Search

Colorectal cancer (CRC) is the second leading cause of cancer death among Latino men in the United States, yet they have low screening rates. This study explored barriers and facilitators of colonoscopy screening among Latino participants in a CRC screening promotion program. Six focus groups were conducted, in Spanish, with 45 Latino men, of which 28 had received and 17 had not received a colonoscopy. Analysis of the discussion transcripts identified barriers to CRC screening, facilitators to CRC screening, and recommendations for health information dissemination. There was consensus among all participants that they had not received adequate information on colonoscopy screening from their health care providers. Unscreened participants wanted more details about the colonoscopy procedure and bowel preparation. Screened men were more knowledgeable than unscreened men about CRC, the colonoscopy procedure, and the benefits of early detection. Participants also expressed their fears, concerns, and perceptions of stigma in relation to colonoscopy screening. They described family and personal testimonials as facilitators to engaging in colorectal cancer screening. Findings underscore the need for ongoing research and educational efforts to address personal and cultural stigma surrounding colonoscopy and CRC, particularly in underserved communities. Study findings also highlight the danger of missing out on opportunities to increase CRC screening when colonoscopy is the primary screening option offered. Additional research is needed to ensure trust in the health care system and to examine the effectiveness of testimonials on CRC screening among Latino men.

Purpose – This research aims to study the effect of R&D (research and development) enablers and barriers as well as industrial property on exploration, their influence on exploitation and finally the possible impact on innovative outcome (IO) as a result variable. The IO can be defined as the orientation towards new or improved products, services and processes, as well as towards penetration and greater market share, which the company has obtained as a result of innovative processes. Design/methodology/approach – For this purpose, a new relationship model is defined, which is empirically contrasted in a quantitative study. We use a sample of large firms from different economic sectors with a high level of investment in R&D. Findings – The results indicate a close relationship between exploration and exploitation processes, as well as a positive impact on the innovative outcome. Moreover, the type of relationship that R&D enablers and barriers have with exploration is demonstrated and the lack of a positive effect of industrial property on exploration. Practical implications – These results may lead to new markets opening up and the creation or improvement of new products, services or processes in diverse sectors of highly innovative firms. Originality/value – This research aims to study the effect of R&D enablers and barriers and industrial property on learning flows and, finally, the possible impact on the innovative outcome. A new theoretical model of relationships is defined, and it is the first time that it is empirically tested. 研究目的 – 本研究旨在探討研究與開發的推動者、研發的障礙和工業產權對探索與開發的影響，並最終探究出其可能對作為結果變項的創新成果帶來的影響。創新成果可解釋為邁向新的或改良的產品，服務和流程的定向，以及邁向滲透和更大的市場份額的定向，而這更大的市場份額是企業的創新流程所帶來的。 研究的設計/方法/理念 – 為達研究目的，我們解說了一個新的關聯模型, 並使用於一項量化研究，進行以實驗為依據的對比。我們使用的樣本，包括來自不同經濟領域，並於研發投放高水平投資的大企業。 研究結果 – 研究結果顯示，探索與開發是兩個關係密切的流程；研究結果亦顯示對創新成果的影響是正面的。而且，結果展示了研發推動者、研發障礙兩者與探索的關聯，以及工業產權對探索是欠缺正面作用的。 實際的意義 – 研究結果或會帶來新市場的開拓，以及在不同領域、高度創新的企業內，帶來新的產品，服務與流程的創造和改良。 研究的原創性和價值 – 本研究旨在探討研發推動者，研發障礙和工業產權對學習心流的影響，並最終探究出其對創新成果可能帶來的影響。研究解說了一個新的、純理論的關聯模型，而這個模型於此是首次憑實驗而被測試的。

The potential of polyphenols for treating chronic-degenerative diseases (particularly neurodegenerative diseases) is attractive. However, the selection of the best polyphenol for each treatment, the mechanisms by which they act, and their efficacy are frequently discussed. In this review, the basics and the advances in the field, as well as suggestions for using natural and synthetic polyphenols alone or in a combinatorial strategy with stem cell assays, are compiled and discussed. Thus, stem cells exhibit several responses when polyphenols are added to their environment, which could provide us with knowledge for advancing the elucidation of the origin of neurodegeneration. But also, polyphenols are being included in the innovative strategies of novel therapies for treating neurodegenerative diseases as well as metabolic diseases related to neurodegeneration. In this regard, flavonoid compounds are suggested as the best natural polyphenols due to their several mechanisms for acting in ameliorative effects; but increasing reports are involving other polyphenols. Even if some facts limiting bioactivity prevent them from conventional use, some natural polyphenols and derivatives hold the promise for being improved compounds, judged by their induced effects. The current results suggest polyphenols as enhancers of stem cell therapy against the targeted diseases.

Abstract Background The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women engage in at least 20 to 30 min of moderate-intensity physical activity on most days of the week. Regular exercise during pregnancy is associated with many benefits for the mother and the developing fetus; yet, a large number of pregnant women do not engage in the recommended amounts. This study aimed to investigate barriers to and interventions for physical activity among pregnant WIC participants in Southern California. Methods We conducted four focus groups (FGs) with pregnant low-income women aged 18 years or older in either their second or third trimester. FGs were conducted at a WIC center in Southern California. The FGs were held according to language (English vs. Spanish-speaking) and BMI category (normal weight vs. overweight and obese). A total of 28 women participated. We used ATLAS. ti. to analyze the focus group transcripts. The study adhered to the Consolidated Criteria for Reporting Qualitative Research. Results The mean age of focus group participants was 28.9 years (SD = 6.6), and the majority were Latina. Intrapersonal barriers to physical activity were fatigue and lack of energy, pain and swelling, lack of childcare, medical restrictions and safety concerns, lack of knowledge about exercise safety, and lack of time. Interpersonal barriers included concerns and lack of support from partners and families, conflicting advice from friends and neighbors, and lack of advice on safe exercise from physicians. Women in all four groups suggested a community-based intervention where they can mingle with each other and share their challenges and concerns. Other suggestions to interventions differed among groups and reflected the women’s experiences and backgrounds. Specifically, to promote education, English-speaking women preferred a brochure while Spanish-speaking women preferred a video. Overweight women emphasized including children in their exercise activities to promote healthy behavior in youth. Conclusions Interventions should be tailored to pregnant women’s needs. Primary care providers should provide reassurance and information to pregnant women and their partners on the type and frequency of safe exercise.

Cells recognize both foreign and host-derived double-stranded RNA (dsRNA) via a signaling pathway that is usually studied in the context of viral infection. It has become increasingly clear that the sensing and handling of endogenous dsRNA is also critical for cellular differentiation and development. The adenosine RNA deaminase, ADAR1, has been implicated as a central regulator of the dsRNA response, but how regulation of the dsRNA response might mediate cell fate during injury and whether such signaling is cell intrinsic remain unclear. Here, we show that the ADAR1-mediated response to dsRNA was dramatically induced in 2 distinct injury models of gastric metaplasia. Mouse organoid and in vivo genetic models showed that ADAR1 coordinated a cell-intrinsic, epithelium-autonomous, and interferon signaling–independent dsRNA response. In addition, dsRNA accumulated within a differentiated epithelial population (chief cells) in mouse and human stomachs as these cells reprogrammed to a proliferative, reparative (metaplastic) state. Finally, chief cells required ADAR1 to reenter the cell cycle during metaplasia. Thus, cell-intrinsic ADAR1 signaling is critical for the induction of metaplasia. Because metaplasia increases cancer risk, these findings support roles for ADAR1 and the response to dsRNA in oncogenesis.

Objective Describe the histological findings of minimally ultrasound-guided invasive autopsies in deceased patients with severe SARS-CoV-2 and compare the diagnostic yield with open autopsies. Design Observational post-mortem cohort study. Minimally invasive ultrasound-guided autopsies were performed in fourteen deceased patients with a confirmed diagnosis of SARS-CoV-2 pneumonia. Histological and clinical findings of lung, kidney, and liver tissue are described and contrasted with those previously reported in the literature. Setting Single-center COVID-19 reference center in Mexico City. Results Fourteen minimally invasive autopsies revealed a gross correlation with open autopsies reports: 1) Lung histology was characterized mainly by early diffuse alveolar damage (12/13). Despite low lung compliances and prolonged mechanical ventilation, the fibrotic phase was rarely observed (2/13). 2) Kidney histopathology demonstrated acute tubular injury (12/13), interstitial nephritis (11/13), and glomerulitis (11/13) as the predominant features 3) Liver histology was characterized by neutrophilic inflammation in all of the cases, as well as hepatic necrosis (8/14) despite minimal alterations in liver function testing. Hepatic steatosis was observed in most cases (12/14). SARS-CoV-2 positivity was widely observed throughout the immunohistochemical analysis. However, endothelitis and micro thrombosis, two of the hallmark features of the disease, were not observed. Conclusion Our data represents the largest minimally invasive, ultrasound-guided autopsy report. We demonstrate a gross histological correlation with large open autopsy cohorts. However, this approach might overlook major histologic features of the disease, such as endothelitis and micro-thrombosis. Whether this represents sampling bias is unclear.

Plants of the genus Opuntia spp are widely distributed in Africa, Asia, Australia and America. Specifically, Mexico has the largest number of wild species; mainly O. streptacantha, O. hyptiacantha, O. albicarpa, O. megacantha and O. ficus-indica. The latter being the most cultivated and domesticated species. Its main bioactive compounds include pigments (carotenoids, betalains and betacyanins), vitamins, flavonoids (isorhamnetin, kaempferol, quercetin) and phenolic compounds. Together, they favor the different plant parts and are considered phytochemically important and associated with control, progression and prevention of some chronic and infectious diseases. Part 1 collected information on its preventive actions against atherosclerotic cardiovascular diseases, diabetes and obesity, hepatoprotection, effects on human infertility and chemopreventive capacity. Now, this second review (Part 2), compiles the data from published research (in vitro, in vivo, and clinical studies) on its neuroprotective, anti-inflammatory, antiulcerative, antimicrobial, antiviral potential and in the treatment of skin wounds. The aim of both reviews is to provide scientific evidences of its beneficial properties and to encourage health professionals and researchers to expand studies on the pharmacological and therapeutic effects of Opuntia spp.

The mobility of the human body depends on, among other things, muscle health, which can be affected by several situations, such as aging, increased oxidative stress, malnutrition, cancer, and the lack or excess of physical exercise, among others. Genetic, metabolic, hormonal, and nutritional factors are intricately involved in maintaining the balance that allows proper muscle function and fiber recovery; therefore, the breakdown of the balance among these elements can trigger muscle atrophy. The study from the nutrigenomic perspective of nutritional factors has drawn wide attention recently; one of these is the use of certain compounds derived from foods and plants known as phytochemicals, to which various biological activities have been described and attributed in terms of benefiting health in many respects. This work addresses the effect that the phytochemicals curcumin from Curcuma longa Linn and sulforaphane from Brassicaceae species have shown to exert on muscle function, recovery, and the prevention of muscle atrophy, and describes the impact on muscle health in general. In the same manner, there are future perspectives in research on novel compounds as potential agents in the prevention or treatment of medical conditions that affect muscle health.

In Mexico, the use of medicinal plants is the first alternative to treat the diseases of the most economically vulnerable population. Therefore, this review offers a list of Mexican plants (native and introduced) with teratogenic effects and describes their main alterations, teratogenic compounds, and the models and doses used. Our results identified 63 species with teratogenic effects (19 native) and the main alterations that were found in the nervous system and axial skeleton, induced by compounds such as alkaloids, terpenes, and flavonoids. Additionally, a group of hallucinogenic plants rich in alkaloids employed by indigenous groups without teratogenic studies were identified. Our conclusion shows that several of the identified species are employed in Mexican traditional medicine and that the teratogenic species most distributed in Mexico are Astragalus mollissimus, Astragalus lentiginosus, and Lupinus formosus. Considering the total number of plants in Mexico (≈29,000 total vascular plants), to date, existing research in the area shows that Mexican plants with teratogenic effects represent ≈0.22% of the total species of these in the country. This indicates a clear need to intensify the evaluation of the teratogenic effect of Mexican plants.

It is demonstrated that data augmentation is a promising approach to reduce the size of the captured dataset required for training automatic road surface classifiers. The context is on-board systems for autonomous or semi-autonomous driving assistance: automatic power-assisted steering. Evidence is obtained by extensive experiments involving multiple captures from a 10-channel multisensor deployment: three channels from the accelerometer (acceleration in the X, Y, and Z axes); three microphone channels; two speed channels; and the torque and position of the handwheel. These captures were made under different settings: three worm-gear interface configurations; hands on or off the wheel; vehicle speed (constant speed of 10, 15, 20, 30 km/h, or accelerating from 0 to 30 km/h); and road surface (smooth flat asphalt, stripes, or cobblestones). It has been demonstrated in the experiments that data augmentation allows a reduction by an approximate factor of 1.5 in the size of the captured training dataset.

The damage caused by chronic alcohol consumption is frequently reported, but the effects caused by weekend recreational consumption, which is much more frequent than even daily consumption, have not, to our knowledge, been reported. The metabolism of ethanol, once consumed, starts from the mouth, and the biotransformation process follows different routes. In this study, the effect of weekend alcohol consumption on the oral cavity was observed. Methods: Thirty male and female rats were divided into six groups (n = 5), with control groups (male/female) and groups administered with 5% and 40% ethanol solution ad libitum consumption 2 days a week for 3 months. After treatment, the animals were sacrificed, an incisional slice of the cheek and back of the tongue was obtained, and the tissues were processed according to the histological technique and routine staining (hematoxylin-eosin, H&E). Samples were observed using light microscopy. Results: Histological changes were observed in samples of tongue and cheek mucosa including different levels of keratinization of the surface layer. Epithelial dysplasia, acanthosis, and chronic inflammation were also observed. The vascularization level also increased because of the ethanol-induced damage. The results were very similar between female and male groups. Conclusion: Weekend alcohol consumption for a period of 3 months causes oral-cavity tissue alterations that could contribute to tumor growth and the development of cancer in the oral cavity.

Opuntia spp. is a diverse and widely distributed genus in Africa, Asia, Australia, and America. Mexico has the largest number of wild species; mainly O. streptacantha, O. hyptiacantha, O. albicarpa, O. megacantha and O. ficus-indica. The latter being the most cultivated and domesticated species. Throughout history, plants and their phytochemicals have played an important role in health care and Opuntia spp. has shown a high nutritional, medicinal, pharmaceutical, and economic impacts. Its main bioactive compounds include pigments (carotenoids, betalains and betacyanins), vitamins, flavonoids (isorhamnetin, kaempferol, quercetin) and phenolic compounds. Together, they favor the different plant parts and are considered phytochemically important and associated with control, progression and prevention of some chronic and infectious diseases. This first review (Part 1), compiles information from published research (in vitro, in vivo, and clinical studies) on its preventive effects against atherosclerotic cardiovascular diseases, diabetes and obesity, hepatoprotection, effects on human infertility and chemopreventive and/or antigenotoxic capacity. The aim is to provide scientific evidences of its beneficial properties and to encourage health professionals and researchers to expand studies on the pharmacological and therapeutic effects of Opuntia spp.

Cells have the ability to adapt to stressful environments as a part of their evolution. Physical exercise induces an increase of a demand for energy that must be met by mitochondria as the main (ATP) provider. However, this process leads to the increase of free radicals and the so-called reactive oxygen species (ROS), which are necessary for the maintenance of cell signaling and homeostasis. In addition, mitochondrial biogenesis is influenced by exercise in continuous crosstalk between the mitochondria and the nuclear genome. Excessive workloads may induce severe mitochondrial stress, resulting in oxidative damage. In this regard, the objective of this work was to provide a general overview of the molecular mechanisms involved in mitochondrial adaptation during exercise and to understand if some nutrients such as antioxidants may be implicated in blunt adaptation and/or an impact on the performance of exercise by different means.

For the writing of this manuscript, we searched information published from 2000 to 2021, through PubMed, Web of Science, Springer, and Science Direct. Focusing on the effects related to respiratory diseases, in addition to possible direct effects towards SARS-CoV-2, coupled with diabetes. Diabetes is a metabolic disease that is characterized by affecting the function of glucose, in addition to insulin insufficiency. This leads to patients with such pathologies as being at greater risk for developing multiple complications and increase exposure to viruses infections. This is the case of severe acute respiratory disease coronavirus 19 (SARS-CoV-2), which gave rise to coronavirus disease 2019 (COVID-19), declared an international public health emergency in March of 2020 Currently, several strategies have been applied in order to prevent the majority of the consequences of COVID-19, especially in patients with chronic diseases such as diabetes. Among the possible treatment options, we found that the use of phytochemical compounds has exhibited beneficial effects for the prevention and inhibition of infection by SARS-CoV-2, as well as for the improvement of the manifestations of diabetes.

Background: Exercise training induces adaptive physiological and morphological modifications in the entire organism; however, excessive loads of training may increase damage in tissues. The purpose of this study was to evaluate the effect of silymarin in lung and liver histological changes in rats subjected to exercise training (ET). Methods: Male Wistar rats were subjected to an 8-week ET treadmill program 5 days per week, 60 min/session, and were previously administered 100 mg ascorbic acid or 100 mg of silymarin. Results: Silymarin increased alveolar and bronchial muscle size, improve vascularization, and reduced tissue inflammation. In liver, silymarin promoted the reduction of lipid content. Conclusion: Silymarin supplementation may improve inflammation in pulmonary tissue after 8 weeks of the ET treadmill program, improve cell recovery, and reduce intrahepatic lipid content.

Asthma is a chronic disease whose main anatomical–functional alterations are grouped into obstruction, nonspecific bronchial hyperreactivity, inflammation and airway remodeling. Currently, the Global Initiative of Asthma 2020 (GINA 2020) suggests classifying it into intermittent cases, slightly persistent, moderately persistent and severely persistent, thus determining the correct guidelines for its therapy. In general, the drugs used for its management are divided into two groups, those with a potential bronchodilator and the controlling agents of inflammation. However, asthmatic treatments continue to evolve, and notable advances have been made possible in biological therapy with monoclonal antibodies and in the relationship between this disease and oxidative stress. This opens a new path to dietary and herbal strategies and the use of antioxidants as a possible therapy that supports conventional pharmacological treatments and reduces their doses and/or adverse effects. This review compiles information from different published research on risk factors, pathophysiology, classification, diagnosis and the main treatments; likewise, it synthesizes the current evidence of herbal medicine for its control. Studies on integrative medicine (IM) therapies for asthmatic control are critically reviewed. An integrative approach to the prevention and management of asthma warrants consideration in clinical practice. The intention is to encourage health professionals and scientists to expand the horizons of basic and clinical research (preclinical, clinical and integrative medicine) on asthma control.

Silymarin (SM) is a mixture of flavolignans extracted from the seeds of species derived from Silybum marianum, commonly known as milk thistle or St. Mary’sthistle. These species have been widely used in the treatment of liver disorders in traditional medicine since ancient times. Several properties had been attributed to the major SM flavolignans components, identified as silybin, isosilybin, silychristin, isosilychristin, and silydianin. Previous research reported antioxidant and protective activities, which are probably related to the activation of the nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2), known as a master regulator of the cytoprotector response. Nrf2 is a redox-sensitive nuclear transcription factor able to induce the downstream-associated genes. The disruption of Nrf2 signaling has been associated with different pathological conditions. Some identified phytochemicals from SM had shown to participate in the Nrf2 signaling pathway; in particular, they have been suggested as activators that disrupt interactions in the Keap1-Nrf2 system, but also as antioxidants or with additional actions regarding Nrf2 regulation. Thus, the study of these molecules makes them appear attractive as novel targets for the treatment or prevention of several diseases.

Roselle (Hibiscus sabdariffa L.), also known as jamaica in Spanish, is a perennial plant that grows in tropical and subtropical regions, including China, Egypt, Indonesia, Mexico, Nigeria, Thailand, and Saudi Arabia. It has a long history of uses, mainly focused on culinary, botanical, floral, cosmetic, and medicinal uses. The latter being of great impact due to the diuretic, choleretic, analgesic, antitussive, antihypertensive, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and anti-cancer effects. These therapeutic properties have been attributed to the bioactive compounds of the plant, mainly phenolic acids, flavonoids, anthocyanins, and organic acids (citric, hydroxycitric, hibiscus, tartaric, malic, and ascorbic). Most literature reviews and meta-analyses on the therapeutic potential of Hibiscus sabdariffa L. (Hs) compounds have not adequately addressed the contributions of its organic acids present in the Hs extracts. This review compiles information from published research (in vitro, in vivo, and clinical studies) on demonstrated pharmacological properties of organic acids found in Hs. The intent is to encourage and aid researchers to expand their studies on the pharmacologic and therapeutic effects of Hs to include assessments of the organic acid components.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a powerful nuclear transcription factor that coordinates an antioxidant cytoprotector system complex stimulated by the increase in inoxidative stress (OS). In the present manuscript, we conduct a review on the evidence that shows the effect different modalities of physical exercise exert on the antioxidant metabolic response directed by Nrf2. During physical exercise, the reactive oxygen species (ROS) are increased; therefore, if the endogenous and exogenous antioxidant defenses are unable to control the elevation of ROS, the resulting OS triggers the activation of the transcriptional factor Nrf2 to induce the antioxidant response. On a molecular basis related to physical exercise, hormesis maintenance (exercise preconditioning) and adaptative changes in training are supported by a growing body of evidence, which is important for detailing the health benefits that involve greater resistance to environmental aggressions, better tolerance to constant changes, and increasing the regenerative capacity of the cells in such a way that it may be used as a tool to support the prevention or treatment of diseases. This may have clinical implications for future investigations regarding physical exercise in terms of understanding adaptations in high-performance athletes but also as a therapeutic model in several diseases.

Geranium schiedeanum has been used in traditional therapies as an antiseptic, antipyretic, and as analgesic. The present study was designed to evaluate the pretreatment with G. schiedeanum total extract (GS) and its active metabolites on stimulating the endogenous antioxidant defense system (EADS): catalase (Cat), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione reduction index (RI GSH/GSSG) in rat liver treated with a sublethal dose (6.6 mmol/Kg) of thioacetamide (TAA) in order to probe the capacity of GS and the active compounds to reduce liver injury. This was assessed by measuring aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (BILT) in rats pretreated or not with TAA, and pretreated or not with GS and its metabolites. The results showed that GS was able to induce the production of EADS enzymes, increasing redox index GSH/GSSG at 24 and 48 h after intoxication, and both the extract and the ellagic acid exhibited a significant reduction of hepatic damage markers. Our data confirmed the hepatoprotective effect of GS and its metabolites, like ellagic acid, support the possible use of this extract in the treatment of liver injury.

Background: The need to advance and achieve success is deeply ingrained in human evolution. As a species, humans developed instincts that allowed them to survive and transmit their genes along generations. The will to win is an instinct that has been maintained in the species for millions of years. Sport is an activity as old as humans themselves and is subject to rules; Objective: The proposal of this work is to explore some of the most recurrent practices to achieve the athletes’ goals, and the origins and historical use of methods or substances to improve performance and its regulation, as well as to review the impact of new technologies on achieving better results and to make a proposal of what actions should be takenin order to prevent bad practices; Methods: A narrative literature review of ethical sports issues and decision-making was performed in the English language; Results: Practically all behavior with regards to the theme of sports is regulated by ethical codes that must be followed by sportspersons, as well as by everyone involved in the athlete’s healthcare and in the athlete’s administrative, marketing, and business aspects. Notwithstanding this, winning and reaping glory implies a reward far greater than fame and fortune, which can lead to poor ethical practices in athletes, as well as in interested parties who detract from the intrinsic value of the spirit of sports. The will to win could exceed the limits of what is permitted in fair-play, like the use of prohibited methods or substances; Conclusions: In this work, we review some of the bioethical aspects ofsports. Additionally, recommendations are offered for good practices and to prevent falling into poor ethical behavior.

Peroxisomes are cellular organelles present in the eukaryotic cells that are responsible for detoxification processes such as oxidation of fatty acids, biosynthesis of glycerolipids and isoprenoids, among others. Due to the number of functions which they carry out, they are conditioned to an elevated production of free radicals (FR), for which they have a sophisticated antioxidant system consisting of enzymes that can neutralize free radical molecules. The importance of peroxisomes in the development of age-related diseases such as diabetes, cancer and cardiovascular disease has been reported recently. In this paper, we review briefly these organelles, treating aspects such as their evolution, functions and the role they play in oxidative stress processes associated with aging.

microRNAs (miRNAs) play an important role in pancreatic development and adult β-cell physiology. Our hypothesis is based on the assumption that each islet cell type has a specific pattern of miRNA expression. We sought to determine the profile of miRNA expression in α-and β-cells, the main components of pancreatic islets, because this analysis may lead to a better understanding of islet gene regulatory pathways. Highly enriched (>98%) subsets of human α-and β-cells were obtained by flow cytometric sorting after intracellular staining with c-peptide and glucagon antibody. The method of sorting based on intracellular staining is possible because miRNAs are stable after fixation. MiRNA expression levels were determined by quantitative high throughput PCR-based miRNA array platform screening. Most of the miRNAs were preferentially expressed in β-cells. From the total of 667 miRNAs screened, the Significant Analysis of Microarray identified 141 miRNAs, of which only 7 were expressed more in α-cells (α-miRNAs) and 134 were expressed more in β-cells (β-miRNAs). Bioinformatic analysis identified potential targets of β-miRNAs analyzing the Beta Cell Gene Atlas, described in the T1Dbase, the web platform, supporting the type 1 diabetes (T1D) community. cMaf, a transcription factor regulating glucagon expression expressed selectively in α-cells (TFα) is targeted by β-miRNAs; miR-200c, miR-125b and miR-182. Min6 cells treated with inhibitors of these miRNAs show an increased expression of cMaf RNA. Conversely, over expression of miR-200c, miR-125b or miR-182 in the mouse alpha cell line αTC6 decreases the level of cMAF mRNA and protein. MiR-200c also inhibits the expression of Zfpm2, a TFα that inhibits the PI3K signaling pathway, at both RNA and protein levels.In conclusion, we identified miRNAs differentially expressed in pancreatic α- and β-cells and their potential transcription factor targets that could add new insights into different aspects of islet biology and pathophysiology.

MicroRNAs regulate gene expression by inhibiting translation or inducing target mRNA degradation. MicroRNAs regulate organ differentiation and embryonic development, including pancreatic specification and islet function. We showed previously that miR-7 is highly expressed in human pancreatic fetal and adult endocrine cells. Here we determined the expression profile of miR-7 in the mouse-developing pancreas by RT-PCR and in situ hybridization. MiR-7 expression was low between embryonic days e10.5 and e11.5, then began to increase at e13.5 through e14.5, and eventually decreased by e18. In situ hybridization and immunostaining analysis showed that miR-7 colocalizes with endocrine marker Isl1, suggesting that miR-7 is expressed preferentially in endocrine cells. Whole-mount in situ hybridization shows miR-7 highly expressed in the embryonic neural tube. To investigate the role of miR-7 in development of the mouse endocrine pancreas, antisense miR-7 morpholinos (MO) were delivered to the embryo at an early developmental stage (e10.5 days) via intrauterine fetal heart injection. Inhibition of miR-7 during early embryonic life results in an overall downregulation of insulin production, decreased β-cell numbers, and glucose intolerance in the postnatal period. This phenomenon is specific for miR-7 and possibly due to a systemic effect on pancreatic development. On the other hand, the in vitro inhibition of miR-7 in explanted pancreatic buds leads to β-cell death and generation of β-cells expressing less insulin than those in MO control. Therefore, in addition to the potential indirect effects on pancreatic differentiation derived from its systemic downregulation, the knockdown of miR-7 appears to have a β-cell-specific effect as well. These findings suggest that modulation of miR-7 expression could be utilized in the development of stem cell therapies to cure diabetes.

Nonspecific inflammation in the transplant microenvironment results in β-cell dysfunction and death influencing negatively graft outcome. MicroRNA (miRNA) expression and gene target regulation in transplanted islets are not yet well characterized. We evaluated the impact of inflammation on miRNA expression in transplanted rat islets. Islets exposed in vitro to proinflammatory cytokines and explanted syngeneic islet grafts were evaluated by miRNA arrays. A subset of 26 islet miRNAs was affected by inflammation both in vivo and in vitro. Induction of miRNAs was dependent on NF-κB, a pathway linked with cytokine-mediated islet cell death. RT-PCR confirmed expression of 8 miRNAs. The association between these miRNAs and mRNA target-predicting algorithms in genome-wide RNA studies of β-cell inflammation identified 238 potential miRNA gene targets. Several genes were ontologically associated with regulation of insulin signaling and secretion, diabetes, and islet physiology. One of the most activated miRNAs was miR-21. Overexpression of miR-21 in insulin-secreting MIN6 cells downregulated endogenous expression of the tumor suppressor Pdcd4 and of Pclo, a Ca2+ sensor protein involved in insulin secretion. Bioinformatics identified both as potential targets. The integrated analysis of miRNA and mRNA expression profiles revealed potential targets that may identify molecular targets for therapeutic interventions.

Alongside Pdx1 and Beta2/NeuroD, the transcription factor MafA has been shown to be instrumental in the maintenance of the beta cell phenotype. Indeed, a combination of MafA, Pdx1 and Ngn3 (an upstream regulator of Beta2/NeuroD) was recently reported to lead to the effective reprogramming of acinar cells into insulin-producing beta cells. These experiments set the stage for the development of new strategies to address the impairment of glycemic control in diabetic patients. However, the clinical applicability of reprogramming in this context is deemed to be poor due to the need to use viral vehicles for the delivery of the above factors. Here we describe a recombinant transducible version of the MafA protein (TAT-MafA) that penetrates across cell membranes with an efficiency of 100% and binds to the insulin promoter in vitro. When injected in utero into living mouse embryos, TAT-MafA significantly up-regulates target genes and induces enhanced insulin production as well as cytoarchitectural changes consistent with faster islet maturation. As the latest addition to our armamentarium of transducible proteins (which already includes Pdx1 and Ngn3), the purification and characterization of a functional TAT-MafA protein opens the door to prospective therapeutic uses that circumvent the use of viral delivery. To our knowledge, this is also the first report on the use of protein transduction in utero.