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A cognitive lab technique (n=156) was used to investigate interactions between individual factors and item factors presumed to affect assessment validity for diverse students, including English language learners. Findings support the concept of "access"--an interaction between specific construct-irrelevant item features and individual characteristics that either permits or inhibits student response to the targeted measurement content of an assessment item. Access issues of 3rd and 5th grade students were explored at three stages during problem solving on mathematics items: 1) apprehension of task demands; 2) formulation of a solution; and 3) articulation of a solution. Adequacy of access at these levels appears to affect student performance. In particular, where students were able to experience increased apprehension in the first stage through the provision of item variations consistent with their individual access needs, they were more likely to formulate correct solution strategies. The implications of these findings are discussed and suggestions for future research are offered.

Background: Skeletal muscle atrophy is one of the main side effects of high-dose or continuous use of glucocorticoids (such as dexamethasone). However, there are limited studies on dexamethasone-induced skeletal muscle atrophy in zebrafish and even fewer explorations of the underlying molecular mechanisms. This study aimed to construct a model of dexamethasone-induced skeletal muscle atrophy in zebrafish and to investigate the molecular mechanisms. Methods: Zebrafish soaked in 0.01 % dexamethasone solution for 10 days. Loli Track (Denmark) and Loligo Swimming Respirometer were used to observe the effect of dexamethasone on swimming ability. The effects of dexamethasone on zebrafish skeletal muscle were observed by Transmission electron microscopy, H&E, and wheat germ agglutinin techniques. Enriched genes and signaling pathways were analyzed using Transcriptome sequencing. Further, the levels of mitochondrial and endoplasmic reticulum-related proteins were examined to investigate possible mechanisms. Results: 0.01 % dexamethasone reduced zebrafish skeletal muscle mass (p

Skeletal muscle atrophy is a common muscle disease that is directly caused by an imbalance in protein synthesis and degradation. At the histological level, it is mainly characterized by a reduction in muscle mass and fiber cross-sectional area (CSA). Patients with skeletal muscle atrophy present with reduced motor ability, easy fatigue, and poor life quality. Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the degradation of heme and has attracted much attention for its anti-oxidation effects. In addition, there is growing evidence that HO-1 plays an important role in anti-inflammatory, anti-apoptosis, pro-angiogenesis, and maintaining skeletal muscle homeostasis, making it a potential therapeutic target for improving skeletal muscle atrophy. Here, we review the pathogenesis of skeletal muscle atrophy, the biology of HO-1 and its regulation, and the biological function of HO-1 in skeletal muscle homeostasis, with a specific focus on the role of HO-1 in skeletal muscle atrophy, aiming to observe the therapeutic potential of HO-1 for skeletal muscle atrophy.

Sarcopenia is a common skeletal muscle degenerative disease characterized by decreased skeletal muscle mass and mitochondrial dysfunction that involves microRNAs (miR) as regulatory factors in various pathways. Exercise reduces age-related oxidative damage and chronic inflammation and increases autophagy, among others. Moreover, whether aerobic exercise can regulate mitochondrial homeostasis by modulating the miR-128/insulin-like growth factor-1 (IGF-1) signaling pathway and can improve sarcopenia requires further investigation. Interestingly, zebrafish have been used as a model for aging research for over a decade due to their many outstanding advantages. Therefore, we established a model of zebrafish sarcopenia using d-galactose immersion and observed substantial changes, including reduced skeletal muscle cross-sectional area, increased tissue fibrosis, decreased motility, increased skeletal muscle reactive oxygen species, and notable alterations in mitochondrial morphology and function. We found that miR-128 expression was considerably upregulated, where as Igf1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha were significantly downregulated; moreover, mitochondrial homeostasis was reduced. Four weeks of aerobic exercise delayed sarcopenia progression and prevented the disruption of mitochondrial function and homeostasis. The genes related to atrophy and miR-128 were downregulated, Igf1 expression was considerably upregulated, and the phosphorylation levels of Pi3k, Akt, and Foxo3a were upregulated. Furthermore, mitochondrial respiration and homeostasis were enhanced. In conclusion, aerobic exercise improved skeletal muscle quality and function via the miR-128/IGF-1 signaling pathway, consequently ameliorating mitochondrial homeostasis in aging skeletal muscle.

Obesity is a highly prevalent disease that can induce metabolic syndrome and is associated with a greater risk of muscular atrophy. Mitochondria play central roles in regulating the physiological metabolism of skeletal muscle; however, whether a decreased mitochondrial function is associated with impaired muscle function is unclear. In this study, we evaluated the effects of a high-fat diet on muscle mitochondrial function in a zebrafish model of sarcopenic obesity (SOB). In SOB zebrafish, a significant decrease in exercise capacity and skeletal muscle fiber cross-sectional area was detected, accompanied by high expression of the atrophy-related markers Atrogin-1 and muscle RING-finger protein-1. Zebrafish with SOB exhibited inhibition of mitochondrial biogenesis and fatty acid oxidation as well as disruption of mitochondrial fusion and fission in atrophic muscle. Thus, our findings showed that muscle atrophy was associated with SOB-induced mitochondrial dysfunction. Overall, these results showed that the SOB zebrafish model established in this study may provide new insights into the development of therapeutic strategies to manage mitochondria-related muscular atrophy.

Arachidonic acid can be metabolized to prostaglandins and epoxyeicosatrienoic acids (EETs) by cyclooxygenase-2 (COX-2) and cytochrome P450 (CYP), respectively. While protective EETs are degraded by soluble epoxide hydrolase (sEH) very fast. We have reported that dual inhibition of COX-2 and sEH with specific inhibitor PTUPB shows anti-pulmonary fibrosis and renal protection. However, the effect of PTUPB on cecal ligation and puncture (CLP)-induced sepsis remains unclear. The current study aimed to investigate the protective effects of PTUPB against CLP-induced sepsis in mice and the underlying mechanisms. We found that COX-2 expressions were increased, while CYPs expressions were decreased in the liver, lung, and kidney of mice undergone CLP. PTUPB treatment significantly improved the survival rate, reduced the clinical scores and systemic inflammatory response, alleviated liver and kidney dysfunction, and ameliorated the multiple-organ injury of the mice with sepsis. Besides, PTUPB treatment reduced the expression of hypoxia-inducible factor-1α in the liver, lung, and kidney of septic mice. Importantly, we found that PTUPB treatment suppressed the activation of NLRP3 inflammasome in the liver and lung of septic mice. Meanwhile, we found that PTUPB attenuated the oxidative stress, which contributed to the activation of NLRP3 inflammasome. Altogether, our data, for the first time, demonstrate that dual inhibition of COX-2 and sEH with PTUPB ameliorates the multiple organ dysfunction in septic mice.

Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts anti-inflammatory functions. We have reported that VIP mediated by lentivirus attenuates acute lung injury (ALI) in lipopolysaccharide (LPS)-induced murine model. However, the exact role of VIP in uncontrolled inflammation during ALI is largely unknown. Accumulating evidence indicates that the NLRP3 inflammasome has a critical role during ALI. In this study, we investigated the effects of VIP on the activation of NLRP3 inflammasome during the development of ALI in mice. Seven days after the intratracheal injection of VIP-lentivirus, a murine ALI model was induced by intratracheal injection of LPS. VIP-lentivirus significantly reduced the expression of NLRP3 inflammasome components in lung tissue, including NLRP3, pro-caspase-1, pro-IL-1β, and pro-IL-18. VIP-lentivirus also inhibited the formation of caspase-1 p10 and the maturation of IL-1β and IL-18. In vitro, exogenous VIP pre-treatment inhibited the priming of NLRP3 inflammasome in murine primary peritoneal macrophages, indicated by down-regulation of expression of NLRP3 inflammasome components. VIP pre-treatment effectively prevented the LPS-induced degradation of I-κB and the synthesis of the downstream of NF-κB, including TNF-α and IL-17A. Furthermore, VIP pre-treatment pronouncedly suppressed the autoproteolysis of caspase-1 and the secretion of IL-1β and IL-18 induced by LPS plus ATP in macrophages. In addition, VIP inhibited the generation of reactive oxygen species in macrophages by decreasing NOX1 and NOX2 expression. These findings illustrate one mechanism that VIP attenuates ALI induced by LPS through inhibiting the activation of the NLRP3 inflammasome and encourage further studies assessing the therapeutic potential of VIP to ALI.

Long-term imbalance between fatigue and recovery may eventually lead to muscle weakness or even atrophy. We previously reported that excessive exercise induces pathological cardiac hypertrophy. However, the effect of excessive exercise on the skeletal muscles remains unclear. In the present study, we successfully established an excessive-exercise-induced skeletal muscle atrophy zebrafish model, with decreased muscle fiber size, critical swimming speed, and maximal oxygen consumption. High-throughput RNA-seq analysis identified differentially expressed genes in the model system compared with control zebrafish. Gene ontology and KEGG enrichment analysis revealed that the upregulated genes were enriched in autophagy, homeostasis, circadian rhythm, response to oxidative stress, apoptosis, the p53 signaling pathway, and the FoxO signaling pathway. Protein–protein interaction network analysis identified several hub genes, including keap1b, per3, ulk1b, socs2, esrp1, bcl2l1, hsp70, igf2r, mdm2, rab18a, col1a1a, fn1a, ppih, tpx2, uba5, nhlrc2, mcm4, tac1, b3gat3, and ddost, that correlate with the pathogenesis of skeletal muscle atrophy induced by excessive exercise. The underlying regulatory pathways and muscle-pressure-response-related genes identified in the present study will provide valuable insights for prescribing safe and accurate exercise programs for athletes and the supervision and clinical treatment of muscle atrophy induced by excessive exercise.

Accumulating evidence indicates that angiotensin (1-7) [Ang-(1-7)] protects against idiopathic pulmonary fibrosis (IPF) in animal experiments. However, whether Ang-(1-7) effectively inhibits epithelial-mesenchymal transition (EMT) induced by transforming growth factor-β1 (TGF-β1) remains unclear. The aim of this study is to examine the eff ;ects of Ang-(1-7) on TGF-β1-induced EMT in human alveolar epithelial cells. We found that angiotensin-converting enzyme 2 (ACE2) /Ang-(1-7)/MasR were decreased in the lungs of mice with IPF induced by bleomycin, and were negatively correlated with Tgfb1 mRNA expression. In vitro, our data showed that exogenous Ang-(1-7) restored the expression of E-cadherin and decreased the expressions of α-SMA and Vimentin induced by TGF-β1 in A549 cells. Ang-(1-7) also reduced TGF-β1-induced migration and synthesis of the extracellular matrix, such as collagen Ⅰ and collagen Ⅲ. Mechanistically, we observed that Ang-(1-7) directly inhibited TGF-β1-induced phosphorylation of Smad2 and Smad3, and suppressed the expression of the downstream target gene of TGF-β1-Smad signaling, including ZEB1, ZEB2, TWIST, and SNAIL1. Additionally, phosphorylation of mTOR induced by TGF-β1 also been suppressed by Ang-(1-7) treatment in A549 cells. Interestingly, we found that TGF-β1 strongly suppressed the expression of ACE2 in A549 cells through inhibiting SIRT1. In conclusion, our findings indicate that Ang-(1-7) directly inhibits TGF-β1-induced EMT in alveolar epithelial cells via disruption of TGF-β1-Smad signaling pathway, contributing to the protective effect against IPF.