Status of soluble ST2 levels in serum of HTLV-1 infected individuals

ST2 is a member of IL-1 receptor family expressed on Th2 cells and regulates Th2 responces. The gene of ST2 encodes soluble ST2 (sST2) and the transmembrane ST2 (ST2L) isoforms through alternative mRNA splicing. The discovery of IL33/ ST2 signaling pathway, has drawn a great scientific attention to this system. sST2 has been shown to be an indacating factor in various infl ammatory conditions. This study aims to evaluate serum sST2 levels in HTLV-1 infected patients. This study included 49 HTLV-1 seropositive cases of which 14 were sympthomatic. Controls consisted of 30 healthy volunteers. sST2 level was measured using a quantitative ELISA assay and the results of the study groups were compared. Corroborating the previous reports, sST2 was lower in females (P = 0.003). The sST2 levels was slightly increased in HTLV-1 patients, though such increase was not statistically significant (P = 0.91), in addition sST2 level did not correlate significantly to the disease duration (P = 0.78). Despite some other chronic viral infection, HTLV-1 seems not to induce high serum sST2. However owing to relatively high normal variation of sST2 levels and rather small sample size, we stongly recommend further reseach with preferably larger sample size to evalute sST2 in HTLV-1 infected patients

Increased Glutathione Reductase Expression and Activity in Colorectal Cancer Tissue Samples: An Investigational Study in Mashhad, Iran

Background: Glutathione reductase is an important enzyme in oxidative metabolism that provides reduced glutathione from its oxidized form in the cells. The role of oxidative stress in tumor tissues has led us to investigate the gene expression and activity of this enzyme in tumor and adjacent resected margins of colorectal cancer tissues, one of the most common malignancies in humans. Methods: We conducted this study on 15 Iranian colorectal cancer patients. RNA was extracted from fresh colon tissues that included tumor and anatomically normal margin tissue. Expression of the glutathione reductase gene was determined using realtime PCR by the ΔΔCt relative quantification method. The gene expression results were standardized with glyceraldehyde 3-phosphate dehydrogenase as the endogenous reference gene. In addition, we measured enzyme activity of glutathione reductase with a commercial kit based on a colorimetric assay. Results: The tumor tissue had higher expression of glutathione reductase compared to the margin tissue (P=0.005). There was significantly greater glutathione reductase enzyme activity in the tumor tissue (116.9±34.31 nmol/min/ml) compared to the noncancerous adjacent tissues (76.7±36.85 nmol/min/ml; P=0.003). Conclusion: These data showed increased glutathione reductase expression and enzyme activity in colorectal tumor tissue. Given the key role of glutathione in synthesis of dNTPs for DNA repair with the glutaredoxin system, the increased glutathione reductase expression and activity might be a reflection of hyperactivity of this enzyme in DNA synthesis and the repair process in colorectal cancer cells

Intraperitoneal administration of Telmisartan prevents postsurgical adhesion band formation

Background Angiotensin II receptor blockers (ARBs) have a potential role in reducing inflammation and fibrosis. We have integrated systems and molecular biology approaches to investigate the therapeutic potential of ARBs in preventing postsurgical adhesion band formation. Material and methods we have followed the ARRIVE guidelines point by point during experimental studies. Telmisartan (1 and 9 mg/kg), valsartan (1 and 9 mg/kg), and losartan (1 and 10 mg/kg) were administered intraperitoneally in different groups of male albino Wistar rat. After 7 d of treatment, macroscopic evidence and score of fibrotic bands based on scaling methods was performed. Moreover, the anti-inflammatory and antifibrosis effects of telmisartan on reduction of fibrotic bands were investigated by using histopathology, ELISA, and real-time polymerase chain reaction methods. Results Telmisartan, but not losartan or valsartan, prevented the frequency as well as the stability of adhesion bands. Telmisartan appears to elicit anti-inflammatory responses by attenuating submucosal edema, suppressing proinflammatory cytokines, decreasing proinflammatory cell infiltration, and inhibiting oxidative stress at the site of peritoneal surgery. We also showed that telmisartan prevents fibrotic adhesion band formation by reducing excessive collagen deposition and suppression of profibrotic genes expression at the peritoneum adhesion tissues. Conclusions These results support the potential application of telmisartan in preventing postsurgical adhesion band formation by inhibiting key pathologic responses of inflammation and fibrosis in postsurgery patients

The logic of kinetic regulation in the thioredoxin system

<p>Abstract</p> <p>Background</p> <p>The thioredoxin system consisting of NADP(H), thioredoxin reductase and thioredoxin provides reducing equivalents to a large and diverse array of cellular processes. Despite a great deal of information on the kinetics of individual thioredoxin-dependent reactions, the kinetic regulation of this system as an integrated whole is not known. We address this by using kinetic modeling to identify and describe kinetic behavioral motifs found within the system.</p> <p>Results</p> <p>Analysis of a realistic computational model of the <it>Escherichia coli </it>thioredoxin system revealed several modes of kinetic regulation in the system. In keeping with published findings, the model showed that thioredoxin-dependent reactions were adaptable (i.e. changes to the thioredoxin system affected the kinetic profiles of these reactions). Further and in contrast to other systems-level descriptions, analysis of the model showed that apparently unrelated thioredoxin oxidation reactions can affect each other via their combined effects on the thioredoxin redox cycle. However, the scale of these effects depended on the kinetics of the individual thioredoxin oxidation reactions with some reactions more sensitive to changes in the thioredoxin cycle and others, such as the Tpx-dependent reduction of hydrogen peroxide, less sensitive to these changes. The coupling of the thioredoxin and Tpx redox cycles also allowed for ultrasensitive changes in the thioredoxin concentration in response to changes in the thioredoxin reductase concentration. We were able to describe the kinetic mechanisms underlying these behaviors precisely with analytical solutions and core models.</p> <p>Conclusions</p> <p>Using kinetic modeling we have revealed the logic that underlies the functional organization and kinetic behavior of the thioredoxin system. The thioredoxin redox cycle and associated reactions allows for a system that is adaptable, interconnected and able to display differential sensitivities to changes in this redox cycle. This work provides a theoretical, systems-biological basis for an experimental analysis of the thioredoxin system and its associated reactions.</p

Studies on ribonucleotide reductase, a target for anticancer therapy, with focus on electron donor aspects : Thioredoxin and glutaredoxin systems

Faithful replication of DNA and its repair are fundamental processes in all living cells which utilize deoxyribonucleotides as DNA building blocks. Ribonucleotide reductase (RNR) is the essential enzyme for de novo synthesis of these precursors from ribonucleoside diphosphates. Each catalytic cycle of RNR, requires disulfide bond reduction which as shown in Escherichia coli,is catalyzed by thioredoxin (Trx) or glutaredoxin (Grx) systems. These are general protein disulfide reductases, and the presence of one system is essential. The Trx system comprises Trx, Trx reductase (TrxR), and NADPH; and the Grx system is composed of Grx, glutathione (GSH), glutathione reductase, and NADPH. This thesis studies mammalian RNR; in S-phase cells RNR comprises a weak complex of a catalytic R1 protein, containing redox active cysteine residues, and a radical generator subunit termed R2. By analyzing recombinant mouse RNR with respect to electron donors, we found that Trx1 and Grx1 had similar catalytic efficiency (kcat/Km). With 4 mM GSH, Grx1 showed a higher affinity (apparent Km-value 0.18 µM) compared to Trx1 which displayed a higher apparent kcat suggesting its major role in S-phase DNA replication. Surprisingly, Grx activity was strongly dependent on GSH concentrations (apparent Km-value 3 mM), and a Grx2 Cys40Ser mutant was active despite only one cysteine residue in the active site. These results demonstrate a GSH-mixed disulfide mechanism for Grx catalysis, in contrast to the dithiol mechanism for Trx. We propose that this may be an advantage with the low levels of RNR for DNA repair or in tumor cells with high RNR and no or low Trx expression. Different isoforms of mouse Grx2 were identified, which were further characterized with respect to subcellular localization, expression pattern, and enzymatic activity. Amoung three different isoforms (Grx2a, Grx2c, and Grx2d), mitochondrial Grx2a was expressed in all tissues, except testis. On the other hand, Grx2c and Grx2d were cytosolic and expressed in testis. Mouse Grx2c had general Grx-activity and could reduce RNR, but Grx2d lacked enzymatic activity. These data provide evidence for additional functions of Grx2 in the cytosol, in cell proliferation, and in cellular differentiation. Motexafin gadolinium (MGd) is a new anticancer agent with promising results in clinical trials, which selectively targets tumor cells and works as a radiation enhancer. It mediates redox reactions generating reactive oxygen species (ROS) with oxidation of intracellular reducing molecules. MGd was an NADPH-oxidizing substrate for TrxR. The reaction involved redox cycling of MGd by oxygen producing superoxide. MGd acted as a non-competitive inhibitor for TrxR. In contrast, direct reaction between MGd and reduced Trx was negligible. MGd inhibited recombinant RNR activity with either the Trx system or dithiothreitol as electron donors. Overall, our results show that MGd induces generation of ROS by TrxR and is a powerful inhibitor of RNR. Further studies on the mechanism of inhibition of RNR by MGd, revealed at least two different mechanisms for its effect: interruption in subunit oligomerization, and direct inhibition of the catalytic subunit (R1). Co-localization of MGd and RNR in the cytoplasm was shown particularly in the S-phase. These data elucidate another important effect of MGd on the cancer cells with overproduction of RNR, and highlights its efficacy as an anticancer agent

Production and Characterization of Monoclonal Antibodies Against the Dimerization Domain of Human HER2

Background Human Epidermal Growth factor Receptor 2 (HER2), also known as ErbB2 is a 185 kDa protein belonging to the Human Epidermal Receptor (HER) family of tyrosine kinase receptors overexpressed in 20% - 30% of patients with breast cancer. Similar to other members of the HER family, HER2 glycoprotein comprises of multiple domains including an extracellular ligand-binding domain, a single transmembrane domain and a cytoplasmic domain with tyrosine kinase activity. The extracellular domain of HER2 with 632 amino acids is composed of four subdomains (I - IV); subdomains I and III form a ligand binding site, and cysteine-rich subdomains II and IV play an important role in dimerization of the receptor. Objectives In this study we aimed to produce murine Monoclonal Antibodies (MAbs) with the ability of specific recognition of the HER2 dimerization arm. Materials and Methods Primarily, BALB/c mice were immunized with a 30-aminoacid peptide as a part of the human HER2 subdomain II. Splenocytes from hyperimmunized mice were fused with myeloma cells (SP2/0), selected in hypoxanthine-aminopterin-thymidine (HAT) medium, and screened by indirect Enzyme-Linked Immunosorbent Assay (ELISA). Secreted MAbs were characterized according to isotypes, reactions with the native HER2 in SKBR3 cells by western blotting, and in tissue sections from HER2 positive breast cancer specimens by Immunohistochemistry (IHC). Results Isotype of 1F1 clone was determined to be IgG1, which reacted with native protein in the western blot experiment and stained 20% of the membrane of neoplastic cells overexpressing HER2 with 3+ grade. However, 3L5 clone showed a low reaction (10%) with native HER2 in immunohistochemistry. Conclusions The results of both western blotting and Immunohistochemistry showed that native HER2 can be detected with 1F1 monoclonal antibody

Medical and Dentistry Students’ Viewpoints about Physician-Scientists as their Basic Science Educators

Background and Objective: A growing concern has emerged that all is not completely well with undergraduate medical education in some parts of the world. An important neglected issue is about the basic science educators. We aimed to investigate the medical and dentistry students' viewpoints on basic science education by instructors with a background of medicine. Materials and Methods: This cross-sectional study was performed on 205 medical and dentistry students studying in basic science stage (microbiology or biochemistry courses) in Mashhad, in 2014. Data was gathered with a questionnaire and was analyzed by SPSS 11.5. P<0.05 was considered as statistically significant. Results: A total of 120 (71.4%) medical students and 48 (28.6%) dentistry students returned the questionnaires. MD-PhD educators are needed in educational programs and their emphasis on important issues got the highest scores with no gender nor major difference (4.2±0.7 and 4.1±0.7, respectively). Total teaching and clinical based teaching scores were not different in two majors. However, more preference for clinically oriented teaching was found in females (p=0.02). Conclusion: This study highlights the medical students' preference for MD-PhD lecturers. This mainly stems from considering clinical aspects of the teaching topics

The role of substance P/neurokinin 1 receptor in the pathogenesis of esophageal squamous cell carcinoma through constitutively active PI3K/Akt/NF-κB signal transduction pathways

One of the most prevalent malignancies is esophageal squamous cell carcinoma (ESCC), which is associated with high morbidity and mortality. Substance P (SP), as one of the peptides released from sensory nerves, causes the enhancement of cellular excitability through the activation of the neurokinin-1 (NK1) receptor in several human tumor cells. Aprepitant, a specific, potent, and long-acting NK1 receptor antagonist, is considered as a novel agent to inhibit proliferation and induce apoptosis in malignant cells. Since the antitumor mechanism of aprepitant in ESCC is not completely understood, we conducted this study and found that aprepitant induced growth inhibition of KYSE-30 cells and arrested cells in the G2/M phase of the cell cycle. Aprepitant also caused apoptotic cell death and inhibited activation of the PI3K/Akt axis and its downstream effectors, including NF-κB in KYSE-30 cells. Besides, quantitative real-time (qRT)-PCR analysis showed a significant down-regulation of NF-κB target genes in KYSE-30 cells, indicating a probable NF-κB-dependent mechanism involved in aprepitant cytotoxicity. Thus, the present study recommends that SP/NK1R system might, therefore, be considered as an emerging and promising therapeutic strategy against ESCC. © 2020, Springer Nature B.V

Aprepitant Promotes Caspase-Dependent Apoptotic Cell Death and G2/M Arrest through PI3K/Akt/NF- κ B Axis in Cancer Stem-Like Esophageal Squamous Cell Carcinoma Spheres

The antagonists of the neurokinin-1 receptor (NK1R) are known for their anti-inflammatory, anxiolytic, antiemetic, and anticancer activities. Aprepitant, a nonpeptide NK1R antagonist, is used in nausea and vomiting, the most common side effects of cancer chemotherapy in patients. It has been established that NK1R activation by substance P (SP), which links cancer promotion and progression to a neurokinin-mediated environment, became one mechanism that corresponds to the mitogenesis of tumor cells. Therefore, this study is aimed at explaining and evaluating the anticancer impacts of aprepitant on esophageal squamous cancer cell (ESCC) spheres by using in vitro experiments, such as resazurin, ROS, annexin-V binding, RT-PCR, and Western blot analysis. As a result, we showed that aprepitant had strong antiproliferative and cytotoxic effects on ESCC cell spheres. Also, aprepitant caused significant G2-M cell cycle arrest depending on concentration increase. Further, exposure of cells to this agent resulted in caspase -8/-9-dependent apoptotic pathway activation by modifying the expression of genes involved in apoptosis. Besides, treatment of the cells by aprepitant abrogates of the PI3K/Akt pathway, as shown by reducing the level of Akt, induces apoptotic cell death. In summary, pharmacological inhibition of NK1R with aprepitant seems to have a significant chance of treating ESCC as a single agent or in conjunction with other chemotherapeutic drugs. © 2021 Hossein Javid et al

Comparison of Two Methods for Measurement of HbA1c in Two University Hospitals of Mashhad

Introduction: The aim of this study was to compare the two analytical techniques for determination of Glycated hemoglobin (HbA1c), consisting immunoturbidimetric and enzymatic methods. Materials and Methods A total of 140 out-patients were included in this study. Measurements of HbA1c were done in blood samples using immunoturbidimetric and enzymatic assay. The two methods were used by clinical laboratories of Ghaem and Emam Reza hospitals in Mashhad, respectively. Results:Our results indicate that there was no significant difference between two methods, though; the average of HbA1c measured by enzymatic method was rather higher than the other method (7.38 and 7.34, respectively). The two methods correlated well with correlation coefficient of 0.967. Conclusion: Both techniques were proved to be sufficiently reliable and the results of the two methods show strong correlation though, the enzymatic method has an additional advantage of simultaneous measuring total Hb which can omit the undesired effect of hemolysis occurring during samplin