Biology subjects

Cheung, W. W.

Publications and source records attributed to Cheung, W. W..

6 recordsLinked to original sources

bioRxiv2022

Linking movement and dive data to prey distribution models: new insights in foraging behaviour and potential pitfalls of movement analyses

BackgroundAnimal movement data are regularly used to infer foraging behaviour and relationships to environmental characteristics, often to help identify critical habitat. To characterize foraging, movement models make a set of assumptions rooted in theory, for example, time spent foraging in an area increases with higher prey density. MethodsWe assessed the validity of these assumptions by associating horizontal movement and diving of satellite-telemetered ringed seals (Pusa hispida) - an opportunistic predator - in Hudson Bay, Canada, to modelled prey data and environmental proxies. ResultsModelled prey biomass data performed better than their environmental proxies (e.g., sea surface temperature) for explaining seal movement, however movement was not related to foraging effort. Counter to theory, seals appeared to forage more in areas with relatively lower prey diversity and biomass, potentially due to reduced foraging efficiency in those areas. ConclusionsOur study highlights the need to validate movement analyses with prey data to effectively estimate the relationship between prey availability and foraging behaviour.

ecology↗

bioRxiv2021

Safety and efficacy of a new vaginal gel, Feminilove, for the treatment of symptoms associated with vaginal dryness and vulvovaginal atrophy in women: an in vitro and in vivo study

Vaginal dryness is a common symptom associated with vulvovaginal atrophy of menopause. The impact of vaginal dryness is very significant as it negatively affects quality of life, daily activities, sexual satisfaction as well as on interpersonal relationships. Symptoms of vaginal dryness is often underreported and undertreated. Recently, vaginal lubricants and moisturizers have been applied as one of the alternative and safe approaches to relieve vaginal dryness for women with mild to moderate vaginal dryness. We evaluated the safety and beneficial effects of a new type of estrogen-free vaginal gel, Feminilove BIO-FRESH moisturizing vaginal gel, using in vitro and in vivo experimental tools. Our results suggest that; 1) Feminilove vaginal gel exhibits minimal cell cytotoxicity on various human vaginal cells; 2) Feminilove vaginal gel exhibits minimal side-effects on the structure of vaginal mucosa stratum of experimental animals; 3) Feminiove vaginal gel inhibits the growth of pathogenic vaginal bacteria (E. coli) while promotes the growth of beneficial vaginal bacteria (Lactobacillus spp); 4) Feminilove vaginal gel elicits an anti-inflammatory response on vaginal epithelial cells; and 5) Feminilove vaginal gel promotes the production of tropoelastin and collagen on cultural vaginal smooth muscle and may restore loose vaginal wall (i.e., tightening effects). In summary, our results indicate that Feminilove BIO-FRESH moisturizing vaginal gel is a safe and effective remedy for vaginal dryness and vulvovaginal atrophy in women.

pharmacology and toxicology↗

bioRxiv2021

The role of IL-1 in adipose browning and muscle wasting in CKD-associated cachexia

Cytokines such as IL-6, TNF- and IL-1{beta} trigger inflammatory cascades which may play a role in the pathogenesis of chronic kidney disease (CKD)-associated cachexia. CKD was induced by 5/6 nephrectomy in mice. We studied energy homeostasis in Il1{beta}-/-/CKD, Il6-/-/CKD and Tnf-/-/CKD mice and compared with wild type (WT)/CKD controls. Parameters of cachexia phenotype were completely normalized in Il1{beta}-/-/CKD mice but were only partially rescued in Il6-/-/CKD and Tnf-/-/CKD mice. We tested the effects of anakinra, an IL-1 receptor antagonist, on CKD-associated cachexia. WT/CKD mice were treated with anakinra (2.5 mg.kg.day, IP) or saline for 6 weeks and compared with WT/sham controls. Anakinra normalized food intake and weight gain, fat and lean mass content, metabolic rate and muscle function, and also attenuated molecular perturbations of energy homeostasis in adipose tissue and muscle in WT/CKD mice. Anakinra attenuated browning of white adipose tissue in WT/CKD mice. Moreover, anakinra normalized gastrocnemius weight and fiber size as well as attenuated muscle fat infiltration in WT/CKD mice. This was accompanied by correcting the increased muscle wasting signaling pathways while promoting the decreased myogenesis process in gastrocnemius of WT/CKD mice. We performed qPCR analysis for the top 20 differentially expressed muscle genes previously identified via RNAseq analysis in WT/CKD mice versus controls. Importantly, 17 differentially expressed muscle genes were attenuated in anakinra treated WT/CKD mice. In conclusion, IL-1 receptor antagonism may represent a novel targeted treatment for adipose tissue browning and muscle wasting in CKD.

physiology↗

bioRxiv2021

Targeting interleukin-1 for reversing fat browning and muscle wasting in infantile nephropathic cystinosis

BackgroundCtns-/- mice, a mouse model of infantile nephropathic cystinosis, exhibit hypermetabolism with adipose tissue browning and profound muscle wasting. Inflammatory cytokines such as IL-1 trigger inflammatory cascades and play an important role in the pathogenesis of cachexia. Anakinra is an FDA-approved IL-1 receptor antagonist that blocks IL-1 signaling and may provide targeted novel therapy. MethodsCtns-/- mice were bred to Il6 -/- and Il1{beta} -/- mice. Ctns-/- mice and wild type control were treated with anakinra (2.5 mg.kg.day, IP) or saline as vehicle for 6 weeks. We quantitated total fat mass and studied expression of molecules regulating adipose tissue browning. We measured gastrocnemius weight, total lean mass content, muscle function (grip strength and rotarod activity), muscle fiber size, muscle fatty infiltration and expression of molecules regulating muscle metabolism. We also evaluated the effects of anakinra on the muscle transcriptome. ResultsIl-1{beta} deficiency or treatment with anakinra normalized food intake and weight gain, fat and lean mass content, metabolic rate and muscle function in Ctns-/- mice. Anakinra also diminished molecular perturbations of energy homeostasis in adipose tissue and muscle, specifically, aberrant expression of beige adipose cell biomarkers (UCP-1, CD137, Tmem26 and Tbx1) and molecules implicated in adipocyte tissue browning (Cox2/Pgf2, Tlr2, Myd88 and Traf6) in inguinal white adipose tissue in Ctns-/- mice. Moreover, anakinra normalized gastrocnemius weight and fiber size as well as attenuated muscle fat infiltration in Ctns-/- mice. This was accompanied by correction of the increased muscle wasting signaling pathways (increased protein content of ERK1/2, JNK, p38 MAPK and NF-{kappa}B p65 and gene expression of Atrogin-1 and Myostatin) and the decreased myogenesis process (decreased gene expression of MyoD and Myogenin) in gastrocnemius of Ctns-/- mice. Finally, anakinra normalized or attenuated 12 of those top 20 differentially expressed muscle genes in Ctns-/- mice. ConclusionsAnakinra attenuates adipose tissue browning and muscle wasting in Ctns-/- mice. IL-1 receptor blockade may represent a novel targeted treatment for cachexia in patients with infantile nephropathic cystinosis.

physiology↗

bioRxiv2018

Ensemble projections of global ocean animal biomass with climate change

Climate change is shifting the abundance and distribution of marine species with consequences for ecosystem functioning, seafood supply, management and conservation. Several approaches for future projection exist but these have never been compared systematically to assess their variability. We conducted standardized ensemble projections including 6 global fisheries and marine ecosystem models, forced with 2 Earth-system models and 4 emission scenarios in a fished and unfished ocean, to derive average trends and associated uncertainties. Without fishing, mean global animal biomass decreased by 5% ({+/-}4%) under low and 17% ({+/-}11%) under high emissions by 2100, primarily driven by increasing temperature and decreasing primary production. These climate-change effects were slightly weaker for larger animals and in a fished ocean. Considerable regional variation ranged from strong biomass increases in high latitudes to strong decreases in mid-low latitudes, with good model agreement on the direction of change but variable magnitude. Uncertainties due to differences among ecosystem or Earth-system models were similar, suggesting equal need for model improvement. Our ensemble projections provide the most comprehensive outlook on potential climate-driven ecological changes in the ocean to date. Realized future trends will largely depend on how fisheries and management adapt to these changes in a changing climate.

ecology↗

bioRxiv2018

Cystinosin regulates kidney inflammation through its interaction with galectin-3

Inflammation is implicated in the pathogenesis of many disorders. Here, we show that cystinosin, protein defective in the lysosomal storage disorder cystinosis, is a critical regulator of galectin-3 during inflammation. Cystinosis is a lysosomal storage disorder and despite ubiquitous expression of cystinosin, kidney is the primary organ to be impacted by the disease. Here, we show that cystinosin interacts with galectin-3 and enhances its lysosomal localization and degradation. Galectin-3 is also found overexpressed in the kidney of the mouse model of cystinosis, Ctns-/-mice. Absence of galectin-3 in Ctns-/- mice led to a better renal function and structure, and decreased macrophage/monocyte infiltration in the kidney. Finally, galectin-3 interacts with a protein implicated in the recruitment of monocytes and macrophages during inflammation, Monocyte Chemoattractant Protein-1 (MCP1), that was found increased in the serum of Ctns-/- mice. These findings highlight a new role of cystinosin and galectin-3 interaction in inflammation, providing a mechanistic explanation for kidney disease pathogenesis in cystinosis, which may lead to the identification of new drug targets to delay its progression.

molecular biology↗