Sequential exposure to fibroblast growth factors (FGF) 2, 9 and 18 enhances hMSC chondrogenic differentiation.

OBJECTIVE: To test the effects of sequential exposure to FGF2, 9 and 18 on human Mesenchymal Stem Cells (hMSC) differentiation during in vitro chondrogenesis. DESIGN: Control and FGF2-expanded hMSC were cultured in aggregates in the presence of rhFGF9, rhFGF18 or rhFGFR3-specific signaling FGF variants, starting at different times during the chondroinductive program. Quantitative real time polymerase chain reaction (qRT-PCR) and immunocytochemistry were performed at different stages. The aggregate cultures were switched to a hypertrophy-inducing medium along with rhFGFs and neutralizing antibodies against FGFR1 and FGFR3. Histological/immunohistochemical/biochemical analyses were performed. RESULTS: FGF2-exposed hMSC during expansion up-regulated Sox9 suggesting an early activation of the chondrogenic machinery. FGF2, FGF9 and 18 modulated the expression profile of FGFR1 and FGFR3 in hMSC during expansion and chondrogenesis. In combination with transforming growth factor-beta (TGF-ß), FGF9 and FGF18 inhibited chondrogenesis when added at the beginning of the program (≤ d7), while exhibiting an anabolic effect when added later (≥d14), an effect mediated by FGFR3. Finally, FGFR3 signaling induced by either FGF9 or FGF18 delayed the appearance of spontaneous and induced hypertrophy-related changes. CONCLUSIONS: The stage of hMSC-dependent chondrogenesis at which the growth factors are added impacts the progression of the differentiation program: increased cell proliferation and priming (FGF2); stimulated early chondrogenic differentiation (TGF-ß, FGF9/FGF18) by shifting the chondrogenic program earlier; augmented extracellular matrix (ECM) production (FGF9/FGF18); and delayed terminal hypertrophy (FGF9/FGF18). Collectively, these factors could be used to optimize pre-implantation conditions of hMSC when used to engineer cartilage grafts.

Congenital hydranencephalic-hydrocephalic syndrome with proliferative vasculopathy: a possible relation with mitochondrial dysfunction.

We report the case of a fetus aborted at gestation week 20 because of hydranencephalic-hydrocephalic syndrome. The fetus was the third pregnancy of a nonconsanguineous couple whose first child exhibited congenital hydranencephalic-hydrocephalic syndrome associated with muscle histology findings consistent with mitochondrial cytopathy and deficiency of complexes III and IV of the respiratory chain and whose second pregnancy had terminated in an elective abortion on detection of progressive hydrocephalus at gestation week 19. The third pregnancy had a normal course according to obstetric and ultrasonography examinations performed at gestation weeks 5, 10, and 15, and negative results were obtained in standard serologic and polymerase chain reaction (PCR) tests for prenatal infections of the mother. However, the ultrasonography examination at gestation week 18 revealed hydrocephalus, in response to which the parents requested an abortion, which was performed at gestation week 20; the fetus was male and with no evident external malformations. Histopathologic studies of the brain and medulla oblongata revealed proliferative vasculopathy (glomeruloid vessels, intracytoplasmic inclusions, and microcalcifications) and intracytoplasmic inclusions in the voluntary muscle. Microbiologic and PCR tests of hepatic and spleen tissue were negative for prenatal infections. In view of the precedent of a sister with mitochondrial dysfunction, these findings raise the pos sibility that at least some cases of familial syndrome of congenital hydranencephalic-hydrocephalic syndrome with proliferative vasculopathy can be attributed to alterations in the mitochondrial respiratory chain.

Voltage-dependent potassium channels Kv1.3 and Kv1.5 in human cancer.

Membrane ion channels participate in cancerous processes such as proliferation, migration and invasion, which contribute to metastasis. Increasing evidence indicates that voltage-dependent K(+) (Kv) channels are involved in the proliferation of many types of cells, including tumor cells. Kv channels have generated immense interest as a promising tool for developing new anti-tumor therapies. Therefore, the identification of potential biomarkers and therapeutic targets in specific cancers is an important prerequisite for the treatment. Since Kv1.3 and Kv1.5 are involved in the proliferation of many mammalian cells, we aimed to study the expression of Kv1.3 and Kv1.5 in a plethora of human cancers. Thus, tissues from breast, stomach, kidney, bladder, lung, skin, colon, ovary, pancreas, brain, lymph node, skeletal muscle and some of their malignant counterparts have been analyzed. Whereas Kv1.3 expression was either decreased or did not change in most tumors, Kv1.5 was overexpressed. However, the presence of Kv1.3 was mostly associated with inflammatory lymphoplasmocytic cells. Independent of the suitability of individual channels as therapeutic targets, the identification of a Kv phenotype from tumor specimens could have a diagnostic value of its own. Our results demonstrate that Kv1.5, and to some extent Kv1.3, are aberrantly expressed in a number of human cancers. These channels could serve both as novel markers of the metastatic phenotype and as potential new therapeutic targets. The concept of Kv channels as therapeutic targets or prognostic biomarkers attracts increasing interest and warrants further investigation.

Phosphoglycolate phosphatase and 2,3-diphosphoglycerate in red cells of normal and anemic subjects.

Red cell phosphoglycolate phosphatase (PGP) and 2,3-diphosphoglycerate (2,3-DPG) were investigated in normal and anemic patients and rabbits. In hemolytic anemia and blood-loss anemia, characterized by a young red cell population, there was an increase in both phosphoglycolate phosphatase activity and 2,3-diphosphoglycerate levels. In aplastic anemia, the phosphoglycolate phosphatase activity was normal, but the 2,3-diphosphoglycerate values were nonetheless increased. Thus, no relationship was found between phosphoglycolate phosphatase activity and 2,3-diphosphoglycerate levels. The lack of correlation between the activity of phosphoglycolate phosphatase and 2,3-DPG levels suggests that modulation of phosphoglycolate phosphatase activity does not control the level of 2,3-DPG in erythrocytes.

Neuroimmunological findings in Guillain Barré syndrome, multiple sclerosis, and idiopathic polyneuropathies.

It is essential to know how the immune system acts in different neurological diseases, some of which are not very well known or are unknown. IgG and albumin were simultaneously quantified in serum and cerebrospinal fluid (CSF) of 47 patients with Guillain Barré Syndrome (GSB), 5 patients with multiple sclerosis (MS), and 14 patients with idiopathic polyneuropathies (IP). IgG local synthesis was observed in all patients, except in patients with IP. These patients showed a decrease in cerebrospinal fluid (CSF) flow.

Blood eosinophilia in Hodgkin's disease. A follow-up of 25 cases in Venezuela.

Twenty-five patients with Hodgkin's disease and high eosinophil counts were observed for an average of 90 months. Fluctuations in the levels of eosinophils were important in the course of observation. No relation with stages, histologic type, or evolution was noticed. Steroid-containing regimens and severe premortem conditions seemed to lower the counts. Relapse-free survival was shorter in our 25 patients than in a control group of 50 patients with Hodgkin's disease and no eosinophilia who had approximately the same stage, histologic type, and treatment of disease. However, the overall survival was somewhat better for the eosinophilic patients with stages IIIB and IV (0.1 greater than P greater than 0.05).

Eosinophilia in Hodgkin's disease: a role for interleukin 5.

In order to clarify the mechanisms of the eosinophilia frequently observed in patients with Hodgkin's disease (HD), 18 patients and 16 age- and sex-matched controls were studied. Increased eosinophil numbers in peripheral blood and serum IgE, as well as decreased cell-mediated immunity were present in HD patients compared with control individuals. Advanced disease was accompanied by lower eosinophil levels, increased IgE, and lower CD4+ T cell counts in peripheral blood. Eosinophilia correlated with CD4+ T cell counts, suggesting that eosinophil production could be under CD4+ T cell control. GM-CSF production in vitro by Phytohemagglutinin-stimulated mononuclear cells was significantly lower in HD patients with eosinophilia. On the other hand, an eosinophil-survival-enhancing activity was found in sera and culture supernatants from controls and HD patients; this activity was stronger for HD patients and was higher for those with eosinophilia. Furthermore, this activity was completely abolished by preincubation with monoclonal antibodies to IL-5, but not with normal mouse serum. Our results suggest that defects of cell-mediated immunity present in patients with HD are accompanied by a predominant type 2 cytokine profile. IL-5 is involved in the increased eosinophil production observed in these patients.