Objective: Mel-18 is a member of the mammalian Polycomb group (PcG) genes. This family of genes regulates global gene expression in many biologic processes, including hematopoiesis and anterior-posterior axis formation by manipulating specific target genes, including members of the Hox family. Here, we demonstrate that mel-18 negatively regulates the self-renewal activity of hematopoietic stem cells (HSCs).
Materials And Methods: Long-term reconstitution activity was evaluated by competitive repopulating unit (CRU) and mean activity of the stem cells (MAS) assays in vivo in bone marrow cells (BMCs) derived from mel-18(-/-) and mel-18 tg mice. The expression levels of mel-18 and Hoxb4 were measured by quantitative real-time reverse transcription polymerase chain reaction.
Results: The Hoxb4 gene was highly expressed in HSCs derived from mel-18(-/-) mice. The observed CRUs were 3.21, 4.77, 3.32, and 1.64 CRU per 10(5) BMCs in mel-18(+/+), mel-18(-/-), C57BL/6, and mel-18 tg, respectively. MAS was 0.58, 0.18, 0.41, and 5.89 in mel-18(+/+), mel-18(-/-), C57BL/6, and mel-18 tg, respectively. The percentage in G0 phase HSCs (lin(-)flk2(-)c-Kit(+)Sca1+ cells) was increased in mel-18(-/-) mice and decreased in mel-18 tg mice.
Conclusion: Loss or knockdown of mel-18 leads to the expression of Hoxb4, an increase in the proportion of HSCs in G0 phase, and the subsequent promotion of HSC self-renewal. These findings will enable us to develop new approaches for controlling HSC activity for hematopoietic transplantations based on ex vivo expansion of HSCs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.exphem.2004.03.001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Efficacy and safety of a modified DVD regimen followed by lenalidomide for the treatment of Newly Diagnosed Multiple Myeloma.
Clinics (Sao Paulo)
January 2025
Department of Hematology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, PR China. Electronic address:
Background: The common drugs used for the treatment of Newly Diagnosed Multiple Myeloma (NDMM) include bortezomib and lenalidomide, but the adverse effects of lenalidomide cannot be ignored, especially when it is used in the initial therapy.
Methods: This retrospective study evaluated the efficacy and safety of a modified DVD regimen (pegylated liposomal doxorubicin, bortezomib, and dexamethasone) followed by lenalidomide in the treatment of NDMM. A total of 40 NDMM patients were treated with a reduced dose of pegylated liposomal doxorubicin (20 mg/m) on day 1, subcutaneous bortezomib (1.
Advances in RNA editing in hematopoiesis and associated malignancies.
Blood
January 2025
State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College; Center for Stem Cell Medicine,, Tianjin, China.
Adenosine-to-inosine (A-to-I) RNA editing is a prevalent RNA modification essential for cell survival. The process is catalyzed by the Adenosine Deaminase Acting on RNA (ADAR) enzyme family that converts adenosines in double-stranded RNAs (dsRNAs) into inosines, which are read as guanosines during translation. Deep sequencing has helped to reveal that A-to-I editing occurs across various types of RNAs to affect their functions.
View Article and Find Full Text PDFA single-cell atlas of the Culex tarsalis midgut during West Nile virus infection.
PLoS Pathog
January 2025
Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
The mosquito midgut functions as a key interface between pathogen and vector. However, studies of midgut physiology and virus infection dynamics are scarce, and in Culex tarsalis-an extremely efficient vector of West Nile virus (WNV)-nonexistent. We performed single-cell RNA sequencing on Cx.
View Article and Find Full Text PDFHatching of whipworm eggs induced by bacterial contact is serine-protease dependent.
PLoS Pathog
January 2025
Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom.
Whipworms (Trichuris spp) are ubiquitous parasites of humans and domestic and wild mammals that cause chronic disease, considerably impacting human and animal health. Egg hatching is a critical phase in the whipworm life cycle that marks the initiation of infection, with newly hatched larvae rapidly migrating to and invading host intestinal epithelial cells. Hatching is triggered by the host microbiota; however, the physical and chemical interactions between bacteria and whipworm eggs, as well as the bacterial and larval responses that result in the disintegration of the polar plug and larval eclosion, are not completely understood.
View Article and Find Full Text PDFThe cellular response of lipopolysaccharide-induced inflammation in keratoconus human corneal fibroblasts to RB-PDT: Insights into cytokines, chemokines and related signaling pathways.
PLoS One
January 2025
Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg/Saar, Germany.
Purpose: Rose Bengal Photodynamic Therapy (RB-PDT) offers dual therapeutic benefits by enhancing corneal stiffness and providing antibacterial activity, presenting significant potential for patients with keratoconus complicated by keratitis. Our purpose was to assess the effect of rose bengal photodynamic therapy (RB-PDT) on the expression of pro-inflammatory cytokines and chemokines, as well as on extracellular matrix (ECM)-related molecules, in lipopolysaccharide (LPS)-induced inflammation of keratoconus human corneal fibroblasts (KC-HCFs). Additionally, the involvement of the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways which are downstream of the Toll-like receptor 4 (TLR4) pathway were examined.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!