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, Volume 48 Issue 6 Previous Issue    Next Issue
Identification of dynamic co-expression networks in peripheral blood of rats after middle cerebral artery occlusion
PAN Zongfu,HU Xiaoping,ZHANG Yiwen,LI Li,HUANG Ping
J Zhejiang Univ (Med Sci), 2019, 48(6): 587-593.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.01
Abstract( 135 )   HTML( 34 )     PDF(1095KB)( 101 )

Objective: To identify the time dependent profiles of gene expression and featured co-expression network modules in peripheral blood of rats after middle cerebral artery occlusion (MCAO). Methods: Microarray GSE119121 from GEO database was analyzed by R language to identify the significantly changed genes in peripheral blood at different time points (0, 1, 2, 3, 6 and 24 h) after MCAO. Gene expression patterns at different time courses were screened by STEM tools. Then, function annotation and pathway enrichment of differentially expressed genes (DEGs) were performed using the Gene Ontology (GO) database and the Kyoto Gene and Genomic Encyclopedia (KEGG) database. Depending on CEMiTool package, gene expression profile matrix was inputted into R to construct the co-expression networks and to analyze modules, and enrichment analysis was conducted to evaluate the correlation between the modules and different time points. Results: Comparing with gene at 0 h, the numbers of DEGs in peripheral blood at different time points after MCAO were 163 (1 h), 502 (2 h), 527 (3 h), 550 (6 h), and 75 (24 h), respectively. Moreover, a total of 38 gene expression patterns were enriched, and pattern 65 and pattern 34 were specifically up-regulated or down-regulated at 2-6 h. Hp, Nos2, P2ry10, and Klf12 were representative genes of these two models. The co-expression network module analysis showed that the gene status in the early acute phase (1-6 h) was positively correlated with the Module 2. Module 3 and Module 4 was positively correlated with phase phase 1-3 h and 2-6 h, respectively. Noteworthy, Module 6 gradually changed from positive correlation (0-2 h) to negative correlation (3-24 h) with the MCAO time course, and Module 6 was mainly related to viral response and innate immune response. The hub genes of Module 6 included Mx1, Mx2, and Rtp4. Conclusion: Our study has identified the featured genes and dynamic co-expression network modules in peripheral blood after acute ischemic stroke, which provides a potential basis for judging the onset time of ischemic stroke.

Application of Logistic regression and decision tree analysis in prediction of acute myocardial infarction events
ZHANG Sheng,HU Zhenjie,YE Lu,ZHENG Yaru
J Zhejiang Univ (Med Sci), 2019, 48(6): 594-602.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.02
Abstract( 87 )   HTML( 13 )     PDF(1713KB)( 43 )

Objective: To evaluate the application of decision tree method and Logistic regression in the prediction of acute myocardial infarction (AMI) events. Methods: The clinical data of 295 patients, who underwent coronary angiography due to angina or chest pain with unidentified causes in Zhejiang provincial People's Hospital during October 2018 and April 2019, were retrospectively analyzed. Fifty five patients were identified as AMI. Logistic regression and decision tree methods were performed to establish predictive models for the occurrence of AMI, respectively; and the models created by decision tree analysis were divided into Logistic regression-independent model (Tree 1) and Logistic regression-dependent model (Tree 2). The performance of Logistic regression and decision tree models were compared using the area under the receiver operating characteristic (ROC) curve. Results: Logistic regression analysis showed that history of coronary artery disease, multi-vessel coronary artery disease, statin use and apolipoprotein (ApoA1) level were independent influencing factors of AMI events (all P < 0.05). Logistic regression-independent decision tree model (Tree 1) showed that multi-vessel coronary artery disease was the root node, and history of coronary artery disease, ApoA1 level (the cutoff value:1.314 g/L) and anti-platelet drug use were descendant nodes. In Logistic regression-dependent decision tree model (Tree 2), multi-vessel coronary artery disease was still the root node, but only followed by two descendant nodes including history of coronary artery disease and ApoA1 level. The area under the curve (AUC) of ROC of Logistic regression model was 0.826, and AUCs of decision tree models were 0.765 and 0.726, respectively. AUC of Logistic regression model was significantly higher than that of Tree 2 (95% CI=0.041-0.145, Z=3.534, P < 0.001), but was not higher than that of Tree 1 (95% CI=-0.014-0.121, Z=-1.173, P>0.05). Conclusion: The predictive value for AMI event was comparable between Logistic regression-independent decision tree model and Logistic regression model, implying the data mining methods are feasible and effective in AMI prevention and control.

Effects of acute hypoxia on expression of pregnane X receptor in liver tissues of rats exposed to high altitude
YUAN Xuechun,XIANG Dawei,MIN Qiong,DING Yidan,ZHAO Anpeng,WANG Rong
J Zhejiang Univ (Med Sci), 2019, 48(6): 603-608.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.03
Abstract( 46 )   HTML( 8 )     PDF(2858KB)( 47 )

Objective: To investigate the effects of high-altitude hypoxic environment on the expression of pregnane X receptor (PXR) in rat liver and related mechanism. Methods: Wistar rats were randomly divided into five groups with 8 rats in each group, the rats were exposed to high-plateau hypoxia for 0 (control group), 12, 24, 36 and 48 h, respectively. Abdominal aortic blood samples were collected for blood gas analysis. HE staining was used to observe the pathological changes of liver tissue. The expression levels of PXR mRNA in liver tissues were determined by RT-PCR. Western blot analysis was performed to determine the protein expression of PXR and protease SUG1 in liver tissues of rats. Results: Compared with the control group, the blood pH of the rats decreased after 12 h of acute hypoxia. After 24 h exposed to hypoxia, SaO2 was lower than 80%, PaO2 was lower than 60 mmHg (1 mmHg=0.133 kPa); and PaCO2 increased after 48 h exposed to hypoxia (P < 0.05). There was obvious edema in the central vein of the liver tissue at 12 h and 24 h after exposure to hypoxia. The liver tissue of the rats exposed to hypoxia for 36 h and 48 h showed inflammatory infiltration. The expression of PXR mRNA was significantly decreased by 63%, 96%, 86%, and 85%at 12, 24, 36 h, and 48 h after exposure to hypoxia (all P < 0.05), respectively. The protein expression of PXR was significantly up-regulated by 93%and 99%after 36 h and 48 h exposure to hypoxia (all P < 0.05), respectively. The protein expression of proteinase SUG1 decreased by 14%, 34%and 46%after 24, 36 and 48 h after hypoxia (all P < 0.01). Conclusion: Acute hypoxia at high altitude can affect the expression of nuclear receptor PXR in rat liver, and protease SUG1 may be a regulatory factor for PXR expression in hypoxia.

Expression of TLR4/MyD88/NF-κB pathway genes and its related inflammatory factors in secondary spinal cord injury
MI Shuang,WU Yanjun,HONG Zhenghua,WANG Zhangfu,FENG Xingbing,ZHENG Guangbin
J Zhejiang Univ (Med Sci), 2019, 48(6): 609-616.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.04
Abstract( 46 )   HTML( 9 )     PDF(1407KB)( 23 )

Objective: To investigate the expression of Toll-like receptor 4 (TLR4)/myeloid differentiation factor (MyD88)/nuclear factor-κB (NF-κB) pathway genes and related inflammatory factors tumor necrosis factor-α (TNF-α), interleukin (IL)-12, IL-6 in patients with secondary spinal cord injury (SSCI) and the correlations with prognosis. Methods: The clinical data of 105 SSCI patients and 40 healthy subjects were reviewed. According to Frankel's classification of spinal cord injury, the patients were divided into complete injury group and incomplete injury group, and according to the improvement of Japanese Orthopedic Association (JOA) scores, the patients were divided into good prognosis group and poor prognosis group. The expression of TLR4, MyD88, NF-κB in peripheral blood mononuclear cells (PBMC) and serum TNF-α, IL-12, IL-6 levels were compared between SSCI patients and healthy controls, between patients with complete and incomplete injury, between patients with poor and good prognosis. Logistic regression analysis was used to analyze the risk factors leading to poor prognosis of SSCI, and Pearson's correlation analysis was used to analyze the correlation between JOA score and the above indicators. Results: The expressions of TLR4, MyD88, NF-κB in PBMC and serum TNF-α, IL-12, IL-6 levels in SSCI patients were significantly higher than those in healthy subjects (all P < 0.01), those in complete injury group were higher than those in incomplete injury group, and those in poor prognosis group were higher than those in good prognosis group (all P < 0.01). The proportions of patients with Frankel grade A, spinal cord edema or hemorrhage, spinal cord injury length longer than 4 cm in poor prognosis group was significantly higher than those in good prognosis group (all P < 0.01). Logistic regression analysis showed that Frankel grade, spinal cord edema or hemorrhage, length of spinal cord injury, relative expressions of TLR4, MyD88, NF-κB in PBMC, serum levels of TNF-α, IL-12 and IL-6 were risk factors for poor prognosis in SSCI patients (P < 0.05 or P < 0.01). Pearson's correlation analysis showed that JOA improvement rate was negatively correlated with the relative expressions of TLR4, MyD88, NF-κB mRNA in PBMC and serum TNF-α, IL-12, IL-6 levels (P < 0.05 or P < 0.01). Conclusion: The activation of TLR4/MyD88/NF-κB pathway and the up-regulation of the expression of related inflammatory factors TNF-α, IL-12 and IL-6 are involved in the progression of SSCI, which are closely related to the neuroinflammatory injury, and can be used as reference indexes for evaluating prognosis in SSCI patients.

Effects of resveratrol on aging of mesenchymal stem cells and its mechanism
ZHANG Dayong,LIN Jiuzhou,WANG Yayan,XU Shan,LUO Chengzhuan,CAI Jiaye,JIANG Xuefan,PAN Jianping
J Zhejiang Univ (Med Sci), 2019, 48(6): 617-624.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.05
Abstract( 91 )   HTML( 10 )     PDF(8207KB)( 39 )

Objective: To investigate the effects of resveratrol (Res) on aging of marrow mesenchymal stem cells (MSCs), and to explore its mechanism. Methods: MSCs were isolated from young SD rats and cultured in vitro. The optimal D-gal concentration for induction of MSCs senescence was determined. Then MSCs were randomly divided into four groups, namely the control group, 10μmol/L, 50μmol/L and 100μmol/L Res groups. After the cells were treated with different concentration of Res for 48 h, the senescence-associated changes were examined with senescence-associated-β-galactosidase (SA-β-gal) staining; the expression of p53, p16 and γ-H2AX was evaluated by Western blot. The total active oxygen species (ROS) level was determined by flow cytometry with DCFH-DA staining. In order to assess the effect of Res on the mitochondrial function, MitoSox Red staining was used to detect mitochondrial ROS levels in each group, mitochondrial membrane potential was detected by JC-1 assay, mPTP method was used to detect mitochondrial membrane channel opening level, and Western blot was used to detect the expression level of cytoplasmic cytochrome C (Cyt-C). Results: D-gal 10 and 50 g/L significantly increased the number of SA-β-gal positive cells and the level of mitochondrial ROS (all P < 0.01). Therefore, 10 g/L D-gal was used to induce the senescence of MSCs in subsequent experiment. Compared with the control group, the number of SA-β-gal positive cells in Res groups significantly decreased (all P < 0.01), the expression of p53, p16 and γ-H2AX decreased, and the total and mitochondrial ROS level also decreased (all P < 0.01). Moreover, mitochondrial membrane potential, open level of mitochondrial membrane channels and the levels of cytoplasm Cyt-C in the Res treatment groups decreased compared with the control group (P < 0.05 or P < 0.01). Conclusion: Resveratrol can protect the mitochondrial function of MSCs, and effectively delay the MSC senescence.

Stilbene glucoside inhibits ultraviolet radiation B-induced photoaging in human skin fibroblasts
XU Meijiao,WANG Yifeng
J Zhejiang Univ (Med Sci), 2019, 48(6): 625-630.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.06
Abstract( 23 )   HTML( 4 )     PDF(4258KB)( 16 )

Objective: To study the effects of tetrahydroxy stilbene-2-O-β-D-glucoside (TSG) on stress-induced premature senescence of human skin fibroblasts (HSF) exposed to ultraviolet radiation B (UVB) and its possible mechanism. Methods: HSFs were repeatedly exposed to UVB at a subcytotoxic level. TSG treatment (0.02, 0.10 and 0.50 mmol/L) was given immediately after each irradiation. The HSFs were divided into six groups:blank control group, model group, UVB+0.02 mmol/L TSG group, UVB+0.10 mmol/L TSG group, UVB+0.50 mmol/L TSG and TSG group (0.50 mmol/L). Cell counting kit-8 (CCK-8) was used to evaluate the proliferative activity of cells; senescence-associated-β-galactosidase (SA-β-gal) staining was performed to estimate the degree of premature senescence in cells; TBA method and WST-1 method were used to detect intracellular malondialdehyde (MDA) and superoxide dismutase (SOD) activities; and ELISA was applied to quantify the secretion level of matrix metalloproteinase1 (MMP-1) in cultured supernatant. Results: Compared with the blank control group, the proliferative activity and SOD level in the model group decreased (P < 0.05), while the percentage of SA-β-gal-positive cells, MDA and MMP-1 levels increased (P < 0.05 or P < 0.01). Compared with the model group, the proliferative activity and SOD level increased in UVB+TSG groups (all P < 0.05), and the percentage of SA-β-gal-positive cells, MDA and MMP-1 levels decreased (P < 0.05 or P < 0.01). Conclusion: TSG can inhibit UVB-induced premature senescence of HSF, which may be related to the inhibition of oxidative stress and high expression of MMP-1.

Chloroxoquinoline inhibits invasion in breast cancer via down-regulating Rho/Rho kinase signaling pathway
LIU Jingwen,YANG Xinglian,SHEN Kaili,ZENG Linghui,SUN Yan
J Zhejiang Univ (Med Sci), 2019, 48(6): 631-637.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.07
Abstract( 62 )   HTML( 5 )     PDF(8655KB)( 35 )

Objective: To investigate the effect of chloroxoquinoline on cytoskeleton of breast cancer cells and its relation with Rho/Rho kinase signaling pathway. Methods: Breast cancer Bcap37 and MDA-MB-453 cells were treated with different concentrations of chloroxoquinoline. Wound healing and Transwell assay were conducted to detect cell migration and invasion, respectively. Rhodamine-phalloidin staining and immunofluorescent staining were used to observe the polymerization state of F-actin and the expression of α-Tublin in breast cancer cells, respectively. Western blot was used to detect the phosphorylation level of key protein in Rho/Rho kinase signaling pathway. Results: Compared with the control group, chloroxoquinoline treatment induced dose-dependent decrease in cell migration and invasion, and Bcap37 and MDA-MB-453 cells treated with chloroxoquinoline showed dose-dependent changes in cell morphology and decrease in cell body. The staining of F-actin and α-Tublin was irregular and clustered. Furthermore, treatment of chloroxoquinoline down-regulated the phosphorylation of the Rho/Rho kinase signaling proteins Cofilin, Limk and Rock2 (all P < 0.01). Conclusions: Chloroxoquinoline inhibits the cytoskeleton in breast cancer Bcap37 and MDA-MB-453 cells and inhibits cell migration. This effect may be associated with down-regulation of Rho/Rho kinase signaling pathway.

Effect of genipin pretreatment on type Ⅰ collagen mineralization
GU Tianyi,SHUAI Jing,CHEN Chaoqun,FENG Jianying
J Zhejiang Univ (Med Sci), 2019, 48(6): 638-643.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.08
Abstract( 39 )   HTML( 3 )     PDF(6910KB)( 13 )

Objective: To investigate the effects of bio-crosslinker genipin pretreatment on type Ⅰ collagen mineralization. Methods: Type Ⅰ collagen gels were prepared and pretreated with 0.5wt%genipin (experimental group) and deionized water (control group) for 2 h, respectively. The pretreated products were subjected to Fourier transform infrared spectroscopy (FT-IR). Reconstituted collagen fibrils were pretreated with genipin or deionized water for 2 h and were mineralized for 4 h. The collagen density and mineralization degree were examined with transmission electron microscopy (TEM) and analyzed with ImageJ software. Then scanning electron microscopy (SEM) and TEM were used to observe the mineralization of cross-linked demineralized dentin collagen. Results: FT-IR spectrum showed that the genipin was crosslinked with collagen. TEM observation and ImageJ results showed that after 4 h mineralization, the mineralization effect of 0.5wt% genipin group was significantly better than that of the control group[(73.3±5.3)%vs.(7.4±3.5)%, P < 0.01]. TEM and SEM observation showed that the mineralization rate of type Ⅰ collagen and demineralized dentin pretreated with genipin were significantly faster than that of the control group. Conclusion: The study demonstrates that 0.5 wt% concentration of genipin can significantly promote the mineralization of type Ⅰ collagen.

Correlation of cardiovascular risk factors with brain iron deposition: A magnetic resonance imaging study
HU Linlin,ZHANG Ruiting,WANG Shuyue,HONG Hui,HUANG Peiyu,ZHANG Minming
J Zhejiang Univ (Med Sci), 2019, 48(6): 644-650.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.09
Abstract( 55 )   HTML( 5 )     PDF(1110KB)( 30 )

Objective: To study the correlation of common cardiovascular risk factors with brain iron deposition. Methods: Eighty-four elderly subjects without neurological diseases or brain trauma were included in the study. The cardiovascular risk factors were comprehensively assessed. MRI examination was performed to obtain high-resolution T1-weighted images and enhanced susceptibility weighted angiography (ESWAN) images, and R2* figure was obtained by post-processing the ESWAN sequence. High definition T1 images were segmented using computer segmentation technique. After registration to the ESWAN image, R2* values of each region of interest were extracted. Multiple linear regression analysis was used to analyze the relationship of R2* values in each area of interest with gender, age and vascular risk factors. Results: Smoking was associated with increased R2* values in the hippocampus, white matter and cortex (β=0.244, 0.317, 0.277, P < 0.05 or P < 0.01). Hypertension was correlated with the increase of R2* in the putamen (β=0.241, P=0.027). Hyperglycemia was associated with the increase of R2* in the thalamus (β=0.234, P < 0.05). In the thalamus, the R2* value of males was higher than that of females (β=0.320, P < 0.05). Age was correlated with the R2* values of thalamus, caudate nucleus, pallidus, white matter and cortex (β=-0.218、-0.254、0.216、-0.280 and -0.238, P < 0.05 or P < 0.01). Conclusion: Common cardiovascular risk factors may lead to iron deposition in the brain, and the deposition patterns vary with the gender, age and different risk factors.

Internal fixation of lateral and medial borders for displaced scapular body fractures via minimally invasive approach: results of 23 cases
GAO Mingxuan,NIE Dejun,CHANG Yanfeng,XIE Weiqiang,WANG Yue,PU Xingyu,ZHANG Wei,LUO Wenyuan
J Zhejiang Univ (Med Sci), 2019, 48(6): 651-656.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.10
Abstract( 47 )   HTML( 4 )     PDF(3118KB)( 36 )

Objective: To evaluate the efficacy of internal fixation of lateral and medial borders for displaced scapular body fractures via the minimally invasive approach. Methods: The internal fixation of lateral and medial borders via minimally invasive approach was applied in surgical treatment of 23 patients with scapular body comminuted fractures from January 2014 to June 2018. The lateral approach was made straightly orienting over the lateral border of scapula. The dissection was taken down to the deltoid fascia. The deltoid was retracted cephalically, revealing the external rotators. Blunt dissection was used down to the lateral border between infraspinatus and teres minor, exposing the fracture site. The medial incision was done along the medial border of the scapula over site of the fracture. Dissections were taken down to the fascia and the periosteum. A subperiosteal dissection was then performed to elevate the infraspinatus to the degree necessary to visualize the fracture. The medial and lateral borders of scapula body were fixed with plates and screws in a frame-like way. Results: One patient developed the delayed healing of the incisions due to liquefactive fat necrosis. The other 22 patients showed no complications of the incisions. The glenopolar angle (GPA) of fractured scapula was increased from preoperative (25±12) degrees to postoperative (41±5) degrees (P < 0.01). The healing time of fractures healed was 3-8 months, with an average time of (4.4±1.3) months. Conclusion: The lateral-medial combined fixation through minimally invasive surgical approach for the scapula body fractures allows visualization of fracture reduction without extensive muscular or subcutaneous flaps, and is associated with successful fracture healing and high functional scores of the shoulder.

Synthesis and cell biological properties of polyaspartic acid drug/gene vector
SHEN Jie,WANG Qiwen,GAO Dongruo,LYU Yuanyuan,TANG Guping
J Zhejiang Univ (Med Sci), 2019, 48(6): 657-667.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.11
Abstract( 51 )   HTML( 3 )     PDF(7966KB)( 35 )

Objective: Taking polysuccinimide as the main chain, amine side chain and alkyl side chain were grafted to prepare the drug/gene co-delivery vector. The property of the polymers with various side links were investigated to select an optimal vector. Methods: Poly-D, L-polysuccinimide was synthesized by polymerization reaction of D, L-aspartic acid as monomer. Therefore, N, N-dimethylenedipropyl-triamine and 3, 3'-diaminodipropylamine were grafted with dodecylamine/adecylamine/octadecylamine at different proportions by ring-opening reaction to obtain amphiphilic PEECs. The structure of the material was confirmed by 1H NMR; the particle size and surface potential of the micelles were measured by dynamic light scattering; the critical micelle concentration (CMC) was determined by pyrene fluorescent probe; the RNA blocking ability was characterized by agarose gel electrophoresis; the release behavior of the PEECs was examined and the cytotoxicity, cellular uptake and gene silencing efficiency of the PEECs were studied at the cellular level. Results: A series of PEECs with different grafting rates was successfully synthesized. The particle sizes and surface potential of the PEEC derived micelles were between 250 nm and 350 nm and 27 mV and 45 mV, respectively, with a small CMC value. The RNA binding ratio of PEECs was at a mass ratio of about 0.8:1. MTT assay demonstrated that PEEC micelles had certain cytotoxicity. PEECs had excellent micelle formation, drug-loading and gene binding abilities, particularly, PEEC16-2 showed high gene silencing efficiency at the cellular level. Conclusion: PEECs are able to co-delivery drug and gene, and PEEC16-2 micelles have the best ability of drug encapsulation and gene delivery.

Research progress on the effects of plateau hypoxia on blood-brain barrier structure and drug permeability
DING Yidan,LI Wenbin,WANG Rong,ZHANG Jianchun
J Zhejiang Univ (Med Sci), 2019, 48(6): 668-673.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.12
Abstract( 73 )   HTML( 5 )     PDF(1049KB)( 43 )

Drugs for the treatment of central nervous system diseases need to enter the brain tissue through the blood-brain barrier to function. In high altitude hypoxic environment, there are changes in tight junction proteins of blood-brain barrier tissue structure, transporters in astrocytes and endothelial cells and ATP in endothelial cells; at the same time the permeability of the blood-brain barrier is increased. These changes are an important reference for rational drug use in patients with central nervous system disease in the plateau region. This article reviews the research progress on the effects of plateau hypoxia on the structure of the blood-brain barrier and related drug permeability.

Research progress on mechanism in adaptation of hemoglobin to plateau hypoxia
LI Xue,LI Wenbin,FENG Shilan,WANG Rong
J Zhejiang Univ (Med Sci), 2019, 48(6): 674-681.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.13
Abstract( 96 )   HTML( 3 )     PDF(3449KB)( 33 )

Low oxygen partial pressure is the main cause of acute mountain sickness.Hemoglobin plays a crucial physiological role in the binding, utilization, transportation and release of oxygen in the body. To increase the capacity of oxygen binding of hemoglobin or the capacity of oxygen supply in tissues can help alleviate altitude sickness. However, increasing hemoglobin content has certain limitations. Using techniques from molecular biology, researchers are looking for endogenous or exogenous substances that can regulate the conformation of hemoglobin to increase oxygen uptake in the alveoli, or the availability of alveolar oxygen in the tissues. At present, the research on allosteric modulators to improve the affinity of hemoglobin has made some progress, and research on applying this mechanism to plateau hypoxia is also underway. This article reviews the relationship between hemoglobin and hypoxia, the structure of hemoglobin and the role of various allosteric modulators in hypoxia, which would provide information for finding new substances regulating the conformation of hemoglobin.

Correlation between histone methylation level and pathological development of osteoarthritis
DU Xiaotian,OUYANG Hongwei
J Zhejiang Univ (Med Sci), 2019, 48(6): 682-687.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.14
Abstract( 80 )   HTML( 5 )     PDF(1056KB)( 38 )

Osteoarthritis is the most common degenerative cartilage disease. A large number of studies have shown the close association between epigenetics and osteoarthritis. Histone methylation is a type of epigenetic modification, and the link between histone methylation and osteoarthritis has also been revealed. In this article, we summarize the correlation between methylation levels of different histones and osteoarthritis in an attempt to explore the changes and regulation mechanisms of histone methylation in osteoarthritis. It has been shown that there are possible relations between the methylation levels of different amino acids on histone H3 and the pathological development of osteoarthritis; specifically, the rise of methylation level at the lysine 4 would aggravate the pathological development of osteoarthritis, while the the pattern of lysine 9 and 27 would be the opposite. These results indicate the possible existence of a complex network of histone methylation modifications. And the specific regulation of histone methylation levels in different positions may delay or prevent the occurrence and development of osteoarthritis.

Research progress on selective immunoproteasome inhibitors
KONG Limin,LU Jingyi,ZHU Huajian,ZHANG Jiankang
J Zhejiang Univ (Med Sci), 2019, 48(6): 688-694.   https://doi.org/10.3785/j.issn.1008-9292.2019.12.15
Abstract( 165 )   HTML( 5 )     PDF(2094KB)( 96 )

Immunoproteasome is associated with various diseases such as hematologic malignancies, inflammatory, autoimmune and central nervous system diseases, and over expression of immunoproteasome is observed in all of these diseases. Immunoproteasome inhibitors can reduce the expression of immunoproteasome by inhibiting the production of related cell-inducing factors and the activity of T lymphocyte for treating related diseases. In order to achieve good efficacy and reduce the toxic effects, key for development of selective immunoproteasome inhibitors is the high selectivity and potent activity of the three active subunits of the proteasome. This review summarizes the structure and functions of immunoproteasome and the associated diseases. Besides, structure, activity and status of selective immunoproteasome inhibitors are also been highlighted.

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