molecular and cellular sources of MIP-2, and focus on its physiological and pathological functions in acute liver injury induced by concanavalin A, lipopolysaccharides, irradiation, ischemia/reperfusion, alcohol, and hypoxia, and hepatectomy-induced liver regeneration and tumor colorectal metastasis. Further understanding of the regulatory mechanisms of MIP-2 secretion and activation may be helpful to develop MIP-2-targeted therapeutic strategies to prevent liver inflammation.

Drilling Combined with Adipose-derived Stem Cells and Bone Morphogenetic Protein-2 to Treat Femoral Head Epiphyseal Necrosis in Juvenile Rabbits

This study was designed to evaluate the effects of drilling through the growth plate and using adipose-derived stem cells （ADSCs） and bone morphogenetic protein-2 （BMP-2） to treat femoral head epiphyseal ischemic necrosis, which can be done in juvenile rabbits. Passagefour bromodeoxyuridine （BrdU）-labeled ADSCs were cultured, assayed with MTT to determine their viability and stained with alizarin red dye to determine their osteogenic ability. Twomonth-old, healthy male rabbits （1.2 to 1.4 kg, n=45） underwent ischemic induction and were randomly divided into five groups （group A： animal model control; group B： drilling; group C： drilling ＆ ADSCs; group D： drilling ＆ BMP-2; and group E： drilling ＆ ADSCs ＆ BMP-2）. Magnetic resonance imaging （MRI）, X-ray imaging, hematoxylin and eosin staining and BrdU immunofluorescence detection were applied 4, 6 and 10 weeks after treatment. Approximately 90% of the ADSCs were labeled with BrdU and showed good viability and osteogenic ability. Similar results were observed in the rabbits in groups C and E at weeks 6 and 10. The animals of groups C and E demonstrated normal hip structure and improved femoral epiphyseal quotients and trabecular areas compared with those of the groups A and B （P〈0.01）. Group D demonstrated improved femoral epiphyseal quotients and trabecular areas compared with those of groups A and B （P〈0.05）. In summary, drilling through the growth plate combined with ADSC and BMP-2 treatments induced new bone formation and protected the femoral head epiphysis from collapsing in a juvenile rabbit model of femoral head epiphyseal ischemic necrosis.