Differential expression of stem cell mobilization-associated molecules on multi-lineage cells from adipose tissue and bone marrow

Our laboratory has characterized a population of stromal cells obtained from adipose tissue termed processed lipoaspirate cells (PLAs). PLAs, like bone-marrow derived mesenchymal stem cells (BM-MSCs), have the capacity to differentiate along the adipogenic, osteogenic, chondrogenic, and myogenic lineages, In order to better characterize these two multi-lineage populations, we examined the surface phenotype of both bone marrow and adipose tissue-derived cells from five patients undergoing surgery. PLA and BM-MSC cells were isolated, subcultivated, and evaluated for cell surface marker expression using flow cytometry. PLA and BM-MSC cells both expressed CD13, CD29, CD44, CD90, CD105, SH-3, and STRO-1. Differences in expression were noted for cell adhesion molecules CD49d (Integrin alpha4), CD54 (ICAM-1), CD34, and CD106 (VCAM-1). While markedly similar, the surface phenotypes of PLA and BM-MSC cells are distinct for several cell adhesion molecules implicated in hematopoietic stem cell homing, mobilization, and proliferation.     

Effects of Air Pollution on Adults with Chronic Obstructive Pulmonary Disease

Few studies have been conducted on the effects of air pollution on patients with chronic obstructive pulmonary disease (COPD). During a 14-mo period, 39 Parisian adults with severe COPD were monitored by their physicians. Daily levels of 4 air pollutants were provided by an urban air-quality network. Exacerbation of COPD was associated only with ozone (O₃) (odds ratio [OR] = 1.44 for a 10-μg/m³ increase in O₃; 95% confidence interval [Cl] = 1.14, 1.82), with a lag of 2-3 days. The effect of O₃ was greater in patients whose carbon dioxide pressure (PaCO₂) was higher than 43 mm Hg (OR = 1.83; 95% Cl = 1.36, 2.47) vs. those with a lower PaCO₂ (OR = 1.26; 95% Cl = 0.90, 1.77). The effect of O₃ was unchanged, regardless of the maintenance medications used. The only air pollutant to which patients with severe COPD were particularly sensitive was O₃.     

Alcohol withdrawal is associated with a downregulation of large-conductance Ca2+-activated K+ channels in rat inferior colliculus neurons

Rationale

Large conductance calcium-activated potassium (BK_Ca or K_Ca1.1) channels are well-known molecular targets for the action of alcohol and therefore may play an important role in the pathogenesis of alcohol withdrawal syndrome.

Objectives

We evaluate the modifications of total outward K⁺ currents and protein expression of BK_Ca channels α-subunit in inferior colliculus (IC) neurons obtained from controls and rats subjected to alcohol withdrawal associated with enhanced susceptibility to seizures.

Methods

Outward K⁺ currents and BK_Ca channel proteins were measured using the whole cell configuration of patch clamp techniques and Western blot analysis, respectively.

Results

Total outward K⁺ current density was significantly reduced in IC neurons at 24 and 48 h during the alcohol withdrawal period when the susceptibility to seizures was maximal and absent, respectively. The iberiotoxin-sensitive (BK_Ca) current density and conductance also were significantly reduced at 24 h following alcohol withdrawal. Consistent with functional data, the levels of protein expression of α-subunit associated with BK_Ca channels also was significantly reduced in IC neurons at 24 and 48 h following alcohol withdrawal.

Conclusions

The downregulation of BK_Ca channels outlasts the finite period of elevated susceptibility to alcohol withdrawal seizures. These findings indicate that BK_Ca channels, per se, may not be fundamentally important for the generation of alcohol withdrawal seizures.