Role of post-translational modification of basic leucine zipper transcription factors in response to abiotic stresses in plants / 生物工程学报

Abiotic stresses substantially affect the growth and development of plants. Plants have evolved multiple strategies to cope with the environmental stresses, among which transcription factors play an important role in regulating the tolerance to abiotic stresses. Basic leucine zipper transcription factors (bZIP) are one of the largest gene families. The stability and activity of bZIP transcription factors could be regulated by different post-translational modifications (PTMs) in response to various intracellular or extracellular stresses. This paper introduces the structural feature and classification of bZIP transcription factors, followed by summarizing the PTMs of bZIP transcription factors, such as phosphorylation, ubiquitination and small ubiquitin-like modifier (SUMO) modification, in response to abiotic stresses. In addition, future perspectives were prospected, which may facilitate cultivating excellent stress-resistant crop varieties by regulating the PTMs of bZIP transcription factors.

Transcription factor EB attenuates neuronal damage following cerebral ischemia via regulating autophagy-lysosomal pathway / 国际脑血管病杂志

The disorder of autophagy lysosomal pathway (ALP) is an important pathogenesis of neuronal damage after cerebral ischemia, and the restoration of ALP may alleviate neuronal damage after cerebral ischemia. As the main transcription factor regulating ALP, transcription factor EB (TFEB) can directly regulate autophagosome generation, autophagosome-lysosome fusion, and autophagic flux by regulating the expression of autophagic genes and lysosomal genes. Therefore, regulating TFEB can alleviate ALP dysfunction and thereby reduce cerebral ischemic damage. This article reviews the structure, biological function of TFEB and its role in regulating ALP to alleviate neuronal damage after cerebral ischemia.

Expression of BZW2 and IVD in hepatocellular carcinoma tissues and effect on prognosis of liver transplant recipients with hepatocellular carcinoma / 器官移植

Objective To investigate the expression levels of basic leucine zipper and W2 domain 2 (BZW2) and isovaleryl-CoA dehydrogenase (IVD) in hepatocellular carcinoma (HCC) and evaluate their effect on clinical prognosis of liver transplant recipients with HCC. Methods Pathological specimens and clinical data of 87 liver transplant recipients with HCC were collected and retrospectively analyzed. The recurrence and metastasis of HCC after liver transplantation were assessed. Immunohistochemical staining was used to detect the expression levels of BZW2 and IVD. The relationship between BZW2, IVD and clinicopathological parameters of HCC and their effect on postoperative recurrence and clinical prognosis of the recipients was analyzed. Results Among 87 recipients, 31 cases recurred with a recurrence rate of 36%. HCC recurred at postoperative 2-49 months and the median recurrence time was postoperative 7 months. Immunohistochemical staining demonstrated that the positive expression rate of BZW2 in the HCC tissues was significantly higher than that in normal liver tissues (76% vs. 30%), and the positive expression rate of IVD was significantly lower compared with that in normal liver tissues (51% vs. 69%) (both P < 0.01). BZW2 expression was significantly correlated with tumor diameter and tumor capsule (both P < 0.05), whereas IVD expression was significantly associated with tumor diameter, alpha-fetoprotein (AFP) level, tumor, node and metastasis (TNM) staging and whether vascular invasion was found or not (all P < 0.05). In the high BZW2 expression group, the cumulative recurrence rate of HCC was significantly higher and the cumulative survival rate was significantly lower than those in the low BZW2 expression group. In the low IVD expression group, the cumulative recurrence rate of HCC was significantly higher and the cumulative survival rate was significantly lower compared with those in the high IVD expression group (all P < 0.05). Conclusions The expression level of BZW2 protein is up-regulated, whereas that of IVD protein is down-regulated in the HCC tissues. Moreover, the cumulative recurrence rate of HCC is relatively high and the cumulative survival rate is relatively low in liver transplant recipients with high BZW2 expression and low IVD expression.

The expression of leucine zipper EF-hand domain transmembrane protein 1, sodium hydrogen exchange protein 1 and adenylate cyclase related protein 2 in gastric cancer tissues and their predictive value for postoperative recurrence / 中国医师进修杂志

Objective:To investigate the expression of leucine zipper EF-hand domain transmembrane protein 1 (LETM1), sodium hydrogen exchange protein 1 (NHE-1) and adenylate cyclase related protein 2 (CAP2) in gastric cancer tissues and the predictive value for postoperative recurrence.Methods:The clinical data of 92 patients with early gastric cancer who underwent surgical treatment from January 2017 to January 2020 in Jiangsu Haimen People′s Hospital were retrospectively analyzed. According to the recurrence condition 6 months after operation, the patients were divided into recurrence group (16 cases) and non recurrence group (76 cases). The expression levels of LETM1, NHE-1 and CAP2 mRNA in cancer tissues and adjacent tissues were detected by real time fluorescent quantitative polymerase chain reaction. Multifactor Logistic regression analysis was used to analyze the related influencing factors of postoperative recurrence. The receiver operating characteristic (ROC) curve was drawn, and the effectiveness of LETM1, NHE-1 and CAP2 mRNA in predicting recurrence was analyzed. The Kaplan-Meier survival curve was drawn, and the survival rate was analyzed in patients with different expression levels of LETM1, NHE-1 and CAP2 mRNA.Results:The LETM1, NHE-1 and CAP2 mRNA in cancer tissues were significantly higher than those in adjacent tissues (0.41±0.12 vs. 0.22±0.07, 0.85±0.27 vs. 0.49±0.15 and 0.31±0.10 vs. 0.19±0.06), and there were statistical differences ( P<0.01). The proportion of N 1 stage in recurrent group was significantly higher than that in non recurrent group: 9/16 vs. 22.37% (17/76), and there was statistical difference ( P<0.05); the LETM1, NHE-1 and CAP2 mRNA of cancer tissues in recurrent group were significantly higher than those in non recurrent group (0.61±0.20 vs. 0.37±0.13, 1.24±0.38 vs. 0.77±0.21 and 0.60±0.19 vs. 0.25±0.10), and there were statistical differences ( P<0.01). Multifactor Logistic regression analysis result showed that, after controlled N stages, the LETM1, NHE-1 and CAP2 mRNA were still independent risk factors for postoperative recurrence in patients with gastric cancer ( OR = 1.52, 3.11 and 1.21; 95% CI 1.26 to 1.82, 2.36 to 4.09 and 1.04 to 1.41; P<0.01). ROC curve analysis result showed that the area under the curve (AUC) of LETM1, NHE-1 and CAP2 mRNA for predicting postoperative recurrence in patients with gastric cancer were 0.768, 0.802 and 0.850, respectively. The AUC of combination the indexes for predicting postoperative recurrence in patients with gastric cancer was 0.965. According to the cut-off value of ROC curve, the patients were divided into LETM1 mRNA high expression (>0.54, 30 cases) and low expression (≤0.54, 62 cases), NHE-1 mRNA high expression (>1.09, 35 cases) and low expression (≤1.09, 57 cases), CAP2 mRNA high expression (>0.49, 28 cases) and low expression (≤0.49, 64 cases). Kaplan-Meier survival curve analysis result showed that the survival rates in patients with high expression of LETM1, NHE-1 and CAP2 mRNA were significantly lower than those in patients with low expression (73.33% vs. 98.39%, 80.00% vs. 96.49% and 78.57% vs. 95.31%), and there were statistical differences ( χ2 = 15.08, 6.95 and 6.75, P<0.01). Conclusions:LETM1, NHE-1 and CAP2 mRNA are related to the recurrence of early gastric cancer after surgery. The detection of the 3 markers is expected to provide a new strategy for the prediction of postoperative recurrence.

Expression of maternal embryonic leucine zipper kinase (MELK) in lung adenocarcinoma and its correlation with prognosis / 国际生物医学工程杂志

Objective:To detect the expression of maternal embryo leucine zipper kinase (MELK) in lung adenocarcinoma, and to explore the clinical prognosis of MELK and lung adenocarcinoma, andto explore the possibility of MELK as a potential biomarker for lung adenocarcinoma.Methods:The mRNA level of MELK in lung adenocarcinoma and normal tissues adjacent to the cancer was analyzed by bioinformatics methods, and the relationship between its expression and the survival rate of patients with lung adenocarcinoma was analyzed. The clinicopathological data of 70 patients with lung adenocarcinoma who underwent surgical treatment were retrospectively analyzed. Immunohistochemical method was used to detect the expression level of MELK protein in lung adenocarcinoma tissue and normal tissues adjacent to the cancer, and to analyze its relationship with clinicopathological characteristics of patients with lung adenocarcinoma.Results:The results of bioinformatics analysis showed that MELK mRNA was significantly highly expressed in lung adenocarcinoma tissue, and was significantly correlated with the overall survival rate ( P=0.009) and disease-free survival rate ( P=0.039) of patients. Immunohistochemical results showed that the expression of MELK in lung adenocarcinoma tissue was significantly higher than that in normal tissues adjacent to the cancer. The high expression of MELK in lung adenocarcinoma tissue was related to tumor size ( P=0.015) and tumor stage ( P=0.006), but not related to age, gender, smoking, tumor differentiation, and lymph node metastasis (all P>0.05). Conclusions:MELK is highly expressed in lung adenocarcinoma tissues and indicates a poor prognosis, and its expression level is related to the tumor stage of lung adenocarcinoma. MELK may serve as a new prognostic biomarker and potential therapeutic targetfor lung adenocarcinoma.

LZTS2 inhibits proliferation, migration and EMT of breast cancer cells by modulating PI3K/AKT signaling pathway / 中国肿瘤生物治疗杂志

@# Objective: To evaluate the expression of leucine zipper tumor suppressor 2 (LZTS2) in human breast cancer tissues and cell lines, and to investigate the effects and mechanisms of LZTS2 over-expression on proliferation, invasion and epithelial-mesenchymal transition (EMT) of breast cancer cells. Methods: Fifty pairs of cancerous tissues and para-cancerous tissues resected from breast cancer patients in Department of Breast Surgery of Kaifeng Central Hospital from January, 2016 to December, 2016, as well as breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-468) and normal mammary epithelial HBL-100 cells were collected for this study; and Real-time quantitative PCR (qPCR) and Western blotting were used to determine the mRNA and protein expressions of LZTS2 in collected tissues and cell lines. MCF-7 cells were transfected with pcDNA-LZTS2 or pcDNA3.1 (negative control) using lipofectamineTM 2000, and the protein expression of LZTS2 at 49-72 h after transfection was measured by Western blotting; Then, the effects of LZTS2 over-expression on proliferation, migration and invasion of MCF-7 cells were detected by MTT assay and Transwell assay, respectively; Furthermore, Western blotting was performed to detect the expressions of EMT associated proteins (Cyclin D1, Vimentin, Ncadherin, E-cadherin) and PI3K/AKT signaling pathways-related molecules. Results: The mRNA and protein expressions of LZTS2 were down-regulated in breast cancerous tissues and cell lines (MCF-7, MDA-MB-468 and MDA-MB-231) as compared with paired para-cancerous tissues or normal mammary epithelial HBL-100 cells (P<0.05 or P<0.01). Compared with and blank control or pcDNA3.1 group, the protein expression of LZTS2 in MCF-7 cells of pcDNA-LZTS2 group significantly increased (P<0.01), while the proliferation, migration and invasion of MCF-7 cells significantly reduced (P<0.05 or P<0.01). In addition, forced expression of LZTS2 significantly down-regulated the protein expressions of Cyclin D1, Vimentin and N-cadherin (P<0.05 or P<0.01) but up-regulated the expression of E-cadherin in MCF-7 cells (P<0.01), indicating LZTS2 over-expression suppressed PI3K / AKT signaling pathway through inhibiting the expression p-PI3K and p-AKT. Conclusion: The findings collectively demonstrated that the expression of LZTS2 was decreased in breast cancer, and over-expression of LZTS2 efficiently inhibited the proliferation, migration and invasion of breast cancer cells, which might be related with the suppression of PI3K/AKT signaling pathway involved in EMT.

Expression of maternal embryonic leucine zipper kinase in esophageal squamous cell carcinoma and its significance / 肿瘤研究与临床

Objective To investigate the expression of maternal embryonic leucine zipper kinase (MELK) in esophageal squamous cell carcinoma and its significance. Methods The surgical resection specimens of 139 patients with esophageal squamous cell carcinoma who were admitted to Peking University Cancer Hospital from August 2009 to July 2013 were selected. MELK expression in esophageal squamous cell cancer tissues was detected by immunohistochemistry. The relationship between MELK expression and clinicopathological characteristics of patients was analyzed. MELK expression in 6 esophageal squamous cell carcinoma cell lines (ECA109, KYSE150, KYSE30, KYSE70, KYSE180 and KYSE510) was tested by Western blot, and the cell line with high MELK expression was selected, and the expression of MELK was knocked down by lentiviral infection. The effect of MELK on tumor cell migration and invasion was examined by Transwell method, and the effect of MELK on cell proliferation was verified by CCK-8 method. Results MELK is highly expressed in 100 cases (71.9％) of esophageal squamous cell carcinoma, and the positive expression rate of MELK in patients with stage T3-T4 was higher than that in patients with stage T1-T2 (χ2=4.702, P= 0.030). The poor differentiation and lymph node metastasis inclined to higher MELK positive expression rate, but the difference was not statistically significant (χ2 = 2.761, P= 0.097; χ2= 0.994, P=0.319). MELK was highly expressed in ECA109 and KYSE150 cells. The Transwell test results showed that the number of migrating cells of EEL109 and KYSE150 cells in the MELK knockdown group was decreased when compared with the negative control group [(77±10) cells vs. (126±8) cells, t=6.56, P<0.05;(37±4) cells vs. (105 ±3) cells, t= 24.27, P< 0.05], and the number of invading cells was decreased [(47 ±7) cells vs. (154±9) cells, t= 17.08, P< 0.05; (37±2) cells vs. (184±4) cells, t= 54.09, P< 0.05]. CCK-8 proliferation studies showed that the proliferation of ECA109 and KYSE150 cells in the MELK knockdown group was inhibited (both P< 0.05). Conclusions The high MELK expression in patients with esophageal squamous cell carcinoma is associated with T stage. High expression of MELK can promote the proliferation and invasion of tumor cells in esophageal squamous cell carcinoma.

The correlation between level of serum APPL1 and urinary albumin excretion rate in patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

Objective To investigate the association of adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 1(APPL1)with urinary albumin excretion rate in patients with type 2 diabetes mellitus (T2DM),and to explore the role of APPL1 in the development of diabetic kidney disease(DKD). Methods According to the urinary albumin/creatinine ratio(UACR),288 newly-diagnozed patients with T2DM were divided into normal albuminuria group(UACR<30 mg/g,n=116),microalbuminuria group(UACR 30 ~300 mg/g,n=95),and macroalbuminuria group(UACR>300 mg/g,n=77). 130 healthy subjects with matched sex and age were used as control group. Serum APPL1,tumor necrosis factor α(TNF-α),and adiponectin levels were measured by ELISA method. Results Serum APPL1 level in T2DM patients was significantly higher than that in control subjects (P<0.01), and increased with the rising of UACR. In patients with T2DM, serum APPL1 level was negatively correlated with estimated glomerular filtration rate(r=-0.246, P<0.01) while it was positively correlated with HbA1C, low density lipoprotein cholesterol, total cholesterol, triglycerides, insulin resistance index, serum creatinine,blood urea nitrogen, systolic blood pressure, TNF-α, and adiponectin(r=0. 119, 0. 167, 0. 209, 0.194,0.273,0.242,0.131,0.144,0.365, and 0.952, respectively, P<0.05 or P<0.01). Conclusion Serum APPL1 level in patients with T2DM was increased with the rising of UACR, suggesting that APPL1 may be involved in the development of DKD.

Identification of the binding region for interaction of optineurin with neural retina leucine / 中华实验眼科杂志

Background Gene encoding optineurin (OPTN) is a causative gene for glaucoma and amyotrophic lateral sclerosis,with a more expression in retina.Our previous study isolated OPTN-interacting proteins and identified that the gene encode the basic leucine zipper (bZIP) transcription factor neural retina leucine (NRL) zipper,a causative gene for retinitis pigmentosa,and further study demonstrated the interaction between OPTN and NRL proteins in nuclei of cultured HeLaS3 cells.Objective This study was to determine the protein binding site of OPTN necessary for NRL binding.Methods A deletion series of OPTN-expression plasmids were constructed and co-expressed with hemagglutinin (HA)-tagged NRL in HeLaS3 cells,respectively.The cytoplasmic and nuclear fractions were used to perform co-immunoprecipitate (CoIP) and Western blot with anti-tag antibodies.Results In the nuclear fractions of cells transfected with the del1 st,del2nd or del3rd plasmid,a band of coimmunoprecipitated HA-labelled NRL (HA-NRL) was detected.However,the del4th plasmid did not produce a band.The NRL band was not found in cytoplasmic fractions from transfected cells with any of the deletion plasmids or with the whole-length OPTN plasmid.Conclusions The protein binding site of OPTN necessary for NRL binding is determined.This result demonstrates the binding of Flag-OPTN and HA-NRL in HeLaS3 cells.A series of partial-deletion OPTN plasmids demonstrated that the tail region (423-577 amino acids) of OPTN was necessary for binding with NRL.

LZTS2 tumor suppressor gene and advancements in tumor re-search / 中国肿瘤临床

Leucine zipper tumor suppressor 2 (LZTS2) is a novel tumor suppressor gene that has been increasingly recognized in recent years. Currently, many studies illustrate that LZTS2 gene, the important candidate tumor suppressor gene, is already involved in the inhibition of tumorigenesis and aberrant proliferation of tumor cells, and other functions of tumor cells. Information from these stud-ies can contribute to the formulation of new strategies for the treatment of tumors.

Expression of a Functional zipFv Antibody Fragment and Its Fusions with Alkaline Phosphatase in the Cytoplasm of an Escherichia coli

BACKGROUND: Expression of recombinant antibodies and their derivatives fused with other functional molecules such as alkaline phosphatase in Escherichia coli is important in the development of molecular diagnostic reagents for biomedical research. METHODS: We investigated the possibility of applying a well-known Fos-Jun zipper to dimerize V(H) and V(L) fragments originated from the Fab clone (SP 112) that recognizes pyruvate dehydrogenase complex-E2 (PDC-E2), and demonstrated that the functional zipFv-112 and its alkaline phosphatase fusion molecules (zipFv-AP) can be produced in the cytoplasm of Origami(DE3) trxB gor mutant E. coli strain. RESULTS: The zipFv-AP fusion molecules exhibited higher antigen-binding signals than the zipFv up to a 10-fold under the same experimental conditions. However, conformation of the zipFv-AP seemed to be influenced by the location of an AP domain at the C-terminus of V(H) or V(L) domain [zipFv-112(H-AP) or zipFv-112(L-AP)], and inclusion of an AraC DNA binding domain at the C-terminus of V(H) of the zipFv-112(L-AP), termed zipFv-112(H-AD/L-AP), was also beneficial. Cytoplasmic co-expression of disulfide-binding isomerase C (DsbC) helped proper folding of the zipFv-112(H-AD/L-AP) but not significantly. CONCLUSION: We believe that our zipFv constructs may serve as an excellent antibody format bi-functional antibody fragments that can be produced stably in the cytoplasm of E. coli.

Detection of point mutation at C-terminal region of phagosomal coat protein (TACO) in patients with leprosy / 나학회지

Mycobacteria, which are highly successful pathogen, resist delivary to lysosomes and instead survive within a specialized vacuole, the mycobacterial phagosome. The bacteria survive intracellularly because they are able to actively recruit and retain TACO ( tryptophane aspartate-containing coat protein ) at the mycobacterial phagosome, where it prevents lysosomal delivary in a cholesterol-dependent manner. In this study, we investigated the difference of TACO expression is whether related to mutant in coro1a gene in patients with leprosy and normal volunteer. First, we screened for detection of a mutant in the leucine zipper motif within the exon 11, and then in the exon 9 to 10, and finally in the coiled-coil region. Interestingly, single base substitutions ( point mutation ) presents at assembly site of U1 snRNP, around of 5' splice site in the intron 9, there are a C to T and G to A transition are at 9 bp and 14 bp downstream of 5' splice site, respectively, and both of it. Among the 3 types of polymorphism, frequency of a G to A transition is markedly increased in patients of lepromatous type, which are new cases or relapsed. Both a C to T and G to A transitions are found in 1 case of tuberculoid type and 2 cases in lepromatoue type, but not found in control group. The silent mutation in leucine zipper motif within the exon 11 is located at codon at 454 ( CTG-->CTA), which is 1st leucine from C-terminal among four leucine zipper. In coiled-coil region, no mutation is found in genomic DNA of patients with leprosy. Further, we will do functional study about the identified point mutation and will screen any possible mutation in the region of promotor and WD repeat.