FNDC1 is a myokine that promotes myogenesis and muscle regeneration.

Myogenesis is essential for skeletal muscle formation and regeneration after injury, yet its regulators are largely unknown. Here we identified fibronectin type III domain containing 1 (FNDC1) as a previously uncharacterized myokine. In vitro studies showed that knockdown of Fndc1 in myoblasts reduces myotube formation, while overexpression of Fndc1 promotes myogenic differentiation.

Upregulation of coagulation factor V by glucocorticoid in the preovulatory follicles of zebrafish.

Increased cortisol levels in the preovulatory follicular fluid suggests a role of glucocorticoid in human ovulation. However, the mechanisms through which cortisol regulates the ovulatory process remain poorly understood. In this study, we examined the upregulation of f5 mRNA by glucocorticoid and its receptor (Gr) in the preovulatory follicles of zebrafish.

Structural and ultrastructural aspects of the skin of large yellow croaker Larimichthys crocea.

The skin color of the large yellow croaker (Larimichthys crocea) is a crucial indicator to determine its economic value. However, the location of pigment cells in the skin structure is uncertain. To determine the pigment cell type in the skin, the vertical order and ultrastructure of pigment cells were examined using light microscopy and transmission electron microscopy.

Neurotransmitter norepinephrine regulates chromatosomes aggregation and the formation of blotches in coral trout Plectropomus leopardus.

Color changes and pattern formations can represent strategies of the utmost importance for the survival of individuals or of species. Previous studies have associated capture with the formation of blotches (areas with light color) of coral trout, but the regulatory mechanisms link the two are lacking. Here, we report that capture induced blotches formation within 4-5 seconds.

A progestin regulates the prostaglandin pathway in the neuroendocrine system in female mudskipper Boleophthalmus pectinirostris.

Sex hormones regulate the reproductive cycle through brain-pituitary axis, but the molecular mechanism is still enigmatic. In the reproductive season, the mudskipper Boleophthalmus pectinirostris possesses a semilunar periodicity spawning rhythm, which coincides with the semilunar periodicity variations in 17α-hydroxyprogesterone, the precursor of 17α,20β-dihydroxy-4-pregnen-3-one (DHP), a sexual progestin in teleosts. In the present study, we investigated in vitro the brain transcriptional differences between DHP-treated tissues and control groups using RNA-seq.

Cytoarchitecture of Mudskipper (Boleophthalmus pectinirostris) Brain.

Mudskippers are intertidal burrowing fish with unique living habits. So far, studies on the cytoarchitecture of the brain in fish with such behaviors remain limited. Therefore, documenting the neuroanatomy of this animal is of interest because of its unique characteristics.

Ultrastructure and regulation of color change in blue spots of leopard coral trout .

The leopard coral trout generally exhibited numerous round, minute blue spots covering its head (about the size of nostril) and body (except ventral side). This is a characteristic that distinguishes them from similar species. Recently, however, we found the leopard coral trout with black spots.

Nuclear Progestin Receptor-mediated Linkage of Blood Coagulation and Ovulation.

Ovulation is a dramatic remodeling process that includes rupture of blood capillaries and clotting, but coagulation is not thought to directly regulate this process. Herein, we report remarkable increases of coagulation factors V (f5, ~3145-fold) and tissue factor (f3a, ~120-fold) in zebrafish ovarian follicle cells during ovulation. This increase was mediated through the nuclear progestin receptor (Pgr), which is essential for ovulation in zebrafish, and was totally abolished in ovarian follicular cells from pgr-/- mutants.

Optineurin promotes myogenesis during muscle regeneration in mice by autophagic degradation of GSK3β.

Skeletal muscle regeneration is essential for maintaining muscle function in injury and muscular disease. Myogenesis plays key roles in forming new myofibers during the process. Here, through bioinformatic screen for the potential regulators of myogenesis from 5 independent microarray datasets, we identify an overlapping differentially expressed gene (DEG) optineurin (OPTN).

Camptothecin effectively treats obesity in mice through GDF15 induction.

Elevated circulating levels of growth differentiation factor 15 (GDF15) have been shown to reduce food intake and lower body weight through activation of hindbrain receptor glial-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL) in rodents and nonhuman primates, thus endogenous induction of this peptide holds promise for obesity treatment. Here, through in silico drug-screening methods, we found that small molecule Camptothecin (CPT), a previously identified drug with potential antitumor activity, is a GDF15 inducer. Oral CPT administration increases circulating GDF15 levels in diet-induced obese (DIO) mice and genetic ob/ob mice, with elevated Gdf15 expression predominantly in the liver through activation of integrated stress response.

Robust host source tracking building on the divergent and non-stochastic assembly of gut microbiomes in wild and farmed large yellow croaker.

Background: Given the lack of genetic background, the source tracking unknown individuals of fish species with both farmed and wild populations often cannot be robustly achieved. The gut microbiome, which is shaped by both deterministic and stochastic processes, can serve as a molecular marker of fish host source tracking, particularly as an alternative to the yet-to-be-established host genetic marker. A candidate for testing the feasibility is the large yellow croaker, Larimichthys crocea, which is carnivorous and ranks the top mariculture fish in China.

Expressions of melanopsins in telencephalon imply their function in synchronizing semilunar spawning rhythm in the mudskipper Boleophthalmus pectinirostris.

The mudskipper Boleophthalmus pectinirostris inhabits intertidal mudflats, exhibiting semilunar reproductive rhythms. To investigate whether melanopsin is possibly involved in the synchronization of the semilunar spawning rhythm in the female mudskipper, we first cloned all four melanopsin subtypes (opn4m1, opn4m3, opn4x1, opn4x2) in B. pectinirostris.

GFP expression pattern in pituitary and gonads under the control of nuclear progesterone receptor promoter in transgenic zebrafish.

Background: The nuclear progesterone receptor (Pgr) is a ligand-dependent transcription factor primarily responsible for mediating progesterone actions relevant for reproduction across vertebrates. Information on the cellular localization of Pgr expression in the reproductive system is required for developing a comprehensive approach to elucidate the role of Pgr in reproduction.

Results: We generated transgenic zebrafish Tg(pgr:eGFP) that express enhanced green fluorescent protein (eGFP) driven by promoter sequence of pgr gene.

Urolithin A exerts antiobesity effects through enhancing adipose tissue thermogenesis in mice.

Obesity leads to multiple health problems, including diabetes, fatty liver, and even cancer. Here, we report that urolithin A (UA), a gut-microflora-derived metabolite of pomegranate ellagitannins (ETs), prevents diet-induced obesity and metabolic dysfunctions in mice without causing adverse effects. UA treatment increases energy expenditure (EE) by enhancing thermogenesis in brown adipose tissue (BAT) and inducing browning of white adipose tissue (WAT).

Mitochondrial aconitase controls adipogenesis through mediation of cellular ATP production.

Mitochondrial aconitase (Aco2) catalyzes the conversion of citrate to isocitrate in the TCA cycle, which produces NADH and FADH2, driving synthesis of ATP through OXPHOS. In this study, to explore the relationship between adipogenesis and mitochondrial energy metabolism, we hypothesize that Aco2 may play a key role in the lipid synthesis. Here, we show that overexpression of Aco2 in 3T3-L1 cells significantly increased lipogenesis and adipogenesis, accompanied by elevated mitochondrial biogenesis and ATP production.

Isorhapontigenin Improves Diabetes in Mice via Regulating the Activity and Stability of PPARγ in Adipocytes.

Isorhapontigenin is a natural bioactive stilbene isolated from various plants and fruits. It has been reported to exhibit several physiological activities including anticancer and anti-inflammation activity in vitro and in experimental animal models. This study aimed to investigate whether isorhapontigenin exerts antidiabetic effects in vivo.

A Potential Nutraceutical Candidate Lactucin Inhibits Adipogenesis through Downregulation of JAK2/STAT3 Signaling Pathway-Mediated Mitotic Clonal Expansion.

The prevalence of obesity has increased dramatically worldwide in the past ~50 years. Searching for safe and effective anti-obesity strategies are urgently needed. Lactucin, a plant-derived natural small molecule, is known for anti-malaria and anti-hyperalgesia.

Upregulation of adamts9 by gonadotropin in preovulatory follicles of zebrafish.

Previously we had identified adamts9 as a downstream target of Pgr, which is essential for ovulation in zebrafish. The primary goal of this study is to determine whether human chorionic gonadotropin (hCG, LH analog) also regulate adamts9 expression prior to ovulation. The expression of adamts9 was induced by hCG in a dose and time dependent manner in zebrafish preovulatory follicles in vitro.

Androgen induces olfactory expression of prostaglandin E receptor Ep1 in the burrow-living fish Bostrychus sinensis.

It is well documented that androgens modify olfactory processing in vertebrates. In fish, several lines of evidence indicate that androgens increase olfactory sensitivity to prostaglandin pheromone, but the molecular mechanism is still unclear. Our previous studies showed that prostaglandin E (PGE) is a sex pheromone in the burrowing-living fish Chinese black sleeper (Bostrychus sinensis) and that the PGE receptor 1 (Ep1) in the olfactory rosette is a candidate receptor for sensing sex pheromone PGE.

Involvement of Membrane Progestin Receptor Beta (mPRβ/Paqr8) in Sex Pheromone Progestin-Induced Expression of Luteinizing Hormone in the Pituitary of Male Chinese Black Sleeper ().

Our previous studies showed that 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) acted as a sex pheromone to induce reproductive success in Chinese black sleeper (), but its functional mechanism remains unclear. In the present study, we cloned the cDNAs of the gonadotropin subunits (αβ, and β), and found that, in exposure to 5 nM DHP, transcript levels of β significantly increased in the pituitary at 6 h post exposure; plasma 11-KT levels increased at 24 h post exposure in mature male fish. In contrast, DHP exposure failed to increase the transcript levels of β in the pituitary of immature male fish, suggesting that the responsiveness to DHP depends on reproductive status.

Silver nanoparticles induce oocyte maturation in zebrafish (Danio rerio).

Public concern regarding silver nanoparticles (AgNPs) in the environment has been increasing since they can cause adverse effects in some aquatic species. However, few data are actually available on the effects of AgNPs on the germ cells. In the present study, we used the zebrafish ovarian follicle as a model to assess the potentially adverse effects of AgNPs on oocyte maturation (germinal vesicle breakdown, GVBD) in vitro.

Cloning and expression of two hepcidin genes in the mudskipper (Boleophthalmus pectinirostris) provides insights into their roles in male reproductive immunity.

The mudskipper Boleophthalmus pectinirostris is a burrow-dwelling fish inhabiting intertidal mudflats. During the spawning season, in a spawning chamber located at the center of their burrow, a pair of male and female fish mate and fertilized eggs adheres onto the inner walls and ceiling with filamentous attachments. During 5 days of incubation, the fertilized eggs are kept clean and hatch with a very high hatching rate under the natural conditions filled with microorganisms.

Progestin increases the expression of gonadotropins in pituitaries of male zebrafish.

Our previous study showed that the in vivo positive effects of 17α,20β-dihydroxy-4-pregnen-3-one (DHP), the major progestin in zebrafish, on early spermatogenesis was much stronger than the ex vivo ones, which may suggest an effect of DHP on the expression of gonadotropins. In our present study, we first observed that fshb and lhb mRNA levels in the pituitary of male adult zebrafish were greatly inhibited by 3 weeks exposure to 10nM estradiol (E2). However, an additional 24h 100nM DHP exposure not only reversed the E2-induced inhibition, but also significantly increased the expression of fshb and lhb mRNA.