Expression of Musashi-1 Increases in Bone Healing

The authors of this manuscript were partially supported by Research Groups #CTS-138 and #CTS-1028 (Junta de Andalucía, Spain). This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.All experiments were performed after the approval of the Committee on Animal Research of the University of Granada (CEEA 2014/357) and under the European Union and Spanish regulations for ethics in animal research (EU Directive 63/2010 and Spanish RD 53/2013) and reported following the ARRIVE guidelines.The data that support the findings of this study are available from the corresponding author upon reasonable request.The authors would especially like to acknowledge the contribution to the histochemical and immunohistochemical studies of Serafin Vélez García and Carmen Ruíz Guzmán, technicians in the Department of Surgery, and María Dolores Rodriguez, in the Department of Pathology and IBIMER of the University of Granada and Justin G. Davis for assistance with the writing style.Musashi-1 (MSI1) is an RNA-binding protein that regulates progenitor cells in adult and developing organisms to maintain self-renewal capacities. The role of musashi-1 in the bone healing environment and its relation with other osteogenic factors is unknown. In the current study, we analyze the expression of MSI1 in an experimental model of rat femoral bone fractures. We also analyze the relation between MSI1 expression and the expression of two osteogenic markers: periostin (POSTN) and runt-related transcription factor 2 (RUNX2). We use histological, immunohistochemical, and qPCR techniques to evaluate bone healing and the expression of MSI1, POSTN, and RUNX2 over time (4, 7, and 14 days). We compare our findings with non-fractured controls. We find that in bone calluses, the number of cells expressing MSI1 and RUNX2 increase over time and the intensity of POSTN expression decreases over time. Within bone calluses, we find the presence of MSI1 expression in mesenchymal stromal cells, osteoblasts, and osteocytes but not in hypertrophic chondrocytes. After 14 days, the expression of MSI1, POSTN, and RUNX2 was significantly correlated. Thus, we conclude that musashi-1 potentially serves in the osteogenic differentiation of mesenchymal stromal cells and bone healing. Therefore, further studies are needed to determine the possibility of musashi-1 ' s role as a clinical biomarker of bone healing and therapeutic agent for bone regeneration.Junta de Andalucia European Commission CTS-138 CTS-102

Osteoarticular Expression of Musashi-1 in an Experimental Model of Arthritis

Background. Collagen-induced arthritis (CIA), a murine experimental disease model induced by immunization with type II collagen (CII), is used to evaluate novel therapeutic strategies for rheumatoid arthritis. Adult stem cell marker Musashi-1 (Msi1) plays an important role in regulating the maintenance and differentiation of stem/precursor cells. The objectives of this investigation were to perform a morphological study of the experimental CIA model, evaluate the effect of TNFα-blocker (etanercept) treatment, and determine the immunohistochemical expression of Msi1 protein. Methods. CIA was induced in 50 male DBA1/J mice for analyses of tissue and serum cytokine; clinical and morphological lesions in limbs; and immunohistochemical expression of Msi1. Results. Clinically, TNFα-blocker treatment attenuated CIA on day 32 after immunization (). Msi1 protein expression was significantly higher in joints damaged by CIA than in those with no lesions () and was related to the severity of the lesions (Spearman’s rho = 0.775, ). Conclusions. Treatment with etanercept attenuates osteoarticular lesions in the murine CIA model. Osteoarticular expression of Msi1 protein is increased in joints with CIA-induced lesion and absent in nonlesioned joints, suggesting that this protein is expressed when the lesion is produced in order to favor tissue repair.This investigation was partially supported by Research Group #CTS-138 (Junta de Andalucía, Spain)

Eosinophilic cholecystitis: an infrequent cause of acute cholecystitis

Eosinophilic cholecystitis (EC) is a rare disease that is characterised by eosinophilic infiltration of the gallbladder. Its pathogenesis is unknown, although many hypotheses have been made. Clinical and laboratory manifestations do not differ from those of other causes of cholecystitis. Diagnosis is histological and usually performed after analysis of the surgical specimen. We report the case of a woman aged 24 years, with symptoms of fever, vomiting and pain in the right upper quadrant. When imaging tests revealed acalculous cholecystitis, an urgent cholecystectomy was performed. Histological examination of the surgical specimen revealed eosinophilic cholecystitis. No cause of the symptoms was found

Expression of Musashi-1 Increases in Bone Healing

Musashi-1 (MSI1) is an RNA-binding protein that regulates progenitor cells in adult and developing organisms to maintain self-renewal capacities. The role of musashi-1 in the bone healing environment and its relation with other osteogenic factors is unknown. In the current study, we analyze the expression of MSI1 in an experimental model of rat femoral bone fractures. We also analyze the relation between MSI1 expression and the expression of two osteogenic markers: periostin (POSTN) and runt-related transcription factor 2 (RUNX2). We use histological, immunohistochemical, and qPCR techniques to evaluate bone healing and the expression of MSI1, POSTN, and RUNX2 over time (4, 7, and 14 days). We compare our findings with non-fractured controls. We find that in bone calluses, the number of cells expressing MSI1 and RUNX2 increase over time and the intensity of POSTN expression decreases over time. Within bone calluses, we find the presence of MSI1 expression in mesenchymal stromal cells, osteoblasts, and osteocytes but not in hypertrophic chondrocytes. After 14 days, the expression of MSI1, POSTN, and RUNX2 was significantly correlated. Thus, we conclude that musashi-1 potentially serves in the osteogenic differentiation of mesenchymal stromal cells and bone healing. Therefore, further studies are needed to determine the possibility of musashi-1's role as a clinical biomarker of bone healing and therapeutic agent for bone regeneration.The authors of this manuscript were partially supported by Research Groups #CTS-138 and #CTS-1028 (Junta de Andalucía, Spain).Ye

Ghrelin and adipose-derived mesenchymal stromal cells improve nerve regeneration in a rat model of epsilon-caprolactone conduit reconstruction

Objective. Attempts have been made to improve nerve conduits in peripheral nerve reconstruction. We investigated the potential therapeutic effect of adipose-derived mesenchymal cells (ASCs) and ghrelin (GHR), a neuropeptide with neuroprotective, trophic, and developmental regulatory actions, on peripheral nerve regeneration in a model of severe nerve injury repaired with nerve conduits. Material and methods. The right sciatic nerves of 24 male Wistar rats were 10-mm transected unilaterally and repaired with Dl-lactic-ε-caprolactone conduits. Rats were then treated locally with saline, ASCs, or GHR. At 12 weeks post-surgery, we assessed limb function by measuring ankle stance angle and percentage muscle mass reduction and evaluated the histopathology, immunohistochemistry, ultrastructure, and morphometry of myelinated fibers. Main Results. Rats receiving GHR or ASCs showed no significant increased functional recovery in ankle stance angle (p=0.372) but a higher nerve area (p=0.015), myelin area (p=0.046) and number of myelinated fibers (p=0.012) in the middle and distal segments of operated sciatic nerves in comparison to saline-treated control animals. Conclusion. These results suggest that utilization of ghrelin or ASCs may improve nerve regeneration using Dl-lactic-ε-caprolactone conduits

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field