Follistatin-induced muscle hypertrophy in aged mice improves neuromuscular junction innervation and function.

Sarcopenia, or age-related loss of muscle mass and strength, is an important contributor to loss of physical function in older adults. The pathogenesis of sarcopenia is likely multifactorial, but recently the role of neurological degeneration, such as motor unit loss, has received increased attention. Here, we investigated the longitudinal effects of muscle hypertrophy (via overexpression of human follistatin, a myostatin antagonist) on neuromuscular integrity in C57BL/6J mice between the ages of 24 and 27 months. Following follistatin overexpression (delivered via self-complementary adeno-associated virus subtype 9 injection), muscle weight and torque production were significantly improved. Follistatin treatment resulted in improvements of neuromuscular junction innervation and transmission but had no impact on age-related losses of motor units. These studies demonstrate that follistatin overexpression-induced muscle hypertrophy not only increased muscle weight and torque production but also countered age-related degeneration at the neuromuscular junction in mice.

Patient mutations linked to arrhythmogenic cardiomyopathy enhance calpain-mediated desmoplakin degradation.

Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder with variable genetic etiologies. Here we focused on understanding the precise molecular pathology of a single clinical variant in DSP, the gene encoding desmoplakin. We initially identified a novel missense desmoplakin variant (p.R451G) in a patient diagnosed with biventricular ACM. An extensive single-family ACM cohort was assembled, revealing a pattern of coinheritance for R451G desmoplakin and the ACM phenotype. An in vitro model system using patient-derived induced pluripotent stem cell lines showed depressed levels of desmoplakin in the absence of abnormal electrical propagation. Molecular dynamics simulations of desmoplakin R451G revealed no overt structural changes, but a significant loss of intramolecular interactions surrounding a putative calpain target site was observed. Protein degradation assays of recombinant desmoplakin R451G confirmed increased calpain vulnerability. In silico screening identified a subset of 3 additional ACM-linked desmoplakin missense mutations with apparent enhanced calpain susceptibility, predictions that were confirmed experimentally. Like R451G, these mutations are found in families with biventricular ACM. We conclude that augmented calpain-mediated degradation of desmoplakin represents a shared pathological mechanism for select ACM-linked missense variants. This approach for identifying variants with shared molecular pathologies may represent a powerful new strategy for understanding and treating inherited cardiomyopathies.

Efficacy of Temporomandibular Joint Arthrocentesis with Sodium Hyaluronate in the Management of Temporomandibular Joint Disorders: A Prospective Randomized Control Trial.

PURPOSE: This study was designed to investigate the efficacy of the temporomandibular joint arthrocentesis with and without injection of sodium hyaluronate (SH) in the treatment of temporomandibular joint disorders. PATIENTS AND METHODS: A total of sixty two TMJs in 34 males and 28 females aged 20-65 years comprised the study material. The patients' complaints were limited mouth opening, TMJ pain, and joint noises during function. Patients were randomly divided into 2 groups in which arthrocentesis plus intra-articular injection of sodium hyaluronate was performed in 1 group and only arthrocentesis was performed in the other group. Both groups contained patients with disc displacement with reduction and without reduction. Clinical evaluation of the patients was done before the procedure, immediately after the procedure, at 1 week and 1, 3 and 6 months postoperatively. Intensity of TMJ pain was assessed using visual analog scales. Maximal mouth opening and lateral jaw movements also were recorded at each follow-up visit. RESULTS: Both techniques increased maximal mouth opening, lateral movements, and function, while reducing TMJ pain and noise. CONCLUSIONS: Although patients benefitted from both techniques, arthrocentesis with injection of SH seemed to be superior to arthrocentesis alone.

Novel obscurins mediate cardiomyocyte adhesion and size via the PI3K/AKT/mTOR signaling pathway.

The intercalated disc of cardiac muscle embodies a highly-ordered, multifunctional network, essential for the synchronous contraction of the heart. Over 200 known proteins localize to the intercalated disc. The challenge now lies in their characterization as it relates to the coupling of neighboring cells and whole heart function. Using molecular, biochemical and imaging techniques, we characterized for the first time two small obscurin isoforms, obscurin-40 and obscurin-80, which are enriched at distinct locations of the intercalated disc. Both proteins bind specifically and directly to select phospholipids via their pleckstrin homology (PH) domain. Overexpression of either isoform or the PH-domain in cardiomyocytes results in decreased cell adhesion and size via reduced activation of the PI3K/AKT/mTOR pathway that is intimately linked to cardiac hypertrophy. In addition, obscurin-80 and obscurin-40 are significantly reduced in acute (myocardial infarction) and chronic (pressure overload) murine cardiac-stress models underscoring their key role in maintaining cardiac homeostasis. Our novel findings implicate small obscurins in the maintenance of cardiomyocyte size and coupling, and the development of heart failure by antagonizing the PI3K/AKT/mTOR pathway.

Effect of proteolytic enzyme bromelain on pain and swelling after removal of third molars.

AIMS AND OBJECTIVES: To evaluate the effect of bromelain on pain and swelling after surgical removal of third molars. MATERIALS AND METHODS: A prospective randomized clinical study was conducted among 40 patients requiring surgical removal of impacted mandibular third molars. All the impacted molars were surgically removed, and the patients were administered bromelain along with amoxicillin. Patients were recalled on day 1, day 3, and day 7 for postoperative pain assessment using visual analogue scale (VAS) and postoperative swelling assessment using facial reference points tragus and pogonion. VAS score was statistically analyzed using repeated analysis of variance with post-hoc Bonferroni test postoperatively on day 1, day 3, and day 7 using the Statistical Package for the Social Sciences software version 14. RESULTS: Out of the total 40 patients, bromelain was effective in 28 (70%) patients. In these patients, there was reduction in swelling and pain after taking bromelain. CONCLUSION: Bromelain can be used as a successful oral enzyme therapy for oral surgery patients, especially after removal of impacted third molars.

Micropropagation and assessment of genetic fidelity of Henckelia incana: an endemic and medicinal Gesneriad of South India.

Henckelia incana is an endemic medicinal plant used for the treatment of fever and skin allergy. In the present study shoot regeneration was evaluated on Murashige and Skoog's (MS) medium supplemented with auxins, Indole-3-acetic acid (IAA), Indole-3- butyric acid (IBA), 1-Naphthaleneacetic acid (NAA), 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and cytokinins, 6-Benzylaminopurine (BAP) and Kinetin (Kn) at concentrations of 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mgl(-1). MS medium with IBA (18.08), NAA (17.83) and IAA (17.58) at 0.5 mgl(-1) concentrations showed efficient regeneration. Regenerated shoots were rooted on half-strength MS medium with and without 0.5 mgl(-1) IBA or NAA. The plantlets were successfully hardened in rooting trays (peat, vermiculite and sand) and transferred to field mileu. The genetic fidelity of in vitro raised plants was assessed by using three different single primer amplification reaction (SPAR) markers namely random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and direct amplification of mini-satellite DNA region (DAMD). The results consistently demonstrated true-to-true type propagation. This is the first report of in vitro propagation and establishment of true-to-true type genetic fidelity in H. incana.