Optimization of a PDMS-Based Cell Culture Substrate for High-Density Human-Induced Pluripotent Stem Cell Adhesion and Long-Term Differentiation into Cardiomyocytes under a Xeno-Free Condition.

Despite the numerous advantages of PDMS-based substrates in various biomedical applications, they are limited by their highly hydrophobic surface that does not optimally interact with cells for attachment and growth. Hence, the lack of lengthy and straightforward procedures for high-density cell production on the PDMS-based substrate is one of the significant challenges in cell production in the cell therapy field. In this study, we found that the PDMS substrate coated with a combination of polydopamine (PDA) and laminin-511 E8 fragments (PDA + LME8-coated PDMS) can support human-induced pluripotent stem cell (hiPSC) attachment and growth for the long term and satisfy their demands of differentiation into cardiomyocytes (iCMs). Compared with prior studies, the density of hiPSCs and their adhesion time on the PDMS surface were increased during iCM production. Although the differentiated iCMs beat and produce mechanical forces, which disturb cellular attachments, the iCMs on the PDA + LME8-coated PDMS substrate showed dramatically better attachment than the control condition. Further, the substrate required less manipulation by enabling one-step seeding throughout the process in iCM formation from hiPSCs under animal-free conditions. In light of the results achieved, the PDA + LME8-coated PDMS substrate will be an up-and-coming tool for cardiomyocyte production for cell therapy and tissue engineering, microfluidics, and organ-on-chip platforms.

Protein Kinase Signaling by Shiga Toxin Subunits.

Background: Escherichia coli produces Shiga toxin (Stx), a pentamer composed of one A subunit and four B subunits. The B subunit of Stx (StxB) mediated the attachment of the holotoxin to the cell surface while the A subunit (StxA) has N-glycosidase activity, resulting in protein synthesis and cell death inhibition. Stx-induced cytotoxicity and apoptosis have been observed in various cell lines, although the signaling effectors are not precisely defined. Activated by protein kinases (PK), the signaling pathway in human tumors plays an oncogenic role. Tumor proliferation, survival, and metastasis are promoted by kinase receptors. In this regard, PK regulatory effects on the cellular constituents of the tumor microenvironment can affect immunosuppressive purposes. Methods: In this study, kinase inhibitors were used to evaluate the influence of Stx and its subunits on HeLa and Vero cells. Selective inhibitors of protein kinase C (PKC), CaM kinase (calmodulin kinase), protein kinase A (PKA), and protein kinase G (PKG) were used to compare the signaling activity of each subunit. Results: The ribotoxic activity in the target cells will lead to rapid protein synthesis inhibition and cell death in the mammalian host. The expression of Bcl2 family members was also assessed. Protein kinase signaling by Stx and its A and B subunits was induced by PKA, PKG, and PKC in HeLa cells. CaM kinase induction was significant in Vero cells. StxB significantly induced the pro-apoptotic Bax signaling factor in HeLa cells. Conclusion: The assessment of different signaling pathways utilized by Stx and its subunits could help in a better understanding of various cell death responses. The use of inhibitors can block cell damage and disease progression and create therapeutic compounds for targeted cancer therapy. Inhibition of these pathways is the primary clinical goal.

Identification of Intestinal Fungal Microflora and Bacterial Pathogens in the Collected Adult Ixodes ricinus from the Northern Provinces of Iran.

Background: Ticks are vectors of many pathogens that involve various important diseases in humans and animals, they have several diverse hosts consequently can retain a diverse group of indigenous microbes, from bacteria to fungi. Little is known about the prevalence and diversity of tick microflora colonizing the midgut and their effects on ticks and their interaction. This information is important for development of vector control strategies. Methods: This study was carried out in northern Iran during autumn 2019. Ticks, Ixodes ricinus caught alive on the bodies of domestic animals in the fall. The tick homogenate was prepared. The identification of fungal isolates was carried out according to a combination of macro and microscopic morphology and molecular sequencing. Pathogenic bacteria of the family Borreliaceae, Francisella tularensis, Borrelia burgdorferi and Coxiella burnetii were tested by real-time PCR. Results: A total of 133 mature I. ricinus ticks were collected from domestic animals, including 71.5% cattle and 28.5% sheep. The tick frequency rates were 87.21% for Mazandaran, 8.28% for Golestan and 4.51% for Gilan Provinces. Total prevalence of fungal tick contamination was 53.4% (75/133) of which Trichoderma harzianum (57%) was the most prevalent species followed by Aspergillus spp. (42%), Mortierella alpine (19%) and Penicillium polonicum (14%). All tick samples were negative for three pathogenic bacteria including Francisella tularensis, Coxiella burnetii, and Borrelia burgdorferi by real-time PCR analysis. Conclusion: These results show a first picture of the microbial diversity of ticks and highlight the importance of microbiota and their role in host-pathogen interaction.

Computational evaluation of modified peptides from human neutrophil peptide 1 (HNP-1).

The development of bacterial resistance toward antibiotics has been led to pay attention to the antimicrobial peptides (AMPs). The common mechanism of AMPs is disrupting the integrity of the bacterial membrane. One of the most accessible targets for α-defensins human neutrophil peptide-1 (HNP-1) is lipid II. In the present study, we performed homology modeling and geometrical validation of human neutrophil defensin 1. Then, the conformational and physicochemical properties of HNP-1 derived peptides 2Abz14S29, 2Abz23S29, and HNP1ΔC18A, as well as their interaction with lipid II were studied computationally. The overall quality of the predicted model of full protein was -5.14, where over 90% of residues were in the most favored and allowed regions in the Ramachandran plot. Although HNP-1 and HNP1ΔC18A were classified as unstable peptides, 2Abz14S29 and 2Abz23S29 were stable, based on the instability index values. Molecular docking showed similar interaction pattern of peptides and HNP-1 to lipid II. Molecular dynamic simulations revealed the overall stability of conformations, though the fluctuations of amino acids in the modified peptides were relatively higher than HNP-1. Further, the binding affinity constant (Kd) of HNP-1 and 2Abz23S29 in complex with lipid II was 10 times stronger than 2Abz14S29 and HNP1ΔC18A. Overall, computational studies of conformational and interaction patterns have signified how derived peptides could have displayed relatively similar antimicrobial results compared to HNP-1 in the reported experimental studies. Chemical modifications not only have improved the physicochemical properties of derived peptides compared to HNP-1, but also they have retained the similar pattern and binding affinity of peptides. Communicated by Ramaswamy H. Sarma.

A Review on Important Zoonotic Bacterial Tick-Borne Diseases in the Eastern Mediterranean Region.

Background: Zoonotic diseases as health concerns worldwide account for more than half of the emerging infectious diseases. Arachnids are powerful vectors to transmit several diseases to humans. Additionally, these emerging zoonotic diseases have been a considerable health threat in the Eastern Mediterranean Region of the WHO (EMRO) due to the large population living close to farms and international trade with nearby countries. Methods: This review study is based on the reported three tick-borne diseases, Lyme disease, Tularemia, and Q fever, from Iran and other EMRO countries. To this end, we searched PubMed central, ISI web of Science, and Google with the related keywords in English at any time. The reported data are then sorted by countries for each disease. Results: According to the published data, 15 countries in the region have one/more emerging infectious diseases. Q fever has been the most frequent infection in EMRO countries, while Lyme was less recorded. Furthermore, Iran is among the countries with documented history of all three investigated diseases. Conclusion: Tick-borne disease is popular among EMRO countries, indicating that they have natural conditions for infections in animals and humans. It appears necessary to develop a disease management strategy and control programs against tick-borne diseases (TBDs). Moreover, the disease-resistant animal could be bred instead of susceptible livestock. Therefore, research studies to control TBDs should be regarded as a top priority plan.

A Synthetic Peptide 2Abz23S29 Reduces Bacterial Titer and Induces Pro-Inflammatory Cytokines in a Murine Model of Urinary Tract Infection.

INTRODUCTION: A urinary tract infection (UTI), which is often caused by uropathogenic E. coli (UPEC) strains, affects many people worldwide annually. UPEC causes the production of pro-inflammatory cytokines by the bladder epithelial cells; however, it has been proven that the UPEC can inhibit the early activation of the innate immune system. METHODS: This study aimed to examine the antibacterial and immunomodulatory effects of different doses of truncated alpha-defensins (human neutrophil peptide (HNP)-1) analog 2Abz23S29 on the mouse UTI model. Experimentally uropathogenic E. coli CFT073-infected mice were treated with low-dose 2Abz23S29 (250µg/mL), high-dose 2Abz23S29 (750µg/mL), ciprofloxacin (cip) (800µg/mL), or high-dose 2Abz23S29plus cip once a day 24 h post-infection. The 2Abz23S29 and cip treatment were given for two consecutive days. RESULTS: The in vivo results showed that fewer UPEC were recovered from the bladders of mice treated transurethrally with 2Abz23S29. Moreover, low-dose 2Abz23S29 significantly decreased the level of the interleukin-6 (IL-6), whereas high-dose 2Abz23S29 increased pro-inflammatory cytokines including IL-6, macrophage inflammatory protein/2 (MIP/2), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) in infected bladders of mice. Besides, the levels of cytokines IL-6 and MIP/2 in infected mice treated with a combination of high-dose 2Abz23S29 and cip were significantly higher than the untreated mice. In contrast, CFT073-infected mice treated with a combination of high-dose 2Abz23S29 and cip showed no changes in cytokines TNF-α and IL-1ß levels, indicating that ciprofloxacin may play an anti-inflammatory role. CONCLUSION: Collectively, apart from the direct antibacterial role of 2Abz23S29, our data illustrated that 2Abz23S29 modulates pro-inflammatory cytokine production of bladder in a dose-dependent manner, which has implications for the development of new anti-infective agents.

Inhibition and eradication activity of truncated α-defensin analogs against multidrug resistant uropathogenic Escherichia coli biofilm.

Today the development of antibiotic resistance, especially in the treatment of bacterial infections associated with biofilms, has led to increasing the importance of antimicrobial peptides (AMPs). In this work, antimicrobial and synergistic activity of three truncated HNP-1 analogs (2Abz14S29, 2Abz23S29, and HNP1ΔC18A) with ß-lactam (amoxicillin and cefixime) and fluoroquinolones (ciprofloxacin and norfloxacin) antibiotics against multidrug-resistant (MDR) uropathogenic E. coli clinical isolates were evaluated. The anti-biofilm potential of peptides at different stages was also investigated. All peptides exhibited additive activity just with ß-lactam antibiotics in a checkerboard synergy assay. Inhibition and eradication of MDR uropathogenic E. coli biofilm were shown by all test peptides at different concentrations. Thus, truncated HNP-1 analogs (2Abz14S29, 2Abz23S29, and HNP1ΔC18A) may have the potential for the treatment of urinary tract infections (UTIs) caused by biofilm-forming MDR uropathogenic E. coli.

Comparing blood versus tissue-based biomarkers expression in breast cancer patients.

Molecular markers have been used as a tool for diagnostic approaches, staging, and evaluation of therapeutic responses in patients with cancer. Cancer molecular markers can also help clinicians to make decision on therapy and prognosis evaluation at the time of diagnosis. In the early diagnosis of breast cancer (BC), estrogen and progesterone receptors (ER/PR) expression levels should be determined through immunohistochemistry (IHC). In molecular genetics, there are some important tissue-based markers that can also be found in blood, such as Mammaglobin (MAM), Cytokeratin 19 (CK19), Mucin (MUC), Proto-oncogene (c-Myc), antigen Ki-67 (Ki67), and Carcinoembryonic antigen (CEA). In this study, the positive level of the marker genes in both blood and tissue of the BC patients were compared using reverse transcription polymerase chain reaction (RT-PCR) method. In addition, the importance of blood vs. tissue-based markers in BC diagnosis also demonstrated and is discussed. CEA (O), ERß, CK19 and, c-Myc molecular markers were significantly different between blood of normal and patients while there was no significant difference of these markers in tissue samples. Blood-based biomarkers can be used for the early diagnosis of BC. Comparing blood versus tissue-based biomarkers indicated that there are correlations between markers in blood and tissue, since blood markers can be substitute to tissue markers in BC patients in the future.

Surface display of uropathogenic Escherichia coli FimH in Lactococcus lactis: In vitro characterization of recombinant bacteria and its protectivity in animal model.

Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) are very common, leading to high patient morbidity and substantial medical costs. The development of non-antibiotic strategies such as food-grade lactic acid bacterium can be recognized as an attractive and safe alternative way against UTI. Here, we report the construction of Lactococcus lactis (L. lactis) strain genetically modified to produce FimH virulence factor of UPEC on the cell surface. We showed the FimH inserted into the pT1NX vector is actively synthesized on L. lactis. The L. lactis-pT1NX-FimH exhibited an auto-aggregation phenotype in liquid cultures and formed robust biofilm on abiotic surface compared to vector-only bacteria. Then, we developed protective biofilms with L. lactis strains and examined their inhibitory effect for exclusion of uropathogenic biofilm formation. In the natural protective biofilm assays, L. lactis-pT1NX-FimH resulted in significant reduction in the pathogen load when compared to the L. lactis-pT1NX. Evaluation of the colonization ability in the bladder showed that L. lactis expressing FimH survived better in the mice bladder than L. lactis harboring vector. Protection assay against UPEC infection was investigated using a UTI mouse model. L. lactis-pT1NX-FimH displayed high effectiveness in the protection of the bladder as compared to the control group after UPEC challenge. The results suggest that genetically engineered L. lactis-pT1NX-FimH can be used as a safe alternative way for control of biofilm formation in UPEC. Furthermore, the possibility of using L. lactis-pT1NX-FimH as a new promising strategy against UTIs caused by UPEC strains is proposed.

Comparative Study of Blood, Tissue and Serum Levels of Carcinoembryonic Antigen (CEA) Detection in Breast Cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) detection was evaluated in breast cancer (BC). The statistical correlation between the CEA mRNA and clinico-pathological features in the peripheral blood (PB) and tissue samples of BC was assessed. MATERIALS AND METHODS: RT-PCR (Reverse transcription-polymerase chain reaction) analysis was applied to study the expression of CEA in PB of 30 healthy females and 30 patients with operable BC before receiving any therapy, as well as in the tissue of 30 BC patients. RESULTS: CEA was observed in a number of normal subjects, but there was a significant difference between the patients and controls. The detected CEA mRNA from tissue samples were the same as PB of patients and a correlation was observed between the CEA mRNA in PB and tissue samples (Pearson chi-square = 8.62, P=0.003). In the PB, CEA mRNA was significantly different in HER-2 (-)/HR (+) compare with HER-2(+)/HR (-) tumor group (p=0.026). Finally, CEA in serum was also significantly different in HER-2(-)/HR (+) compared with HER-2(+)/HR (+) and HER-2(+)/HR (-) subtypes (p=0.008 and p=0.043, respectively). CONCLUSION: CEA mRNA evaluation is diagnostically valuable as a breast cancer marker. Additionally, CEA can significantly improve the sensitivity of diagnosis.

Modulation of Molecular Biomarker Expression in Response to Chemotherapy in Invasive Ductal Carcinoma.

Breast cancer (BC) has varied morphological and biological features and is classified based on molecular and morphological examinations. Molecular classification of BC is based on biological gene-expression profiling. In this study, biomarker modulation was assessed during BC treatment in 30 previously untreated patients. Heterogeneity among patients was pathologically diagnosed and classified into luminal and basal-like immunohistochemical profiles based on estrogen, progesterone, and human epidermal growth factor receptor (ER/PR/HER2) status. Marker heterogeneity was compared with mRNA biomarker expression in patients with BC before and after therapy. Reverse transcription-polymerase chain reaction was performed for molecular characterization. Expression and modulation of biological markers, CK19, hMAM, CEA, MUC, Myc, Ki-67, HER2/neu, ErbB2, and ER, were assessed after treatment, where the expression of the biomarkers CK19, Ki-67, Myc, and CEA was noted to be significantly decreased. Marker expression modulation was determined according to different stages and pathological characteristics of patients; coexpression of three markers (CK19, Ki-67, and Myc) was specifically modulated after therapy. In the histopathologically classified basal-like group, two markers (CK19 and Ki-67) were downregulated and could be considered as diagnostic biomarkers. In conclusion, pathological characteristics and marker variation levels can be evaluated to decide a personalized treatment for patients.

Relationship between erb-B2 mRNA Expression in Blood and Tissue of Invasive Ductal Carcinoma Breast Cancer Patients and Clinicopathological Characteristics of the Tumors.

Molecular detection methods such as RT-PCR for detecting breast cancer-associated gene expression in the peripheral blood have the potential to modify breast cancer (BC) staging and therapy. In this regard, we evaluated the potential of erb-B2 molecular marker in BC detection and analyzed the expression of erb-B2 mRNA in the peripheral blood and fresh tissue samples of 50 pretreated female BC patients and 50 healthy females by reverse transcription-PCR (RT-PCR) method. We also assessed the correlation of erb-B2 mRNA marker positivity in peripheral blood and tumor tissue samples with clinical and pathological factors in BC patients in order to evaluate its prognostic value. It was shown that there is a significant difference between healthy females and BC patients with expression of the erb-B2 molecular marker (p<0.01). A significant difference between the expression of erb-B2 in the peripheral blood and tissue samples of BC patients (p<0.01) and the frequency of circulating erb-B2 mRNA expression in peripheral blood and in tissue was detected by RT-PCR. No correlation was found between erb-B2 mRNA expression in blood or tumor tissue samples and lymph node, tumor grade, tumor stage, tumor size, patient's age, ki67, estrogen receptor (ER), progesterone receptor (PGR), P53, and HER-2 status. However, in a small subset of 31 BC patients we found that expression of erb-B2 in peripheral blood or in both peripheral blood and tumor tissue was directly correlated with lympho-vascular invasion and perineural invasion as poor prognostic features. The highest rates of erb-B2 expression in peripheral blood or tumor tissue were in the ER and PR negative and HER-2 positive group. This study suggests that the application of the RT-PCR and immunohistochemical methods for erb-B2 molecular marker detection would provide a higher detection rate, especially in early stage BC.

Effect of shiga toxin and its subunits on cytokine induction in different cell lines.

Shiga toxins (Stxs) are bacterial virulence factors produced by Shigella dysenteriae serotype 1 and Escherichia coli strains. Stxs are critical factors for the development of diseases such as severe bloody diarrhea and hemolytic uremic syndrome. Additionally, Stxs trigger the secretion of pro- inflammatory cytokines and chemokines, particularly in monocytes or macrophages. The inflammatory cytokines result in the modulation of the immune system, local inflammations and enhancement of cytotoxicity. In this study, stimulation of the pro- inflammatory cytokines IL-1α, IL-1ß, IL-6, IL-8, and TNF-α was assessed by recombinant Stx (rStx) and its subunits (rStxA and rStxB). Cytokines expression at mRNA level was investigated by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) method in HeLa cells and THP1 monocyte/ macrophage cell lines. After incubation with rStx and its recombinant subunits, the expression of IL-1α, IL- 6 and IL- 8 mRNAs was strongly induced in HeLa cells. In HeLa cells, low expression of IL-1α mRNA was shown by rStxB induction. Furthermore, the expression of IL-1α and IL-1ß mRNAs in undifferentiated THP1 cells was only induced by rStx. In differentiated THP1 cells, rStx and its recombinant subunits elicited the expression of IL-1α, IL-1ß, IL-8 and IL- 6 mRNAs. On the other hand, expression of TNF-α mRNA was only induced by rStx. Based on the data, the profile of cytokine induction in response to the rStx, and its subunits differs depending on the cell types.

Relationship between preoperative serum CA 15-3 and CEA levels and clinicopathological parameters in breast cancer.

BACKGROUND: CEA and CA 15.3 serum tumor markers are currently used in clinical practice for monitoring therapy. The aim of this study was to evaluate serum level of these markers among healthy females and invasive breast carcinoma (IBC) patients and to determine any relationships with clinicopathological factors. MATERIALS AND METHODS: 60 Iranian females were enrolled in this study, 30 healthy and 30 diagnosed with breast cancer who had not received any preoperative chemotherapy or hormone therapy. Enzyme linked immunosorbent assays were used for the quantitative determination of the cancer associated antigens, CEA and MUC1 (CA 15- 3). RESULTS: The serological levels of CEA and CA 15-3 (5.0033 ± 0.49 µg/L and 178.1667 ± 15.11 U/ml) in the breast cancer patients were significantly higher (p=0.00) than the serum levels of normal controls (1.1237 ± 0.11 µg/L and 21.13 ± 3.058 U/ml). Regarding the CEA marker, a significant correlation with grade of tumor was shown. Furthermore, there was a low correlation between CA 15-3 and CEA marker with correlation coefficient r=0.08. CONCLUSIONS: Collectively, markedly high levels of CEA and CA 15-3 were found in our patients, pointing to their use as additional tools after clinical diagnosis.

Non-coding CK19 RNA in peripheral blood and tissue of breast cancer patients.

Breast carcinoma is the major cause of cancer-related death in women. The incidence of this carcinoma is rising and there are many attempts to decrease this problem. The aim of this study was detection of full-length cytokeratin 19 (CK19) mRNA, in peripheral blood and tissue of breast cancer patients in early stage of cancer. In this study, RT-PCR (reverse transcriptase-polymerase chain reaction) technique was used for detection of CK19 mRNA in peripheral blood and tissue of breast cancer patients. Primers were established to amplify the CK19 as a tumor marker. Moreover, CYFRA 21-1 subunit of CK19 protein was measured in the serum of patients. CK19 mRNA was detected and sequenced. It is shown that the most released CK19 mRNAs in blood and tissue of cancer patients are non-coding RNA. The mutated forms of mRNA are the incomplete transcripts of protein-coding gene as a long non-coding RNA (lncRNA) that could regulate gene expression. Moreover, small non-coding RNA (ncRNA) as fragments of CK19 is mostly observed in this experiment. They may play a role in tumorogenesis and their biologic exact function in breast cancer should be further elucidated.