Mesenchymal stem cells are functionally abnormal in patients with immune thrombocytopenic purpura.

Background Aims: Immune thrombocytopenic purpura (ITP) is a bleeding disorder characterized by an accelerated destruction of platelets as a result of the presence of autoreactive antibodies. Patients with ITP also display activated platelet-autoreactive T cells. Mesenchymal stem cells (MSC) inhibit both T- and B-cell activation and may have functional impairments in autoimmune disorders.

Comparison of ex vivo expansion culture conditions of mesenchymal stem cells for human cell therapy.

Background: Mesenchymal stem cells (MSCs) are multipotent stem cells. Based on their properties, several clinical trials have been designed to explore their potential therapeutic effect. Fetal calf serum (FCS, commonly used for in vitro expansion) is an undesirable source of xenogeneic antigens and bears the risk of transmitting contaminations.

The effect of mesenchymal stem cells on the viability, proliferation and differentiation of B-lymphocytes.

Background: Mesenchymal stem cells are multilineage non-hematopoietic progenitor cells that play a key role in supporting the lymphohematopoietic system. Their distribution in bone marrow and secondary lymphoid organs allows an intimate interaction with T- and B-lymphocytes. While their effect on T-lymphocytes has been extensively analyzed, data on the effect of mesenchymal stem cells on B cells are more limited.

Optimization of mesenchymal stem cell expansion procedures by cell separation and culture conditions modification.

Objective: Optimization of the mesenchymal stem cells (MSC) isolation and expansion method.

Materials And Methods: Mononuclear cells (MNC) from bone marrow aspirates were obtained by both density gradient centrifugation (standard method) and gravity sedimentation. Cells were cultured in standard conditions (10% fetal calf serum and normal oxygen tension [21% O(2)]) and expansion results compared to those obtained with the same culture conditions to which platelet lysate (PL) preparations were added; in addition, the 21% O(2) concentration was compared to a lower (5%) concentration (hypoxia) until the fourth cell passage.

Multifunctional role of Erk5 in multiple myeloma.

Multiple myeloma is characterized by the accumulation of terminally differentiated B cells in the bone marrow, due to increased proliferation and restricted apoptosis of the myelomatous clone. Here we have studied the participation of a novel mitogen-activated protein kinase (MAPK) route, the extracellular signal-regulated kinase 5 (Erk5) pathway, in the regulation of myeloma cell proliferation and apoptosis. Erk5 was expressed in cells isolated from patients and in myeloma cell lines.

Imatinib mesylate (STI571) inhibits multiple myeloma cell proliferation and potentiates the effect of common antimyeloma agents.

c-Kit has been shown to be mutated in several types of tumours, and its activity has been correlated with increased proliferation rates in a subset of multiple myeloma (MM) patients. We have investigated the effect of imatinib mesylate (STI571), an inhibitor of c-Kit, on MM cells. STI571 inhibited the proliferation of MM cells by arresting cell cycle progression.