Nano-carrier DMSN for effective multi-antigen vaccination against SARS-CoV-2.

The pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has had a profound impact on the global health and economy. While mass vaccination for herd immunity is effective, emerging SARS-CoV-2 variants can evade spike protein-based COVID-19 vaccines. In this study, we develop a new immunization strategy by utilizing a nanocarrier, dendritic mesoporous silica nanoparticle (DMSN), to deliver the receptor-binding domain (RBD) and conserved T-cell epitope peptides (DMSN-P-R), aiming to activate both humoral and cellular immune responses in the host. The synthesized DMSN had good uniformity and dispersion and showed a strong ability to load the RBD and peptide antigens, enhancing their uptake by antigen-presenting cells (APCs) and promoting antigen delivery to lymph nodes. The DMSN-P-R vaccine elicited potent humoral immunity, characterized by highly specific RBD antibodies. Neutralization tests demonstrated significant antibody-mediated neutralizing activity against live SARS-CoV-2. Crucially, the DMSN-P-R vaccine also induced robust T-cell responses that were specifically stimulated by the RBD and conserved T-cell epitope peptides of SARS-CoV-2. The DMSN demonstrated excellent biocompatibility and biosafety in vitro and in vivo, along with degradability. Our study introduces a promising vaccine strategy that utilizes nanocarriers to deliver a range of antigens, effectively enhancing both humoral and cellular immune responses to prevent virus transmission.

Fibroblast growth factor 1 ameliorates adipose tissue inflammation and systemic insulin resistance via enhancing adipocyte mTORC2/Rictor signal.

Obesity-induced activation and proliferation of resident macrophages and infiltration of circulating monocytes in adipose tissues contribute to adipose tissue inflammation and insulin resistance. These effects further promote the development of metabolic syndromes, such as type 2 diabetes, which is one of the most prevalent health conditions severely threatening human health worldwide. Our study examined the potential molecular mechanism employed by fibroblast growth factor 1 (FGF1) to improve insulin sensitivity. The leptin receptor-deficient obese mice (db/db) served as an insulin-resistant model. Our results demonstrated that FGF1-induced amelioration of insulin resistance in obese mice was related to the decreased levels of pro-inflammatory adipose tissue macrophages (ATMs) and plasma inflammatory factors. We found that FGF1 enhanced the adipocyte mTORC2/Rictor signalling pathway to inhibit C-C chemokine ligand 2 (CCL2) production, the major cause of circulating monocytes infiltration, activation and proliferation of resident macrophages in adipose tissues. Conversely, these alleviating effects of FGF1 were substantially abrogated in adipocytes with reduced expression of mTORC2/rictor. Furthermore, a model of adipocyte-specific mTORC2/Rictor-knockout (AdRiKO) obese mice was developed to further understand the in vitro result. Altogether, these results demonstrated adipocyte mTORC2/Rictor was a crucial target for FGF1 function on adipose tissue inflammation and insulin sensitivity.

Production of bioactive recombinant human myeloid-derived growth factor in Escherichia coli and its mechanism on vascular endothelial cell proliferation.

Myeloid-derived growth factor (MYDGF) is a novel protein secreted by bone marrow cells that features important physiological functions. In recent years, MYDGF has gained considerable interest due to their extensive beneficial effect on cardiac repair and protects cardiomyocytes from cell death. However, its precise molecular mechanisms have not been well elucidated. The purpose of this study was to produce sufficient amount of biologically active recombinant human (rh) MYDGF more economically and effectively by using in vitro molecular cloning techniques to study its clinical application. The prokaryotic expression system of Escherichia coli was established for the preparation of rhMYDGF. Finally, a large amount of high biologically active and purified form of recombinant protein was obtained. Moreover, we investigated the potential mechanism of rhMYDGF-mediated proliferation and survival in human coronary artery endothelial cells (HCAECs). Mechanistically, the results suggested that MAPK/STAT3 and the cyclin D1 signalling pathways are indispensable for rhMYDGF-mediated HCAEC proliferation and survival. Therefore, this study successfully established a preparation protocol for biologically active rhMYDGF and it may be a most economical way to produce high-quality active rhMYDGF for future clinical application.

Fibroblast growth factor 1 ameliorates diabetic nephropathy by an anti-inflammatory mechanism.

Inflammation plays a central role in the etiology of diabetic nephropathy, a global health issue. We observed a significant reduction in the renal expression of fibroblast growth factor 1, a known mitogen and insulin sensitizer, in patients with diabetic nephropathy and in mouse models implying that fibroblast growth factor 1 possesses beneficial anti-inflammatory and renoprotective activities in vivo. To test this possibility, we investigated the effects of chronic intraperitoneal administration of fibroblast growth factor 1 into both the streptozotocin-induced type 1 diabetes and db/db type 2 diabetes models. Indeed, recombinant fibroblast growth factor 1 significantly suppressed renal inflammation (i.e., cytokines, macrophage infiltration), glomerular and tubular damage, and renal dysfunction in both type 1 and type 2 diabetes mice. Fibroblast growth factor 1 was able to correct the elevated blood glucose levels in type 2 but not in type 1 diabetic mice, suggesting that the anti-inflammatory effect of fibroblast growth factor 1 was independent of its glucose-lowering activity. The mechanistic study demonstrated that fibroblast growth factor 1-mediated inhibition of the renal inflammation in vivo was accompanied by attenuation of the nuclear factor κB and c-Jun N-terminal kinase signaling pathways, further validated in vitro using cultured glomerular mesangial cells and podocytes. Thus, fibroblast growth factor 1 holds great promise for developing new treatments for diabetic nephropathy through countering inflammatory signaling cascades in injured renal tissue.

Potent long-acting rhFGF21 analog for treatment of diabetic nephropathy in db/db and DIO mice.

BACKGROUND: Fibroblast growth factor 21 (FGF21) is an endocrine-acting hormone that has the potential to treat diabetic nephropathy. However, development of FGF21 into a therapeutic has been hindered due to its low intrinsic bio-stability. In our previous study, we have developed a recombinant human FGF21 (rhFGF21) variant by site-directed mutagenesis and solid-phase PEGylation, which retained its biological function. The aim of this study is to elucidate whether the therapeutic effect of PEGylated rhFGF21 (PEG-rhFGF21) on diabetic nephropathy in DIO (diet induced obesity) mice is more significant than rhFGF21 in vivo. RESULTS: After administration with rhFGF21 and PEG-rhFGF21 for 2 months, biochemical data and histological examination showed that PEG-rhFGF21 significantly lowered lipid levels in the kidney, decreased urine albumin/creatinine ratio (ACR) and improved mesangial expansion, demonstrating that PEG-rhFGF21 was more efficacious in ameliorating functional and morphological abnormalities induced by diabetic nephropathy in db/db and DIO mice. CONCLUSIONS: Our findings suggest that PEG-rhFGF21 treatment is more effective in treating diabetic nephropathy than rhFGF21, through enhancements of systemic metabolic alterations and anti-inflammatory mechanisms. These findings help provide a theoretical basis to develop more long-acting and efficacious protein drugs for diabetic nephropathy.

Fgf21-Dubosiella axis mediates the protective effects of exercise against NAFLD development.

AIM: To explore the mechanism of gut microbiota mediates protective effects of exercise against non-alcoholic fatty liver disease (NAFLD) development. MAIN METHODS: The male C57BL/6 mice were fed with high fat food (HFD) or normal diet (CON) respectively, and the obese mice were randomly divided into sedentariness (HFD) and exercise groups (HFD + Exe). The total intervention period was 18 weeks. Antibiotic treatment and fecal microbiota transplantation were applied to evaluate gut microbiota mediates the protective effects of exercise against NAFLD development. 16S rDNA profiling of gut microbiota and extracorporeal rehydration of Dubosiella newyorkensis were performed to identify the crucial role of Dubosiella in NAFLD improvement during exercise training. FGF21 knock-out mice were used to reveal the potential mechanism of exercise increased the abundance of Dubosiella. RT-PCR, Western blot, Histopathological examinations and Biochemical testing were performed to evaluate the lipid deposition and function in the liver. KEY FINDINGS: Treadmill exercise significantly ameliorated hepatic function and mitigated lipid accumulation in NAFLD mice, and these hepatoprotective benefits were mostly mediated by the Dubosiella. In addition, the increased abundance of Dubosiella during exercise training was modulated by FGF21 specifically. SIGNIFICANCE: In short, Dubosiella, chiefly regulated by FGF21 signaling during exercise training, has been discovered to govern the protective impacts of exercising counter to the development of NAFLD and exhibits a promising treatment target for NAFLD.

Paracrine FGFs target skeletal muscle to exert potent anti-hyperglycemic effects.

Several members of the FGF family have been identified as potential regulators of glucose homeostasis. We previously reported that a low threshold of FGF-induced FGF receptor 1c (FGFR1c) dimerization and activity is sufficient to evoke a glucose lowering activity. We therefore reasoned that ligand identity may not matter, and that besides paracrine FGF1 and endocrine FGF21, other cognate paracrine FGFs of FGFR1c might possess such activity. Indeed, via a side-by-side testing of multiple cognate FGFs of FGFR1c in diabetic mice we identified the paracrine FGF4 as a potent anti-hyperglycemic FGF. Importantly, we found that like FGF1, the paracrine FGF4 is also more efficacious than endocrine FGF21 in lowering blood glucose. We show that paracrine FGF4 and FGF1 exert their superior glycemic control by targeting skeletal muscle, which expresses copious FGFR1c but lacks ß-klotho (KLB), an obligatory FGF21 co-receptor. Mechanistically, both FGF4 and FGF1 upregulate GLUT4 cell surface abundance in skeletal muscle in an AMPKα-dependent but insulin-independent manner. Chronic treatment with rFGF4 improves insulin resistance and suppresses adipose macrophage infiltration and inflammation. Notably, unlike FGF1 (a pan-FGFR ligand), FGF4, which has more restricted FGFR1c binding specificity, has no apparent effect on food intake. The potent anti-hyperglycemic and anti-inflammatory properties of FGF4 testify to its promising potential for use in the treatment of T2D and related metabolic disorders.

Global inventory of atmospheric fibrous microplastics input into the ocean: An implication from the indoor origin.

Atmospheric transport could be a significant pathway for inland microplastics (MPs, with size＜5 mm) to the ocean in addition to catchment runoff and coastal discharge. However, atmospheric input of MPs to the ocean is rarely quantified. To address this issue, transport of atmospheric MPs from source to sink was studied in the Asia-Pacific region during nine cruises from October 2018 to September 2019. Both deposited atmospheric MPs (DAMPs) and suspended atmospheric MPs (SAMPs) were collected, ranging from 23.04 n/(m2·d) to 67.54 n/(m2·d), and 0 to 1.37 n/m3, respectively. Size composition revealed that atmospheric deposition of MPs originating in terrestrial regions seems inadequate and insufficient to quantify the atmospheric input to the ocean. In addition, combined with aerodynamic modelling, for the first time, we estimated that 7.64-33.76 t of fibrous atmospheric MPs was globally generated in 2018, which is 3 % and 31 % of riverine input MPs of The Yangtze River and The Pearl River in terms of mid-point mass, respectively. The increasing load of ingestible plastics from sea air could have a far-reaching impact on marine ecosystem.

Paracrine-endocrine FGF chimeras as potent therapeutics for metabolic diseases.

BACKGROUND: The development of a clinically useful fibroblast growth factor 21 (FGF21) hormone has been impeded by its inherent instability and weak FGF receptor (FGFR) binding affinity. There is an urgent need for innovative approaches to overcome these limitations. METHODS: We devised a structure-based chimerisation strategy in which we substituted the thermally labile and low receptor affinity core of FGF21 with an HS binding deficient endocrinised core derived from a stable and high receptor affinity paracrine FGF1 (FGF1ΔHBS). The thermal stability, receptor binding ability, heparan sulfate and ßKlotho coreceptor dependency of the chimera were measured using a thermal shift assay, SPR, SEC-MALS and cell-based studies. The half-life, tissue distribution, glucose lowering activity and adipose tissue remodeling were analyzed in normal and diabetic mice and monkeys. FINDINGS: The melting temperature of the engineered chimera (FGF1ΔHBS-FGF21C-tail) increased by ∼22 °C relative to wild-type FGF21 (FGF21WT), and resulted in a ∼5-fold increase in half-life in vivo. The chimera also acquired an ability to bind the FGFR1c isoform - the principal receptor that mediates the metabolic actions of FGF21 - and consequently was dramatically more effective than FGF21WT in correcting hyperglycemia and in ameliorating insulin resistance in db/db mice. Our chimeric FGF21 also exerted a significant beneficial effect on glycemic control in spontaneous diabetic cynomolgus monkeys. INTERPRETATION: Our study describes a structure-based chimerisation approach that effectively mitigates both the intrinsically weak receptor binding affinities and short half-lives of endocrine FGFs, and advance the development of the FGF21 hormone into a potentially useful drug for Type 2 diabetes.

Uncoupling the Mitogenic and Metabolic Functions of FGF1 by Tuning FGF1-FGF Receptor Dimer Stability.

The recent discovery of metabolic roles for fibroblast growth factor 1 (FGF1) in glucose homeostasis has expanded the functions of this classically known mitogen. To dissect the molecular basis for this functional pleiotropy, we engineered an FGF1 partial agonist carrying triple mutations (FGF1ΔHBS) that diminished its ability to induce heparan sulfate (HS)-assisted FGF receptor (FGFR) dimerization and activation. FGF1ΔHBS exhibited a severely reduced proliferative potential, while preserving the full metabolic activity of wild-type FGF1 in vitro and in vivo. Hence, suboptimal FGFR activation by a weak FGF1-FGFR dimer is sufficient to evoke a metabolic response, whereas full FGFR activation by stable and sustained dimerization is required to elicit a mitogenic response. In addition to providing a physical basis for the diverse activities of FGF1, our findings will impact ongoing drug discoveries targeting FGF1 and related FGFs for the treatment of a variety of human diseases.