Corneal transparency depends on an avascular microenvironment, regularly organized stromal collagen, and regulated inflammatory repair response.CD34+ cells should not be regarded as a single functional population; rather, they comprise cornea-resident mesenchymal stem cell-like cells, peripheral blood-derived endothelial progenitor cells(EPCs), and fibrocytes with distinct origins, phenotypes, and pathological effects. Resident CD34+ cells are mainly associated with limbal stem cell niche maintenance and stromal homeostasis, whereas recruited EPCs and fibrocytes may contribute to corneal neovascularization and scarring under hypoxic, inflammatory, or TGF-β-driven conditions. This review summarizes the biological characteristics, corneal distribution, and key signaling pathways of CD34+ cells, including VEGF/VEGFR-2, SDF-1/CXCR4, NF-κB, and TGF-β/Smad signaling. And further discuss their roles in infectious keratitis, limbal stem cell deficiency, keratoconus, and post-traumatic corneal fibrosis. By integrating controversial findings with clinical evidence and translational limitations, this review suggests that future CD34-related therapies should shift from non-selective CD34 modulation toward spatiotemporally precise strategies that preserve resident reparative subpopulations while inhibiting recruited proangiogenic and profibrotic cells.

Eight previously undescribed lanostane triterpenoids, including five nortriterpenoids with 26 carbons, ganothenoids A-E (1-5), and three lanostanoids, ganothenoids F-H (6-8), along with 24 known ones (9-32), were isolated from the fruiting bodies of Ganodrma theaecolum. The structures of the novel compounds were elucidated using comprehensive spectroscopic methods, including electronic circular dichroism (ECD) and nuclear magnetic resonance (NMR) calculations. Compounds 1-32 were assessed for their neuroprotective effects against H₂O₂-induced damage in human neuroblastoma SH-SY5Y cells, as well as their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase. Compound 4 demonstrated the most potent neuroprotective activity against H₂O₂-induced oxidative stress by suppressing G₀/G₁ phase cell cycle arrest, reducing reactive oxygen species (ROS) levels, and inhibiting cell apoptosis through modulation of B-cell lymphoma 2 protein (Bcl-2) and Bcl-2 associated X-protein (Bax) protein expression. Compounds 26, 12, and 28 exhibited PTP1B inhibitory activities with IC₅₀ values ranging from 13.92 to 56.94 μmol·L^-1, while compound 12 alone displayed significant inhibitory effects on α-glucosidase with an IC₅₀ value of 43.56 μmol·L^-1. Additionally, enzyme kinetic analyses and molecular docking simulations were conducted for compounds 26 and 12 with PTP1B and α-glucosidase, respectively.
Humans ; Fruiting Bodies, Fungal/chemistry* ; Triterpenes/isolation & purification* ; Neuroprotective Agents/isolation & purification* ; Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism* ; Ganoderma/chemistry* ; Apoptosis/drug effects* ; Hypoglycemic Agents/isolation & purification* ; Molecular Structure ; alpha-Glucosidases/metabolism* ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Oxidative Stress/drug effects* ; Hydrogen Peroxide/toxicity* ; Molecular Docking Simulation