Exosomes and miRNAs in disease pathogenesis and opportunities for molecular targeting

Exosomes/extracellular vesicles (EVs) are cell-derived mixed-populations of vesicles released by almost all cells into the intercellular microenvironment, ending up in the circulation. Exosomes contain proteins, RNAs and lipid molecules reflecting the status of the parental cell at the time of release, making them promising candidates for biomarker discovery. The contents of exosomes are protected by a lipid bilayer, leading to better stability of bio-macromolecules. Recent evidence suggests a novel role for exosomes as conveyors of information among cells and across tissues, through horizontal transfer of proteins, lipids, and nucleic acids. Exosomes have been the subject of numerous research in recent years; however, their roles still have to be identified in the pathogenesis of different diseases. MicroRNAs (miRNAs) are small (18-25 nucleotide long) non-coding RNAs which play pivotal roles in the gene expression process and it is estimated that about one third of the human genome is controlled by miRNAs. miRNA regulatory processes have been found to influence many essential biological pathways, such as cellular development, proliferation, apoptosis, and cellular signaling. A great proportion of miRNAs has been reported to be associated with the exosome function of different biofluids. The aim of this research was to elucidate the role of exosomes/EVs as well as miRNAs in the pathogenesis of different diseases, including alcoholic liver disease, hepatitis C, and cancer. This knowledge may lead to the development of novel molecular diagnostic approaches, as well as innovative drug delivery modalities for small RNA-targeted therapy. My research resulted in a) the establishment of new methods and approaches to the study of exosomes/EVs, as well as comparative literature on the efficacy of several isolation and characterization techniques. b) identification of the role of exosomes and miRNA-122 in the cross talk between hepatocytes and immune cells in alcoholic liver disease c) identification of the role of exosomes in HCV pathogenesis, including the potential of molecular therapies based on miRNA and exosome targeting in vitro and in vivo d) understanding the bio-distribution of exosomes and miRNA in an in vivo murine model and f) exploring the utility of miRNA and exosomes in biofluids in cancer biomarker discovery

Leprosy of the larynx: A case report

Leprosy is an ancient deforming disease caused by Mycobacterium leprae, which is still poorly understood and often feared by the general public and even by some in the health care professions Fortunately, the outlook for patients has dramatically improved over the last three decades with the introduction of multi-drug treatment and management strategies that have somewhat diminished the stigma of this diagnosis. We report a rare case of leprosy of larynx. A 45 year old man presented with complaints cough, dyspnea and hoarseness since many years ago. Because of demonstration of acid fast bacilli in smear of his sputum, the diagnosis of tuberculosis was made and anti tuberculosis treatment was initiated. But he developed fever and his symptoms exacerbated. In examination there was a tender erythematous nodule on right supraclavicular region, loss of eyebrows and lashes and disseminated hyper and hypo pigmented cutaneous lesions on abdomen, thorax, back with normal chest x ray. Laryngoscopy to rule out laryngeal tuberculosis was done and granulomatous lesion was seen. Laryngeal and skin biopsy was performed which numerous acid fast bacilli, macrophages and foamy cells suggestive of lepromatous leprosy were demonstrated in both specimens. Treatment was started on multi bacillary regime of WHO multidrug therapy. In conclusion, this report highlights the importance of systemic involvement in lepromatous leprosy especially when the initial presentation is laryngitis or respiratory symptoms. Laryngeal leprosy may mistaken with tuberculosis laryngitis due to respiratory problems and existence of acid fast bacilli in respiratory secretions. © 2009 Tehran University of Medical Sciences. All rights reserved

Extracellular vesicles in oral squamous carcinoma carry oncogenic miRNA profile and reprogram monocytes via NF-kappaB pathway

Extracellular vesicles (EVs) are carriers of different biomacromolecules that participate in cellular signaling and disease pathogenesis. Although it has been shown that EVs can play an active role in cellular communication and different stages of cancer progression, the role of EVs in oral squamous cell carcinoma (OSCC) cancer pathogenesis, especially in the crosstalk of cancer cells with immune cells is unknown. Here, we present a detailed analysis of findings regarding the profile of EVs in OSCC and the role of EVs and associated miRNAs in the crosstalk of malignant cells with monocytes. We demonstrate that EVs are detectable in significantly higher quantities in the plasma of patients with OSCC. Oncogenic miRNAs (such as miR-21, miR-27) were detectable in high quantities in the circulating EVs and plasma of patients with OSCC. EVs isolated from the circulation of OSCC patients and OSCC cell lines showed comparable miRNA signature, indicating the tumor origin of EVs in the circulation of patients with OSCC. Danger signals such as LPS and ethanol increased the production of EVs. EVs were taken up by monocytes after co-culture. Mechanistically, uptake of EVs derived from oral cancer cells by monocytes caused activation of the inflammatory pathway, NF-kappaB activation, and establishment of a pro-inflammatory and pro-tumorigenic milieu marked by increased levels of IL-6, CCL2, PEG2 and MMP9 levels. Series of experiments involving the introduction of exogenous oncogenic miR-21 mimic induced a similar pro-inflammatory and pro-tumorigenic profile in monocytes. Inhibiting miR-21 function in monocytes attenuated the pro-inflammatory phenotype of monocytes after EV challenge. These results indicate the role of EV-associated miR-21 in modulating the immune response in monocytes

Cutaneous tuberculosis presented by chest wall fistula formation

زمینه و هدف: سل یک معظل بهداشتی جهانی است که از نظر سازمان جهانی بهداشت (WHO) در راس شش بیماری شایع عفونی خطرناک قرار دارد. گرچه یکی از هر سه نفر مردم در دنیا آلوده به مایکوباکتریوم توبرکولوزیس هستند ولی سل پوستی بیماری نادری است. در این مطالعه ما به معرفی یک مورد نادر سل پوستی با تظاهر فسیتول متعدد مزمن در جدار قفسه سینه می پردازیم. گزارش مورد: مردی 50 ساله افغانی با سابقه دیابت وابسته به انسولین که با شکایت ضایعه پوستی به شکل فیستول در پوست ناحیه قفسه سینه از 3 ماه قبل مراجعه نمود. شروع ضایعه به صورت پاپول بوده که پس از مدتی فیستولیزه شده و همراه با سوزش و ترشح چرکی بوده است. با توجه به سیر طول کشیده بیماری و عدم پاسخ به درمان با آنتی بیوتیک و ملیت بیمار، سل پوستی در راس تشخیص های بیمار قرار گرفت و با توجه به مشاهده گرانولوم های متعدد متشکل از هیستوسیت ها، ژانت سل های تیپ لانگهانس در بیوپسی پوست و مشاهده باسیل های متعدد اسید فاست در اسمیر با رنگ آمیزی زیل نلسون از ترشحات فیستول ها تشخیص سل پوستی قطعی شد و بیمار تحت درمان با داروهای ضد سل قرار گرفت که علایمی از بهبودی نسبی پس از 6 هفته و بهبودی کامل پس از 6 ماه ملاحظه گردید. نتیجه گیری: سل پوستی می تواند به اشکال بسیار غیر معمول از جمله فیستول در هر محلی از جمله جدار قفسه سینه تظاهر کند. لذا باید در تشخیص افتراقی ضایعات جلدی طول کشیده همراه با تشکیل فیستول این بیماری مد نظر قرار گیرد.

Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5) and 18 water samples (7.6) were positive for Vibrio cholerae. Non-agglutinating (Nag) isolates (75.4) were more common than serotype Inaba (13.2) and Ogawa (11.4). Nag serotypes were mostly resistant to cefixime (44) and ampicillin (33). In contaminated water samples also the most frequent cases were Nag serotype (50). Nag serotype showed 22.2 of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes

Assessment of salivary and serum antioxidant status in patients with recurrent aphthous stomatitis

Objective: The aim of this study was to determine the possible association of oxidant/antioxidant status and recurrent aphthous stomatitis (RAS). Study design: The study consis ted of thirty-one patients with RAS and thirty-two healthy controls from whom saliva and blood samples were collected. Superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase (CAT) were measured in erythrocytes and total antioxidant status (TAS) was measured in plasma and saliva. Results: Erythrocyte SOD activity was significantly lower in RAS patients in comparison to healthy controls (P=0.012). No significant differences were found in erythrocyte GSHPx, CAT activities, and salivary and plasma TAS between RAS patients and control subjects (p>0.1). Conclusion: Changes in SOD activity may be important in the inflammatory reactions observed in RAS, but other tested defense systems such as CAT and GSHPx do not seem to play a primary role in the aetiopathogenesis of RAS. Moreover, the antioxidant system in saliva and plasma is not as affected as in erythrocytes in RAS patients, and therefore it may not be considered an appropriate indicator of the body?s total antioxidant status

Effective Factors on Needle Stick Injuries in Health Care Workers

Aims: Needle stick accidents are a serious health risk for blood-borne infections among health care workers. This study was conducted to evaluate the frequency of needle stick injuries in health care workers and its related factors. Instrument & Methods: This cross-sectional study was carried on HCWs of Shahid Beheshti Hospital of Kashan City, Iran (270 individuals), from September 2013 to March 2014. Due to the low number of samples, all those who had the experience of needle stick injuries and confirmed to participate were entered to the study. A researcher-made questionnaire with 20 questions was used. Data were analyzed by SPSS 16 software using descriptive statistics. Findings: The most injuries of needle sticks (75.2) were superficial and the most common device for NSIs was the needle of syringe (51.8). Blood sampling was the most common activity during NSIs (28.4). The most common contamination was blood and its products (69.5). 61 participants (43.3) used gloves during NSIs. 118 participants (83.7) were vaccinated completely against hepatitis B, and 19 participants (13.5) had incomplete HBV vaccination. 4 participants (2.8) had no history of vaccination against hepatitis B. Conclusion: Needle stick injuries among health care workers of Kashan Hospital are relatively high

Exosomes derived from alcohol-treated hepatocytes horizontally transfer liver specific miRNA-122 and sensitize monocytes to LPS

Hepatocyte damage and inflammation in monocytes/macrophages are central to the pathogenesis of alcoholic hepatitis (AH). MicroRNAs (miRNAs) regulate all of these processes. MiRNA-122 is abundantly expressed in hepatocytes while monocytes/macrophages have low levels. The role of exosomes in AH and possible cross talk between hepatocyte-derived exosomes and immune cells is not explored yet. Here, we show that the number of exosomes significantly increases in the sera of healthy individuals after alcohol binge drinking and in mice after binge or chronic alcohol consumption. Exosomes isolated from sera after alcohol consumption or from in vitro ethanol-treated hepatocytes contained miRNA-122. Exosomes derived from ethanol-treated Huh7.5 cells were taken up by the recipients THP1 monocytes and horizontally transferred a mature form of liver-specific miRNA-122. In vivo, liver mononuclear cells and Kupffer cells from alcohol-fed mice had increased miRNA-122 levels. In monocytes, miRNA-122 transferred via exosomes inhibited the HO-1 pathway and sensitized to LPS stimulation and increased levels of pro-inflammatory cytokines. Finally, inflammatory effects of exosomes from ethanol-treated hepatocytes were prevented by using RNA interference via exosome-mediated delivery of a miRNA-122 inhibitor. These results demonstrate that first, exosomes mediate communication between hepatocytes and monocytes/macrophages and second, hepatocyte-derived miRNA-122 can reprogram monocytes inducing sensitization to LPS

Factors affecting the outcome of community-acquired pneumonia among the patients hospitalized in Beheshti hospital (Kashan-Iran)

Background: Community-acquired pneumonia (CAP) is a common infectious disease with high morbidity and mortality. The goal of this study was to evaluate the factors affecting the outcome of pneumonia among the Beheshti hospital patients. Materials and Methods: This cohort study was done on pneumonia patients (n=140) in Kashan Beheshti hospital during 2014-2015. A questionnaire consisting the demographic, clinical and paraclinical findings and outcomes was filled-out. Results: Eighty three (59.3) out of 140 patients were male and 57(40.7) women. The majority of cases were ≥50 years old (mean age 60.02±1.70) .There was a history of diabetes in 54(38.6) .The most common signs and symptoms were coughing and the lung rales. The ninty-one and 9 of the cases were improved and complicated condition, respectively. The complication were: pleural effusion (77), empiyema (15) and abscess (8).There was positive CRP (100); increased ESR (82) and leukocytosis (80). While, there was no statistical association between the sex, age and clinical symptoms with the disease complication and outcome, there was a significant correlation between the first BS, HbA1C, CRP, duration of hospitalization, radiographic pattern and diabetes with disease outcome. Conclusion: Considering the association between the diabetes in one side and some factors (outcome of pneumonia, duration of hospitalization, history of pneumonia, times of admission, BS at admission, HbA1c, bilateral involvement, leukocytosis, increased ESR, CRP and CURB 65, the diabetes should be considered as an important factor affecting the pneumonia outcome. The managed control of diabetes can improve the pneumonia outcome

Exosome-mediated Delivery of RNA Interference and miRNA Mimic

Exosomes, membranous nanovesicles, naturally carry bio-macromolecules and play pivotal roles in both physiological intercellular crosstalk and disease pathogenesis. Here, we showed that B cell-derived exosomes can function as vehicles to deliver exogenous miRNA-155 mimic or inhibitor into hepatocytes or macrophages, respectively. Stimulation of B cells significantly increased exosome production. Unlike in parental cells, baseline level of miRNA-155 was very low in exosomes derived from stimulated B cells. Exosomes loaded with a miRNA-155 mimic significantly increased miRNA-155 levels in primary mouse hepatocytes and the liver of miRNA-155 knockout mice. Treatment of RAW macrophages with miRNA-155 inhibitor loaded exosomes resulted in statistically significant reduction in LPS-induced TNFα production and partially prevented LPS-induced decrease in SOCS1 mRNA levels. Furthermore, exosome-mediated miRNA-155 inhibitor delivery resulted in functionally more efficient inhibition and less cellular toxicity compared to conventional transfection methods. Similar approaches could be useful in modification of target biomolecules in vitro and in vivo