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A chemical investigation of the soft coral Lobophytum sp. and the sponge Xestospongia sp. from the South China Sea led to the isolation of five steroids, including two new compounds (1 and 4) and one known natural product (3). Compounds 1–3 were derived from the soft coral Lobophytum sp., while 4 and 5 were obtained from the sponge Xestospongia sp. The structures of these compounds were determined by extensive spectroscopic analysis, the time-dependent density functional theory–electronic circular dichroism (TDDFT-ECD) calculation method, and comparison with the spectral data previously reported in the literature. The antibacterial and anti-inflammatory activities of isolated compounds were evaluated in vitro. Compounds 1–3, 4, and 5 exhibited weak antibacterial activity against vancomycin-resistant Enterococcus faecium G1, Streptococcus parauberis KSP28, Photobacterium damselae FP2244, Lactococcus garvieae FP5245, and Pseudomonas aeruginosa ZJ028. Moreover, compound 3 showed significant anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells, with an IC50 value of 13.48 μM.

Background: Eurycomanone (EN) is a diterpenoid compound isolated from the roots of Eurycoma longifolia (E. longifolia). Previous studies have confirmed that E. longifolia can enhance bone regeneration and bone strength. We previously isolated and identified ten quassinoids from E. longifolia, and the result displayed that five aqueous extracts have the effects on promotion of bone formation, among whom EN showed the strongest activity. However, the molecular mechanism of EN on bone formation was unknown, and we further investigated in this study. Methods: After the verification of purity of extracted EN, following experiments were conducted. Firstly, the pharmacologic action of EN on normal bone mineralization and the therapeutic effect of EN on Dex-induced bone loss using zebrafish larvae. The mineralization area and integral optical density (IOD) were evaluated using alizarin red staining. Then the vital signaling pathways of EN relevant to OP was identified through network pharmacology analysis. Eventually in vitro, the effect of EN on cell viability, osteogenesis activities were investigated in human bone marrow mesenchymal stem cells (hMSCs) and C3H10 cells, and the molecular mechanisms by which applying AKT inhibitor A-443654 in hMSCs. Results: In zebrafish larvae, the administration in medium of EN (0.2, 1, and 5 μM) dramatically enhanced the skull mineralization area and integral optical density (IOD), and increased mRNA expressions of osteoblast formation genes (ALP, RUNX2a, SP7, OCN). Meanwhile, exposure of EN remarkably alleviated the inhibition of bone formation induced by dexamethasone (Dex), prominently improved the mineralization, up-regulated osteoblast-specific genes and down-regulated osteoclast-related genes (CTSK, RANKL, NFATc1, TRAF6) in Dex-treated bone loss zebrafish larvae. Network pharmacology outcomes showed the MAPK and PI3K-AKT signaling pathways are closely associated with 10 hub genes (especially AKT1), and AKT/GSK-3β/β-catenin was selected as the candidate analysis pathway. In hMSCs and C3H10 cells, results showed that EN at appropriate concentrations of 0.008–5 μM effectively increased the cell proliferation. In addition, EN (0.04, 0.2, and 1 μM) significantly stimulated osteogenic differentiation and mineralization as well as significantly increased the protein phosphorylation of AKT and GSK-3β, and expression of β-catenin, evidencing by the results of ALP and ARS staining, qPCR and western blotting. Whereas opposite results were presented in hMSCs when treated with AKT inhibitor A-443654, which effectively inhibited the pro-osteogenesis effect induced by EN, suggesting EN represent powerful potential in promoting osteogenesis of hMSCs, which may be closely related to the AKT/GSK-3β/β-catenin signaling pathway. Conclusions: Altogether, our findings indicate that EN possesses remarkable effect on bone formation via activating AKT/GSK-3β/β-catenin signaling pathway in most tested concentrations. The translational potential of this article: This study demonstrates EN is a new effective monomer in promoting bone formation, which may be a promising anabolic agent for osteoporosis (OP) treatment.

Background: Treacher Collins syndrome (TCS, MIM #154500), a severe congenital disorder, predominantly involves dysplasia of craniofacial bones and is characterized by features such as downslanting palpebral fissures, lower eyelid colobomas, microtia, and other craniofacial anomalies. Despite its clinical importance, the underlying pathogenic mutations in TCS remain largely uncharacterized, representing a critical knowledge gap for researchers in the field. Results: To address this, we performed mutation screening on a familial TCS case (trio) and 11 sporadic cases from a Chinese population. We identified 11 mutations predominantly localized to the central repeat domain (CRD) and the C-terminal domain (CTD, including the nuclear localization sequence) of TCOF1. The de novo frameshift mutation identified in the trio led to TCOF1 truncation, disrupting the central repeat domain crucial for binding transcriptional factors. Immunoprecipitation assays revealed that this pathogenic mutation attenuates the interaction between TCOF1 and transcription-related proteins, such as Pol II. Furthermore, cellular luciferase assays demonstrated that the mutation compromises the nuclear localization capability of TCOF1. Conclusions: Our findings establish TCOF1 as the primary pathogenic gene in this Chinese TCS cohort, with mutations predominantly in the CRD and CTD, thereby expanding the known mutation spectrum of TCS and informing its prevention strategies. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is crucial for plant growth and development. Exogenous dopamine has been shown to improve the N‐deficiency tolerance of apple. However, the potential regulatory mechanisms by which dopamine mitigates low‐N stress remain unclear. Our data indicated that the dopamine levels in apple (Malus domestica) were elevated by the overexpression (OE) of MdTYDC, which encodes tyrosine decarboxylase, a key enzyme in dopamine biosynthesis. The photosynthetic capacity of the OE lines was enhanced, and the root system was more extensive under low‐N stress compared with the wild‐type (WT) plants. This enhancement contributed to a greater net nitrate influx at the root surface in the OE lines compared with the WT. Transcriptomic and carbohydrate analyses suggested that the OE of MdTYDC in apple enhanced N‐deficiency tolerance by promoting the expression of carbohydrate‐related genes, which increased the content of soluble sugars and sorbitol. Both exogenous dopamine and MdTYDC OE activated the expression of MdORG2 (a bHLH transcription factor), which, in turn, directly binds to the promoter of MdTYDC, activating its expression, increasing dopamine levels, and consequently conferring strong low‐N tolerance in apple. Thus, this reveals the molecular pathways by which dopamine regulates low‐N tolerance in apple through pathways involving MdTYDC and MdORG2. Summary statement: MdTYDC‐mediated dopamine biosynthesis in apples enhanced low‐N tolerance. Furthermore, dopamine‐induced the expression of a bHLH transcription factor, MdORG2, which directly activated MdTYDC expression, leading to increased dopamine levels and thereby conferring enhanced N‐deficiency tolerance. [ABSTRACT FROM AUTHOR]

The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the process of bone remodeling. Excessive osteoclast differentiation plays a pivotal role in the pathogenesis of bone diseases such as rheumatoid arthritis and osteoporosis. In the present study, we examined whether 7,8-epoxy-11-sinulariolide acetate (Esa), a marine natural product present in soft coral Sinularia siaesensis, attenuates inflammation and osteoclastogenesis in vitro. The results indicated that Esa significantly inhibited lipopolysaccharide (LPS)-induced inflammation model of RAW264.7 cells and suppressed receptor activator for nuclear factor-κB ligand (RANKL)-triggered osteoclastogenesis. Esa significantly down-regulated the protein expression of iNOS, COX-2, and TNF-α by inhibiting the NF-κB/MAPK/PI3K pathways and reducing the release of reactive oxygen species (ROS) in RAW264.7 macrophages. Besides, Esa treatment significantly inhibited osteoclast differentiation and suppressed the expression of osteoclast-specific markers such as NFATC1, MMP-9, and CTSK proteins. These findings suggest that Esa may be a potential agent for the maintenance of bone homeostasis associated with inflammation.

Three new cembranoids (1–3) and a new casbanoid (4), along with three known analogues (5–7), have been isolated from the soft coral Sinularia nanolobata collected off Ximao Island. The structures, including the absolute configurations of new compounds, were established using extensive spectroscopic data analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations, and the comparison with spectroscopic data of known compounds. In the in vitro bioassay, compounds 1 and 5 exhibited moderate cytotoxic activities against human erythroleukemia (HEL) cell lines, with IC50 values of 37.1 and 42.4 μM, respectively.

Soil alkalization is an adverse factor limiting plant growth and yield. As a signaling molecule and secondary metabolite, γ‐aminobutyric acid (GABA) responds rapidly to alkaline stress and enhances the alkaline resistance of plants. However, the molecular mechanisms by which the GABA pathway adapts to alkaline stress remain unclear. In this study, a transcription factor, MdNAC104 is identified, from the transcriptome of the alkaline‐stressed roots of apple, which effectively reduces GABA levels and negatively regulates alkaline resistance. Nevertheless, applying exogenous GABA compensates the negative regulatory mechanism of overexpressed MdNAC104 on alkaline resistance. Further research confirms that MdNAC104 repressed the GABA biosynthetic gene MdGAD1/3 and the GABA transporter gene MdALMT13 by binding to their promoters. Here, MdGAD1/3 actively regulates alkaline resistance by increasing GABA synthesis, while MdALMT13 promotes GABA accumulation and efflux in roots, resulting in an improved resistance to alkaline stress. This subsequent assays reveal that MdSINA2 interacts with MdNAC104 and positively regulates root GABA content and alkaline resistance by ubiquitinating and degrading MdNAC104 via the 26S proteasome pathway. Thus, the study reveals the regulation of alkaline resistance and GABA homeostasis via the MdSINA2‐MdNAC104‐MdGAD1/3/MdALMT13 module in apple. These findings provide novel insight into the molecular mechanisms of alkaline resistance in plants. [ABSTRACT FROM AUTHOR]

SUMMARY: Water use efficiency (WUE) is crucial for apple tree fitness and survival, especially in response to climatic changes. The receptor‐like kinase FERONIA is reportedly an essential regulator of plant stress responses, but its role in regulating WUE under water deficit conditions is unclear. Here, we found that overexpressing the apple FERONIA receptor kinase gene, MdMRLK2, enhanced apple WUE under long‐term water deficit conditions. Under drought treatment, 35S::MdMRLK2 apple plants exhibited higher photosynthetic capacity and antioxidant enzyme activities than wild‐type (WT) plants. 35S::MdMRLK2 apple plants also showed increased biomass accumulation, root activity, and water potential compared to WT plants. Moreover, MdMRLK2 physically interacts with and phosphorylates cinnamoyl‐CoA reductase 1, MdCCR1, an enzyme essential for lignin synthesis, at position Ser260. This interaction likely contributed to increased vessel density, vascular cylinder area, and lignin content in 35S::MdMRLK2 apple plants under drought conditions. Therefore, our findings reveal a novel function of MdMRLK2 in regulating apple WUE under water deficit conditions. Significance Statement: The FERONIA receptor kinase MdMRLK2 positively regulates apple water deficit tolerance by phosphorylating an enzyme essential for lignin synthesis, MdCCR1, and enhancing water use efficiency. [ABSTRACT FROM AUTHOR]