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.
The exocrine pancreas can give rise to endocrine insulin-producing cells upon ectopic expression of key transcription factors. However, the need for genetic manipulation remains a translational hurdle for diabetes therapy. Here we report the conversion of adult human nonendocrine pancreatic tissue into endocrine cell types by exposure to bone morphogenetic protein 7. The use of this U.S. Food and Drug Administration–approved agent, without any genetic manipulation, results in the neogenesis of clusters that exhibit high insulin content and glucose responsiveness both in vitro and in vivo. In vitro lineage tracing confirmed that BMP-7–induced insulin-expressing cells arise mainly from extrainsular PDX-1+, carbonic anhydrase II− (mature ductal), elastase 3a (acinar)−, and insulin− subpopulations. The nongenetic conversion of human pancreatic exocrine cells to endocrine cells is novel and represents a safer and simpler alternative to genetic reprogramming.
Objectives Latinos are disproportionately vulnerable to severe COVID-19 due to workplace exposure, multigenerational households, and existing health disparities. Rolling out COVID-19 vaccines among vulnerable Latinos is critical to address disparities. This study explores vaccine perceptions of Latino families to inform culturally centered strategies for vaccine dissemination. Method Semistructured telephone interviews with Latino families (22 mothers and 24 youth, 13–18 years old) explored COVID-19 vaccine perceptions including (1) sources of information, (2) trust of vaccine effectiveness and willingness to get vaccinated, and (3) access to the vaccine distribution. We identified thematic patterns using immersion–crystallization. Results We found that (1) 41% expressed optimism and willingness to receive the vaccine coupled with concerns about side effects; (2) 45% expressed hesitancy or would refuse vaccination based on mistrust, myths, fear of being used as “guinea pigs,” and the perceived role of politics in vaccine development; (3) families “digested” information gathered from social media, the news, and radio through intergenerational communication; and (4) participants called for community-led advocacy and “leading by example” to dispel fear and misinformation. Optimistic participants saw the vaccine as a way to protect their families, allowing youth to return to schools and providing safer conditions for frontline essential workers. Conclusions Culturally centered vaccine promotion campaigns may consider the Latino family unit as their target audience by providing information that can be discussed among parents and youth, engaging a range of health providers and advocates that includes traditional practitioners and community health workers, and disseminating information at key venues, such as schools, churches, and supermarkets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.