Insulin resistance disrupts epithelial repair and niche-progenitor Fgf signaling during chronic liver injury

Insulin provides important information to tissues about feeding behavior and energy status. Defective insulin signaling is associated with ageing, tissue dysfunction, and impaired wound healing. In the liver, insulin resistance leads to chronic damage and fibrosis, but it is unclear how tissue-repair mechanisms integrate insulin signals to coordinate an appropriate injury response or how they are affected by insulin resistance. In this study, we demonstrate that insulin resistance impairs local cellular crosstalk between the fibrotic stroma and bipotent adult liver progenitor cells (LPCs), whose paracrine interactions promote epithelial repair and tissue remodeling. Using insulin-resistant mice deficient for insulin receptor substrate 2 (Irs2), we highlight dramatic impairment of proregenerative fibroblast growth factor 7 (Fgf7) signaling between stromal niche cells and LPCs during chronic injury. We provide a detailed account of the role played by IRS2 in promoting Fgf7 ligand and receptor (Fgfr2- IIIb) expression by the two cell compartments, and we describe an insulin/IRS2-dependent feed-forward loop capable of sustaining hepatic re-epithelialization by driving FGFR2-IIIb expression. Finally, we shed light on the regulation of IRS2 and FGF7 within the fibrotic stroma and show—using a human coculture system—that IRS2 silencing shifts the equilibrium away from paracrine epithelial repair in favor of fibrogenesis. Hence, we offer a compelling insight into the contribution of insulin resistance to the pathogenesis of chronic liver disease and propose IRS2 as a positive regulator of communication between cell types and the transition between phases of stromal to epithelial repair

Pancreatic fusocellular sarcoma: The importance of endoscopic ultrasound-guided fine needle aspiration in the differential diagnosis of solid pancreatic tumors Sarcoma fusocelular de páncreas: importancia de la PAAF guiada por ultrasonografía endoscópica en el diagnóstico diferencial de los tumores sólidos pancreáticos

In the presence of a pancreatic tumor, the main diagnostic problem is to determine the benign o malignant nature of the lesion, and then to evaluate its resectability. A preoperative biopsy was usually rejected based on the fact that negative results do not exclude malignancy, that such biopsy may hamper the possibility of curative surgery because of potential seeding along the biopsy&rsquo;s trajectory, that surgical morbidity and mortality are low, and also because of the high diagnostic sensitivity of the various imaging techniques. Biopsy for solid pancreatic tumors was limited to irresectable tumors, and isolated cases with suspicion of tuberculosis, lymphoma or neuroendocrine tumors. Nowadays the performance of a pancreatic biopsy is becoming essential for the correct management of solid lesions, and is useful not only to establish malignancy, but also for a better knowledge of all kind of pathologies and, thus, for better therapeutic management. In this context, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has proven a safe technique with a low rate of complications and a diagnostic accuracy superior to other procedures, this being considered the method of choice for the study of solid pancreatic lesions. An illustrative example is the case we report in this article -a patient diagnosed of a solid, locally advanced-stage pancreatic tumor with imaging techniques (abdominal ultrasounds and EUS) under EUS-guided FNA; the procedure could establish a final diagnosis of pancreatic fusocellular sarcoma.<br>Ante una lesión pancreática se plantea clásicamente la duda diagnóstica entre su naturaleza benigna o maligna, para posteriormente valorar la resecabilidad de la lesión. Se rechazaba la biopsia preoperatoria basándose en que un resultado negativo no excluye malignidad, que la punción podría impedir una cirugía curativa por el riesgo de recidiva tumoral en el trayecto de la biopsia, por la baja morbi-mortalidad quirúrgica y por la alta sensibilidad diagnóstica de las técnicas de imagen. La biopsia de las lesiones sólidas pancreáticas se limitaba a tumores irresecables y a casos aislados de sospecha de tuberculosis, linfoma o tumor neuroendocrino. En la actualidad, la realización de una biopsia pancreática se está convirtiendo en un punto fundamental para el correcto manejo de las lesiones sólidas, siendo útil no sólo para la determinación de malignidad, sino para el mejor estudio y conocimiento de cualquier patología, y por ello, a un mejor manejo terapéutico. En este contexto, la punción guiada por ultrasonografía endoscópica (USE) ha demostrado ser una técnica segura, con un bajo índice de complicaciones, de una precisión diagnóstica superior a otros procedimientos, considerándose actualmente de elección para el estudio de lesiones sólidas pancreáticas. Como ejemplo ilustrativo presentamos el caso de un paciente con el diagnóstico de un tumor sólido pancreático en las pruebas de imagen (ecografía abdominal y USE), en un estadio localmente avanzando, siendo la punción guiada por USE la que permitió establecer el diagnóstico final de sarcoma fusocelular pancreático

Human Suprapatellar Fat Pad-Derived Mesenchymal Stem Cells Induce Chondrogenesis and Cartilage Repair in a Model of Severe Osteoarthritis

Cartilage degeneration is associated with degenerative bone and joint processes in severe osteoarthritis (OA). Spontaneous cartilage regeneration is extremely limited. Often the treatment consists of a partial or complete joint implant. Adipose-derived stem cell (ASC) transplantation has been shown to restore degenerated cartilage; however, regenerative differences of ASC would depend on the source of adipose tissue. The infra- and suprapatellar fat pads surrounding the knee offer a potential autologous source of ASC for patients after complete joint substitution. When infrapatellar- and suprapatellar-derived stromal vascular fractions (SVF) were compared, a significantly higher CD105 (+) population was found in the suprapatellar fat. In addition, the suprapatellar SVF exhibited increased numbers of colony formation units and a higher population doubling in culture compared to the infrapatellar fraction. Both the suprapatellar- and infrapatellar-derived ASC were differentiated in vitro into mature adipocytes, osteocytes, and chondrocytes. However, the suprapatellar-derived ASC showed higher osteogenic and chondrogenic efficiency. Suprapatellar-derived ASC transplantation in a severe OA mouse model significantly diminished the OA-associated knee inflammation and cartilage degenerative grade, significantly increasing the production of glycosaminoglycan and inducing endogenous chondrogenesis in comparison with the control group. Overall, suprapatellar-derived ASC offer a potential autologous regenerative treatment for patients with multiple degenerative OA

Resting cysts of the toxigenic dinoflagellate genus Alexandrium in recent sediments from the Western Mediterranean coast, including the first description of cysts of A. kutnerae and A. peruvianum

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Similar Clinical Course and Significance of Circulating Innate and Adaptive Immune Cell Counts in STEMI and COVID-19

This study aimed to assess the time course of circulating neutrophil and lymphocyte counts and their ratio (NLR) in ST-segment elevation myocardial infarction (STEMI) and coronavirus disease (COVID)-19 and explore their associations with clinical events and structural damage. Circulating neutrophil, lymphocyte and NLR were sequentially measured in 659 patients admitted for STEMI and in 103 COVID-19 patients. The dynamics detected in STEMI (within a few hours) were replicated in COVID-19 (within a few days). In both entities patients with events and with severe structural damage displayed higher neutrophil and lower lymphocyte counts. In both scenarios, higher maximum neutrophil and lower minimum lymphocyte counts were associated with more events and more severe organ damage. NLR was higher in STEMI and COVID-19 patients with the worst clinical and structural outcomes. A canonical deregulation of the immune response occurs in STEMI and COVID-19 patients. Boosted circulating innate (neutrophilia) and depressed circulating adaptive immunity (lymphopenia) is associated with more events and severe organ damage. A greater understanding of these critical illnesses is pivotal to explore novel alternative therapies

Lack of GDAP1 Induces Neuronal Calcium and Mitochondrial Defects in a Knockout Mouse Model of Charcot-Marie-Tooth Neuropathy

27 páginas, 9 figuras.Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2), axonal dominant (CMT2K) and demyelinating recessive (CMT4A) forms of Charcot-Marie-Tooth (CMT) neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE) upon mobilization of endoplasmic reticulum (ER) Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs) in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria-endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.This work has been funded by grants from the Spanish Ministry of Economy and Competitiveness, grants no. SAF2009-07063 and SAF2012-32425 (to FP), the Collaborative Joint Project awarded by IRDiRC and funded by ISCIII grant IR11/TREAT-CMT, Instituto de Salud Carlos III (to both FP and JMC), the Generalitat Valenciana Prometeo Programme 2009/059 and 2014/029 (to FP) and the Swiss National Science Foundation, grant no. 31003A_135735/1 (to RC). This work has also been funded by the CIBERER, an initiative from the Instituto de Salud Carlos III. MB-M is the recipient of a FPI fellowship, from the Spanish Ministry of Economy and Competitiveness. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe