Current Issues in Molecular Biology

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease of the pulmonary vasculature characterized by obliterative remodeling of small pulmonary arteries, leading to sustained elevation of pulmonary vascular resistance, right ventricular failure, and premature death. The diagnostic gold standard remains right heart catheterization, requiring a mean pulmonary artery pressure greater than 20 mmHg at rest, a pulmonary arterial wedge pressure of 15 mmHg or below, and a pulmonary vascular resistance exceeding 2 Wood units. PAH is an autosomal dominant disorder with markedly incomplete penetrance of approximately 20–30%, indicating that germline mutations alone are insufficient to cause disease. Disease manifestation requires additional “second hits”, including chronic hypoxia, systemic inflammation, hemodynamic stress, hormonal influences, and common genetic modifiers such as single-nucleotide polymorphisms (SNPs). This genetic and environmental complexity underpins the broad clinical heterogeneity observed across PAH subtypes, which include idiopathic PAH, heritable PAH, and disease associated with connective tissue disorders, HIV infection, portal hypertension, congenital heart disease, schistosomiasis, and drug or toxin exposure. This review provides a comprehensive and critical appraisal of the molecular-genetic architecture of PAH. Thirty genes have now been implicated in disease pathogenesis, spanning seven functional categories: receptors of the TGF-β/BMP signaling family (BMPR2, ACVRL1, ENG, BMPR1B); circulating BMP ligands (GDF2, BMP10); transcription factors (TBX4, SOX17, KLF4, FOXF1, SMAD1, SMAD4, SMAD9); membrane and polyamine transporters (ATP13A3, AQP1); potassium channel regulators (KCNA5, KCNK3, ABCC8); metabolic and mitochondrial genes (EIF2AK4, NFU1, GGCX); signaling receptors and structural proteins (NOTCH3, KDR, CAV1, PLEKHH2); vasoactive and extracellular matrix regulators (KLK1, CBLN2, CD248); and epigenetic regulators (TET2, TOPBP1). Among these, BMPR2 is the dominant contributor, accounting for 53–86% of heritable PAH and 14–35% of idiopathic cases. The remaining genes each account for fewer than 5% of cases individually, collectively reflecting a broad landscape of rare and ultra-rare genetic contributions. For each gene, we critically evaluate the strength of genetic evidence, pathogenic mechanisms, degree of mechanistic resolution, and clinical relevance. We further discuss the contribution of emerging technologies, including whole-genome sequencing, single-cell and spatial transcriptomics, multi-omics integration, iPSC-derived vascular models, and artificial intelligence, to expanding the PAH genetic architecture beyond single-gene discovery. A key theme across this landscape is convergence: despite mechanistic diversity at the gene level, most PAH-associated variants ultimately impair endothelial quiescence, promote smooth muscle proliferation, and drive apoptosis resistance through disruption of BMP signaling amplitude, transcriptional stability, ion channel homeostasis, metabolic integrity, or epigenetic regulation. This convergence supports both a unified therapeutic rationale and a precision medicine framework for genotype-stratified intervention in PAH.

Dendrobium nobile Lindl. is a valuable medicinal orchid in traditional Chinese medicine. It abounds in alkaloids with extensive pharmacological properties, holding promising prospects for pharmaceutical development. In this review, the relevant literature was systematically retrieved from PubMed, Web of Science and CNKI using the keywords Dendrobium nobile Lindl., alkaloids, dendrobine, pharmacological activities and biosynthetic pathways. We comprehensively summarize the chemical composition, pharmacological effects, biosynthetic routes, clinical application potential and research prospects of alkaloids derived from D. nobile. The main alkaloid components including dendrobine, dendramine and nobilonine are classified into dendrobine, dendroxine and nobiline structural types. This paper further elaborates the anti-inflammatory, antioxidant and neuroprotective effects of these alkaloids, as well as their regulatory mechanisms on apoptosis-associated proteins and signaling cascades. Key enzymes and regulatory genes participating in the mevalonate pathway-mediated biosynthesis of sesquiterpenoid alkaloids are also discussed. Collectively, this review provides a theoretical basis and reference for subsequent basic research and therapeutic development of D. nobile alkaloids.

β2-adrenergic receptor (β2-AR) agonists have been implicated in neuroprotection, yet their mechanisms remain obscure. We examined whether salbutamol (SA, short-acting) or formoterol (FO, long-acting) protect PC-12 cells from okadaic acid (OA), and evaluated receptor dependence, antioxidant capacity, and apoptotic signaling. Viability was quantified with crystal violet and MTT assays. OA reduced viability to approximately 60%, and SA or FO (0.1–10 µM) improved survival, which reached 76–83% at 10 µM (p < 0.05). β2-AR blockage with ICI-118,551, and ADRB2 mRNA knockdown did not abolish protection by FO or SA, suggesting a possible β2-AR-independent protective component. However, as knockdown was not confirmed at the protein level and signaling was not directly assessed, the evidence remains provisional. FO, but not SA, exhibited direct antioxidant activity in the DPPH assay, but both at 50 μΜ lowered H₂O₂-induced intracellular reactive oxygen species (from 167.9% to baseline, p < 0.05). Both compounds reduced the OA-induced expression of selected pro-apoptotic transcripts, although these mRNA data do not establish the functional inhibition of apoptosis. FO reduced fold change relative to untreated control from 5.8 to 2.6 for Bax, and 6.4 to 3.4 for Bak, whereas SA achieved a significant reduction only for Bax, from 5.8 to 4.4. Taken together, SA and FO offer a partial protection to PC-12 cells from OA cytotoxicity through pathways suggesting a β2-AR-independent protective component, with FO showing additional antioxidant properties and a reduced expression of selected pro-apoptotic transcripts. These findings provide preliminary evidence that select β2 agonists may exert cytoprotective effects that are consistent with, but do not establish, a receptor-independent component. These findings warrant further protein-level and functional validation.