Hnrnpk protects against osteoarthritis through targeting WWC1 mRNA and inhibiting Hippo signaling pathway.

Osteoarthritis (OA) is an age-related or post-traumatic degenerative whole joint disease characterized by the rupture of articular cartilage homeostasis, the regulatory mechanisms of which remain elusive. This study identifies the essential role of heterogeneous nuclear ribonucleoprotein K (hnRNPK) in maintaining articular cartilage homeostasis. Hnrnpk expression is markedly downregulated in human and mice OA cartilage. The deletion of Hnrnpk effectively accelerates the development of post-traumatic and age-dependent OA in mice. Mechanistically, the KH1 and KH2 domain of Hnrnpk bind and degrade the mRNA of WWC1. Hnrnpk deletion increases WWC1 expression, which in turn leads to the activation of Hippo signaling and ultimately aggravates OA. In particular, intra-articular injection of LPA and adeno-associated virus serotype 5 expressing WWC1 RNA interference ameliorates cartilage degeneration induced by Hnrnpk deletion, and intra-articular injection of adeno-associated virus serotype 5 expressing Hnrnpk protects against OA. Collectively, this study reveals the critical roles of Hnrnpk in inhibiting OA development through WWC1-dependent downregulation of Hippo signaling in chondrocytes and defines a potential target for the prevention and treatment of OA.

The microbiome dynamics and interaction of endosymbiotic Symbiodiniaceae and fungi are associated with thermal bleaching susceptibility of coral holobionts.

The thermal bleaching percentage of coral holobionts shows interspecific differences under heat-stress conditions, which are closely related to the coral-associated microbiome. However, the ecological effects of community dynamics and interactions between Symbiodiniaceae and fungi on coral thermal bleaching susceptibility remain unclear. In this study, we analyzed the diversity, community structure, functions, and potential interaction of Symbiodiniaceae and fungi among 18 coral species from a high thermal bleaching risk atoll using next-generation sequencing. The results showed that heat-tolerant C3u sub-clade and Durusdinium dominated the Symbiodiniaceae community of corals and that there were no core amplicon sequence variants in the coral-associated fungal community. Fungal richness and the abundance of confirmed functional animal-plant pathogens were significantly positively correlated with the coral thermal bleaching percentage. Fungal indicators, including Didymellaceae, Chaetomiaceae, Schizophyllum, and Colletotrichum, were identified in corals. Each coral species had a complex Symbiodiniaceae-fungi interaction network (SFIN), which was driven by the dominant Symbiodiniaceae sub-clades. The SFINs of coral holobionts with low thermal bleaching susceptibility exhibited low complexity and high betweenness centrality. These results indicate that the extra heat tolerance of coral in Huangyan Island may be linked to the high abundance of heat-tolerant Symbiodiniaceae. Fungal communities have high interspecific flexibility, and the increase of fungal diversity and pathogen abundance was correlated with higher thermal bleaching susceptibility of corals. Moreover, fungal indicators were associated with the degrees of coral thermal bleaching susceptibility, including both high and intermediate levels. The topological properties of SFINs suggest that heat-tolerant coral have limited fungal parasitism and strong microbial network resilience.IMPORTANCEGlobal warming and enhanced marine heatwaves have led to a rapid decline in coral reef ecosystems worldwide. Several studies have focused on the impact of coral-associated microbiomes on thermal bleaching susceptibility in corals; however, the ecological functions and interactions between Symbiodiniaceae and fungi remain unclear. We investigated the microbiome dynamics and potential interactions of Symbiodiniaceae and fungi among 18 coral species in Huangyan Island. Our study found that the Symbiodiniaceae community of corals was mainly composed of heat-tolerant C3u sub-clade and Durusdinium. The increase in fungal diversity and pathogen abundance has close associations with higher coral thermal bleaching susceptibility. We first constructed an interaction network between Symbiodiniaceae and fungi in corals, which indicated that restricting fungal parasitism and strong interaction network resilience would promote heat acclimatization of corals. Accordingly, this study provides insights into the role of microorganisms and their interaction as drivers of interspecific differences in coral thermal bleaching.

Self-amplifying loop of NF-κB and periostin initiated by PIEZO1 accelerates mechano-induced senescence of nucleus pulposus cells and intervertebral disc degeneration.

Abnormal mechanical load is a main risk factor of intervertebral disc degeneration (IDD), and cellular senescence is a pathological change in IDD. In addition, extracellular matrix (ECM) stiffness promotes human nucleus pulposus cells (hNPCs) senescence. However, the molecular mechanism underlying mechano-induced cellular senescence and IDD progression is not yet fully elucidated. First, we demonstrated that mechano-stress promoted hNPCs senescence via NF-κB signaling. Subsequently, we identified periostin as the main mechano-responsive molecule in hNPCs through unbiased sequencing, which was transcriptionally upregulated by NF-κB p65; moreover, secreted periostin by senescent hNPCs further promoted senescence and upregulated the catabolic process in hNPCs through activating NF-κB, forming a positive loop. Both Postn (encoding periostin) knockdown via siRNA and periostin inactivation via neutralizing antibodies alleviated IDD and NPCs senescence. Furthermore, we found that mechano-stress initiated the positive feedback of NF-κB and periostin via PIEZO1. PIEZO1 activation by Yoda1 induced severe IDD in rat tails without compression, and Postn knockdown alleviated the Yoda1-induced IDD in vivo. Here, we reported for the first time that self-amplifying loop of NF-κB and periostin initiated via PIEZO1 under mechano-stress accelerated NPCs senescence, leading to IDD. Furthermore, periostin neutralizing antibodies, which may serve as potential therapeutic agents for IDD, interrupted this loop.

Description of Prasinibacter corallicola gen. nov., sp. nov., a zeaxanthin-producing bacterium isolated from stony coral Porites lutea.

Thermal stress is considered one of the main causes of mass scleractinian coral degradation; however, it is still unknown how corals can adapt to future global warming. In this study, 11 strains of coral-associated Flavobacteria were shown to produce zeaxanthin, a carotenoid antioxidant, which may help coral holobionts to alleviate thermal stress. In addition, a novel zeaxanthin-producing Flavobacterium, designated R38T, was identified using polyphasic taxonomy. Although strain R38T shared a maximum 16S rRNA gene sequence similarity of 93% with Mesoflavibacter aestuarii KYW614T, phylogenetic analyses based on whole genome and 16S rRNA gene sequences revealed that strain R38T forms a distinct branch in a robust cluster composed of strain R38T and Leptobacterium flavescens KCTC 22160T under the family Flavobacteriaceae. Strain R38T exhibited average nucleotide identities of 70.2% and 72.5% for M. aestuarii KYW614T and L. flavescens KCTC 22160T, respectively. The only detected respiratory quinone was menaquinone 6 (MK-6). The genomic DNA G + C content was 33.2 mol%. The major polar lipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, one unidentified ninhydrin phospholipid, three unidentified ninhydrin-positive lipids, and three unidentified lipids. The major cellular fatty acids were iso - C15: 0, iso - C15: 0 ω6c, C16:2 DMA, and C13:1 ω3c. The distinct biochemical, chemotaxonomic, phylogenetic, and phylogenomic differences from validly published taxa suggest that strain R38T represents a new species of a new genus, for which Prasinibacter corallicola gen. nov., sp. nov. is proposed. The type strain R38T (= MCCC 1K03889T = KCTC 72444T).

Keratin-Based Composite Bioactive Films and Their Preservative Effects on Cherry Tomato.

In this study, keratins were extracted from pig nail waste through the reduction method using L-cysteine as a reductant. Curcumin was successively incorporated in a mixed solution including keratin, gelatin, and glycerin to prepare different kinds of keratin/gelatin/glycerin/curcumin composite films. The morphology of the keratin/ gelatin/glycerin/curcumin composite films were examined using scanning electron microscopy. The structures and the molecular interactions between curcumin, keratin, and pectin were examined using Fourier transform infrared spectroscopy and X-ray diffraction, and the thermal properties were determined through thermogravimetric analysis. The tensile strengths of keratin/gelatin/glycerin/curcumin and keratin/gelatin/curcumin composite films are 13.73 and 12.45 MPa, respectively, and their respective elongations at break are 56.7% and 4.6%. In addition, compared with the control group (no film wrapped on the surface of tomato), the ratio of weight loss of the keratin (7.0%)/gelatin (10%)/glycerin (2.0%)/curcumin (1.0%) experimental groups is 8.76 ± 0.2%, and the hardness value of the tomatoes wrapped with composite films is 11.2 ± 0.39 kg/cm3. Finally, the composite films have a superior antibacterial effect against Staphylococcus aureus and Escherichia coli because of the addition of curcumin. As the concentration of curcumin reaches 1.0%, the antibacterial activity effect of the film is significantly improved. The diameter of the inhibition zone of E. coli is (12.16 ± 0.53) mm, and that of S. aureus is (14.532 ± 0.97) mm. The multifunctional keratin/gelatin/glycerin/curcumin bioactive films have great potential application in the food packaging industry.

Microbiome of juvenile corals in the outer reef slope and lagoon of the South China Sea: insight into coral acclimatization to extreme thermal environments.

Environmental conditions between the outer reef slope (ORS) and lagoon in tropical atolls are significantly different, but the variations of juvenile coral-microbiomes in the two environments and their relationship with coral thermal acclimatization are poorly understood. We explored this issue based on local water conditions and the microbiome of juvenile corals in the ORS and lagoon in the central South China Sea. Coral-symbiotic Symbiodiniaceae showed significant differences among coral species; Pocillopora verrucosa and Pachyseris rugosa in the ORS, and Acropora formosa in the lagoon were dominated by Durusdinium, but other corals were dominated by Cladocopium. Although A. formosa in the ORS were dominated by Cladocopium (C3u), they were dominated by Durusdinium (D1/D1a) and Cladocopium (C50) in the lagoon. Other coral species were both dominated by Cladocopium in the lagoon and ORS. The relative abundance of bacteria in the Deinococcus-Thermus was generally higher in the lagoon corals than in the ORS corals. Our study indicates that P. verrucosa, P. rugosa and Porites lutea may have high thermal tolerance based on the relatively high abundance of heat-tolerant Durusdinium and Thermus scotoductus. Likewise, A. formosa in the lagoon may acclimatize to the thermal environment based on a high relative abundance of heat-tolerant Durusdinium.

MET promotes the proliferation and differentiation of myoblasts.

The receptor tyrosine kinase MET plays a vital role in skeletal muscle development and in postnatal muscle regeneration. However, the effect of MET on myogenesis of myoblasts has not yet been fully understood. This study aimed to investigate the effects of MET on myogenesis in vivo and in vitro. Decreased myonuclei and down-regulated expression of myogenesis-related markers were observed in Met p.Y1232C mutant heterozygous mice. To explore the effects of MET on myoblast proliferation and differentiation, Met was overexpressed or interfered in C2C12 myoblast cells through the lentiviral transfection. The Met overexpression cells exhibited promotion in myoblast proliferation, while the Met deficiency cells showed impediment in proliferation. Moreover, myoblast differentiation was enhanced by the stable Met overexpression, but was impaired by Met deficiency. Furthermore, this study demonstrated that SU11274, an inhibitor of MET kinase activity, suppressed myoblast differentiation, suggesting that MET regulated the expression of myogenic regulatory factors (MRFs) and of desmin through the classical tyrosine kinase pathway. On the basis of the above findings, our work confirmed that MET promoted the proliferation and differentiation of myoblasts, deepening our understanding of the molecular mechanisms underlying muscle development.

Nanopore long-read RNAseq reveals regulatory mechanisms of thermally variable reef environments promoting heat tolerance of scleractinian coral Pocillopora damicornis.

Some scleractinian corals exhibit high thermal adaptability to climate changes, although the mechanism of their adaptation is unclear. This study investigated the adaptability of scleractinian coral Pocillopora damicornis to thermally variable reef environments by applying a nanopore-based RNA sequencing method to characterize different transcription responses that promote heat tolerance of P. damicornis. We identified 1414 novel genes and optimized 6256 mis-annotated loci. Based on full-length transcriptome data, we identified complex alternative polyadenylation and alternative splicing events, which can improve our understanding of the genome annotation and gene structures of P. damicornis. Furthermore, we constructed differentially expressed lncRNA-mRNA co-expression networks, which may play a crucial role in the P. damicornis thermal adaptive response. KEGG function enrichment analysis revealed that P. damicornis from the high-temperature pool had a lower metabolic rate than that from the low-temperature pool. We hypothesize that metabolic readjustment, in the form of a lower metabolic rate, positively correlated with increased heat tolerance in P. damicornis in thermally variable reef environments. Our study provides novel insights into lncRNAs that promote thermally tolerance of scleractinian corals in the thermally variable reef environment, suggesting potential mechanisms for their adaptation to global warming in the future.

A novel ZRS variant causes preaxial polydactyly type I by increased sonic hedgehog expression in the developing limb bud.

PURPOSE: Preaxial polydactyly (PPD) is a common congenital hand malformation classified into four subtypes (PPD I-IV). Variants in the zone of polarizing activity regulatory sequence (ZRS) within intron 5 of the LMBR1 gene are linked to most PPD types. However, the genes responsible for PPD I and the underlying mechanisms are unknown. METHODS: A rare large four-generation family with isolated PPD I was subjected to genome-wide genotyping and sequence analysis. In vitro and in vivo functional studies were performed in Caco-2 cells, 293T cells, and a knockin transgenic mouse model. RESULTS: A novel g.101779T>A (reference sequence: NG_009240.2; position 446 of the ZRS) variant segregates with all PPD I-affected individuals. The knockin mouse with this ZRS variant exhibited PPD I phenotype accompanying ectopic and excess expression of Shh. We confirmed that HnRNP K can bind the ZRS and SHH promoters. The ZRS mutant enhanced the binding affinity for HnRNP K and upregulated SHH expression. CONCLUSION: Our results identify the first PPD I disease-causing variant. The variant leading to PPD I may be associated with enhancing SHH expression mediated by HnRNP K. This study adds to the ZRS-associated syndromes classification system for PPD and clarifies the underlying molecular mechanisms.

Denitrobaculum tricleocarpae gen. nov., sp. nov., a marine bacterium from coralline algae Tricleocarpa sp.

A Gram-stain-negative, non-spore-forming, aerobic, motile, curved rod-shaped bacterium, designed strain R148T was isolated from a coralline algae Tricleocarpa sp. collected from Weizhou island, PR China. The optimal growth of R148T occurred at 25 °C, pH 8-9 in the presence of 0.5 % (w/v) NaCl on the basis of amended marine broth 2216. The genomic DNA G+C content was 59.5 mol%. The only detected respiratory quinone was Q-10. The major polar lipids were phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and three unidentified ninhydrin-positive lipids. The major cellular fatty acids were C18 : 1ω7c, C16 : 1ω7c, C19 : 0cyclo 9, 10 DMA and C18 : 0. The results of 16S rRNA gene-based global alignment indicated that the closest neighbour of strain R148T was Pelagibius litoralis DSM 21314T (93.1 % similarity), the second is Limibacillus halophilus KCTC 42420T (92.2 %). The results of phylogenetic analysis indicated that R148T forms a distinct branch in the robust clade of R148T and P. litoralis DSM 21314T, while the taxonomic position of this clade in the family Rhodospirillaceae is ambiguous among phylogenetic approaches. The low 16S rRNA gene similarity and distinct polar lipid and cellular fatty acid profile could readily distinguish R148T from closely related type strains. So R148T is suggested to represent a novel species in a novel genus, for which the name Denitrobaculum tricleocarpae gen. nov., sp. nov. is proposed. The type strain is R148T (=MCCC 1K03781T=KCTC 72137T).

Exilibacterium tricleocarpae gen. nov., sp. nov., a marine bacterium from coralline algae Tricleocarpa sp.

A Gram-stain-negative, non-spore-forming, aerobic, curved rod-shaped bacterium, designed strain R142T, was isolated from a coralline algae Tricleocarpa sp. in the Beibu Gulf, China. Optimal growth occurred with 0-0.5 % (w/v) NaCl, at 25 °C and at pH 8. Global alignment based on 16S rRNA gene sequences indicated that strain R142T shared 93.8 % similarity with its closest type strain, Pseudomaricurvus alkylphenolicus KU14GT. Phylogenetic analyses showed that strain R142T forms a distinct branch alongside Maricurvus nonylphenolicus KU41ET, Pseudoteredinibacter isoporae SW-11T, Pseudomaricurvus alkylphenolicus KU14GT, Pseudomaricurvus alcaniphilus MEBiC06469T and Aestuariicella hydrocarbonica SM-6T. The major polar lipids of strain R142T were phosphatidylethanolamine and phosphatidylglycerol. The primary cellular fatty acids were C16 : 0, C16 : 1ω7c, C18 : 1ω7c, C18 : 0 and C14 : 0. The genome DNA G+C ratio was 56.4 mol%. The only detected respiratory quinone was ubiquinone 8. The low 16S rRNA gene sequence similarity and differences in cellular fatty acids readily distinguished strain R142T from all validly published type strains. Strain R142T is therefore suggested to represent a novel species of a new genus, for which the name Exilibacterium tricleocarpae gen. nov., sp. nov. is proposed. The type strain of Exilibacterium tricleocarpae is R142T (=MCCC 1K03816T=KCTC 72138T).

Poritiphilus flavus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from coral Porites lutea.

A novel Gram-stain-negative, non-endospore-forming, non-motile, aerobic bacterium (strain R33T) was isolated from coral Porites lutea and subjected to a polyphasic taxonomic study. The G+C content was 44.5 mol%. The only detected respiratory quinone was menaquinone 6 (MK-6). The major cellular fatty acids were iso-C15 : 0 and iso-C15 : 1 ω6c. The major polar lipids were phosphatidylethanolamine and two unidentified lipids. Global alignment based on 16S rRNA gene sequences indicated that strain R33T shares the highest sequence identity of 93.2 % with Muriicola marianensis A6B8T in the family Flavobacteriaceae. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R33T forms a distinct branch in a stable clade comprising strain R33T and members of the genera Muriicola, Robiginitalea, Eudoraea and Zeaxanthinibacter. The phylogenomic analysis also supported this 16S rRNA gene-based phylogenetic result. Comparative genomic analysis indicated that strain R33T is rich in AraC-type DNA-binding domain-containing protein-coding genes, which means the regulation of carbon utilization is very complex. Low 16S rRNA gene identity, different polar lipids and/or cellular fatty acid profiles could readily distinguish strain R33T from any validly published type strains. Therefore, strain R33T is suggested to represent a new species in a new genus, for which the name Poritiphilus flavus gen. nov., sp. nov. is proposed. The type strain is R33T (=MCCC 1K03853T=KCTC 72443T).

An approach for assessing ecosystem-based adaptation in coral reefs at relatively high latitudes to climate change and human pressure.

Relatively high-latitude waters are supposed as a refuge for corals under ocean warming. A systematic assessment of the Weizhou Island reef in the northern South China Sea, a relatively high-latitude region, shows that the ecosystem restoration index decreased from 0.96 to 0.62 during the period between 1990 and 2015. Although the biotic community, supporting services, and regulating services remained at good or very good states, the provisioning services, cultural services, and especially habitat structure deteriorated to very poor or moderate states. Gray relational analysis showed that these ecological declines exhibited a strong relationship with human pressures from tourism activities and the petrochemical industry. The recoveries of the biotic community and supporting services that benefited from wintertime warming appeared to be partly offset by intensive human pressures. The long-term effects on ecosystem structure and functions suggest that anthropogenic disturbances have impaired the possibility of this area serving as a potential thermal refuge for reef-building corals in the South China Sea. This study thus provides an integrated approach for assessing the adaptive responses of coral reef ecosystems to climate change and local human activities.

Melatonin prevents bone destruction in mice with retinoic acid-induced osteoporosis.

BACKGROUND: The protective effect of melatonin against bone metabolism imbalance in osteoporosis (OP) induced by drugs such as retinoic acid (RA) is unclear. The aim of this study was to explore the role of melatonin in bone destruction based on a mouse model. METHODS: RA-induced OP model mice were established. To assess the effect of melatonin on these mice, micro-CT was used to characterize the trabecular structure of normal mice and those treated with RA (model), RA + low-dose melatonin (Mlt-L), RA + high-dose melatonin (Mlt-H), and RA + alendronate sodium (positive control). The shape of the trabecular bone, the length and diameter of the femoral head and the height and diameter of vertebra(L1) of each group were also measured and the number of osteoclasts was determined by Tartrate-resistant acid phosphatase (TRACP) staining. Meanwhile, the expression of alkaline phosphatase (ALP) was evaluated by immunohistochemistry assays. The differences between groups in terms of liver and kidney oxidation-related indexes and serum and urinary indicators related to bone metabolism were also analyzed. Furthermore, qRT-PCR and western blotting were used to evaluate the effect of melatonin on osteogenic and osteoclastic differentiation in MC3T3-E1 and RAW264.7 cells, respectively. RESULTS: RA induction led to a decrease in the amount and density of trabecular bone, a decrease in the length and diameter of the femur and height, diameter of the vertebra (L1), a decrease in bone mass and density and the expression of ALP, and an increase in the number of osteoclasts. Melatonin treatment alleviated these effects induced by RA, increasing the amount of trabecular bone in OP mice, improving the microstructure of the femur and vertebra(L1) and increasing bone mass bone density and the expression of ALP, as well as decreasing the number of osteoclasts. Additionally, blood and urinary bone metabolism-related indicators showed that melatonin promoted bone formation and inhibited bone resorption. Determination of oxidant and antioxidant biomarkers in the livers and kidneys of the mice revealed that melatonin promoted the antioxidant level and suppressed the level of oxidant molecules in these organs. In vitro, RA promoted osteoclasts and inhibit osteogenesis by increasing oxidative stress levels in the RAW264.7 and MC3T3-E1 cells, but melatonin reversed this effect. Melatonin may, therefore, play a role in the ERK/SMAD and NF-κB pathways. CONCLUSIONS: Melatonin can alleviate bone loss in RA-induced OP model mice, repair the trabecular microstructure, and promote bone formation. These effects may be related to reducing oxidation levels in vivo and vitro through the ERK/SMAD and NF-κB pathways.

MTNR1B loss promotes chordoma recurrence by abrogating melatonin-mediated ß-catenin signaling repression.

Chordoma is an extremely rare malignant bone tumor with a high rate of relapse. While cancer stem cells (CSCs) are closely associated with tumor recurrence, which depend on its capacity to self-renew and induce chemo-/radioresistance, whether and how CSCs participate in chordoma recurrence remains unclear. The current study found that tumor cells in recurrent chordoma displayed more dedifferentiated CSC-like properties than those in corresponding primary tumor tissues. Meanwhile, MTNR1B deletion along with melatonin receptor 1B (MTNR1B) down-regulation was observed in recurrent chordoma. Further investigation revealed that activation of Gαi2 by MTNR1B upon melatonin stimulation could inhibit SRC kinase activity via recruiting CSK and SRC, increasing SRC Y530 phosphorylation, and decreasing SRC Y419 phosphorylation. This subsequently suppressed ß-catenin signaling and stemness via decreasing ß-catenin p-Y86/Y333/Y654. However, MTNR1B loss in chordoma mediated increased CSC properties, chemoresistance, and tumor progression by releasing melatonin's repression of ß-catenin signaling. Clinically, MTNR1B deletion was found to correlate with patients' survival. Together, our study establishes a novel convergence between melatonin and ß-catenin signaling pathways and reveals the significance of this cross talk in chordoma recurrence. Besides, we propose that MTNR1B is a potential biomarker for prediction of chordoma prognosis and selection of treatment options, and chordoma patients might benefit from targeting MTNR1B/Gαi2/SRC/ß-catenin axis.

Mutant MAPK7-Induced Idiopathic Scoliosis is Linked to Impaired Osteogenesis.

BACKGROUND/AIMS: Three rare MAPK7 variants that predispose individuals to adolescent idiopathic scoliosis have previously been identified. However, the mechanism underlying the effects of the mutations remain unknown. METHODS: Human mesenchymal stem cells (hMSCs) were isolated from both patients and healthy volunteer donors, and MAPK7 expression was detected by western blotting and real-time quantitative PCR (RT-qPCR). Zebrafish embryos were injected with mapk7 morpholinos or co-injected with morpholinos and wild-type (WT) MAPK7 messenger RNA (mRNA) at the one-cell stage, followed by calcein staining to evaluate bone formation. hMSCs were transfected with MAPK7 small interfering RNAs and osteogenesis was induced for 14 days. Alizarin red staining was performed and osteoblast markers were detected by western blotting and RT-qPCR. Since RPS6KA3 is a downstream target of MAPK7 and plays an important role in the osteogenesis, zebrafish embryos were then injected with rps6ka3 morpholinos, or co-injected with rps6ka3 or mapk7 morpholinos and WT RPS6KA3 mRNA at the one-cell stage. RESULTS: MAPK7 expression in the patient group was much lower than in the control group. Morpholino-induced mapk7 knockdown in zebrafish embryos led to body curvature, which was significantly reversed by WT MAPK7 mRNA. Calcein staining revealed that mapk7-knockdown delayed the ossification of the vertebrae. MAPK7 silencing in hMSCs impaired osteogenesis and downregulated osteoblast marker expression. Morpholino-induced rps6ka3-knockdown in zebrafish embryos led to body curvature, which was reversed by WT RPS6KA3 mRNA. Interestingly, RPS6KA3 mRNA also partially reversed the phenotype induced by mapk7 morpholinos. CONCLUSION: Impaired osteogenesis is linked to mutant MAPK7-induced idiopathic scoliosis , and RPS6KA3 may play an important role in this process.

Dual novel mutations in SLC26A2 in two siblings with multiple epiphyseal dysplasia 4 from a Chinese family: a case report.

BACKGROUND: Multiple epiphyseal dysplasia (MED) is a heterogeneous genetic condition characterized by variable phenotypes, such as short stature (mild to moderate), joint deformities, abnormal gait, scoliosis, and brachydactyly. Recessive mutations in the SLC26A2 gene cause a phenotype of multiple epiphyseal dysplasia-4 (MED-4). In the present study, we identified novel compound heterozygous mutations in the SLC26A2 gene in a Chinese family with two affected sibs with MED-4. CASE PRESENTATION: Radiographs revealed hip dysplasia, brachydactyly and scoliosis in patient 1. Radiological examinations in patient 2 also showed hip dysplasia recently. Both of them were diagnosed with MED-4. SLC26A2 c.824 T > C and SLC26A2 c.1198C > T were identified in two siblings in this family, which were inherited from both parents, one mutation from each. CONCLUSIONS: This is the first Chinese MED-4 family attributed to SLC26A2 mutations, and these results show that these novel compound heterozygous mutations in SLC26A2 contribute to MED-4.

Metabolic and immune costs balance during natural acclimation of corals in fluctuating environments.

Epigenetic modifications based on DNA methylation can rapidly improve the potential of corals to adapt to environmental pressures by increasing their phenotypic plasticity, a factor important for scleractinian corals to adapt to future global warming. However, the extent to which corals develop similar adaptive mechanisms and their specific adaptation processes remain unclear. Here, to reveal the regulatory mechanism by which DNA methylation improves thermal tolerance in Pocillopora damicornis under fluctuating environments, we analyzed genome-wide DNA methylation signatures in P. damicornis and compared the differences in the methylation and transcriptional responses of P. damicornis from fluctuating and stable environments using whole-genome bisulfite sequencing and nanopore-based RNA sequencingtranscriptome sequencing. We discovered low methylation levels in P. damicornis (average methylation 4.14%), with CpG accounting for 74.88%, CHH for 13.27%, and CHG for 11.85% of this methylation. However, methylation levels did not change between coral samples from the fluctuating and stable environments. The varied methylation levels in different regions of the gene revealed that the overall methylation level of the gene body was relatively high and showed a bimodal methylation pattern. Methylation occurs primarily in exons rather than introns within the gene body In P. damicornis, there was only a weak correlation between methylation and transcriptional changes at the individual gene level, and the methylation and gene expression levels generally exhibited a bell-shaped relationship, which we speculate may be due to the specificity of cnidarian species. Correlation analysis between methylation levels and the transcriptome revealed that the highest proportion of the top 20 enriched KEGG pathways was related to immunity. Additionally, P. damicornis collected from a high-temperature pool had a lower metabolic rate than those collected from a low-temperature pool. We hypothesize that the dynamic balance of energy-expenditure costs between immunity and metabolism is an important strategy for increasing P. damicornis tolerance. The fluctuating environment of high-temperature pools may increase the heat tolerance in corals by increasing their immunity and thus lowering their metabolism.

Evolutionary radiation and microbial community dynamics shape the thermal tolerance of Fungiidae in the southern South China Sea.

Fungiidae have shown increased thermal adaptability in coral reef ecosystems under global warming. This study analyzes the evolutionary divergence and microbial communities of Fungiidae in the Sanjiao Reef of the southern South China Sea and explores the impact of coral evolution radiation and microbial dynamics on the heat tolerance of Fungiidae. The results found that Cycloseris was an ancient branch of Fungiidae, dating back approximately 147.8953 Mya, and Fungiidae differentiated into two ancestral clades (clades I and II) before 107.0312 Ma. Fungiidae exhibited specific symbioses with the Cladocopium C27 sub-clade. Notably, the Cladocopium C1 sub-clade has a high relative abundance in clade I, whereas the heat-tolerant Cladocopium C40 and C3u sub-clades subdominante in clade II. Regarding bacterial communities, Cycloseris costulata, the earliest divergent species, had higher bacterial ß-diversity, while the latest divergent species, Lithophyllon scabra, displayed lower bacterial α-diversity and higher community stability. Beneficial bacteria dominante Fungiidae's bacterial community (54%). The co-occurrence network revealed that microbial networks in clade II exhibited lower complexity and greater resilience than those in clade I. Our study highlights that host evolutionary radiation and microbial communities shaped Fungiidae's thermal tolerance. The variability in subdominant Symbiodiniaceae populations may contribute to interspecific differences in thermal tolerance along the evolutionary branches of Fungiidae. The presence of abundant beneficial bacteria may further enhance the thermal ability of the Fungiidae. Furthermore, the later divergent species of Fungiidae have stronger heat tolerance, possibly driven by the increased regulation ability of the host on the bacterial community, greater microbial community stability, and interaction network resistance.IMPORTANCECoral reefs are facing significant threats due to global warming. The heat tolerance of coral holobionts depends on both the coral host and its microbiome. However, the association between coral evolutionary radiation and interspecific differences in microbial communities remains unclear. In this study, we investigated the role of evolutionary radiation and microbial community dynamics in shaping the thermal acclimation potential of Fungiidae in the Sanjiao Reef of the southern South China Sea. The study's results suggest that evolutionary radiation enhances the thermal tolerance of Fungiidae. Fungiidae species that have diverged more recently have exhibited a higher presence of heat-tolerant Symbiodiniaceae taxa, more stable bacterial communities, and a robust and resilient microbial interaction network, improving the thermal adaptability of Fungiidae. In summary, this study provides new insights into the thermal adaptation patterns of corals under global warming conditions.