Rheb1-Deficient Neutrophils Promote Hematopoietic Stem/Progenitor Cell Proliferation via Mesenchymal Stem Cells

Human embryonic stem cell-derived immunity-and-matrix-regulatory cells on collagen scaffold effectively treat rat corneal alkali burn

Corneal alkali burns (CAB) are a severe form of ocular injury that often leads to significant vision loss, with limited effective treatment options available beyond corneal transplantation. Immunity and matrix-regulatory cells (IMRCs) have emerged as a promising alternative due to their ability to modulate immune responses and support tissue repair. This study investigates the efficacy of IMRCs on collagen scaffolds (IMRCs-col) for treating CAB in a rat model. We developed a novel treatment combining IMRCs with a collagen scaffold to align with the ocular surface structure. In vitro analyses showed that IMRCs-col significantly upregulated the expression of immune regulatory molecules, including IL-1RA and SCF. Additionally, IMRCs-col effectively inhibited the production of pro-inflammatory cytokines (IL-8 and Gro-a/CXCL1) while promoting pro-regenerative cytokines (bFGF, HGF, and PDGF). In an animal model of CAB, IMRCs-col transplantation demonstrated substantial efficacy in restoring corneal opacity and reducing neovascularization. Histological examination revealed reduced inflammation and improved corneal tissue regeneration compared to untreated CAB. Enhanced activation of pathways associated with anti-inflammatory responses and tissue repair was observed at days 3, 7, and 21 post-treatment.

Rapamycin Promotes the Expansion of Myeloid Cells by Increasing G-CSF Expression in Mesenchymal Stem Cells

Rapamycin, also known as sirolimus, an inhibitor of mammalian target of rapamycin (mTOR), is a regulatory kinase responsible for multiple signal transduction pathways. Although rapamycin has been widely used in treating various hematologic diseases, the effects of rapamycin are still not fully understood. Here we found that both oral and intraperitoneal administration of rapamycin led to the expansion of myeloid lineage, while intraperitoneal administration of rapamycin impaired granulocyte differentiation in mice. Rapamycin induced bone marrow mesenchymal stem cells to produce more G-CSF in vitro and in vivo, and promoted the myeloid cells expansion. Our results thus demonstrated that intraperitoneal administration of rapamycin might promote the expansion of myeloid lineage while impair myeloid cell differentiation in vivo.