miR-195b is required for proper cellular homeostasis in the elderly.

Over the last decade we have witnessed an increasing number of studies revealing the functional role of non-coding RNAs in a multitude of biological processes, including cellular homeostasis, proliferation and differentiation. Impaired expression of non-coding RNAs can cause distinct pathological conditions, including herein those affecting the gastrointestinal and cardiorespiratory systems, respectively. miR-15/miR-16/miR-195 family members have been broadly implicated in multiple biological processes, including regulation of cell proliferation, apoptosis and metabolism within distinct tissues, such as heart, liver and lungs. While the functional contribution of miR-195a has been reported in multiple biological contexts, the role of miR-195b remains unexplored. In this study we dissected the functional role of miR-195b by generating CRISPR-Cas9 gene edited miR-195b deficient mice. Our results demonstrate that miR-195b is dispensable for embryonic development. miR-195b-/- mice are fertile and displayed no gross anatomical and/or morphological defects. Mechanistically, cell cycle regulation, metabolism and oxidative stress markers are distinctly impaired in the heart, liver and lungs of aged mice, a condition that is not overtly observed at midlife. The lack of overt functional disarray during embryonic development and early adulthood might be due to temporal and tissue-specific compensatory mechanisms driven by selective upregulation miR-15/miR-16/miR-195 family members. Overall, our data demonstrated that miR-195b is dispensable for embryonic development and adulthood but is required for cellular homeostasis in the elderly.

NMJ-related diseases beyond the congenital myasthenic syndromes.

Neuromuscular junctions (NMJs) are a special type of chemical synapse that transmits electrical stimuli from motor neurons (MNs) to their innervating skeletal muscle to induce a motor response. They are an ideal model for the study of synapses, given their manageable size and easy accessibility. Alterations in their morphology or function lead to neuromuscular disorders, such as the congenital myasthenic syndromes, which are caused by mutations in proteins located in the NMJ. In this review, we highlight novel potential candidate genes that may cause or modify NMJs-related pathologies in humans by exploring the phenotypes of hundreds of mouse models available in the literature. We also underscore the fact that NMJs may differ between species, muscles or even sexes. Hence the importance of choosing a good model organism for the study of NMJ-related diseases: only taking into account the specific features of the mammalian NMJ, experimental results would be efficiently translated to the clinic.

The efficacy of patient specific instrumentation (PSI) in total hip arthroplasty (THA): A systematic review and meta-analysis.

Background: Patient-specific instrumentation (PSI) has been suggested to reduce improper component positioning, though the effectiveness of PSI in total hip arthroplasty (THA) remains inconclusive. The purpose of this study was to evaluate the radiographic parameters and clinical outcomes comparing PSI and standard instrumentation (SI). Methods: This systematic review and meta-analysis was conducted in accordance with the 2020 PRISMA statement and was registered on PROSPERO. PubMed, Embase, Scopus, Google Scholar, and ClinicalTrials.gov were searched for relevant studies pertaining to the use of PSI in THA. Inclusion criteria included PSI used in THA, PSI was directly compared to SI, and publication in English. Exclusion criteria included non-primary THA, review articles, abstracts, book chapters, and animal models. Results: 2,458 studies were initially identified, with 13 studies (677 THAs: 338 controls, 339 PSI) meeting all criteria. PSI was favored for the deviation from the preoperative plan for acetabular cup position for anteversion (p = 0.04) and inclination (p = 0.0002); risk of acetabular cup positioning outside the Lewinnek safe zone for anteversion (p = 0.005) and inclination (p < 0.0001); and postoperative Harris Hip Score (p = 0.0002). No significant differences were found for the deviation from the preoperative plan for femoral stem position for anteversion (p = 0.74) or varus/valgus (p = 0.15); intraoperative time (p = 0.55); or intraoperative blood loss (p = 0.62). Conclusion: The use of PSI in THA is effective in improving acetabular component positioning and postoperative functional outcomes, without increasing intraoperative time or blood loss, compared to SI.

Characteristics and Trends of the Most Cited Clinical Orthopaedics and Related Research Articles.

Background: Clinical Orthopaedics and Related Research is one of the most influential and reputable scientific journals in the field of orthopaedics. Some of the most reputable publications related to orthopaedic research can be attributed to this journal and it continues to have a significant impact on modern research. Objective: The purpose of this study is to identify the most influential articles, in terms of number of citations, published by Clinical Orthopaedics and Related Research. The goal of analyzing the most cited articles in is to create a baseline for future researchers to build upon and to uncover any trends in orthopaedic research. Methods: Preferred Reporting Items for Systematic Reviews guidelines were used to structure the data collection and analysis of this study. The Scopus database was used to compile the publication data. Data was then exported to an excel sheet to be further analyzed via a multi-author review process. Results: The most cited article was "A Clinical Method of Functional Assessment of the Shoulder" by Constant et al.. The 50 articles analyzed in this study were cited a total of 32,404 times, averaging 719 citations per year, per publication. The oldest article was published in 1971, and the newest in 2008. The United States was the country with the most attributable publications and The University of Florida was the most contributory institution. Conclusions: Our study recognizes Clinical Orthopaedics and Related research as having a strong predilection for older articles and a continued strength for modern publications.

Calorie Restriction Rescues Mitochondrial Dysfunction in Adck2-Deficient Skeletal Muscle.

ADCK2 haploinsufficiency-mediated mitochondrial coenzyme Q deficiency in skeletal muscle causes mitochondrial myopathy associated with defects in beta-oxidation of fatty acids, aged-matched metabolic reprogramming, and defective physical performance. Calorie restriction has proven to increase lifespan and delay the onset of chronic diseases associated to aging. To study the possible treatment by food deprivation, heterozygous Adck2 knockout mice were fed under 40% calorie restriction (CR) and the phenotype was followed for 7 months. The overall glucose and fatty acids metabolism in muscle was restored in mutant mice to WT levels after CR. CR modulated the skeletal muscle metabolic profile of mutant mice, partially rescuing the profile of WT animals. The analysis of mitochondria isolated from skeletal muscle demonstrated that CR increased both CoQ levels and oxygen consumption rate (OCR) based on both glucose and fatty acids substrates, along with mitochondrial mass. The elevated aerobic metabolism fits with an increase of type IIa fibers, and a reduction of type IIx in mutant muscles, reaching WT levels. To further explore the effect of CR over muscle stem cells, satellite cells were isolated and induced to differentiate in culture media containing serum from animals in either ad libitum or CR diets for 72 h. Mutant cells showed slower differentiation alongside with decreased oxygen consumption. In vitro differentiation of mutant cells was increased under CR serum reaching levels of WT isolated cells, recovering respiration measured by OCR and partially beta-oxidation of fatty acids. The overall increase of skeletal muscle bioenergetics following CR intervention is paralleled with a physical activity improvement, with some increases in two and four limbs strength tests, and weights strength test. Running wheel activity was also partially improved in mutant mice under CR. These results demonstrate that CR intervention, which has been shown to improve age-associated physical and metabolic decline in WT mice, also recovers the defective aerobic metabolism and differentiation of skeletal muscle in mice caused by ADCK2 haploinsufficiency.

Regulation of myogenic gene expression.

Skeletal muscle development and regeneration is governed by the combined action of Myf5, MyoD, Mrf4 and MyoG, also known as the myogenic regulatory factors (MRFs). These transcription factors are expressed in a highly spatio-temporal restricted manner, ensuring the significant functional and metabolic diversity observed between the different muscle groups. In this review, we will discuss the multiple layers of regulation that contribute to the control of the exquisite expression patterns of the MRFs in particular, and of myogenic genes in general. We will highlight all major regulatory processes that play a role in myogenesis: from those that modulate chromatin status and transcription competence, such as DNA methylation, histone modification, chromatin remodeling, or non-coding RNAs, to those that control transcript and protein processing and modification, such as alternative splicing, polyadenylation, other mRNA modifications, or post-translational protein modifications. All these processes are exquisitely and tightly coordinated to ensure the proper activation, maintenance and termination of the myogenic process.

Isolation of Mitochondria from Mouse Skeletal Muscle for Respirometric Assays.

Most of the cell's energy is obtained through the degradation of glucose, fatty acids, and amino acids by different pathways that converge on the mitochondrial oxidative phosphorylation (OXPHOS) system, which is regulated in response to cellular demands. The lipid molecule Coenzyme Q (CoQ) is essential in this process by transferring electrons to complex III in the electron transport chain (ETC) through constant oxidation/reduction cycles. Mitochondria status and, ultimately, cellular health can be assessed by measuring ETC oxygen consumption using respirometric assays. These studies are typically performed in established or primary cell lines that have been cultured for several days. In both cases, the respiration parameters obtained may have deviated from normal physiological conditions in any given organ or tissue. Additionally, the intrinsic characteristics of cultured single fibers isolated from skeletal muscle impede this type of analysis. This paper presents an updated and detailed protocol for the analysis of respiration in freshly isolated mitochondria from mouse skeletal muscle. We also provide solutions to potential problems that could arise at any step of the process. The method presented here could be applied to compare oxygen consumption rates in diverse transgenic mouse models and study the mitochondrial response to drug treatments or other factors such as aging or sex. This is a feasible method to respond to crucial questions about mitochondrial bioenergetics metabolism and regulation.

Characterization of an eutherian gene cluster generated after transposon domestication identifies Bex3 as relevant for advanced neurological functions.

BACKGROUND: One of the most unusual sources of phylogenetically restricted genes is the molecular domestication of transposable elements into a host genome as functional genes. Although these kinds of events are sometimes at the core of key macroevolutionary changes, their origin and organismal function are generally poorly understood. RESULTS: Here, we identify several previously unreported transposable element domestication events in the human and mouse genomes. Among them, we find a remarkable molecular domestication that gave rise to a multigenic family in placental mammals, the Bex/Tceal gene cluster. These genes, which act as hub proteins within diverse signaling pathways, have been associated with neurological features of human patients carrying genomic microdeletions in chromosome X. The Bex/Tceal genes display neural-enriched patterns and are differentially expressed in human neurological disorders, such as autism and schizophrenia. Two different murine alleles of the cluster member Bex3 display morphological and physiopathological brain modifications, such as reduced interneuron number and hippocampal electrophysiological imbalance, alterations that translate into distinct behavioral phenotypes. CONCLUSIONS: We provide an in-depth understanding of the emergence of a gene cluster that originated by transposon domestication and gene duplication at the origin of placental mammals, an evolutionary process that transformed a non-functional transposon sequence into novel components of the eutherian genome. These genes were integrated into existing signaling pathways involved in the development, maintenance, and function of the CNS in eutherians. At least one of its members, Bex3, is relevant for higher brain functions in placental mammals and may be involved in human neurological disorders.

Screening of Embolic Sources by Point-of-Care Ultrasound in the Acute Phase of Ischemic Stroke.

Our objective was to evaluate hand-held echocardiography as point of care ultrasound scanning (POCUS) to detect sources of embolism in the acute phase of stroke. Prospective, unicentric observational cohort study of non-lacunar ischemic stroke patients evaluated by V Scan device. The main sources of embolism (MSEs) were classified into embolic valvulopathies and severe ventricular dysfunction. We looked for atrial fibrillation (AF) predictors in strokes of undetermined etiology. MSEs were detected in 19.23% (25/130). Large vessel occlusion (LVO) (odds ratio [OR]: 4.24, 95% confidence interval [CI]: 1.01-17.85) and chronic heart failure (OR: 13.25, 95% CI: 3.54-49.50) were independent predictors of MSEs. LVO (OR: 6.54, 95% CI: 1.62-26.27) and left atrial area >20 cm2 (OR: 7.01, 95% CI: 1.75-28.09) independently predicted AF. Patients with LVO and chronic heart disease may benefit from hand-held echocardiography as part of POCUS in the acute phase of ischemic stroke. Left atrial area measured was an independent predictor of AF in strokes of undetermined etiology.

Recessive mutations in muscle-specific isoforms of FXR1 cause congenital multi-minicore myopathy.

FXR1 is an alternatively spliced gene that encodes RNA binding proteins (FXR1P) involved in muscle development. In contrast to other tissues, cardiac and skeletal muscle express two FXR1P isoforms that incorporate an additional exon-15. We report that recessive mutations in this particular exon of FXR1 cause congenital multi-minicore myopathy in humans and mice. Additionally, we show that while Myf5-dependent depletion of all FXR1P isoforms is neonatal lethal, mice carrying mutations in exon-15 display non-lethal myopathies which vary in severity depending on the specific effect of each mutation on the protein.

Baseline ASPECTS and e-ASPECTS Correlation with Infarct Volume and Functional Outcome in Patients Undergoing Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: The role of Alberta Stroke Program Early CT score (ASPECTS) in predicting which patients are likely to benefit from endovascular therapy (EVT) is not well defined. An automated software (e-ASPECTS) has been created to solve its poor interrater reliability. We aim to evaluate correlation between radiologist (Rx) and e-ASPECTS scoring with cerebral blood volume (CBV) infarct core and with final infarct volume; as well as with long-term functional outcome. METHODS: We included patients with acute ischemic stroke and large vessel occlusion who underwent EVT. We measured baseline radiologist (Rx) ASPECTS and e-ASPECTS, and baseline CBV infarct core on CT perfusion. Final infarct volume was measured on 24-hour control CT. RESULTS: We included 184 patients, in which 82.1% of patients achieved complete recanalization. Median Rx-ASPECTS/e-ASPECTS was 9 (IQR 8-10 vs. IQR 7.75-10) and mean CBV lesion was 29.51 (±47.41) mL. Correlation (rs ) between ASPECTS and e-ASPECTS was .44 (P < .01). Both ASPECTS scores correlated with CBV after 180 minutes of symptom onset (rs = -.41 vs. -.54, P < .01) and with final infarct volume in patients with complete recanalization (rs = -.40 vs. -.43, P < .01). In a logistic regression, either Rx-ASPECTS, e-ASPECTS, and CBV (OR 1.60 vs. 1.87 vs. .96; P < .05) predicted a low infarct volume. Rx-ASPECTS and e-ASPECTS also predicted functional independence (mRS 0-2) at 3 months (1.52 vs. 1.37; P < .05). CONCLUSION: ASPECTS and e-ASPECTS showed a mild correlation with CBV. Rx-ASPECTS, e-ASPECTS, and CBV predicted a low infarct volume after thrombectomy in recanalized patients but only Rx-ASPECTS and e-ASPECTS predicted functional independence at 3 months.

Regulatory landscape fusion in rhabdomyosarcoma through interactions between the PAX3 promoter and FOXO1 regulatory elements.

BACKGROUND: The organisation of vertebrate genomes into topologically associating domains (TADs) is believed to facilitate the regulation of the genes located within them. A remaining question is whether TAD organisation is achieved through the interactions of the regulatory elements within them or if these interactions are favoured by the pre-existence of TADs. If the latter is true, the fusion of two independent TADs should result in the rewiring of the transcriptional landscape and the generation of ectopic contacts. RESULTS: We show that interactions within the PAX3 and FOXO1 domains are restricted to their respective TADs in normal conditions, while in a patient-derived alveolar rhabdomyosarcoma cell line, harbouring the diagnostic t(2;13)(q35;q14) translocation that brings together the PAX3 and FOXO1 genes, the PAX3 promoter interacts ectopically with FOXO1 sequences. Using a combination of 4C-seq datasets, we have modelled the three-dimensional organisation of the fused landscape in alveolar rhabdomyosarcoma. CONCLUSIONS: The chromosomal translocation that leads to alveolar rhabdomyosarcoma development generates a novel TAD that is likely to favour ectopic PAX3:FOXO1 oncogene activation in non-PAX3 territories. Rhabdomyosarcomas may therefore arise from cells which do not normally express PAX3. The borders of this novel TAD correspond to the original 5'- and 3'- borders of the PAX3 and FOXO1 TADs, respectively, suggesting that TAD organisation precedes the formation of regulatory long-range interactions. Our results demonstrate that, upon translocation, novel regulatory landscapes are formed allowing new intra-TAD interactions between the original loci involved.

Identification and Characterization of the Dermal Panniculus Carnosus Muscle Stem Cells.

The dermal Panniculus carnosus (PC) muscle is important for wound contraction in lower mammals and represents an interesting model of muscle regeneration due to its high cell turnover. The resident satellite cells (the bona fide muscle stem cells) remain poorly characterized. Here we analyzed PC satellite cells with regard to developmental origin and purported function. Lineage tracing shows that they originate in Myf5(+), Pax3/Pax7(+) cell populations. Skin and muscle wounding increased PC myofiber turnover, with the satellite cell progeny being involved in muscle regeneration but with no detectable contribution to the wound-bed myofibroblasts. Since hematopoietic stem cells fuse to PC myofibers in the absence of injury, we also studied the contribution of bone marrow-derived cells to the PC satellite cell compartment, demonstrating that cells of donor origin are capable of repopulating the PC muscle stem cell niche after irradiation and bone marrow transplantation but may not fully acquire the relevant myogenic commitment.

MRF4 negatively regulates adult skeletal muscle growth by repressing MEF2 activity.

The myogenic regulatory factor MRF4 is highly expressed in adult skeletal muscle but its function is unknown. Here we show that Mrf4 knockdown in adult muscle induces hypertrophy and prevents denervation-induced atrophy. This effect is accompanied by increased protein synthesis and widespread activation of muscle-specific genes, many of which are targets of MEF2 transcription factors. MEF2-dependent genes represent the top-ranking gene set enriched after Mrf4 RNAi and a MEF2 reporter is inhibited by co-transfected MRF4 and activated by Mrf4 RNAi. The Mrf4 RNAi-dependent increase in fibre size is prevented by dominant negative MEF2, while constitutively active MEF2 is able to induce myofibre hypertrophy. The nuclear localization of the MEF2 corepressor HDAC4 is impaired by Mrf4 knockdown, suggesting that MRF4 acts by stabilizing a repressor complex that controls MEF2 activity. These findings open new perspectives in the search for therapeutic targets to prevent muscle wasting, in particular sarcopenia and cachexia.

[Structure and Family Type in Patients With Substance Abuse or Dependence Psychoactive Rehabilitation Center of Addiction in the Municipality of Chia Cundinamarca]. / Estructura y tipología familiar en pacientes con dependencia o abuso de sustancias psicoactivas en un centro de rehabilitación de adicciones en el Municipio de Chía, Cundinamarca.

OBJECTIVE: To determine the family type, family structure in a group of patients with a diagnosis of substance abuse or dependence who were at a rehabilitation center for addiction during the period between August and October 2009. METHODS: Through a descriptive qualitative-interpretative methodology 10 patients who met inclusion criteria for substance dependence or abuse were studied. The fieldwork and transcripts were made for three months by non-participant observation, non-structured interviews and examination of patients' clinical history. RESULTS: Seven of the families interviewed were single-parent families with an unconventional organization on "gender roles". Single-parent families favored loneliness, difficulty in rule-setting, de-idealization of the place of the father in the family structure and a constant search for complicity. In the analysis by categories, we found that in 10 families in the study of individuals with addictions it is common to find family structure characteristics such as inadequate communication, lack of authority rules and limits, presence of triangulations, the lack of cohesion due to the existence of a disconnected relationship pattern and changed roles compared to conventional gender. The search for the affection of the mother at her emotional overload absence of roles and lack of father, raised by the separation of the couple, was found as an essential aspect underlying the addictive behavior. A pattern of parental abandonment is configured. CONCLUSION: The findings confirmed what has been mentioned by various authors regarding the characteristics of the family typology structure and personal factors in patients with addictions, in addition to their need for affection combined with the desire for the mother's presence. The family typology does not determine for itself the abuse of psychoactive substances, but the influence of other factors such as family structure, especially deficient affective interactions, which should be considered in the development of therapeutic strategies.

Estructura y tipología familiar en pacientes con dependencia o abuso de sustancias psicoactivas en un centro de rehabilitación de adicciones en el Municipio de Chía, Cundinamarca / Structure and Family Type in Patients With Substance Abuse or Dependence Psychoactive Rehabilitation Center of Addiction in the Municipality of Chia Cundinamarca

Objetivo: Determinar la estructura y la tipología familiar de un grupo de pacientes con dependencia o abuso de sustancias que se encontraban en un centro de rehabilitación de adicciones durante el periodo comprendido entre agosto y octubre de 2009. Métodos: A través de una metodología descriptiva cualitativa-interpretativa, se estudió a 10 pacientes y sus familias que cumplían los criterios de inclusión por dependencia o abuso de sustancias; el trabajo de campo y las transcripciones se realizaron durante 3 meses mediante observación no participante, entrevista no estructurada y revisión de la historia clínica del paciente. Resultados: De las familias entrevistadas, siete eran monoparentales, con una organización no convencional respecto a «roles de género¼. La familia monoparental favorece la soledad, la dificultad para poner reglas, la desidealización del lugar del padre en la estructura familiar y la búsqueda de una complicidad constante. En el análisis por categorías, se concluyó que en las 10 familias del estudio de personas con adicciones son frecuentes características de la estructura familiar como la comunicación inadecuada, la ausencia de autoridad, reglas y límites, la presencia de triangulaciones, la falta de cohesión dada por la existencia de un patrón de relación desligado y el cambio de roles convencionales con respecto a género. La búsqueda del afecto de la madre ante su ausencia emocional por la sobrecarga en los roles y la falta del padre, suscitada por la separación de la pareja, se encontró como un aspecto esencial subyacente al comportamiento adictivo. Se configura un patrón de abandono parental. Conclusiones: Se confirma lo mencionado por diversos autores acerca de las características de la tipología y la estructura familiar encontradas en pacientes con adicciones, además de su necesidad de afecto junto con la premura por una figura maternal. La tipología familiar no determina por sí misma el abuso de sustancias psicoactivas, sino la influencia de otros factores como la estructura familiar, especialmente las interacciones afectivas deficientes, lo cual debe considerarse en el desarrollo de las estrategias terapéuticas.

Objective: To determine the family type, family structure in a group of patients with a diagnosis of substance abuse or dependence who were at a rehabilitation center for addiction during the period between August and October 2009. Methods: Through a descriptive qualitative-interpretative methodology 10 patients who met inclusion criteria for substance dependence or abuse were studied. The fieldwork and transcripts were made for three months by non-participant observation, non-structured interviews and examination of patients' clinical history. Results: Seven of the families interviewed were single-parent families with an unconventional organization on "gender roles". Single-parent families favored loneliness, difficulty in rule-setting, de-idealization of the place of the father in the family structure and a constant search for complicity. In the analysis by categories, we found that in 10 families in the study of individuals with addictions it is common to find family structure characteristics such as inadequate communication, lack of authority rules and limits, presence of triangulations, the lack of cohesion due to the existence of a disconnected relationship pattern and changed roles compared to conventional gender. The search for the affection of the mother at her emotional overload absence of roles and lack of father, raised by the separation of the couple, was found as an essential aspect underlying the addictive behavior. A pattern of parental abandonment is configured. Conclusion: The findings confirmed what has been mentioned by various authors regarding the characteristics of the family typology structure and personal factors in patients with addictions, in addition to their need for affection combined with the desire for the mother's presence. The family typology does not determine for itself the abuse of psychoactive substances, but the influence of other factors such as family structure, especially deficient affective interactions, which should be considered in the development of therapeutic strategies.