Molecular characterization of a new fish specific chemokine CXCL_F6 in large yellow croaker (Larimichthys crocea) and its role in inflammatory response.

Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in regulating cell migration and activation. Currently, five subgroups of fish specific CXC chemokines, named CXCL_F1-CXCL_F5, have been identified in teleost fish. However, understanding of the functions of these fish specific CXC chemokines is still limited. Here, a new member of fish specific CXC chemokines, LcCXCL_F6, was cloned from large yellow croaker Larimichthys crocea. Its open reading frame (ORF) is 369 nucleotides long, encoding a peptide of 122 amino acids (aa). The deduced LcCXCL_F6 protein contains a 19-aa signal peptide and a 103-aa mature polypeptide, which has four conserved cysteine residues (C28, C30, C56, and C72), as found in other known CXC chemokines. Phylogenetic analysis showed LcCXCL_F6 formed a separate clade with sequences from other fish species, tentatively named CXCL_F6, distinct from the clades formed by fish CXCL_F1-5 and mammalian CXC chemokines. The LcCXCL_F6 transcripts were constitutively expressed in all examined tissues and significantly up-regulated in the spleen and head kidney tissues by poly (I:C) and Vibrio alginolyticus. Its transcripts were also detected in primary head kidney leukocytes (HKLs), peripheral blood leucocytes (PBLs), and large yellow croaker head kidney (LYCK) cell line, and significantly up-regulated by poly(I:C), lipopolysaccharide (LPS), and peptidoglycan (PGN) in HKLs. Recombinant LcCXCL_F6 protein (rLcCXCL_F6) could not only chemotactically attract monocytes/macrophages and lymphocytes from PBLs, but also enhance NO release and expression of proinflammatory cytokines (TNF-α, IL-1ß, and CXCL8) in monocytes/macrophages. These results indicate that LcCXCL_F6 plays a role in mediating the inflammatory response.

Molecular characterization and functional activity of CXCL8_L3 in large yellow croaker Larimichthys crocea.

CXCL8, also called interleukin-8, is a typical CXC chemokine that plays a key role in promoting inflammation. Phylogenetically, fish CXCL8 chemokines can be divided into three subgroups, CXCL8_L1, CXCL8_L2, and CXCL8_L3, of which CXCL8_L3 is a new subgroup. The CXCL8_L3 gene sequences have been reported in many fish species, but their function remains unknown. Here, a CXCL8_L3 (LycCXCL8_L3) gene was cloned from large yellow croaker Larimichthys crocea. Its open reading frame (ORF) was 309 nucleotides long, encoding a peptide of 102 amino acids. The deduced LycCXCL8_L3 protein contains an 18-aa signal peptide and an 84-aa mature polypeptide, which has four conserved cysteine residues (C30, C32, C57, and C73) as found in other known CXCL8 chemokines. Phylogenetic analysis showed LycCXCL8_L3 formed a major clade with CXCL8_L3 sequences from other fish species. The LycCXCL8_L3 transcript was constitutively expressed in all examined tissues and significantly up-regulated in the spleen and head kidney tissues by inactivated trivalent bacterial vaccine. The LycCXCL8_L3 transcript was also detected in peripheral blood leukocytes (PBLs), primary head kidney macrophages (PKM), and large yellow croaker head kidney cell line (LYCK), with the highest levels in PKM. Recombinant LycCXCL8_L3 (rLycCXCL8_L3) protein could not only chemotactically attract lymphocytes and eosinophils in PBLs, but also enhance the respiratory burst activity of PKM. These results indicate that LycCXCL8_L3 may play an important role in the inflammatory response of large yellow croaker. To our knowledge, this is the first report on functional study of the CXCL8_L3 in fish.

Identification of a fish specific chemokine CXCL_F2 in large yellow croaker (Larimichthys crocea) reveals its primitive chemotactic function.

Chemokines are a superfamily of cytokines regulating immune cell migration under both inflammatory and normal physiological conditions. Currently, a number of fish specific CXC chemokines, named as CXCL_F1-5, have been identified in several species. However, understanding of their functional characteristics is still limited. In this study, we identified a fish specific chemokine CXCL_F2 (LycCXCL_F2) from large yellow croaker (Larimichthys crocea). The open reading frame (ORF) of LycCXCL_F2 is 348 nucleotides long, encoding a protein of 115 amino acids (aa). The deduced LycCXCL_F2 protein contains a 20-aa signal peptide and a 95-aa mature polypeptide. Phylogenetic analysis showed that LycCXCL_F2 fell into a major clade formed by CXCL_F2 sequences and was separated from CXCL_F1 and CXCL_F3-5 subgroups. LycCXCL_F2 mRNA transcript was constitutively expressed in various tissues, with the highest levels in spleen and head kidney. After stimulation with inactivated trivalent bacterial vaccines, LycCXCL_F2 mRNA transcription was significantly increased in both spleen and head kidney. Moreover, recombinant LycCXCL_F2 protein exhibited obvious chemotaxis to monocytes, lymphocytes and eosnophils of PBLs isolated from large yellow croaker, but could not induce the respiratory burst of macrophages. These results indicate that this fish specific CXC chemokine LycCXCL_F2 possesses primitive chemotactic activity and may play a role in immune response in large yellow croaker.

Synthesis, structure, photophysical property, stability of tetraphenylethylene-based boranil, and applications in cell imaging.

A new family of tetraphenylethylene-based N,O-chelated boranil complexes (TPE-BAs) with aggregation-induced emission (AIE) characteristics were developed. X-ray crystallographic analysis indicated that the terminal substituents on the aniline moiety significantly affected the intermolecular stacking mode, thereby influencing the photophysical properties. The stabilities of these compounds are closely related to the substituents on the aniline moiety. Electron-donor-substituted TPE-BA-OMe exhibited the best stability, whereas the electron-acceptor-substituted compounds exhibited poor stability. Benefitting from its AIE properties and suitable lipophilicity, TPE-BA-OMe served as an excellent fluorescent probe for the specific bioimaging of lipid droplets in living cells.

Exome sequencing-aided precise diagnosis of four families with type I Stickler syndrome.

BACKGROUND: Stickler syndrome is a multisystemic disorder characterized by ophthalmological and non-ophthalmological abnormalities, frequently misdiagnosed due to high clinical heterogeneity. Stickler syndrome type I (STL1) is predominantly caused by mutations in the COL2A1 gene. METHODS: Exome sequencing and co-segregation analysis were utilized to scrutinize 35 families with high myopia, and pathogenic mutations were identified. Mutant COL2A1 was overexpressed in cells for mechanistic study. A retrospective genotype-phenotype correlation analysis was further conducted. RESULTS: Two novel pathogenic mutations (c.2895+1G>C and c.3505G>A (p.Val1169Ile)) and two reported mutations (c.1597C>T (p.Arg533*) and c.1693C>T (p.Arg565Cys)) in COL2A1 were identified causing STL1. These mutations are all in the G-X-Y triplet, and c.2895+1G>C contributed to aberrant RNA splicing. COL2A1 mutants tended to form large aggregates in the endoplasmic reticulum (ER) and elevated ER stress. Additionally, mutations c.550G>A (p.Ala184Thr) and c.2806G>A (p.Gly936Ser) in COL2A1 were found in high myopia families, but were likely benign, although c.2806G>A (p.Gly936Ser) is on G-X-Y triplet. Moreover, genotype-phenotype correlation analysis revealed that mutations in exon 2 mainly contribute to retinal detachment, whereas mutations in the collagen alpha-1 chain region of COL2A1 tend to cause non-ophthalmologic symptoms. CONCLUSION: This study broadens the COL2A1 gene mutation spectrum, provides evidence for ER stress caused by pathogenic COL2A1 mutations and highlights the importance of non-ophthalmological examination in clinical diagnosis of high myopia.

Synthesis, Structures, and Photophysical Properties of Zigzag BNBNB-Embedded Anthracene-Fused Fluoranthene.

Three zigzag BNBNB-embedded anthracene-fused fluoranthenes are synthesized from 1,3,2-benzodiazaboroles through an indole-type N-directed C-H borylation reaction. Single-crystal X-ray diffraction analyses confirm the double bond character of all four alternating B-N bonds and reveal the five-center four-π-electron nature of the BNBNB group. Experimental spectra and density functional theory calculations indicate that borylation remarkably enhances the planarity, extends π-conjugation, and leads to a bathochromic shift in the absorption and emission bands, with remarkable fluorescence quantum yields in solution (92%).

Synthesis, Structure, and Photophysical Properties of BN-Embedded Analogue of Coronene.

Two BN-embedded benzo[ghi]perylene (Bzp) and coronene derivatives (BN-Bzp and BN-Cor) have been successfully synthesized from binaphthyl precursors by new efficient one-pot-multibond routes, and their single crystal structures were analyzed. Both experimental spectra and DFT theoretical calculations indicated that the absorption and emission of these BN-embedded polycyclic aromatic hydrocarbons are significantly enhanced comparing with those of their all carbon analogues. Especially, the fluorescence quantum yield of BN-Cor is nearly 20 times higher than that of ordinary coronene.

Mutation pattern and genotype-phenotype correlations of SETD2 in neurodevelopmental disorders.

SETD2 encodes an important protein for epigenetic modification of histones which plays an essential role in early development. Variants in SETD2 have been reported in neurodevelopmental disorders including autism spectrum disorder (ASD). However, most de novo SETD2 variants were reported in different large-cohort sequencing studies, mutation pattern and comprehensive genotype-phenotype correlations for SETD2 are still lacking. We have applied target sequencing to identify rare, clinical-relevant SETD2 variants and detected two novel de novo SETD2 variants, including a de novo splicing variant (NM_014159: c.4715+1G>A) and a de novo missense variant (c.3185C>T: p.P1062L) in two individuals with a diagnosis of ASD. To analyze the correlations between SETD2 mutations and corresponding phenotypes, we systematically review the reported individuals with de novo SETD2 variants, classify the pathogenicity, and analyze the detailed phenotypes. We subsequently manually curate 17 SETD2 de novo variants in 17 individuals from published literature. Individuals with de novo SETD2 variants present common phenotypes including speech and motor delay, intellectual disability, macrocephaly, ASD, overgrowth and recurrent otitis media. Our study reveals new SETD2 mutations and provided a relatively homozygous phenotype spectrum of SETD2-related neurodevelopmental disorders which will be beneficial for disease classification and diagnosis in clinical practice.

A trypsin inhibitor-like protein secreted by Cotesia vestalis teratocytes inhibits hemolymph prophenoloxidase activation of Plutella xylostella.

To establish successful infections, endoparasitoid wasps must develop strategies to evade immune responses of the host. Here, we identified and characterized a teratocytes-expressed gene encoding a trypsin inhibitor-like protein containing a cysteine-rich domain from Cotesia vestalis, CvT-TIL. CvT-TIL had a high expression level during the later developmental stage of teratocytes and was secreted into host hemolymph. Further experiments showed CvT-TIL strongly suppressed the prophenoloxidase activation of host hemolymph in a dose-dependent manner by interacting with PxPAP3 of PO cascade. Our results not only provide evidence for an inhibition between CvT-TIL gene and the host's melanization activity, but also expand our knowledge about the mechanisms by which parasitoids regulate humoral immunity of the host.