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Androgen excess and metabolic abnormality largely contribute to the pathogenesis of polycystic ovarian syndrome (PCOS), which primarily precipitates ovarian dysfunction and infertility in reproductive-age women. Impaired mitochondrial function and epigenetic alteration have been linked to the development of PCOS. However, it is unknown whether acetate would exert a therapeutic effect on ovarian mitochondrial dysfunction in PCOS. Herein, the study hypothesized that acetate reverses ovarian mitochondrial dysfunction in experimental PCOS rat model, possibly through modulation of mitofusin-2 (MFn2). Eight-week-old female Wistar rats were randomized into four groups (n = 5). Induction of PCOS was performed by 1 mg/kg letrozole (p.o.), administered for 21 days. Thereafter, the rats were treated with acetate (200 mg/kg; p.o.) for 6 weeks. The PCOS rats demonstrated androgen excess, multiple ovarian cysts, elevated anti-mullerian hormone and leptin and decreased SHBG, adiponectin and 17-[beta] estradiol with corresponding increase in ovarian transforming growth factor-[beta]1. Additionally, inflammation (tumor growth factor and nuclear factor-kB), elevated caspase-6, decreased hypoxia-inducible factor-1[alpha] and elevated histone deacetylase-2 (HDAC2) were observed in the ovaries of PCOS rats, while mitochondrial abnormality with evidence of decreased adenosine triphosphate synthase and MFn2 was observed in rats with PCOS. Treatment with acetate reversed the alterations. The present results collectively suggest that acetate ameliorates ovarian mitochondrial abnormality, a beneficial effect that is accompanied by MFn2 with consequent normalization of reproductive-endocrine profile and ovarian function. Perhaps, the present data provide hope for PCOS individuals that suffer infertility. Keywords: Androgen, HDAC2, Infertility, Mitochondrial dysfunction, Mitofusin-2, PCOS, Author(s): Kehinde S. Olaniyi[sup.1] and Stephanie E. Areloegbe[sup.1] Introduction Endocrine-metabolic disorder, particularly polycystic ovarian syndrome (PCOS) has a worldwide prevalence of 6-21%, and accounts for over 70% of infertility cases [...]

Microvillus inclusion disease (MVID), caused by loss-of-function mutations in the motor protein myosin Vb (MYO5B), is a severe infantile disease characterized by diarrhea, malabsorption, and acid/base instability, requiring intensive parenteral support for nutritional and fluid management. Human patient-derived enteroids represent a model for investigation of monogenic epithelial disorders but are a rare resource from MVID patients. We developed human enteroids with different loss-of function MYO5B variants and showed that they recapitulated the structural changes found in native MVID enterocytes. Multiplex immunofluorescence imaging of patient duodenal tissues revealed patient-specific changes in localization of brush border transporters. Functional analysis of electrolyte transport revealed profound loss of [Na.sup.+]/[H.sup.+] exchange (NHE) activity in MVID patient enteroids with near-normal chloride secretion. The chloride channel-blocking antidiarrheal drug crofelemer dose-dependently inhibited agonist-mediated fluid secretion. MVID enteroids exhibited altered differentiation and maturation versus healthy enteroids. [gamma]-Secretase inhibition with DAPT recovered apical brush border structure and functional [Na.sup.+]/[H.sup.+] exchange activity in MVID enteroids. Transcriptomic analysis revealed potential pathways involved in the rescue of MVID cells including serum/glucocorticoid-regulated kinase 2 (SGK2) and NHE regulatory factor 3 (NHERF3). These results demonstrate the utility of patient-derived enteroids for developing therapeutic approaches to MVID., Introduction Microvillus inclusion disease (MVID) is a rare congenital diarrhea and enteropathy (CoDE) caused by loss-of-function mutations in the motor protein myosin Vb (MYO5B) (1-5). In general, patients with severe [...]

CD8 cytotoxic T lymphocytes (CTLs) rely on rapid reorganization of the branched F-actin network to drive the polarized secretion of lytic granules, initiating target cell death during the adaptive immune response. Branched F-actin is generated by the nucleation factor actin-related protein 2/3 (Arp2/3) complex. Patients with mutations in the actin-related protein complex 1B (ARPC1B) subunit of Arp2/3 show combined immunodeficiency, with symptoms of immune dysregulation, including recurrent viral infections and reduced [CD8.sup.+] T cell count. Here, we show that loss of ARPC1B led to loss of CTL cytotoxicity, with the defect arising at 2 different levels. First, ARPC1B is required for lamellipodia formation, cell migration, and actin reorganization across the immune synapse. Second, we found that ARPC1B is indispensable for the maintenance of TCR, CD8, and GLUT1 membrane proteins at the plasma membrane of CTLs, as recycling via the retromer and WASH complexes was impaired in the absence of ARPC1B. Loss of TCR, CD8, and GLUT1 gave rise to defects in T cell signaling and proliferation upon antigen stimulation of ARPC1B-deficient CTLs, leading to a progressive loss of [CD8.sup.+] T cells. This triggered an activation-induced immunodeficiency of CTL activity in ARPC1B-deficient patients, which could explain the susceptibility to severe and prolonged viral infections., Introduction The actin cytoskeleton coordinates a wide variety of cell functions ranging from cell division and differentiation to migration. The ability to reorganize the actin network in response to both [...]

ABSTRACT The freshness of Pacific white shrimp (Litopenaeus vannamei) stored for 0, 2, 4, 6, 8, and 10 days under vacuum-packing at 4°C was assessed by physicochemical, sensory, and microbiological [...]

Purpose Tropomyosin receptor kinase (Trk) A, a high-affinity receptor of nerve growth factor, is a therapeutic target for both noxious and neuropathic pain. The present study examined the effects of an inhibitory peptide of Trk activity (IPTRK) 3 that inhibits TrkA activity on cancer-induced pain in a mouse melanoma model. Methods The hind paws of mice were inoculated with B16-F1 mouse melanoma cells on day 0. We administered IPTRK3 (20 mg/kg i.p.) repetitively on days 5, 6, 7, 8, and 9, and evaluated pain-related behaviors on days 0, 5, 10, 15, and 20 after tumor inoculation. Results Following inoculation, mice demonstrated mechanical allodynia and thermal hyperalgesia with an increased number of flinches, and paw volume increased gradually. However, an intraperitoneal injection of IPTRK3 significantly inhibited mechanical allodynia on day 15 and suppressed the number of flinches on day 20. The increased paw volume was significantly suppressed on day 20 after tumor inoculation. IPTRK3, however, showed no significant effect on thermal hyperalgesia. Conclusions These results suggest that TrkA inhibitory peptide likely suppress melanoma-induced pain with concomitant reduction in the increased paw volume in a mouse skin cancer pain model. Keywords Cancer pain * Cell-penetrating peptide * Nerve growth factor * TrkA, Introduction Many people suffer from severe cancer pain despite recent progress in palliative care. Better management of cancer pain relief is still warranted [1], and, consequently, several novel drugs are [...]

PRESENTATION O.B. is a 67-year-old African-American man who has had type 2 diabetes for 11 years. He was diagnosed incidentally through laboratory testing. Metformin was initiated at diagnosis and eventually [...]

Skeletal muscle atrophy occurs in a variety of clinical settings, including cachexia, disuse, and denervation. Inflammatory cytokines have been shown to be mediators of cancer cachexia; however, the role of cytokines in denervation- and immobilization-induced skeletal muscle loss remains unknown. In this study, we demonstrate that a single cytokine, TNF-like weak inducer of apoptosis (TWEAK), mediates skeletal muscle atrophy that occurs under denervation conditions. Transgenic expression of TWEAK induces atrophy, fibrosis, fiber-type switching, and the degradation of muscle proteins. Importantly, genetic ablation of TWEAK decreases the loss of muscle proteins and spared fiber cross-sectional area, muscle mass, and strength after denervation. Expression of the TWEAK receptor Fn14 (fibroblast growth factor--inducible receptor 14) and not the cytokine is significantly increased in muscle upon denervation, demonstrating an unexpected inside-out signaling pathway; the receptor up-regulation allows for TWEAK activation of nuclear factor [kappa]B, causing an increase in the expression of the E3 ubiquitin ligase MuRF1. This study reveals a novel mediator of skeletal muscle atrophy and indicates that the TWEAK--Fn14 system is an important target for preventing skeletal muscle wasting. doi/10.1083/jcb.200909117

We studied the response of dysferlin-null and control skeletal muscle to large- and small-strain injuries to the ankle dorsiflexors in mice. We measured contractile torque and counted fibers retaining 10-kDa fluorescein dextran, necrotic fibers, macrophages, and fibers with central nuclei and expressing developmental myosin heavy chain to assess contractile function, membrane resealing, necrosis, inflammation, and myogenesis. We also studied recovery after blunting myogenesis with X-irradiation. We report that dysferlin-null myofibers retain 10-kDa dextran for 3 days after large-strain injury but are lost thereafter, following necrosis and inflammation. Recovery of dysferlin-null muscle requires myogenesis, which delays the return of contractile function compared with controls, which recover from large-strain injury by repairing damaged myofibers without significant inflammation, necrosis, or myogenesis. Recovery of control and dysferlin-null muscles from small-strain injury involved inflammation and necrosis followed by myogenesis, all of which were more pronounced in the dysferlin-null muscles, which recovered more slowly. Both control and dysferlin-null muscles also retained 10-kDa dextran for 3 days after small-strain injury. We conclude that dysferlin-null myofibers can survive contraction-induced injury for at least 3 days but are subsequently eliminated by necrosis and inflammation. Myogenesis to replace lost fibers does not appear to be significantly compromised in dysferlin-null mice. inflammation; limb-girdle muscular dystrophy type 2B; Miyoshi myopathy; muscle injury doi: 10.1152/ajpcell.00122.2009

Blood sugar dysregulation and hypoglycemia, along with insulin resistance, are all conditions which health care practitioners routinely see. Estimates indicate that approximately 60% of the American population is overweight, 20% [...]

Titin (also called connectin) is a major protein in sarcomere assembly as well as providing elastic return of the sarcomere postcontraction in cardiac and striated skeletal muscle tissues. In addition, it has been speculated that titin is associated with nuclear functions, including chromosome and spindle formation, and regulation of muscle gene expression. In the present study, a short isoform of titin was detected in a human osteoblastic cell line, MG-63 cells, by both immunostaining and Western blot analysis. Confocal images of titin staining showed both cytoplasmic and nuclear localization in a punctate pattern. Therefore, we hypothesized that human titin may contain a nuclear localization signal (NLS). A functional NLS, 200-PAKKTKT-206, located in a low-complexity, titin-specific region between Z2 and Z repeats, was found by sequentially deleting segments of the N[H.sub.2]-terminal sequence in conjunction with an enhanced green fluorescent protein reporter system and confirmed by site-directed mutagenesis. Overexpression of titin's amino terminal fragment (Z1Z2Zr) in human osteoblasts (MG-63) increased cell proliferation by activating the Wnt/[beta]-catenin pathway. RT-PCR screens of tissue panels demonstrated that residues 1-206 were ubiquitously expressed at low levels in all tissues and cell types analyzed. Our data implicate a dual role for titin's amino terminal region, i.e., a novel nuclear function promoting cell division in addition to its known structural role in Z-line assembly. Wnt; catenin; osteoblast

Protein ingestion stimulates muscle protein synthesis and improves net muscle protein balance. Insulin resistance has been suggested to result in a reduced muscle protein synthetic response to food intake. As such, we hypothesized that type 2 diabetes patients have a impaired muscle protein synthetic response to food ingestion. To test this hypothesis, 10 male type 2 diabetes patients using their normal oral glucose-lowering medication (68 [+ or -] 2 y) and 10 matched, normoglycemic men (65 [+ or -] 2 y) were randomly assigned to 2 crossover treatments in which whole body and muscle protein synthesis were measured following the consumption of either carbohydrate (CHO) or carbohydrate with a protein hydrolysate (CHO+PRO). Primed, continuous infusions with L-[[ring-.sup.13][C.sub.6]]phenylalanine and L-[[ring-.sup.2] [H.sub.2]]tyrosine were applied and blood and muscle samples were collected to assess whole-body protein balance and mixed muscle protein fractional synthetic rate over a 6-h period. Whole-body phenylalanine and tyrosine flux were higher after the CHO+PRO treatment compared with the CHO treatment in the diabetes and control group (P < 0.01). Protein balance was negative following CHO but positive following CHO+PRO treatment in both groups. Muscle protein synthesis rates were higher in both groups following the CHO+PRO (0.086 [+ or -] 0.014%/h) treatment than in the CHO treatment (0.040 [+ or -] 0.003%/h; P < 0.01) with no difference between the diabetes patients and normoglycemic controls. We conclude that the muscle protein synthetic response to CHO or CHO+PRO ingestion is not substantially impaired in longstanding, type 2 diabetes patients treated with oral blood glucose-lowering medication.

The present experiment was designed to measure the synthetic and breakdown rates of muscle protein in the hindlimb of rabbits with or without clamping the femoral artery. L-[[ring-.sup.13][C.sub.6]]phenylalanine was infused as a tracer for measurement of muscle protein kinetics by means of an arteriovenous model, tracer incorporation, and tracee release methods. The ultrasonic flowmeter, dye dilution, and microsphere methods were used to determine the flow rates in the femoral artery, in the leg, and in muscle capillary, respectively. The femoral artery flow accounted for 65% of leg flow. A 50% reduction in the femoral artery flow reduced leg flow by 28% and nutritive flow by 26%, which did not change protein synthetic or breakdown rate in leg muscle. Full clamp of the femoral artery reduced leg flow by 42% and nutritive flow by 59%, which decreased (P < 0.05) both the fractional synthetic rate from 0.19 [+ or -] 0.05 to 0.14 [+ or -] 0.03%/day and fractional breakdown rate from 0.28 [+ or -] 0.07 to 0.23 [+ or -] 0.09%/day of muscle protein. Neither the partial nor full clamp reduced (P = 0.27-0.39) the intracellular phenylalanine concentration or net protein balance in leg muscle. We conclude that the flow threshold to cause a fall of protein turnover rate in leg muscle was a reduction of 30-40% of the leg flow. The acute responses of muscle protein kinetics to the reductions in blood flow reflected the metabolic priorities to maintain muscle homeostasis. These findings cannot be extrapolated to more chronic conditions without experimental validation. stable isotope; gas chromatograph-mass spectrometer; arteriovenous balance; fractional synthetic rate; fractional breakdown rate

Myocardin (Myocd) is a potent transcriptional coactivator that has been implicated in cardiovascular development and adaptation of the cardiovascular system to hemodynamic stress. To determine the function of myocardin in the developing cardiovascular system, [Myocd.sup.F/F]/[Wnt1-Cre.sup.+] and [Myocd.sup.F/F]/[Pax3-Cre.sup.+] mice were generated in which the myocardin gene was selectively ablated in neural crest--derived SMCs populating the cardiac outflow tract and great arteries. Both [Myocd.sup.F/F]/[Wnt1-Cre.sup.+] and [Myocd.sup.F/F]/[Pax3-Cre.sup.+] mutant mice survived to birth, but died prior to postnatal day 3 from patent ductus arteriosus (PDA). Neural crest--derived SMCs populating the ductus arteriosus (DA) and great arteries exhibited a cell autonomous block in expression of myocardin-regulated genes encoding SMC-restricted contractile proteins. Moreover, Myocd-deficient vascular SMCs populating the DA exhibited ultrastructural features generally associated with the SMC synthetic, rather than contractile, phenotype. Consistent with these findings, ablation of the Myocd gene in primary aortic SMCs harvested from Myocd conditional mutant mice caused a dramatic decrease in SMC contractile protein expression. Taken together, these data demonstrate that myocardin regulates expression of genes required for the contractile phenotype in neural crest--derived SMCs and provide new insights into the molecular and genetic programs that may underlie PDA., Introduction Congenital heart disease is the most common cause of infantile deaths from birth defects in the United States. One of the most common congenital heart defects, affecting approximately 1 [...]

Marked sarcomere disorganization is a well-documented characteristic of cardiomyocytes in the failing human myocardium. Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (MLC2v), which is involved in the development of [...]

Insulin resistance is a major factor in the pathogenesis of type 2 diabetes and is strongly associated with obesity. Increased concentrations of intracellular fatty acid metabolites have been postulated to [...]