Novel Isoalantolactone-Based Derivatives as Potent NLRP3 Inflammasome Inhibitors: Design, Synthesis, and Biological Characterization.

The NLRP3 inflammasome has been recognized as a promising therapeutic target in drug discovery for inflammatory diseases. Our initial research identified a natural sesquiterpene isoalantolactone (IAL) as the active scaffold targeting NLRP3 inflammasome. To improve its activity and metabolic stability, a total of 64 IAL derivatives were designed and synthesized. Among them, compound 49 emerged as the optimal lead, displaying the most potent inhibitory efficacy on nigericin-induced IL-1ß release in THP-1 cells, with an IC50 value of 0.29 µM, approximately 27-fold more potent than that of IAL (IC50: 7.86 µM), and exhibiting higher metabolic stability. Importantly, 49 remarkably improved DSS-induced ulcerative colitis in vivo. Mechanistically, we demonstrated that 49 covalently bound to cysteine 279 in the NACHT domain of NLRP3, thereby inhibiting the assembly and activation of NLRP3 inflammasome. These results provided compelling evidence to further advance the development of more potent NLRP3 inhibitors based on this scaffold.

Identification of Eukaryotic Translation Initiation Factor 4B as a Novel Candidate Gene for Congenital Hypothyroidism.

CONTEXT: Congenital hypothyroidism (CH) is the most common endocrine disorder in neonates, but its etiology is still poorly understood. OBJECTIVE: We performed whole exome sequencing to identify novel causative gene for CH and functional studies to validate its role in the occurrence of CH. METHODS: Whole exome sequencing in 98 CH patients not harboring known CH candidate genes and bioinformatic analysis were performed. Functional analysis was performed using morpholino, a synthetic short antisense oligonucleotide that contains 25 DNA bases on a methylene morpholine backbone, in zebrafish and CRISPR‒Cas9-mediated gene knockout in mice. RESULTS: Eukaryotic translation initiation factor 4B (EIF4B) was identified as the most promising candidate gene. The EIF4B gene was inherited in an autosomal recessive model, and one patient with thyroid dysgenesis carried EIF4B biallelic variants (p.S430F/p.P328L). In zebrafish, the knockdown of eif4ba/b expression caused thyroid dysgenesis and growth retardation. Thyroid hormone levels were significantly decreased in morphants compared with controls. Thyroxine treatment in morphants partially rescued growth retardation. In mice, the homozygous conceptuses of Eif4b+/- parents did not survive. Eif4b knockout embryos showed severe growth retardation, including thyroid dysgenesis and embryonic lethality before E18.5. CONCLUSION: These experimental data supported a role for EIF4B function in the pathogenesis of the hypothyroid phenotype seen in CH patients. Our work indicated that EIF4B was identified as a novel candidate gene in CH. EIF4B is essential for animal survival, but further studies are needed to validate its role in the pathogenesis of CH.

Exploring the Immunomodulatory Properties of Red Onion (Allium cepa L.) Skin: Isolation, Structural Elucidation, and Bioactivity Study of Novel Onion Chalcones Targeting the A2A Adenosine Receptor.

Onions are versatile and nutritious food widely used in various cuisines around the world. In our ongoing pursuit of bioactive substances with health benefits from red onion (Allium cepa L.) skin, a comprehensive chemical investigation was undertaken. Consequently, a total of 44 compounds, including three previously unidentified chalcones (1-3) were extracted from red onion skin. Of these isolates, chalcones 1-4 showed high affinity to A2A adenosine receptor (A2AAR), and chalcone 2 displayed the best binding affinity to A2AAR, with the IC50 value of 33.5 nM, good A2AAR selectivity against A1AR, A2BAR, and A3AR, and high potency in the cAMP functional assay (IC50 of 913.9 nM). Importantly, the IL-2 bioassay and the cell-mediated cytotoxicity assay demonstrated that chalcone 2 could boost T-cell activation. Furthermore, the binding mechanism of chalcone 2 with hA2AAR was elucidated by molecular docking. This work highlighted that the active chalcones in red onion might have the potential to be developed as A2AAR antagonists used in cancer immunotherapy.

Genetic screening and functional analysis of TPO variants in Chinese patients with congenital hypothyroidism.

INTRODUCTION: Congenital hypothyroidism (CH), the most common neonatal endocrine disorder world-wide, can be caused by variants in the thyroid peroxidase (TPO) gene. This study aimed to identify TPO variants in Chinese patients with CH, analyze their impact on TPO function, and establish relationships between TPO genotypes and clinical characteristics. METHODS: A total of 328 patients with CH were screened for TPO variants by performing whole exome sequencing. The function of the detected TPO variants was investigated via transfection assays in vitro. The pathogenic effect of five novel variants was further assessed in silico. RESULTS: Among 328 patients with CH, 19 TPO variants, including six novel ones, were identified in 43 patients. Eighteen patients (5.5%) carried biallelic TPO variants. In vitro experiments showed that TPO activity was impaired to varying degrees in 17 variants. Furthermore, we determined that a residual TPO enzyme activity threshold of 15% may serve as a criterion for differentiating CH severity. CONCLUSIONS: According to our study, the prevalence of TPO variants among Chinese patients with CH was 13.1 %. Five novel variants led to impaired TPO function by altering its structure or by affecting its expression or cellular localization, which should result in impaired thyroid hormone synthesis.

Pathogenic variations in MAML2 and MAMLD1 contribute to congenital hypothyroidism due to dyshormonogenesis by regulating the Notch signalling pathway.

BACKGROUND: In several countries, thyroid dyshormonogenesis is more common than thyroid dysgenesis in patients with congenital hypothyroidism (CH). However, known pathogenic genes are limited to those directly involved in hormone biosynthesis. The aetiology and pathogenesis of thyroid dyshormonogenesis remain unknown in many patients. METHODS: To identify additional candidate pathogenetic genes, we performed next-generation sequencing in 538 patients with CH and then confirmed the functions of the identified genes in vitro using HEK293T and Nthy-ori 3.1 cells, and in vivo using zebrafish and mouse model organisms. RESULTS: We identified one pathogenic MAML2 variant and two pathogenic MAMLD1 variants that downregulated canonical Notch signalling in three patients with CH. Zebrafish and mice treated with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butylester, a γ-secretase inhibitor exhibited clinical manifestations of hypothyroidism and thyroid dyshormonogenesis. Through organoid culture of primary mouse thyroid cells and transcriptome sequencing, we demonstrated that Notch signalling within thyroid cells directly affects thyroid hormone biosynthesis rather than follicular formation. Additionally, these three variants blocked the expression of genes associated with thyroid hormone biosynthesis, which was restored by HES1 expression. The MAML2 variant exerted a dominant-negative effect on both the canonical pathway and thyroid hormone biosynthesis. MAMLD1 also regulated hormone biosynthesis through the expression of HES3, the target gene of the non-canonical pathway. CONCLUSIONS: This study identified three mastermind-like family gene variants in CH and revealed that both canonical and non-canonical Notch signalling affected thyroid hormone biosynthesis.

The isl2a transcription factor regulates pituitary development in zebrafish.

Background: ISL LIM homeobox 2, also known as insulin gene enhancer protein ISL-2 (ISL2), is a transcription factor gene that participates in a wide range of developmental events. However, the role of ISL2 in the hypothalamus-pituitary-thyroid axis is largely unknown. In the present study, we characterized the expression patterns of ISL2 and revealed its regulative role during embryogenesis using zebrafish. Methods: We used the CRISPR/Cas9 system to successfully establish homozygous ISL2-orthologue (isl2a and isl2b) knockout zebrafish. Moreover, we utilized these knockout zebrafish to analyze the pituitary and thyroid phenotypes in vivo. For further molecular characterization, in situ hybridization and immunofluorescence were performed. Results: The isl2a mutant zebrafish presented with thyroid hypoplasia, reduced whole-body levels of thyroid hormones, increased early mortality, gender imbalance, and morphological retardation during maturity. Additionally, thyrotropes, a pituitary cell type, was notably decreased during development. Importantly, the transcriptional levels of pituitary-thyroid axis hormones-encoding genes, such as tshba, cga, and tg, were significantly decreased in isl2a mutants. Finally, the thyroid dysplasia in isl2a mutant larvae may be attributed to a reduction in proliferation rather than changes in apoptosis. Conclusions: In summary, isl2a regulates the transcriptional levels of marker genes in hypothalamus-pituitary-thyroid axis, and isl2a knockout causing low thyroid hormone levels in zebrafish. Thus, isl2a identified by the present study, is a novel regulator for pituitary cell differentiation in zebrafish, resulting in thyroid gland hypoplasia and phenotypes of hypothyroidism.

An epigenetic modifier enhances the generation of anti-phytopathogenic compounds from the endophytic fungus Chaetomium globosporum of Euphorbia humifusa.

Endophytic fungi are striking resources rich in bioactive structures with agrochemical significance. In order to maximize the opportunity of search for bioactive compounds, chemical epigenetic manipulation was introduced to enhance the structural diversity of the fungal products, and an UPLC-ESIMS and bioassay-guided separation was used to detect novel bioactive metabolites. Consequently, four previously undescribed compounds including two cyclopentenones (globosporins A and B) and two monoterpenoid indole alkaloids (globosporines C and D), as well as three known compounds, were isolated from the endophytic fungus Chaetomium globosporum of Euphorbia humifusa by exposure to a DNA methyltransferase inhibitor 5-azacytidine. Their structures including the absolute configurations were elucidated by the analysis of NMR spectroscopic data, HRESIMS, and TD-DFT-ECD calculations. The indole alkaloids (globosporines C and D) showed antimicrobial activities against three phytopathogenic microbes (Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Pseudomonas syringae pv. lachrymans) with MICs in the range of 14-72 µg/mL. Mostly, globosporine D was proved to be potently anti-phytopathogenic against X. oryzae pv. oryzae in vitro and in vivo, which suggested that it has the potential to be developed as a candidate for the prevention of rice bacterial leaf blight. This work provides an efficient and environmentally friendly approach for expanding fungal products with agricultural importance.

The ethanolic extract of Artemisia anomala exerts anti-inflammatory effects via inhibition of NLRP3 inflammasome.

BACKGROUND: Artemisia anomala S. Moore (Compositae), known as "Nan-Liu-Ji-Nu" in traditional Chinese medicine (TCM), has been used to treat many inflammatory diseases, including enteritis, acute icteric hepatitis, rheumatism, toothache, tonsillitis, and chronic bronchitis, for centuries. Our preliminary studies have demonstrated that the ethanolic extract of A. anomala (EAA) might be with the potential of inhibiting the activation of the NLRP3 inflammasome. However, the anti-inflammatory activity of EAA based on NLRP3 inflammasome inhibition is still unclear. PURPOSE: This work aimed to elucidate the anti-inflammatory mechanism of EAA by inhibiting NLRP3 inflammasome activation. METHODS: Lipopolysaccharide (LPS)-primed bone marrow-derived macrophages (BMDMs) were used to evaluate the inhibitory effects on NLRP3 inflammasome activation. The level of IL-1ß was determined by ELISA. The expression levels of IL-1ß, caspase-1, NLRP3, and ASC were assayed using western blot analysis. ASC oligomerization and speck formation were detected by immunofluorescence microscopy. The measurements of intracellular chloride and potassium were conducted using N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) probe assay and inductively coupled plasma-optical emission spectrometry (ICP-OES), respectively. Mitochondrial reactive oxygen species (mtROS) were examined using the MitoSOX method. Acridine orange (AO) staining was used to detect the permeability of the lysosomal membrane. A DSS-induced ulcerative colitis model was established to evaluate the anti-inflammatory effects of EAA in vivo. Finally, high-performance liquid chromatography (HPLC) was employed to identify and quantify the major constituents of EAA. RESULTS: In BMDMs, EAA significantly inhibited the release of IL-1ß induced by LPS. The mechanistic study revealed that EAA inhibited NLRP3 inflammasome activation by blocking the oligomerization of ASC and suppressed the LPS-induced priming step. Furthermore, EAA protected lysosomes by inhibiting the TAK1-JNK pathway, thereby inhibiting the assembly of downstream NLRP3 inflammasome and the production of IL-1ß. In addition, EAA exerted potent protective effects in an ulcerative colitis model by decreasing the content of colonic IL-1ß and alleviating the process of ulcerative colitis. HPLC analysis identified eight main components of EAA, including isofraxidin (1), quercetin-7-O-ß-D-glucopyranoside (2), apigenin-7-O-ß-D-glucopyranoside (3), 7-methoxycoumarin (4), quercetin (5), luteolin (6), kaempferol (7), and eupatorin (8), Of these compounds, quercetin and kaempferol were found to be the most potent ingredients. CONCLUSION: These findings collectively reveal that EAA exerts anti-inflammatory effects by both suppressing the NLRP3 priming step and protecting lysosomes to inhibit NLRP3 inflammasome activation, suggesting that this traditional herbal medicine might be used to treat NLRP3-driven inflammatory diseases.

Tpo knockout in zebrafish partially recapitulates clinical manifestations of congenital hypothyroidism and reveals the involvement of TH in proper development of glucose homeostasis.

Congenital hypothyroidism (CH) is a highly prevalent but treatable neonatal endocrine disorder. Thyroid peroxidase (TPO) catalyzes key reactions in thyroid hormone (TH) synthesis. TPO mutations have been found to underlie approximately 5% of congenital hypothyroidism in Chinese patients with more severe phenotypes, the treatment of whom usually requires a higher dose of L-thyroxine. The Tpo gene of zebrafish has 66% homology with the human TPO gene, and synteny analysis has indicated that it is likely a human TPO ortholog. In this study, we generated a tpo-/- mutant zebrafish line through knockout of tpo with CRISPR/Cas9 and investigated the associated phenotypes. Tpo-/- mutant zebrafish displayed growth retardation; an increased number of thyroid follicular cells; and abnormal extrathyroidal phenotypes including pigmentation defects, erythema in the thoracic region, delayed scale development and failure of swim bladder secondary lobe formation. All these abnormal phenotypes were reversed by 30 nM thyroxine (T4) treatment starting at 1 month of age. Tpo-/- mutants also showed increased glucose levels during larval stages, and the increases were induced at least in part by increasing glucagon and decreasing insulin expression. Our work indicates that tpo-mutant zebrafish may serve as a human congenital hypothyroidism model for studying TPO- and TH-related disease mechanisms.

Gestational Leucylation Suppresses Embryonic T-Box Transcription Factor 5 Signal and Causes Congenital Heart Disease.

Dysregulated maternal nutrition, such as vitamin deficiencies and excessive levels of glucose and fatty acids, increases the risk for congenital heart disease (CHD) in the offspring. However, the association between maternal amino-acid levels and CHD is unclear. Here, it is shown that increased leucine levels in maternal plasma during the first trimester are associated with elevated CHD risk in the offspring. High levels of maternal leucine increase embryonic lysine-leucylation (K-Leu), which is catalyzed by leucyl-tRNA synthetase (LARS). LARS preferentially binds to and catalyzes K-Leu modification of lysine 339 within T-box transcription factor TBX5, whereas SIRT3 removes K-Leu from TBX5. Reversible leucylation retains TBX5 in the cytoplasm and inhibits its transcriptional activity. Increasing embryonic K-Leu levels in high-leucine-diet fed or Sirt3 knockout mice causes CHD in the offspring. Targeting K-Leu using the leucine analogue leucinol can inhibit LARS activity, reverse TBX5 K-Leu modification, and decrease the occurrence of CHD in high-leucine-diet fed mice. This study reveals that increased maternal leucine levels increases CHD risk in the offspring through inhibition of embryonic TBX5 signaling, indicating that leucylation exerts teratogenic effects during heart development and may be an intervening target of CHD.

Lymphocyte infiltration and thyrocyte destruction are driven by stromal and immune cell components in Hashimoto's thyroiditis.

Hashimoto's thyroiditis (HT) is the most common autoimmune disease characterized by lymphocytic infiltration and thyrocyte destruction. Dissection of the interaction between the thyroidal stromal microenvironment and the infiltrating immune cells might lead to a better understanding of HT pathogenesis. Here we show, using single-cell RNA-sequencing, that three thyroidal stromal cell subsets, ACKR1+ endothelial cells and CCL21+ myofibroblasts and CCL21+ fibroblasts, contribute to the thyroidal tissue microenvironment in HT. These cell types occupy distinct histological locations within the thyroid gland. Our experiments suggest that they might facilitate lymphocyte trafficking from the blood to thyroid tissues, and T cell zone CCL21+ fibroblasts may also promote the formation of tertiary lymphoid organs characteristic to HT. Our study also demonstrates the presence of inflammatory macrophages and dendritic cells expressing high levels of IL-1ß in the thyroid, which may contribute to thyrocyte destruction in HT patients. Our findings thus provide a deeper insight into the cellular interactions that might prompt the pathogenesis of HT.

Mutation Screening and Functional Study of SLC26A4 in Chinese Patients with Congenital Hypothyroidism

Objective: Defects in the human solute carrier family 26 member 4 (SLC26A4) gene are reported to be one of the causes of congenital hypothyroidism (CH). We aimed to identify SLC26A4 mutations in Chinese patients with CH and analyze the function of the mutations. Methods: Patients with primary CH were screened for 21 CH candidate genes mutations by targeted next-generation sequencing. All the exons and exon-intron boundaries of SLC26A4 were identified and analyzed. The function of six missense mutation in SLC26A4 were further investigated in vitro. Results: Among 273 patients with CH, seven distinct SLC26A4 heterozygous mutations (p.S49R, p.I363L, p.R409H, p.T485M, p.D661E, p.H723R, c.919-2A>G) were identified in 10 patients (3.66%, 10/273). In vitro experiments showed that mutation p.I363L, p.R409H, p.H723R affect the membrane location and ion transport of SLC26A4, while p.S49R did not. Mutation p.T485M and p.D661E only affected ion transport, but had no effect on the membrane location. Conclusion: The prevalence of SLC26A4 mutations was 3.66% in Chinese patients with CH. Five mutations (p.I363L, p.R409H, p.T485M, p.D661E and p.H723R) impaired the membrane location or ion transport function of SLC26A4, suggesting important roles for Ile363, Arg409, Thr485, Asp661, and His723 residues in SLC26A4 function. As all variants identified were heterozygous, the pathogenesis of these patients cannot be explained, and the pathogenesis of these patients needs further study.

The mutation screening in candidate genes related to thyroid dysgenesis by targeted next-generation sequencing panel in the Chinese congenital hypothyroidism.

OBJECTIVE: Congenital hypothyroidism (CH) is known to be due to thyroid dyshormonogenesis (DH), which is mostly inherited in an autosomal recessive inheritance pattern or thyroid dysgenesis (TD), whose inheritance pattern is controversial and whose molecular etiology remains poorly understood. DESIGN AND METHODS: The variants in 37 candidate genes of CH, including 25 genes related to TD, were screened by targeted exon sequencing in 205 Chinese patients whose CH cannot be explained by biallelic variants in genes related to DH. The inheritance pattern of the genes was analyzed in family trios or quartets. RESULTS: Of the 205 patients, 83 patients carried at least one variant in 19 genes related to TD, and 59 of those 83 patients harbored more than two variants in distinct candidate genes for CH. Biallelic or de novo variants in the genes related to TD in Chinese patients are rare. We also found nine probands carried only one heterozygous variant in the genes related to TD that were inherited from a euthyroid either paternal or maternal parent. These findings did not support the monogenic inheritance pattern of the genes related to TD in CH patients. Notably, in family trio or quartet analysis, of 36 patients carrying more than two variants in distinct genes, 24 patients carried these variants inherited from both their parents, which indicated that the oligogenic inheritance pattern of the genes related to TD should be considered in CH. CONCLUSIONS: Our study expanded the variant spectrum of the genes related to TD in Chinese CH patients. It is rare that CH in Chinese patients could be explained by monogenic germline variants in genes related to TD. The hypothesis of an oligogenic origin of the CH should be considered.

Correlation of DUOX2 residual enzymatic activity with phenotype in congenital hypothyroidism caused by biallelic DUOX2 defects.

DUOX2 is the most frequently mutated gene in patients with congenital hypothyroidism (CH) in China. However, no reliable genotype-phenotype relationship has been found in patients with DUOX2 mutations. In this study, DUOX2 mutations were screened in 266 CH patients, and the enzymatic activity of 89 DUOX2 variants was determined in vitro. Furthermore, the DUOX2 residual activity in 76 CH patients caused by DUOX2 biallelic mutations was calculated. The thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels were found to be higher and lower in patients with DUOX2 residual activity ≤22%, respectively, compared to patients with residual enzymatic activity >22%. Moreover, we interpreted the pathogenicity of DUOX2 variants by applying the ACMG classification criteria with or without PS3/BS3 evidence. The results indicated that residual DUOX2 enzymatic activity was closely related to the clinical phenotypes of CH patients caused by DUOX2 biallelic mutations. These findings suggest that the residual enzymatic activity of 22% may be a cutoff value for estimating the severity of hypothyroidism in CH patients with biallelic DUOX2 mutations. Well-established functional studies are useful and necessary to evaluate the pathogenicity of DUOX2 variants, improving the accuracy and scope of genetic consultations.

Upregulation of GBP1 in thyroid primordium is required for developmental thyroid morphogenesis.

PURPOSE: Congenital hypothyroidism (CH) is a common congenital endocrine disorder in humans. CH-related diseases such as athyreosis, thyroid ectopy, and hypoplasia are primarily caused by dysgenic thyroid development. However, the underlying molecular mechanisms remain unknown. METHODS: To identify novel CH candidate genes, 192 CH patients were enrolled, and target sequencing of 21 known CH-related genes was performed. The remaining 98 CH patients carrying no known genes were subjected to exome sequencing (ES). The functions of the identified variants were confirmed using thyroid epithelial cells in vitro and in zebrafish model organisms in vivo. RESULTS: Four pathogenic GBP1 variations from three patients were identified. In zebrafish embryos, gbp1 knockdown caused defective thyroid primordium morphogenesis and hypothyroidism. The thyroid cells were stuck together and failed to dissociate from each other to form individual follicles in gbp1-deficient embryos. Furthermore, defects were restored with wild-type human GBP1 (hGBP1) messenger RNA (mRNA) except for mutated hGBP1 (p.H150Y, p.L187P) overexpression. GBP1 promoted ß-catenin translocation into the cytosol and suppressed the formation of cellular adhesion complexes. Suppression of cell-cell adhesion restored the thyroid primordium growth defect observed in gbp1-deficient zebrafish embryos. CONCLUSION: This study provides further understanding regarding thyroid development and shows that defective cellular remodeling could cause congenital hypothyroidism.

Genetic Manipulation on Zebrafish duox Recapitulate the Clinical Manifestations of Congenital Hypothyroidism.

Congenital hypothyroidism (CH) is a highly prevalent but treatable neonatal endocrine disorder. Thyroid dyshormonogenesis is the main cause of congenital hypothyroidism in Chinese CH patients, and DUOX2 is the most frequent mutated gene involved in H2O2 production. In humans, the primary sources for H2O2 production are DUOX1 and DUOX2, while in zebrafish there is only a single orthologue for DUOX1 and DUOX2. In this study, duox mutant zebrafish were generated through knockdown duox by morpholino or knockout duox by CRISPR Cas9. The associated phenotypes were investigated and rescued by thyroxine (T4) treatment. Mutant zebrafish displayed hypothyroid phenotypes including growth retardation, goiter and, infertility. Homozygous mutants in adults also displayed extrathyroidal abnormal phenotypes, including lacking barbels, pigmentation defects, erythema in the opercular region, ragged fins, and delayed scales. All these abnormal phenotypes can be rescued by 10 nM T4 treatment. Strikingly, the fertility of zebrafish was dependent on thyroid hormone; T4 treatment should be continued and cannot be stopped over 2 weeks in hypothyroid zebrafish in order to achieve fertility. Thyroid hormones played a role in the developing and maturing of reproductive cells. Our work indicated that duox mutant zebrafish may provide a model for human congenital hypothyroidism.

Novel Compound Heterozygous Pathogenic Mutations of SLC5A5 in a Chinese Patient With Congenital Hypothyroidism.

Background and Objectives: Defects in the human sodium/iodide symporter (SLC5A5) gene have been reported to be one of the causes of congenital hypothyroidism (CH). We aimed to identify SLC5A5 mutations in Chinese patients with CH and to evaluate the function of the mutation. Methods: Two hundred and seventy-three patients with primary CH were screened for mutations in SLC5A5 using next-generation sequencing. We investigated the expression and cellular localization of the novel compound heterozygous mutation in SLC5A5. The functional activity of the mutants was further examined in vitro. Results: In 273 patients with CH, two previously undescribed pathogenic mutations p.Gly51AlafsTer45 (G51fs) and p.Gly421Arg (G421R) in a compound heterozygous state in SLC5A5 were identified in a pediatric patient. G51fs was located in the first intercellular loop connecting transmembrane segment I and II, whereas G421R was in the transmembrane segment (TMS) XI. G51fs and G421R resulted in a truncated NIS and reduced protein expression, respectively. In vitro experiments further showed that the normal function of iodine transport of sodium-iodide symporter (NIS) mutants was markedly impaired. Conclusion: The undescribed compound heterozygous mutation of SLC5A5 was discovered in a Chinese CH patient. The mutation led to significantly reduced NIS expression and impaired iodide transport function accompanied by the impaired location of the NIS on the plasma membrane. Our study thus provides further insights into the roles of SLC5A5 in CH pathogenesis.

Molecular and clinical genetics of the transcription factor GLIS3 in Chinese congenital hypothyroidism.

The transcription factor GLIS3 is an important factor in hormone biosynthesis and thyroid development, and mutations in GLIS3 are relatively rare. Deletions of more than one of the 11 exons of GLIS3 occur in most patients with various extrathyroidal abnormalities and congenital hypothyroidism (CH), and only 18 missense variants of GLIS3 related to thyroid disease have been reported. The aim of this study was to report the family history and molecular basis of patients with CH who carry GLIS3 variants. Three hundred and fifty-three non-consanguineous infants with CH were recruited and subjected to targeted exome sequencing of CH-related genes. The transcriptional activity and cellular localization of the variants in GLIS3 were investigated in vitro. We identified 20 heterozygous GLIS3 exonic missense variants, including eight novel sites, in 19 patients with CH. One patient carried compound heterozygous GLIS3 variants (p.His34Arg and p.Pro835Leu). None of the variants affected the nuclear localization. However, three variants (p.His34Arg, p.Pro835Leu, and p.Ser893Phe) located in the N-terminal and C-terminal regions of the GLIS3 protein downregulated the transcriptional activation of several genes required for thyroid hormone (TH) biosynthesis. This study of patients with CH extends the current knowledge surrounding the spectrum of GLIS3 variants and the mechanisms by which they cause TH biosynthesis defects.

Three-dimensional microscopy and image fusion reconstruction analysis of the thyroid gland during morphogenesis.

Thyroid dysgenesis (TD) is a major cause of primary congenital hypothyroidism; however, the molecular mechanism underlying this process is unclear. Current knowledge regarding the morphogenesis of the thyroid gland and vascular anomalies affecting thyroid development is limited. To monitor the early stages of thyroid gland development, we generated double transgenic zebrafish embryos Tg(tg:mCherry/flk1:EGFP). We described the volume of the thyroid from 2 days postfertilization (dpf) to 5 dpf using 3D reconstruction images. We treated zebrafish embryos with the fibroblast growth factor (FGF) inhibitor PD166866 to better understand the impact of vascular defects on thyroid development and the effects of drug administration at specific time periods on different stages of thyroid development. The 3D reconstruction data revealed that the thyroid glands underwent significant transformation at critical time points. PD166866 treatment from 48 to 72 hours postfertilization (hpf) and from 72 to 96 hpf did not cause obvious reductions in thyroid volume but did result in observable abnormalities in thyroid morphology. The treatment also affected thyroid volume from 36 to 48 hpf, thus indicating that there are time-point-specific effects of drug administration during thyroid development. Three-dimensional image reconstruction provides a comprehensive picture of thyroid anatomy and can be used to complement anatomical fluorescence information. The effects of an FGF pathway inhibitor on thyroid development were determined to be time-point-dependent.

Flavonoids with Inhibitory Effects on NLRP3 Inflammasome Activation from Millettia velutina.

Eight new flavonoids, including two ß-hydroxy/methoxychalcones, velutones A and B (1 and 2), two 1,3-diarylpropan-1-ols, velutols C and D (3 and 4), a dihydroxychalcone, velutone E (5), a chalcone, velutone F (6), a furanoflavanone, velutone G (7), and a furanoflavonol, velutone H (8), and 14 known compounds were isolated from Millettia velutina. Their structures were determined by high-resolution electrospray ionisation mass spectrometry (HR-ESIMS) and spectroscopic data analyses and time-dependent density functional theory electronic circular dichroism (TD-DFT-ECD) calculations. Among the isolated constituents, compound 6 exhibited the most potent inhibitory effect (IC50: 1.3 µM) against nigericin-induced IL-1ß release in THP-1 cells. The initial mechanism of action study revealed that compound 6 suppressed NLRP3 inflammasome activation via blocking ASC oligomerization without affecting the priming step, which subsequently inhibited caspase-1 activation and IL-1ß secretion. Most importantly, compound 6 exerted potent protective effects in the LPS-induced septic shock mice model by improving the survival rate of mice and suppressing serum IL-1ß release. These results demonstrated that compound 6 had the potential to be developed as a broad-spectrum NLRP3 inflammasome inhibitor for the treatment of NLRP3-related disease.