Intraocular delivery of ZIF-90-RhB-GW2580 nanoparticles prevents the progression of photoreceptor degeneration.

Photoreceptor degeneration is one of the major causes of progressive blindness which lacks of curative treatment. GW2580, a highly selective inhibitor of colony-stimulating factor 1 receptor, has the protective potential on neurons; however, little was known about the application of GW2580 on photoreceptor degeneration. In this study, BV-2 and 661W cells coculture system was constructed to investigate the interaction between microglia and photoreceptors. GW2580 was loaded into zeolitic imidazolate framework-90-rhodamine B (ZIF-90-RhB) to synthesize a novel kind of nanoparticles, namely, ZIF-90-RhB-GW2580, through a one-step self-assembly approach. A photoreceptor degeneration model was generated by intense light exposure in zebrafish and ZIF-90-RhB-GW2580 nanoparticles were delivered by the intraocular injection. The results showed that in vitro GW2580 treatment promoted phenotypic transformation in microglia and led to the blockade of photoreceptor apoptosis. Following the intraocular delivery of ZIF-90-RhB-GW2580 nanoparticles, the microglial proliferation and inflammatory response were significantly inhibited; moreover, the photoreceptors underwent alleviated injury with a recovery of retinal structure and visual function. In conclusion, the intraocular injection of ZIF-90-RhB-GW2580 at the early stage enables the precise delivery and sustained release of the GW2580, thus preventing the progression of photoreceptor degeneration.

Knockout of zebrafish colony-stimulating factor 1 receptor by CRISPR/Cas9 affects metabolism and locomotion capacity.

Colony-stimulating factor 1 receptor (CSF1R) is a tyrosine kinase receptor and a key regulator of proliferation, differentiation, migration, and colonization in macrophage lineage cells. CSF1R was found to be involved in the pathogenesis of immune disorders, hematopoietic diseases, tissue damage, tumor growth and metastasis, and so on. Hence, understanding the role of CSF1R is important. CSF1R is highly conserved among vertebrates. In zebrafish, it is encoded by the colony-stimulating factor 1 receptor a (csf1ra) gene. In this study, a csf1ra-/- zebrafish mutant line was generated using clustered regularly interspaced short palindromic repeats (CRISPR)-associated 9 (CRISPR/Cas9) technology. csf1ra-/- larvae lacked the yellow cast on their heads and over their flanks, while adult mutants had poorly formed stripes. RNA-sequence analysis revealed that genes related to bile acid secretion, fat digestion and absorption, and pancreatic secretion were differentially expressed in csf1ra-/- mutants, which led to fatty changes in the liver. In addition, genes related to locomotion were also significantly changed, with the more active movement observed in csf1ra-/- larvae. Our study demonstrated that csf1ra participates in the metabolic process and behavior. This study provides new insights into csf1ra function during zebrafish development.

Tetrabromobisphenol a exacerbates the overall radioactive hazard to zebrafish (Danio rerio).

The major health risks of dual exposure to two hazardous factors of plastics and radioactive contamination are obscure. In the present study, we systematically evaluated the combinational toxic effects of tetrabromobisphenol A (TBBPA), one of the most influential plastic ingredients, mainly from electronic wastes, and γ-irradiation in zebrafish for the first time. TBBPA (0.25 µg/mL for embryos and larvae, 300 µg/L for adults) contamination aggravated the radiation (6 Gy for embryos and larvae, 20 Gy for adults)-induced early dysplasia and aberrant angiogenesis of embryos, further impaired the locomotor vitality of irradiated larvae, and worsened the radioactive multiorganic histologic injury, neurobehavioural disturbances and dysgenesis of zebrafish adults as well as the inter-generational neurotoxicity in offspring. TBBPA exaggerated the radiative toxic effects not only by enhancing the inflammatory and apoptotic response but also by further unbalancing the endocrine system and disrupting the underlying gene expression profiles. In conclusion, TBBPA exacerbates radiation-induced injury in zebrafish, including embryos, larvae, adults and even the next generation. Our findings provide new insights into the toxicology of TBBPA and γ-irradiation, shedding light on the severity of cocontamination of MP components and radioactive substances and thereby inspiring novel remediation and rehabilitation strategies for radiation-injured aqueous organisms and radiotherapy patients.

Fluorescent Imaging-Guided Chemo- and Photodynamic Therapy of Hepatocellular Carcinoma with HCPT@NMOFs-RGD Nanocomposites.

Background: Hepatocellular carcinoma (HCC), arising from hepatocytes, is the most common primary liver cancer. It is urgent to develop novel therapeutic approaches to improve the grim prognosis of advanced HCC. 10-hydroxycamptothecin (HCPT) has good antitumor activity in cells; however, its hydrophobicity limits its application in the chemotherapy of HCC. Recently, nanoscale porphyrin metal-organic frameworks have been used as drug carriers due to their low biotoxicity and photodynamic properties. Methods: Nanoscale zirconium porphyrin metal-organic frameworks (NMOFs) were coated with arginine-glycine-aspartic acid (RGD) peptide to prepare NMOFs-RGD first. The HepG2 cell line, zebrafish embryos and larvae were used to test the biotoxicity and fluorescence imaging capability of NMOFs-RGD both in vitro and in vivo. Then, NMOFs were used as the skeleton, HCPT was assembled into the pores of NMOFs, while RGD peptide was wrapped around to synthesize a novel kind of nanocomposites, HCPT@NMOFs-RGD. The tissue distribution and chemo- and photodynamic therapeutic effects of HCPT@NMOFs-RGD were evaluated in a doxycycline-induced zebrafish HCC model and xenograft mouse model. Results: NMOFs-RGD had low biotoxicity, good biocompatibility and excellent imaging capability. In HCC-bearing zebrafish, HCPT@NMOFs-RGD were specifically enriched in the tumor by binding specifically to integrin αvß3 and led to a reduction in tumor volume. Moreover, the xenografts in mice were eliminated remarkably following HCPT@NMOFs-RGD treatment with laser irradiation, while little morphological change was found in other main organs. Conclusion: The nanocomposites HCPT@NMOFs-RGD accomplish tumor targeting and play synergistic chemo- and photodynamic therapeutic effects on HCC, offering a novel imaging-guided drug delivery and theranostic platform.

The adenosine A (2A) receptor antagonist SCH58261 protects photoreceptors by inhibiting microglial activation and the inflammatory response.

Photoreceptor degeneration is a principal event in a variety of human retinal diseases. Progressive apoptosis of photoreceptors leads to impaired vision and blindness, for which there is no curative treatment. Adenosine 2A receptors (A2AR) are expressed in microglia. Blockade of A2AR has been shown to protect neurons via suppression of inflammation. However, the therapeutic effects of A2AR antagonists on photoreceptor degeneration have not been characterized. In this study, adult zebrafish were exposed to short term high-intensity light to induce photoreceptor death. SCH58261, a selective A2AR antagonist, was immediately injected into the vitreous body. Photoreceptor degeneration and microglia-induced inflammation were evaluated using immunohistochemistry, quantitative real-time polymerase chain reaction, polarization sensitive optical coherence tomography, and optomotor response. Co-culture of BV2 and 661W cells was used to investigate the interaction between microglia and photoreceptors. The results showed that A2AR was over-expressed during photoreceptor degeneration. Following intraocular SCH58261 injection, microglial activation and release of inflammatory factors were inhibited, and photoreceptor survival increased. Inactivation of microglia prevented apoptosis and autophagy in photoreceptors. Our results showed that SCH58261 intervention at the early stage of photoreceptor degeneration protected photoreceptors through inhibition of the inflammatory response, apoptosis, and autophagy.

Celecoxib Exerts a Therapeutic Effect Against Demyelination by Improving the Immune and Inflammatory Microenvironments.

BACKGROUND: The myelin sheath can be damaged by genetic and/or environmental factors, leading to demyelinating diseases, for which effective treatments are lacking. Recently, cyclooxygenase-2 (COX-2) overexpression was detected in demyelinating lesions both in patients and animal models, opening an avenue for promoting endogenous remyelination. The aim of this study was to investigate the therapeutic effect of celecoxib, a selective COX-2 inhibitor, against demyelination in a zebrafish model. METHODS: The biotoxicity of celecoxib was evaluated on zebrafish embryos. Metronidazole was used to deplete the oligodendrocytes in Tg (mbp:nfsB-egfp) transgenic fish. Celecoxib was then administered both in larvae and adults. The regeneration of the myelin sheath and the underlying mechanisms were explored by immunohistochemistry, flow cytometry, Western blot analysis, quantitative real-time polymerase chain reaction, and behavioral test. RESULTS: Celecoxib had low in vivo toxicity. A stable and practical demyelination model was established by metronidazole induction. Following celecoxib treatment, the number of oligodendrocytes was increased significantly and the concentric structure of the myelin sheath reappeared. The locomotor ability was notably improved and was close to its physiological levels. The expression of arg1, mrc1, il-10, and il-4 was upregulated, while that of il-1ß, il-12, tnf-α, il-6, caspase-3 and caspase-7 was downregulated. CONCLUSION: Inhibition of COX-2 contributed to the transformation of microglia/macrophages from the M1 to the M2 phenotype, improved the inflammatory microenvironment, and suppressed caspase-dependent apoptosis, thus exerting a therapeutic effect against demyelination.