In this video collection, authors of findings published in JCI Insight present personally guided tours of their results. The journal accepts video submissions from authors of recently accepted manuscripts. Instructions can be found on the Author's Take Guidelines page.
Fibrosis is characterized by excess ECM deposition and occurs in a variety of organ systems, resulting in reduced function and possible failure. Therapeutic strategies for limiting and preventing fibrosis are lacking, and drivers of this pathogenic response are not fully understood. In this episode, Manuel Mayr and colleagues used a proteomic approach to evaluate the effect of targeting microRNA-21 (miR-21), which has been implicated in the fibrogenic response. While inhibition of miR-21 did not markedly alter ECM deposition, reduction of miR-21 limited the release of TGF-β1 and other profibrotic factors from platelets. These results provide a previously unrecognized mechanism for the known antifibrotic effects of miR-21 inhibition.
Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS characterized by progressive demyelination and disability. Epstein-Barr (EBV) virus has been implicated in the pathogenesis of MS, as high anti-EBV titers have been reported in patients with MS. In this episode, Michael Pender and Rajiv Khanna discuss the results of an open-label, dose escalation trial designed to evaluate the safety and efficacy of adoptively transferred in vitro-expanded EBV-specific T cells for patients with progressive MS. Clinical improvement was seen 7 of the 10 patients, with the greatest benefit for patients that received T cells with strong EBV reactivity. The results from this initial trial indicate that the EBV-specific adoptive T cell therapy is well tolerated and support further investigation of this approach in efficacy trials.
Patients with J wave syndromes (JWS), such as Brugada syndrome and early repolarization syndrome are vulnerable to life-threatening ventricular arrhythmias. Factors that promote JWS are not fully understood and models of the disease are limited. In this episode, Mu Chen and Peng-Sheng Chen describe their work, which shows that activation small-conductance calcium-activated potassium (SK) current (IKAS) in conjunction with inhibition of the sodium current with CyPPA induces JWS-associated phenotypes in perfused rabbit hearts. Moreover, inhibition of IKAS in this model eliminated JWS-like manifestations. The results of this study provide important insight into the drivers of JWS and suggest that IKAS inhibition be further explored for JWS.
Prostate cancer is a highly heterogenous disease, both within the primary tumor of a single individual and among individuals with the disease; therefore, diagnosis and determination of appropriate treatment options are challenging. In this episode, Simpa Salami, Ganesh Palapattu, and colleagues investigated the ability of commercially available gene expression assays to detect the coexistence of high-grade unsampled disease in formalin-fixed paraffin-embedded primary prostate tumor samples. The results of this study indicate that low- and high-grade foci have distinct prognostic gene expression profiles and suggest that sequencing of a low-grade area of a given tumor may not provide information about unsampled areas. Moreover, this work indicates that results from expression-based assays may not present the full picture of an individual’s disease.
Maternal diet has profound, long-lasting effects on offspring. For example, maternal malnutrition results in fetal exposure to excessive glucocorticoid, which can result in metabolic reprogramming and hypertension. In this episode, Toshiro Fujita and colleagues exposed pregnant rodents to a low-protein diet or to the synthetic glucocorticoid dexamethasone and demonstrated that the offspring of these dams were prone to salt-sensitive hypertension. In utero glucocorticoid exposure resulted in aberrant DNA methylation of hypothalamic angiotensin receptor type 1a, resulting in increased expression. Moreover, mice lacking the DNA methyltransferase 3a became hypertensive in the absence of glucocorticoid exposure, while animals lacking the angiotensin receptor were protected from prenatal glucocorticoid exposure-induced hypertension. Together, these results reveal epigenetic modulation of angiotensin signaling underlies development of hypertension that results from prenatal exposure to glucocorticoids.