Dysferlinopathies are muscle dystrophies caused by mutations in the gene encoding dysferlin, a relevant protein for membrane repair and trafficking. These diseases are untreatable, possibly due to the poor knowledge of relevant molecular targets. Previously, we have shown that human myofibers from patient biopsies as well as myotubes derived from immortalized human myoblasts carrying a mutated form of dysferlin express connexin proteins, but their relevance in myoblasts fate and function remained unknown. In the present work, we found that numerous myoblasts bearing a mutated dysferlin when induced to acquire myogenic commitment express PPARγ, revealing adipogenic instead of myogenic commitment. These cell cultures presented many mononucleated cells with fat accumulation and within 48 h of differentiation formed fewer multinucleated cells. In contrast, dysferlin deficient myoblasts treated with boldine, a connexin hemichannels blocker, neither expressed PPARγ, nor accumulated fat and formed similar amount of multinucleated cells as wild type precursor cells. We recently demonstrated that myofibers of skeletal muscles from blAJ mice (an animal model of dysferlinopathies) express three connexins (Cx39, Cx43, and Cx45) that form functional hemichannels (HCs) in the sarcolemma. In symptomatic blAJ mice, we now show that eight-week treatment with a daily dose of boldine showed a progressive recovery of motor activity reaching normality. At the end of this treatment, skeletal muscles were comparable to those of wild type mice and presented normal CK activity in serum. Myofibers of boldine-treated blAJ mice also showed strong dysferlin-like immunoreactivity. These findings reveal that muscle dysfunction results from a pathophysiologic mechanism triggered by mutated dysferlin and downstream connexin hemichannels expressed de novo lead to a drastic reduction of myogenesis and favor muscle damage. Thus, boldine could represent a therapeutic opportunity to treat dysfernilopathies.

Plant cell culture is a source of plant material from which bioactive metabolites can be extracted. In this work, the in vitro propagation of Leptocarpha rivularis, an endemic Chilean shrub with anticancer activity, is described. Different media were tested and optimized for the introduction, propagation, and rooting steps of the micropropagation process. At the end of this process, 83% of plants were successfully acclimatized under greenhouse conditions. Callus induction from the internodal stem segment was performed using various combinations of phytohormones. Green-colored, friable, and non-organogenic callus was generated with a callus induction index higher than 90%. The chemical composition of extracts and callus, obtained from clonal plants, was assessed and the results indicate that the phytochemical profiles of extracts from micropropagated plants are like those found for plants collected from natural habitats, leptocarpine (LTC) being the major component. However, no LTC was detected in callus extract. HeLa and CoN cells, treated with LTC or extract of micropropagated plants, exhibit important diminution on cell viability and a drastic decrease in gene expression of IL-6 and mmp2, genes associated with carcinogenic activity. These effects are more important in cancer cells than in normal cells. Thus, micropropagated L. rivularis could be developed as a potential source of efficient antiproliferative agents.

Background: Little is known about the interaction between the nasopharyngeal bacterial profile and the nutritional status in children. In this study, our main goal was to evaluate the associations between overnutrition and the presence of four potentially pathogenic bacteria in the nasopharynx of infants with viral lower respiratory tract infections (LRTI). In addition, we determined whether changes in the nasopharyngeal bacterial profile were associated with mucosal and serum proinflammatory cytokines and with clinical disease severity. Methods: We enrolled 116 children less than 2 years old hospitalized for viral LRTI during two consecutive respiratory seasons (May 2016 to August 2017); their nutritional status was assessed, and nasopharyngeal and blood samples were obtained. S. aureus, S. pneumoniae, H. influenzae, M. catarrhalis, and respiratory viruses were identified in nasopharyngeal samples by qPCR. Cytokine concentrations were measured in nasopharyngeal and blood samples. Disease severity was assessed by the length of hospitalization and oxygen therapy. Results: Nasopharyngeal pathogenic bacteria were identified in 96.6% of the enrolled children, and 80% of them tested positive for two or more bacteria. The presence and loads of M. catarrhalis was higher (p = 0.001 and p = 0.022, respectively) in children with overnutrition (n = 47) compared with those with normal weights (n = 69). In addition, the detection of >2 bacteria was more frequent in children with overnutrition compared to those with normal weight (p = 0.02). Multivariate regression models showed that the presence and loads of S. pneumoniae and M. catarrhalis were associated with higher concentrations of IL-6 in plasma and TNF-α in mucosal samples in children with overnutrition. Conclusions: The nasopharyngeal profile of young children with overnutrition was characterized by an over representation of pathogenic bacteria and proinflammatory cytokines.