Enhancing osteoporosis treatment using a targeted, sustained-release drug delivery system based on macrocyclic amphiphile.

Osteoporosis, a prevalent systemic bone metabolic disorder, primarily affects postmenopausal women and is characterized by increased bone fragility and a heightened risk of fractures. The efficacy of current osteoporosis treatments is often limited by non-specific drug targeting and undesirable off-target skeletal side effects. To address this challenge, we have developed a novel hydroxyapatite-responsive drug delivery system. This system utilizes a self-assembled p-phosphonatocalix[4]arene tetradodecyl ether (PC4A12C), engineered to specifically target and sustain the release of osteoporosis medication at sites of bone remodeling. Our focus centers on icariin (ICA), a drug known for its potent osteogenic properties and minimal adverse effects. In vitro, ICA-loaded PC4A12C (ICA@PC4A12C) demonstrated enhanced proliferation, differentiation, and mineralization in bone marrow mesenchymal stem cells (BMSCs). In vivo, ICA@PC4A12C exhibited superior efficacy in specifically targeting bone tissue, ensuring a controlled and slow release of icariin directly within the bone environment. In an osteoporosis mouse model, treatment with ICA@PC4A12C showed notable enhancement in osteogenic activity and a significant increase in bone density compared to ICA alone. These results demonstrate the potential of PC4A12C as an effective drug carrier in the development of advanced antiosteoporotic drug delivery systems.

Early statin exposure influences cardiac and skeletal development with implications for ion channel transcriptomes in zebrafish.

Statins, widely prescribed for cholesterol management by inhibiting HMG-CoA reductase in the cholesterol biosynthesis pathway, may also influence vertebrate development. In this study, we investigated the developmental effects of two widely used statins, atorvastatin (ATO) and pravastatin (PRA), on zebrafish offspring. For ATO, we administered doses classified as low (1 µM), medium (5 µM), and high (10 µM), while for PRA, the corresponding concentrations were set at low (18 µM), medium (180 µM), and high (270 µM). Our results showed significant reductions in birth and hatching rates, along with decreased body length in offspring at all ATO concentrations and medium to high PRA concentrations. A notable increase in malformation rates, especially in the spine and heart, was observed across all ATO treatments and in medium and high PRA groups. Additionally, we observed reduced heart contraction rates, decreased heart size, lower bone volumes, and diminished expression of mRNA osteogenic markers. Elevated venous sinus-artery bulb (SV-BA) ratios, increased thoracic area, and abnormal cartilage development were also prominent in all ATO-treated groups. Transcriptome analysis revealed alterations in genes predominantly associated with ion channels. These findings provide insights into the potential impacts of specific concentrations of statins on offspring development and highlight potential gene interactions with statins.

Deficiency of Acetyltransferase nat10 in Zebrafish Causes Developmental Defects in the Visual Function.

Purpose: N4-acetylcytidine (ac4C) is a post-transcriptional RNA modification catalyzed by N-acetyltransferase 10 (NAT10), a critical factor known to influence mRNA stability. However, the role of ac4C in visual development remains unexplored. Methods: Analysis of public datasets and immunohistochemical staining were conducted to assess the expression pattern of nat10 in zebrafish. We used CRISPR/Cas9 and RNAi technologies to knockout (KO) and knockdown (KD) nat10, the zebrafish ortholog of human NAT10, and evaluated its effects on early development. To assess the impact of nat10 knockdown on visual function, we performed comprehensive histological evaluations and behavioral analyses. Transcriptome profiling and real-time (RT)-PCR were utilized to detect alterations in gene expression resulting from the nat10 knockdown. Dot-blot and RNA immunoprecipitation (RIP)-PCR analyses were conducted to verify changes in ac4C levels in both total RNA and opsin mRNA specifically. Additionally, we used the actinomycin D assay to examine the stability of opsin mRNA following the nat10 KD. Results: Our study found that the zebrafish NAT10 protein shares similar structural properties with its human counterpart. We observed that the nat10 gene was prominently expressed in the visual system during early zebrafish development. A deficiency of nat10 in zebrafish embryos resulted in increased mortality and developmental abnormalities. Behavioral and histological assessments indicated significant vision impairment in nat10 KD zebrafish. Transcriptomic analysis and RT-PCR identified substantial downregulation of retinal transcripts related to phototransduction, light response, photoreceptors, and visual perception in the nat10 KD group. Dot-blot and RIP-PCR analyses confirmed a pronounced reduction in ac4C levels in both total RNA and specifically in opsin messenger RNA (mRNA). Additionally, by evaluating mRNA decay in zebrafish treated with actinomycin D, we observed a significant decrease in the stability of opsin mRNA in the nat10 KD group. Conclusions: The ac4C-mediated mRNA modification plays an essential role in maintaining visual development and retinal function. The loss of NAT10-mediated ac4C modification results in significant disruptions to these processes, underlining the importance of this RNA modification in ocular development.

Morroniside ameliorates glucocorticoid-induced osteoporosis and promotes osteoblastogenesis by interacting with sodium-glucose cotransporter 2.

CONTEXT: Morroniside (MOR) possesses antiosteoporosis (OP) effects, but its molecular target and relevant mechanisms remain unknown. OBJECTIVE: We investigated the effects of MOR on glucocorticoid-induced OP and osteoblastogenesis and its underlying mechanisms. MATERIALS AND METHODS: The effects of MOR (10-100 µM) on the proliferation and differentiation of MC3T3-E1 cells were studied in vitro. The glucocorticoid-induced zebrafish OP model was treated with 10, 20 and 40 µM MOR for five days to evaluate its effects on vertebral bone density and related osteogenic markers. In addition, molecular targets prediction and molecular docking analysis were carried out to explore the binding interactions of MOR with the target proteins. RESULTS: In cultured MC3T3-E1 cells, 20 µM MOR significantly increased cell viability (1.64 ± 0.12 vs. 0.95 ± 0.16; p < 0.01) and cell differentiation (1.57 ± 0.01 vs. 1.00 ± 0.04; p < 0.01) compared to the control group. MOR treatment significantly ameliorated vertebral bone loss in the glucocorticoid-induced OP zebrafish model (0.86 ± 0.02 vs. 0.40 ± 0.03; p < 0.01) and restored the expression of osteoblast-specific markers, including ALP, Runx2 and Col-І. Ligand-based target prediction and molecular docking revealed the binding interaction between MOR and the glucose pockets in sodium-glucose cotransporter 2 (SGLT2). DISCUSSION AND CONCLUSIONS: These findings demonstrated that MOR treatment promoted osteoblastogenesis and ameliorated glucocorticoid-induced OP by targeting SGLT2, which may provide therapeutic potential in managing glucocorticoid-induced OP.

Progesterone Changes the Pregnancy-Induced Adaptation of Cardiomyocyte Kv2.1 Channels via MicroRNA-29b.

The cardiovascular system adaptation occurs during pregnancy to ensure adequate maternal circulation. Progesterone (P4) is widely used in hormone therapy to support pregnancy, but little is known about its effects on maternal cardiac function. In this study, we investigated the cardiac repolarization and ion channel expression in pregnant subjects and mice models and studied the effects of P4 administrations on these pregnancy-mediated adaptations. P4 administrations shortened the prolongation of QTC intervals and action potential duration (APD) that occurred during pregnancy, which was mainly attributable to the reduction in the voltage-gated potassium (Kv) current under basal conditions. In vitro studies indicated that P4 regulated the Kv2.1 channel in a bidirectional manner. At a low dose (1 µM), P4 induced upregulation of Kv2.1 through P4 receptor, while at a higher dose (5 µM), P4 downregulated Kv2.1 by targeting microRNA-29b (miR-29b). Our data showed that P4 modulated maternal cardiac repolarization by regulating Kv2.1 channel activity during pregnancy. Kv2.1, as well as miR-29b, might be used as potential therapeutic targets for adaptations of the maternal cardiovascular system or evaluation of progesterone medication during pregnancy.