Association of the triglyceride glucose index with all-cause and cardiovascular mortality in a general population of Iranian adults.

BACKGROUND: The triglyceride glucose (TyG) index is a new and low-cost marker to determine insulin resistant which may be a predictor of cardiovascular disease (CVD). Although available evidence showed that its association with CVD mortality (CVM) and all-cause mortality (ACM) may differ in different populations, scarce data are available in this regard specially in low and middle-income countries. PURPOSE: To examine the association between TyG index and risk of CVM and ACM in Iranians. METHODS: This prospective cohort study included 5432 adults (age ≥ 35 years) with no history of CVD events. Fasting glucose and triglyceride were measured at baseline in all participants and TyG index was calculated. Cox frailty model was used to calculate hazard ratios (HRs) for CVM and ACM across the tertiles of TyG index. RESULTS: After a median follow-up of 11.25 years, a total number of 191 cardiovascular deaths, and 487 all-cause mortality was recorded. The risk of both CVM and ACM increased across the tertiles of TyG index. In the adjusted model for lifestyle and metabolic variables, the risks of ACM and CVM increased by 41% (95% CI 1.11, 1.81; P for trend = 0.005) and 64% (95% CI 1.07, 2.50; P for trend = 0.024), respectively. However, adjustment for diabetes mellitus disappeared the significance for both ACM and CVM. These associations may vary by sex. TyG was not related to the risk of non-CVD mortality. CONCLUSION: The predicting value of TyG index for ACM and CVM might be mediated by diabetes status. Further studies are required to confirm these findings.

Various techniques for transcatheter retrieval of the atrial septal defect or patent foramen ovale closure devices: a systematic review.

Atrial septal abnormalities are common congenital lesions that remain asymptomatic in many patients until adulthood. Adults with atrial septal defects (ASD) most commonly have ostium secundum ASD. Transcatheter closure has become increasingly popular in recent years as a successful alternative method to surgery for treating ASD and patent foramen ovale (PFO). The overall rate of ASD transcatheter closure device embolization has been reported to be less than 1%; however, retrieving the device via surgery or by trans-catheter route can be necessary. The current manuscript describes a systematic review of the techniques used to retrieve ASD closure devices, as well as their success rates, complications, and limitations. A comprehensive search was performed covering various databases including PubMed, MEDLINE, SCOPUS, Google Scholar, and Cochrane Library from inception until April 2022 for English-published case reports, case series, and experimental studies investigating the indications, safety, and limitations of ASD closure and ASD device retrieval by trans-catheter approaches. Finally, 20 studies were included in our review. Our findings showed that most of the studies used a single snare technique; of these, all but one reported 100% success. Double tool retrieval methods (snare plus snare, snare plus bioptome, or snare plus forceps) and the gooseneck snare technique yielded 100% success. One study that used the lasso technique reported unsuccessful retrieval and the need for surgical intervention. More recently, the novel "coronary wire trap technique" was introduced, which provides a simpler method for embolized device removal by trapping the device for retrieval using coronary wire.

Association of triglyceride glucose index with cardiovascular events: insights from the Isfahan Cohort Study (ICS).

BACKGROUND: There is limited evidence regarding the evaluation of the association between the triglyceride glucose (TyG) index, an indicator of insulin resistance, and the incident risk of cardiovascular disease (CVD). Therefore, we aimed to examine the relationship between the TyG index and CVD incidence in a cohort of Iranian adults. METHODS: This study was performed in the framework of the Isfahan Cohort Study (ICS). The study population included 5,432 individuals aged ≥ 35 years. CVD events, including acute myocardial infarction (MI), stroke, and unstable angina (UA), were diagnosed by physicians. The TyG index was calculated as Ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. The relationship between the TyG index and CVD events was investigated using Cox regression models. Receiver operating characteristics (ROC) curve analysis was used to determine the best cut-off for the TyG index for predicting CVD outcomes. RESULTS: During a median follow-up period of 11.2 years, a total number of 819 CVD, 164 MI, 172 stroke, and 384 UA were recorded. Following adjustment for multiple confounders, elevated TyG levels were associated with a higher risk of CVD (HR = 1.48; 95% CI 1.22-1.79; p < 0.001), MI (HR = 2.24; 95% CI 1.42-3.52; p < 0.001), stroke (HR = 1.45; 95% CI 0.96-2.19; p = 0.042), but not UA (HR = 1.28; 95% CI 0.96-1.69). The optimal TyG index cut-off was 8.91 for predicting CVD (sensitivity 58%; specificity 58%), 9.04 for predicting MI (sensitivity 57%; specificity 65%), 8.92 for predicting stroke (sensitivity 57%; specificity 57%), and 8.98 for predicting UA (sensitivity 53%; specificity 61%). CONCLUSION: We found a robust, direct association between the TyG index and the incidence of CVD events. This emphasizes the significance of observing the TyG index as an indicator of the occurrence of CVD events.

A healthy diet, physical activity, or either in relation to cardiovascular and all-cause mortality: A prospective cohort study.

OBJECTIVES: The aim of our study was to compare four lifestyles-healthy diet and low activity, unhealthy diet and high activity, unhealthy diet and low activity, and healthy diet and high activity-in relation to the risk of cardiovascular disease (CVD) and all-cause mortality. METHODS: A total of 6504 adults ages ≥35 y were recruited to participate in the Isfahan Cohort Study and followed for 13 y. Diet was assessed using a validated 48-item food frequency questionnaire, and the quality of diet was assessed using the Dietary Quality Index. Physical activity (PA) was evaluated using the International Physical Activity Questionnaire. The primary outcomes were CVD and all-cause mortality. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and the 95% CIs. RESULTS: During 771 440 person-years of follow-up, 390 and 147 deaths occurred due to all causes and CVD, respectively. High PA, either with a healthy or unhealthy diet, was associated with a lower risk of death from CVD (HR = 0.43; 95% CI, 0.26-0.69, and HR = 0.32; 95% CI, 0.18-0.56, respectively) and also all-cause mortality(HR = 0.53, 95% CI, 0.39-0.71, and HR = 0.5, 95% CI, 0.36-0.68). Moreover, type of PA was important, such that when leisure time PA was considered, none of the lifestyles was associated with a lower risk of CVD and all-cause mortality. However, for occupational PA, the result was the same as the total PA. CONCLUSIONS: Having high PA (total or occupational), with or without adhering to a healthy diet, is associated with a lower risk of death from any cause and CVD; although leisure time PA, irrespective of adhering to a healthy diet, was not associated with a lower risk of all-cause and CVD mortality.

Unmasking the complex roles of hypocalcemia in cancer, COVID-19, and sepsis: Engineered nanodelivery and diagnosis.

Calcium (Ca2+) homeostasis is essential for maintaining physiological processes in the body. Disruptions in Ca2+ signaling can lead to various pathological conditions including inflammation, fibrosis, impaired immune function, and accelerated senescence. Hypocalcemia, a common symptom in diseases such as acute respiratory distress syndrome (ARDS), cancer, septic shock, and COVID-19, can have both potential protective and detrimental effects. This article explores the multifaceted role of Ca2+ dysregulation in inflammation, fibrosis, impaired immune function, and accelerated senescence, contributing to disease severity. Targeting Ca2+ signaling pathways may provide opportunities to develop novel therapeutics for age-related diseases and combat viral infections. However, the role of Ca2+ in viral infections is complex, and evidence suggests that hypocalcemia may have a protective effect against certain viruses, while changes in Ca2+ homeostasis can influence susceptibility to viral infections. The effectiveness and safety of Ca2+ supplements in COVID-19 patients remain a subject of ongoing research and debate. Further investigations are needed to understand the intricate interplay between Ca2+ signaling and disease pathogenesis.

Unraveling the potential of M13 phages in biomedicine: Advancing drug nanodelivery and gene therapy.

M13 phages possessing filamentous phage genomes offer the benefits of selective display of molecular moieties and delivery of therapeutic agent payloads with a tolerable safety profile. M13 phage-displayed technology for resembling antigen portions led to the discovery of mimetic epitopes that applied to antibody-based therapy and could be useful in the design of anticancer vaccines. To date, the excremental experiences have engaged the M13 phage in the development of innovative biosensors for detecting biospecies, biomolecules, and human cells with an acceptable limit of detection. Addressing the emergence of antibiotic-resistant bacteria, M13 phages are potent for packaging the programmed gene editing tools, such as CRISPR/Cas, to target multiple antimicrobial genes. Moreover, their display potential in combination with nanoparticles inspires new approaches for engineering targeted theragnostic platforms targeting multiple cellular biomarkers in vivo. In this review, we present the available data on optimizing the use of bacteriophages with a focus on the to date experiences with M13 phages, either as monoagent or as part of combination regimens in the practices of biosensors, vaccines, bactericidal, modeling of specific antigen epitopes, and phage-guided nanoparticles for drug delivery systems. Despite increasing research interest, a deep understanding of the underlying biological and genetic behaviors of M13 phages is needed to enable the full potential of these bioagents in biomedicine, as discussed here. We also discuss some of the challenges that have thus far limited the development and practical marketing of M13 phages.

Advances in nanobased platforms for cardiovascular diseases: Early diagnosis, imaging, treatment, and tissue engineering.

Cardiovascular diseases (CVDs) present a significant threat to health, with traditional therapeutics based treatment being hindered by inefficiencies, limited biological effects, and resistance to conventional drug. Addressing these challenges requires advanced approaches for early disease diagnosis and therapy. Nanotechnology and nanomedicine have emerged as promising avenues for personalized CVD diagnosis and treatment through theranostic agents. Nanoparticles serve as nanodevices or nanocarriers, efficiently transporting drugs to injury sites. These nanocarriers offer the potential for precise drug and gene delivery, overcoming issues like bioavailability and solubility. By attaching specific target molecules to nanoparticle surfaces, controlled drug release to targeted areas becomes feasible. In the field of cardiology, nanoplatforms have gained popularity due to their attributes, such as passive or active targeting of cardiac tissues, enhanced sensitivity and specificity, and easy penetration into heart and artery tissues due to their small size. However, concerns persist about the immunogenicity and cytotoxicity of nanomaterials, necessitating careful consideration. Nanoparticles also hold promise for CVD diagnosis and imaging, enabling straightforward diagnostic procedures and real-time tracking during therapy. Nanotechnology has revolutionized cardiovascular imaging, yielding multimodal and multifunctional vehicles that outperform traditional methods. The paper provides an overview of nanomaterial delivery routes, targeting techniques, and recent advances in treating, diagnosing, and engineering tissues for CVDs. It also discusses the future potential of nanomaterials in CVDs, including theranostics, aiming to enhance cardiovascular treatment in clinical practice. Ultimately, refining nanocarriers and delivery methods has the potential to enhance treatment effectiveness, minimize side effects, and improve patients' well-being and outcomes.

Impact of diabesity phenotype on cardiovascular diseases, major cardiovascular events and all-cause mortality.

To investigate the longitudinal association of different phenotypes of diabetes and obesity with the incidence of cardiovascular disease (CVD), CVD- and all-cause mortality. A total of 5432 adults, aged ≥ 35 years and free of CVD were included in this cohort study. Diabesity phenotypes were defined in six categories based on the presence of diabetes (normal (NG), prediabetes and diabetes) and obesity (obese, non-obese). Fasting blood sugar, 2-h post prandial glucose, or using anti-diabetic medicines were used to define diabetes, and body mass index and waist circumference were used to define obesity. Cox proportional hazards models were used to estimate hazard ratios (HRs) for incident CVD, CVD- and all-cause mortality across these categories. After a median follow-up of 11.25 years, 819 CVD cases, 181 CVD deaths and 488 all-cause deaths occurred. In multivariable-adjusted models and irrespective of obesity definition, the phenotypes of normal glucose-obese, prediabetes-obese and pre-diabetes-non obese were not associated with CVD incidence in comparison with NG-non obese phenotype, however, the phenotypes of diabesity, either defined by general or abdominal obesity, were associated with increased risk of incident CVD events (HR = 1.42, 95% CI 1.01, 1.99, and HR = 1.46, 95% CI 1.07, 1.98, respectively). These findings were sex-specific and only in men with a phenotype of abdominal obesity-diabetes, a positive link was observed for CVD incidence (HR = 1.60, 95% CI 1.01, 2.52). No significant association was found between diabesity and death from CVD or all causes. Diabesity is a predictor of CVD and stroke incidence, but not CVD or all-cause mortality, among Iranians. This association is more pronounced amongst men than women.

Comparison of reference intervals for biochemical and hematology markers derived by direct and indirect procedures based on the Isfahan cohort study.

INTRODUCTION: Indirect methods for reference interval (RI) establishment apply statistical techniques to generate RIs for test result interpretation using stored laboratory data. They present unique advantages relative to traditional direct approaches such as fewer resource requirements; however, there is debate regarding their performance. Herein, we aimed to compare indirect and direct approaches for RI establishment by harnessing data from the Isfahan Cohort Study (ICS). This cohort includes both healthy individuals and those with a history of disease, enabling a direct comparison. METHODS: Participants were recruited as part of ICS, including 6504 adults aged 34 years and older. Sociodemographic characteristics, anthropometry, blood pressure, various biochemical indices, and hematology parameters were collected. The refineR method was used to establish indirect RIs (before applying exclusion criteria). Direct RIs were calculated using nonparametric methods per CLSI EP28-A3 guidelines (after applying exclusion criteria). Bias ratios were calculated for each parameter to assess significant differences in estimations. RESULTS: Direct and indirect RI estimations for most hematological and biochemical parameters were comparable. Statistically significant bias ratios between methods were observed for the upper limits of total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), hemoglobin (female), and platelet count as well as the lower limits of mean corpuscular hemoglobin (female), mean corpuscular volume, hemoglobin, and hematocrit (female). CONCLUSION: Data presented indicate RIs derived from direct and indirect approaches are similar, but not identical. Further work should focus on the clinical significance of such differences as well as the investigation of necessary data-cleaning criteria before indirect method application.

The potential therapeutic impacts of trehalose on cardiovascular diseases as the environmental-influenced disorders: An overview of contemporary findings.

Cardiovascular diseases (CVDs) as environmental-influenced disorders, are a major concern and the leading cause of death worldwide. A range of therapeutic approaches has been proposed, including conventional and novel methods. Natural compounds offer a promising alternative for CVD treatment due to their ability to regulate molecular pathways with minimal adverse effects. Trehalose is natural compound and disaccharide with unique biological functions and cardio-protective properties. The cardio-protective effects of trehalose are generated through its ability to induce autophagy, which is mediated by the transcription factors TFEB and FOXO1. The stimulation of TFEB plays a significant role in regulating autophagy genes and autophagosome formation. Activation of FOXO1 through dephosphorylation of Foxo1 and blocking of p38 mitogen-activated protein kinase (p38 MAPK) also triggers autophagy dramatically. Trehalose has been shown to reduce CVD risk factors, including atherosclerosis, cardiac remodeling after a heart attack, cardiac dysfunction, high blood pressure, and stroke. It also reduces structural abnormalities of mitochondria, cytokine production, vascular inflammation, cardiomyocyte apoptosis, and pyroptosis. This review provides a molecular overview of trehalose's cardioprotective functions, including its mechanisms of autophagy and its potential to improve CVD symptoms based on clinical evidence.

Crosstalk of Transcriptional Regulators of Adaptive Immune System and microRNAs: An Insight into Differentiation and Development.

MicroRNAs (miRNAs), as small regulatory RNA molecules, are involved in gene expression at the post-transcriptional level. Hence, miRNAs contribute to gene regulation of various steps of different cell subsets' differentiation, maturation, and activation. The adaptive immune system arm, which exhibits the most specific immune responses, is also modulated by miRNAs. The generation and maturation of various T-cell subsets concomitant with B-cells is under precise regulation of miRNAs which function directly on the hallmark genes of each cell subset or indirectly through regulation of signaling pathway mediators and/or transcription factors involved in this maturation journey. In this review, we first discussed the origination process of common lymphocyte progenitors from hematopoietic stem cells, which further differentiate into various T-cell subsets under strict regulation of miRNAs and transcription factors. Subsequently, the differentiation of B-cells from common lymphocyte progenitors in bone marrow and periphery were discussed in association with a network of miRNAs and transcription factors.

Gene Editing-Based Technologies for Beta-hemoglobinopathies Treatment.

Beta (ß)-thalassemia is a group of human inherited abnormalities caused by various molecular defects, which involves a decrease or cessation in the balanced synthesis of the ß-globin chains in hemoglobin structure. Traditional treatment for ß-thalassemia major is allogeneic bone marrow transplantation (BMT) from a completely matched donor. The limited number of human leukocyte antigen (HLA)-matched donors, long-term use of immunosuppressive regimen and higher risk of immunological complications have limited the application of this therapeutic approach. Furthermore, despite improvements in transfusion practices and chelation treatment, many lingering challenges have encouraged researchers to develop newer therapeutic strategies such as nanomedicine and gene editing. One of the most powerful arms of genetic manipulation is gene editing tools, including transcription activator-like effector nucleases, zinc-finger nucleases, and clustered regularly interspaced short palindromic repeat-Cas-associated nucleases. These tools have concentrated on γ- or ß-globin addition, regulating the transcription factors involved in expression of endogenous γ-globin such as KLF1, silencing of γ-globin inhibitors including BCL11A, SOX6, and LRF/ZBTB7A, and gene repair strategies. In this review article, we present a systematic overview of the appliances of gene editing tools for ß-thalassemia treatment and paving the way for patients' therapy.

The Molecular Basis of COVID-19 Pathogenesis, Conventional and Nanomedicine Therapy.

In late 2019, a new member of the Coronaviridae family, officially designated as "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), emerged and spread rapidly. The Coronavirus Disease-19 (COVID-19) outbreak was accompanied by a high rate of morbidity and mortality worldwide and was declared a pandemic by the World Health Organization in March 2020. Within the Coronaviridae family, SARS-CoV-2 is considered to be the third most highly pathogenic virus that infects humans, following the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV). Four major mechanisms are thought to be involved in COVID-19 pathogenesis, including the activation of the renin-angiotensin system (RAS) signaling pathway, oxidative stress and cell death, cytokine storm, and endothelial dysfunction. Following virus entry and RAS activation, acute respiratory distress syndrome develops with an oxidative/nitrosative burst. The DNA damage induced by oxidative stress activates poly ADP-ribose polymerase-1 (PARP-1), viral macrodomain of non-structural protein 3, poly (ADP-ribose) glycohydrolase (PARG), and transient receptor potential melastatin type 2 (TRPM2) channel in a sequential manner which results in cell apoptosis or necrosis. In this review, blockers of angiotensin II receptor and/or PARP, PARG, and TRPM2, including vitamin D3, trehalose, tannins, flufenamic and mefenamic acid, and losartan, have been investigated for inhibiting RAS activation and quenching oxidative burst. Moreover, the application of organic and inorganic nanoparticles, including liposomes, dendrimers, quantum dots, and iron oxides, as therapeutic agents for SARS-CoV-2 were fully reviewed. In the present review, the clinical manifestations of COVID-19 are explained by focusing on molecular mechanisms. Potential therapeutic targets, including the RAS signaling pathway, PARP, PARG, and TRPM2, are also discussed in depth.

Generation of HBsAg DNA aptamer using modified cell-based SELEX strategy.

Aptamers as potential alternatives for antibodies could be employed against hepatitis B surface antigen (HBsAg), the great hallmark and first serological marker in HBV, for further theragnostic applications. Therefore, isolation HBsAg specific aptamer was performed in this study with a modified Cell-SELEX method. HEK293T overexpressing HBsAg and HEK293T as target and control cells respectively, were incubated with single-stranded rounds of DNA library during six SELEX and Counter SELEX rounds. Here, we introduced the new modified Cell-SELEX using deoxyribonuclease I digestion to separate single stranded DNA aptamers against the HBsAg. Characterization and evaluation of selected sequences were performed using flow cytometry analysis. The results led to isolation of 15 different ssDNA clones in six rounds of selection which were categorized to four clusters based on common structural motifs. The evaluation of SELEX progress showed growth in aptamer affinity with increasing in the cycle number. Taken together, the application of modified cell-SELEX demonstrated the isolation of HBsAg-specific ssDNA aptamers with proper affinity. Modified cell-SELEX as an efficient method can shorten the selection procedure and increase the success rate while the benefits of cell-based SELEX will be retained. Selected aptamers could be applied in purification columns, diagnostic kits, and drug delivery system against HBV-related liver cancer.

Recombinant C-Reactive Protein: A Potential Candidate for the Treatment of Cutaneous Leishmaniasis of BALB/c Mice Caused by Leishmania major.

PURPOSE: Leishmaniasis, a widespread parasitic disease, is a public health concern that is endemic in more than 90 countries. Owing to the drug resistance and also undesirable complications, designing new therapeutic methods are essential. C-reactive protein (CRP) is an acute phase protein of plasma with several immune modulatory functions. This study aimed to evaluate the effect of human recombinant CRP (hrCRP) on treating cutaneous leishmaniasis in mice models. METHODS: hrCRP was expressed in E. coli Rosetta-gami and extracted from the SDS-PAGE gel. Male BALB/c mice were inoculated subcutaneously at the base of their tails by 1 × 105 stationary-phase of Leishmania major promastigotes (MHRO/IR/75/ER) suspended in sterile phosphate buffered saline (PBS). Nodules and subsequently, ulcers developed 14 days post-injection. 1.5 µg of the purified protein was administered on lesions of pre-infected mice by Leishmania major in the intervention group for five consecutive days. RESULTS: The mean area of the lesions was decreased by about seven folds in the intervention group as compared to the control group after two weeks of the treatment (p = 0.024). The results were verified by the real-time polymerase chain reaction so that the parasite burden was determined 27 times in the control group as compared to the intervention group (p = 0.02). Two weeks after treatment, the conversion of the lesions to scars in the intervention group was observed. CONCLUSION: The results indicate a potential therapeutic role for hrCRP in improving cutaneous leishmaniasis due to Leishmania major in mice models. The healing was in a stage-dependent manner.

MicroRNAs as the actors in the atherosclerosis scenario.

Atherosclerosis is considered as the most common cardiovascular disease and a leading cause of global mortality, which develops through consecutive steps. Various cellular and molecular biomarkers such as microRNAs are identified to be involved in atherosclerosis progression. MicroRNAs are a group of endogenous, short, non-coding RNAs, which are able to bind to specific sequences on target messenger RNAs and thereby modulate gene expression post-transcriptionally. MicroRNAs are key players in wide range of biological processes; thus, their expression level is regulated in pathophysiological conditions. Ample evidences including in vitro and in vivo studies approved a critical role of microRNAs in epigenetic and the sequential processes of atherosclerosis from risk factors to plaque formation, progression, and rupture. Based on these findings, miRNAs seems to be promising candidates for therapeutic approach. This review summarizes the role of miRNAs in atherosclerosis development, epigenetic, and therapy. Moreover, the application of exosomes in miRNA delivery, and/or their prognostic and diagnostic values are also discussed.

Optimization and Comparison of Different Methods and Factors for Efficient Transformation of Brucella abortus RB51strain.

BACKGROUND: The development of protective vaccines for Brucella spp. has been hampered by the difficulty in transformation of Brucella cells with foreign DNA for genetic manipulation. It seems that the formation of Brucella spheroplasts would increase the efficiency of transformation. The aim of this study was to devise an efficient method for the transformation of Brucella spp. MATERIALS AND METHODS: At first, spheroplast of Brucella was prepared by glycine and ampicillin induction and transformed using optimized protocols of CaCl2, electroporation, and lipofection methods. Then, the efficacy of transformation was compared between the three-mentioned methods. RESULTS: Ampicillin-induced spheroplasts from early-log phase culture of brucella when incubated in a medium-containing 0.2 M sucrose during cell recovery had higher transformation efficiency in three different methods. Comparison of the transformation efficiency of Brucella abortus RB51 using the CaCl2, lipofection, and electroporation methods revealed that the transformation efficiency with the lipofection method was significantly higher than with other two methods (P < 0.05). CONCLUSIONS: Lipofection method by lipofectamine 2000 on ampicillin-induced spheroplasts can be a suitable approach for Brucella transformation.

Development of α4 integrin DNA aptamer as a potential therapeutic tool for multiple sclerosis.

One of the most important molecules for multiple sclerosis pathogenesis is α4 integrin, which is responsible for autoreactive leukocytes migration into the brain. The monoclonal antibody, natalizumab, was introduced to market for blocking the extravasation of autoreactive leukocytes via inhibition of α4 integrin. However, the disadvantages of antibodies provided a suitable background for other agents to be replaced with antibodies. Considering the profound advantages of aptamers over antibodies, aptamer isolation against α4 integrin was intended in the current study. The α4 integrin-specific aptamers were selected using cell-systematic evolution of ligands by exponential enrichment (SELEX) method with human embryonic kidney (HEK)-293T overexpressing α4 integrin and HEK-293T as target and control cells, respectively. Evaluation of selected aptamer was performed through flow cytometric analysis. The selected clones were then sequenced and analyzed for any possible secondary structure and affinity. The results of this study led to isolation of 13 different single-stranded DNA clones in 11 rounds of selection which were categorized to three clusters based on common structural motifs and the equilibrium dissociation constant (K d ) of the most stable structure was calculated. The evaluation of SELEX progress showed growth in aptamer affinity with increasing of the number of cycles. Taken together, the findings of this study demonstrated the isolation of α4-specific single-stranded DNA aptamers with suitable affinity for ligand, which can further be replaced with natalizumab.

Display of human and rabbit monocyte chemoattractant protein-1 on human embryonic kidney 293T cell surface.

Monocyte chemoattractant protein-1 (MCP-1/CCL2) is a protein that is secreted immediately upon endothelial injury, and thereby it plays a key role in inflammation via recruitment of leucocytes to the site of inflammation at the beginning and throughout the inflammatory processes. Aim of this study was to develop two separate cell lines displaying either human MCP-1 (HMCP-1) or rabbit MCP-1 (RMCP-1) on their surface. A DNA fragment containing HMCP-1- or RMCP-1-encoding sequence was inserted into a pcDNA plasmid. Escherichia coli cells strain TOP 10F' was separately transformed with the pcDNA/RMCP-1 or /HMCP-1 ligation mixture. Following the cloning and construct verification, human embryonic kidney cell line (HEK 293T) was transfected with either of the linearized plasmids. Plasmid integration into the genomic DNA of HEK 293T cells was verified by polymerase chain reaction (PCR). HMCP-1 and RMCP-1 expression was evaluated at RNA and protein levels by real-time PCR and flow cytometry, respectively. PCR products of the expected sizes were amplified from the chromosomal DNA of transfected HEK 293T cells, i.e. 644 bp for H-MCP1 and 737 bp for RMCP-1 constructs. Real-time PCR revealed that the copy numbers of RMCP1 and HMCP1 mRNA per cell were 294 and 500, respectively. Flow cytometry analysis indicated 85% for RMCP-1 and 87% for HMCP-1 expression levels on the surface of transfected cells, when compared with an isotype control. The experiments thus confirmed that the MCP-1 genes were integrated into the HEK 293T genomic DNA and the encoded proteins were stably expressed on the cell surface.

Construction and characterization of human embryonic kidney-(HEK)-293T cell overexpressing truncated α4 integrin.

Blockade of α4 integrin by antibodies could be an appropriate treatment strategy in multiple sclerosis and Crohn's disease. Considering disadvantages of antibodies, other elements (e.g. aptamers) have been proposed for antibodies replacement. Isolation of aptamers through cell-SELEX (systematic evolution of ligands by exponential enrichment) method requires positive and negative expressing α4 integrin cell lines. For a better isolation, we intended to construct a negative cell line lacking of specific ligand binding site of α4 integrin. Escherichia coli strain top 10 was used for truncated integrin subunit α4 (TITGA-4) expression vector. Human embryonic kidney (HEK)-293T cell was transfected with linearized TITGA-4 plasmid and subsequently screened for stable truncated TITGA-4 expressing cells. Chromosomal DNA of truncated TITGA-4-transfected cells was extracted and the presence of truncated TITGA-4 gene in HEK-293T genome was confirmed by polymerase chain reaction (PCR). The expression level of truncated TITGA-4 on HEK-293T cells was also analysed by real-time PCR and flow cytometry. Real-time PCR and flow cytometric analysis showed significant difference of truncated TITGA-4 expression between untransfected HEK-293T cells compared to transfected cells. The results suggest that we have successfully constructed the truncated integrin α4 expressing HEK-293T cell, which will facilitate further research into the production of antibody, nanobody, and aptamer against α4 integrin.