Spexin2 Is a Novel Food Regulator in Gallus gallus.

Spexin2 (SPX2), a paralog of SPX1, is a newly identified gene in non-mammalian vertebrates. Limited studies in fish have evidenced its important role in food intake and energy balance modulation. However, little is known about its biological functions in birds. Using the chicken (c-) as a model, we cloned the full-length cDNA of SPX2 by using RACE-PCR. It is 1189 base pair (bp) in length and predicted to generate a protein of 75 amino acids that contains a 14 amino acids mature peptide. Tissue distribution analysis showed that cSPX2 transcripts were detected in a wide array of tissues, with abundant expression in the pituitary, testis, and adrenal gland. cSPX2 was also observed to be ubiquitously expressed in chicken brain regions, with the highest expression in the hypothalamus. Its expression was significantly upregulated in the hypothalamus after 24 or 36 h of food deprivation, and the feeding behavior of chicks was obviously suppressed after peripheral injection with cSPX2. Mechanistically, further studies evidenced that cSPX2 acts as a satiety factor via upregulating cocaine and amphetamine regulated transcript (CART) and downregulating agouti-related neuropeptide (AGRP) in hypothalamus. Using a pGL4-SRE-luciferase reporter system, cSPX2 was demonstrated to effectively activate a chicken galanin II type receptor (cGALR2), a cGALR2-like receptor (cGALR2L), and a galanin III type receptor (cGALR3), with the highest binding affinity for cGALR2L. Collectively, we firstly identified that cSPX2 serves as a novel appetite monitor in chicken. Our findings will help clarify the physiological functions of SPX2 in birds as well as its functional evolution in vertebrates.

A Bacteria-Inspired Morphology Genetic Biomedical Material: Self-Propelled Artificial Microbots for Metastatic Triple Negative Breast Cancer Treatment.

Morphology genetic biomedical materials (MGBMs), referring to fabricating materials by learning from the genetic morphologies and strategies of natural species, hold great potential for biomedical applications. Inspired by the cargo-carrying-bacterial therapy (microbots) for cancer treatment, a MGBM (artificial microbots, AMBs) was constructed. Rather than the inherent bacterial properties (cancerous chemotaxis, tumor invasion, cytotoxicity), AMBs also possessed ingenious nitric oxide (NO) generation strategy. Mimicking the bacterial construction, the hyaluronic acid (HA) polysaccharide was induced as a coating capsule of AMBs to achieve long circulation in blood and specific tissue preference (tumor tropism). Covered under the capsule-like polysaccharide was the combinatorial agent, the self-assembly constructed by the amphiphilic dendrons with abundant l-arginine residues peripherally (as endogenous NO donor) and hydrophobic chemotherapeutic drugs at the core stacking on the surface of SWNTs (the photothermal agent) for a robust chemo-photothermal therapy (chemo-PTT) and the elicited immune therapy. Subsequently, the classic inducible nitric oxide synthase (iNOS) pathway aroused by immune response was revolutionarily utilized to oxidize the l-arginine substrates for NO production, the process for which could also be promoted by the high reactive oxygen species level generated by chemo-PTT. The NO generated by AMBs was intended to regulate vasodilation and cause a dramatic invasion (as the microbots) to disperse the therapeutic agents throughout the solid tumor for a much more enhanced curative effect, which we defined as "self-propulsion". The self-propelled AMBs exhibiting impressive primary tumor ablation, as well as the distant metastasis regression to conquer the metastatic triple negative breast cancer, provided pioneering potential therapeutic opportunities, and enlightened broad prospects in biomedical application.

Bioinspired Artificial Tobacco Mosaic Virus with Combined Oncolytic Properties to Completely Destroy Multidrug-Resistant Cancer.

Although biomimetic virus-like strategies have been widely used in antitumor applications, construction of uniquely shaped virus-like agents and optimization of their specific morphological features to achieve diverse antitumor functions are worthwhile pursuits. Here, a novel strategy to construct an artificial tobacco mosaic virus (ATMV) that closely mimics the structure of the rod-like tobacco mosaic virus (TMV) is developed. The supramolecular array is self-assembled from small, repeated subunits of tailor-made capsid-mimicking dendrons onto RGD-modified single-walled carbon nanotube to construct the ATMVs with high structural stability. The ATMVs are tactfully designed with shielding, targeting, and arming approaches, including shielding the viruses against premature elimination, selectively targeting tumor tissue, and arming the viruses with oncolytic abilities. The elongated particles are concealed in blood until they arrived at a tumor site, then they induce robust composite oncolytic processes including cytomembrane penetration, endoplasmic reticulum disruption to cause Ca2+ release, chemotherapeutic delivery, and photothermal therapy. Excitingly, the ATMVs not only lyse primary infected cells, but permeate adjacent cells for secondary infection, spreading cell-to-cell and continuing to induce lysis even deep in solid tumors. This work inspires a uniquely shaped virus-like agent with tactically optimized oncolytic functions that completely defeated large drug-resistant colon tumor (LoVo/Adr, ≈500 mm3 ).