A Novel PVDF Ultrafiltration Membrane Modified by C(OH)-Ag.

Ultrafiltration membranes in the fields of water treatment and biomedicine should have high permeability as well as antibacterial and antifouling capabilities. In this study, based on the hydrophilicity of fullerol (C(OH)) and the bacteriostatic properties of silver (Ag), a fullerol-silver (C(OH)-Ag) complex was prepared as a multifunctional additive. A polyvinylidene fluoride (PVDF)-composited C(OH)-Ag ultrafiltration membrane (C(OH)-Ag/PVDF) was prepared by immersion precipitation phase transformation.

Self-Assembled Nanoparticles with Well-Defined Oligosaccharide Promote Osteogenesis by Regulating Golgi Stress Response.

Osteoporosis, a prevalent disease characterized by low bone density and increased fracture risk, poses significant health challenges for the elderly. Current treatments offer short-term benefits but are limited by long-term efficacy and adverse effects, highlighting the need for new strategies. Chondroitin sulfate polysaccharides (CS), a major component of the bone matrix, are crucial for bone and cartilage health.

Epidermal growth factor receptor-dependent DNA repair promotes murine and human hematopoietic regeneration.

Chemotherapy and irradiation cause DNA damage to hematopoietic stem cells (HSCs), leading to HSC depletion and dysfunction and the risk of malignant transformation over time. Extrinsic regulation of HSC DNA repair is not well understood, and therapies to augment HSC DNA repair following myelosuppression remain undeveloped. We report that epidermal growth factor receptor (EGFR) regulates DNA repair in HSCs following irradiation via activation of the DNA-dependent protein kinase-catalytic subunit (DNA-PKcs) and nonhomologous end joining (NHEJ).

Chronic myeloid leukemia stem cells require cell-autonomous pleiotrophin signaling.

Tyrosine kinase inhibitors (TKIs) induce molecular remission in the majority of patients with chronic myelogenous leukemia (CML), but the persistence of CML stem cells hinders cure and necessitates indefinite TKI therapy. We report that CML stem cells upregulate the expression of pleiotrophin (PTN) and require cell-autonomous PTN signaling for CML pathogenesis in BCR/ABL+ mice. Constitutive PTN deletion substantially reduced the numbers of CML stem cells capable of initiating CML in vivo.

PTPσ inhibitors promote hematopoietic stem cell regeneration.

Receptor type protein tyrosine phosphatase-sigma (PTPσ) is primarily expressed by adult neurons and regulates neural regeneration. We recently discovered that PTPσ is also expressed by hematopoietic stem cells (HSCs). Here, we describe small molecule inhibitors of PTPσ that promote HSC regeneration in vivo.

Dickkopf-1 Treatment Stimulates Hematopoietic Regenerative Function in Infused Endothelial Progenitor Cells.

Acute high-dose radiation injury damages the bone marrow hematopoietic stem and progenitor cell compartment. This damage compromises the functional ability of the bone marrow to produce mature blood cells and results in an increased risk of death due to hematopoietic complications. Past work has shown that the bone marrow endothelium provides critical cues, which promote hematopoietic stem cell regeneration after injury.

Glycopolymers/PEI complexes as serum-tolerant vectors for enhanced gene delivery to hepatocytes.

Serum stability is a crucial factor for ideal polymeric gene vectors. In this work, a series of serum-tolerant and low-toxicity glycopolymers/poly(ethyleneimine) (PEI) complexes were designed for gene delivery. Atomic transfer radical polymerization (ATRP) was used to synthesize the comb-shaped random copolymers dextran-g-poly(2-dimethylaminoethyl methacrylate-co-2-lactobionamidoethyl methacrylate) (DDrL).

Distinct Bone Marrow Sources of Pleiotrophin Control Hematopoietic Stem Cell Maintenance and Regeneration.

Bone marrow (BM) perivascular stromal cells and vascular endothelial cells (ECs) are essential for hematopoietic stem cell (HSC) maintenance, but the roles of distinct niche compartments during HSC regeneration are less understood. Here we show that Leptin receptor-expressing (LepR+) BM stromal cells and ECs dichotomously regulate HSC maintenance and regeneration via secretion of pleiotrophin (PTN). BM stromal cells are the key source of PTN during steady-state hematopoiesis because its deletion from stromal cells, but not hematopoietic cells, osteoblasts, or ECs, depletes the HSC pool.

Wild-type Kras expands and exhausts hematopoietic stem cells.

Oncogenic Kras expression specifically in hematopoietic stem cells (HSCs) induces a rapidly fatal myeloproliferative neoplasm in mice, suggesting that Kras signaling plays a dominant role in normal hematopoiesis. However, such a conclusion is based on expression of an oncogenic version of Kras. Hence, we sought to determine the effect of simply increasing the amount of endogenous wild-type Kras on HSC fate.

Dickkopf-1 promotes hematopoietic regeneration via direct and niche-mediated mechanisms.

The role of osteolineage cells in regulating hematopoietic stem cell (HSC) regeneration following myelosuppression is not well understood. Here we show that deletion of the pro-apoptotic genes Bak and Bax in osterix (Osx, also known as Sp7 transcription factor 7)-expressing cells in mice promotes HSC regeneration and hematopoietic radioprotection following total body irradiation. These mice showed increased bone marrow (BM) levels of the protein dickkopf-1 (Dkk1), which was produced in Osx-expressing BM cells.

Deletion of the Imprinted Gene Grb10 Promotes Hematopoietic Stem Cell Self-Renewal and Regeneration.

Imprinted genes are differentially expressed by adult stem cells, but their functions in regulating adult stem cell fate are incompletely understood. Here we show that growth factor receptor-bound protein 10 (Grb10), an imprinted gene, regulates hematopoietic stem cell (HSC) self-renewal and regeneration. Deletion of the maternal allele of Grb10 in mice (Grb10 mice) substantially increased HSC long-term repopulating capacity, as compared to that of Grb10 mice.

Protein tyrosine phosphatase-σ regulates hematopoietic stem cell-repopulating capacity.

Hematopoietic stem cell (HSC) function is regulated by activation of receptor tyrosine kinases (RTKs). Receptor protein tyrosine phosphatases (PTPs) counterbalance RTK signaling; however, the functions of receptor PTPs in HSCs remain incompletely understood. We found that a receptor PTP, PTPσ, was substantially overexpressed in mouse and human HSCs compared with more mature hematopoietic cells.