IL-15 receptor α (IL-15Rα) is a component of the heterotrimeric plasma membrane receptor for the pleiotropic cytokine IL-15. However, IL-15Rα is not merely an IL-15 receptor subunit, as mice lacking ...either IL-15 or IL-15Rα have unique phenotypes. IL-15 and IL-15Rα have been implicated in muscle phenotypes, but a role in muscle physiology has not been defined. Here, we have shown that loss of IL-15Rα induces a functional oxidative shift in fast muscles, substantially increasing fatigue resistance and exercise capacity. IL-15Rα-knockout (IL-15Rα-KO) mice ran greater distances and had greater ambulatory activity than controls. Fast muscles displayed fatigue resistance and a slower contractile phenotype. The molecular signature of these muscles included altered markers of mitochondrial biogenesis and calcium homeostasis. Morphologically, fast muscles had a greater number of muscle fibers, smaller fiber areas, and a greater ratio of nuclei to fiber area. The alterations of physiological properties and increased resistance to fatigue in fast muscles are consistent with a shift toward a slower, more oxidative phenotype. Consistent with a conserved functional role in humans, a genetic association was found between a SNP in the IL15RA gene and endurance in athletes stratified by sport. Therefore, we propose that IL-15Rα has a role in defining the phenotype of fast skeletal muscles in vivo.
Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation) within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and ...stimulating molecules.
In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R) in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate) in the presence or in the absence of methanandamide (Met-AEA), a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716) or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP). By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity) and on membrane enriched fraction (C/P content and anisotropy).
Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility.
Faecal samples obtained from either asymptomatic or diarrhoeic calves in Italy were screened for bovine kobuviruses (BKVs) using specific primers. BKV RNA was detected in 4.9 % of the samples, with ...higher positivity rates in diarrhoeic calves (5.3 %) than in asymptomatic animals (4.8 %), although the difference was not statistically significant. Upon sequence analysis, all of the Italian viruses formed a tight group along with BKV-like sequences previously detected in Thailand and Japan.
The present experiments compared the ability of pig oocytes matured either in vivo or in vitro to structurally reorganize the penetrated sperm chromatin into male pronucleus (PN) and to carry out, in ...parallel, the epigenetic processes of global chromatin methylation and acetylation, 12-14 h after in vitro fertilization (IVF). In addition, PN distribution of histone deacetylase (HDAC), a major enzyme interfacing DNA methylation and histone acetylation, was investigated. The ability of the oocyte to operate an efficient block to polyspermy was markedly affected by maturation. The monospermic fertilization rate was significantly higher for in vivo than for in vitro matured (IVM) oocytes (P < 0.01) which, furthermore, showed a reduced ability to transform the chromatin of penetrated sperm into male PN (P < 0.01). Indirect immunofluorescence analysis of global DNA methylation, histone acetylation and HDAC distribution (HDAC-1, -2 and -3), carried out in monospermic zygotes that reached the late PN stage, showed that IVM oocytes also had a reduced epigenetic competence. In fact, while in about 80% of in vivo matured and IVF oocytes the male PN underwent a process of active demethylation and showed a condition of histone H4 hyperacetylation, only 40% of IVM/IVF zygotes displayed a similar PN remodelling asymmetry. Oocytes that carried out the first part of maturation in vivo (up to germinal vesicle breakdown; GVBD) and then completed the process in vitro, displayed the same PN asymmetry as oocytes matured entirely in vivo. A crucial role of HDAC in the establishment of PN acetylation asymmetry seems to be confirmed by the use of HDAC inhibitors as well as by the abnormal distribution of the enzyme between the two PN in IVM zygotes. Collectively, these data demonstrated that some pig IVM oocytes fail to acquire full remodelling competence which is independent from their ooplasmic ability to morphologically reorganize the sperm nucleus into PN.
Interleukin-15 (IL-15) is a cytokine that is highly expressed in skeletal muscle. In addition to its well-characterized effects on innate immunity, IL-15 has been proposed to modulate skeletal muscle ...and adipose tissue mass, as well as insulin sensitivity. In the present study, an IL-15 gain-of-function model, transgenic mice with skeletal muscle-specific oversecretion of IL-15 (IL-15 Tg mice), was utilized to test the hypotheses that IL-15 promotes insulin sensitivity and resistance to diet-induced obesity (DIO) by increasing circulating adiponectin levels, and that IL-15 regulates skeletal muscle metabolism without inducing overt muscle hypertrophy. Compared to closely related control mice, IL-15 Tg mice exhibited lower total body fat following high-fat feeding, lower intra-abdominal fat following both low- and high-fat feeding, and greater insulin sensitivity. However, this was not accompanied by increased total or high molecular weight serum adiponectin levels in IL-15 Tg mice. While overall lean body mass did not differ, IL-15 Tg mice exhibited increased mass of the oxidative soleus muscle, and increased expression of mRNA encoding the slow isoform of troponin I (TnnI 1) in the predominately glycolytic extensor digitorum longus muscle. Skeletal muscle tissue from IL-15 Tg mice also exhibited alterations in the expression of several genes associated with fatty acid metabolism, such as SIRT1, SIRT4, and uncoupling protein 2 (UCP2). These findings suggest changes in oxidative metabolism, rather than induction of adiponectin expression, appear to be responsible for the DIO-resistant and more insulin-sensitive phenotype of IL-15 Tg mice.
Intravenous bisphosphonates are the current standard of care for the treatment of hypercalcemia of malignancy and for the prevention of skeletal complications associated with bone metastases. ...Recently, retrospective case studies have reported an association between long-term bisphosphonate therapy and osteonecrosis of the jaws.
The data for twelve patients, referred to either an oral and maxillofacial surgeon or to an oral medicine specialist for the management of clinically apparent chronic oral osteonecrosis of unknown etiology, were reviewed. All had received cancer-related therapy simultaneously with bisphosphonate management.
The typical presenting symptoms were pain and exposed bone at the site of a previous tooth extraction. In most patients, the lesions initially occurred after dental extraction or other odontostomatological procedures, while five had a spontaneous event. Biopsy of the involved area showed the presence of necrotic lacunae, with infiltration of lymphocytes and histiocytes. In nine cases, there was histological or cytological diagnosis of suspicious osteomyelitis. No correlation was observed between the intraoral lesions and myelosuppression secondary to antineoplastic therapy.
Based on the patients' respective histories, clinical presentations and responses to surgical and antibiotic treatments, it appears that the pathogenesis of this osteonecrotic process is most consistent with localized vascular insufficiency. In our opinion, the mechanism by which bisphosphonates compromise bone vascularity may be related to their effect on the osteoclasts. The potent bisphosphonate-mediated inhibition of osteoclast function serves to decrease bone resorption and inhibit normal bone turnover remodeling, resulting in microdamage accumulation and a reduction in some mechanical properties of the bone.
Neural Networks design is a complex and often daunting task, particularly for
resource-constrained scenarios typical of mobile-sized models. Neural
Architecture Search is a promising approach to ...automate this process, but
existing competitive methods require large training time and computational
resources to generate accurate models. To overcome these limits, this paper
contributes with: i) a novel training-free metric, named Entropic Score, to
estimate model expressivity through the aggregated element-wise entropy of its
activations; ii) a cyclic search algorithm to separately yet synergistically
search model size and topology. Entropic Score shows remarkable ability in
searching for the topology of the network, and a proper combination with
LogSynflow, to search for model size, yields superior capability to completely
design high-performance Hybrid Transformers for edge applications in less than
1 GPU hour, resulting in the fastest and most accurate NAS method for ImageNet
classification.
Neural Networks design is a complex and often daunting task, particularly for resource-constrained scenarios typical of mobile-sized models. Neural Architecture Search is a promising approach to ...automate this process, but existing competitive methods require large training time and computational resources to generate accurate models. To overcome these limits, this paper contributes with: i) a novel training-free metric, named Entropic Score, to estimate model expressivity through the aggregated element-wise entropy of its activations; ii) a cyclic search algorithm to separately yet synergistically search model size and topology. Entropic Score shows remarkable ability in searching for the topology of the network, and a proper combination with LogSynflow, to search for model size, yields superior capability to completely design high-performance Hybrid Transformers for edge applications in less than 1 GPU hour, resulting in the fastest and most accurate NAS method for ImageNet classification. Code available here 1 .
IL-15 receptor alpha(IL-15Ralpha) is a component of the heterotrimeric plasma membrane receptor for the pleiotropic cytokine IL-15. However, IL-15Ralphais not merely an IL-15 receptor subunit, as ...mice lacking either IL-15 or IL-15Ralphahave unique phenotypes. IL-15 and IL -15Ralphahave been implicated in muscle phenotypes, but a role in muscle physiology has not been defined. Here, we have shown that loss of IL-15R alphainduces a functional oxidative shift in fast muscles, substantially increasing fatigue resistance and exercise capacity. IL-15Ralpha-knockout (IL-15Ralpha-KO) mice ran greater distances and had greater ambulatory activity than controls. Fast muscles displayed fatigue resistance and a slower contractile phenotype. The molecular signature of these muscles included altered markers of mitochondrial biogenesis and calcium homeostasis. Morphologically, fast muscles had a greater number of muscle fibers, smaller fiber areas, and a greater ratio of nuclei to fiber area. The alterations of physiological properties and increased resistance to fatigue in fast muscles are consistent with a shift toward a slower, more oxidative phenotype. Consistent with a conserved functional role in humans, a genetic association was found between a SNP in the IL15RA gene and endurance in athletes stratified by sport. Therefore, we propose that IL-15Ralphahas a role in defining the phenotype of fast skeletal muscles in vivo.
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