This series showcases video summaries of new findings published in the Journal of Clinical Investigation. This format allows authors to to provide a personally guided tour of their results and makes the research more accessible to a broad readership. The JCI accepts videos from authors of recently accepted manuscripts. Instructions can be found on the Author's Take Guidelines page.
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a life-threatening condition that results from the development of maternal antibodies that target and destroy fetal platelets. Intracranial hemorrhage (ICH) is the most serious complication of FNAIT and is thought to be the result of severe thrombocytopenia. In this episode, Heyu Ni and colleagues present evidence that the development of ICH in FNAIT specifically occurs as the result of maternal anti-platelet β3 integrins and not as the result of maternal antibodies against other platelet factors. In a murine model of anti–β3 integrin–mediated FNAIT, ICH was the result of impaired angiogenesis and was prevented by administration of intravenous immunoglobulin. The results of this study suggest that current platelet transfusion therapies for FNAIT should be reexamined and intravenous immunoglobulin be further explored to treat this disease.
The inherited disorder dyskeratosis congenita is characterized by short telomeres, mucocutaneous abnormalities, and bone marrow failure. The underlying genetic mutations are known in ~40% of cases and are found within genes associated with telomere maintenance and function. In this episode, Tom Vulliamy and Hemanth Tummala discuss their work, which identifies biallelic mutations in the gene encoding poly(A)-specific ribonuclease (PARN) in three families with severe dyskeratosis congenita. These mutations inhibit the deadenylation activity of PARN, resulting in the downregulation of 4 genes involved in telomere maintenance and shortened telomeres. The results of this study establish a causative role for PARN in a severe form of dyskeratosis congenita.
Mutations in the RAS oncogene are present in almost 25% of all cancers. Direct targeting of RAS for limiting these cancers has been challenging; therefore, elucidation of the pathways downstream of RAS has potential to provide therapeutic targets. In this episode, David Virshup and Jit Kong Cheong discuss their work, which identifies the serine/threonine kinase casein kinase 1a (CK1a) as a key negative regulator of oncogenic RAS-induced autophagy. Combined pharmacological inhibition of both CK1a and autophagy attenuated the growth of RAS-driven tumor xenografts. The results of this study support further exploration of CK1a as a therapeutic target for oncogenic RAS-driven cancers.
The inherited form of blindness retinitis pigmentosa (RP) results from a progressive loss of photoreceptors. RP-associated mutations directly promote the death of rod cells, which are required for vision in low light, and indirectly promote the subsequent degeneration of cone cells, which are necessary for daytime vision. While the mechanisms that mediate cone death are not fully understood, an increase in oxidative stress has been implicated in the degradation of these cells. In this episode, Connie Cepko and Wenjun Xiong detail their work, which shows that adeno-associated virus-mediated delivery of antioxidant genes prolongs photoreceptor survival and improves visual acuity in multiple murine RP models. The results of this study suggest that targeted delivery of antioxidant genes has potential to ameliorate other diseases characterized by oxidative stress-induced cell degradation.
Retinitis pigmentosa (RP) is an inherited degenerative eye disease that results from the presence of mutations in rod-associated genes. Cone cells, which mediate day light vision, also progressively degrade in RP; however, the mechanisms that mediate loss of these cells are not completely understood. In RP, dying cones exhibit signs of starvation, suggesting metabolic dysfunction in these cells. In this episode, Claudio Punzo and Aditya Venkatesh present their work, which demonstrates that constitutive activation of the metabolic regulator mTORC1 prolongs cone survival and maintains cone function in murine models of RP. The results of this study support further exploration of strategies to improve metabolic function for maintaining cone function in RP.
Copyright © 2015 American Society for Clinical Investigation