Membrane lipid dynamics must be precisely regulated for normal cellular function, and disruptions in lipid homeostasis are linked to the progression of several diseases. However, little is known about the sensory mechanisms for detecting membrane composition and how lipid metabolism is regulated in response to membrane stress. We find that phosphoinositide (PI) kinase signaling controls a conse...

Irvalec is a marine-derived antitumor agent currently undergoing phase II clinical trials. In vitro, Irvalec induces a rapid loss of membrane integrity in tumor cells, accompanied of a significant Ca(2+) influx, perturbations of membrane conductivity, severe swelling and the formation of giant membranous vesicles. All these effects are not observed in Irvalec-resistant cells, or are significant...

In this study, different assays were used to assess the structural and functional integrity of the sperm plasma membrane following freezing-thawing of the whole ejaculates (WEs) and sperm-rich fractions (SRFs) of boar semen. Besides sperm viability assessments (motility and mitochondrial membrane potential using a mitochondrial specific dye, JC-1 with propidium iodide, PI), sperm plasma membran...

The study was conducted to determine the influence of D-aspartic acid (D-Asp) as antioxidant supplement and thawing rates on ram sperm motility, membrane integrity, abnormality, viability, mitochondria activity, malondialdehyde and antioxidant activities, and total antioxidant capacity after freezing-thawing process. Semen samples from five mature rams (3-4 years old) were diluted with extender...

the major limitation in the application of bioactive molecule is their low permeation across plasma membrane. in 1988 it was discovered, that a natural polycationic protein, the trans-acting activator of transcription (tat) of the human immunodeficiency virus (hiv-1), passed very efficiently through cell membrane of cultured mammalian cells. tat became known as the first cell penetrating peptid...

OBJECTIVE The aim of the present study was to investigate the effects of four equilibration times (2, 4, 8 and 16 hours) and two extenders (tris or Bioxcell®) on cryopreservation of buffalo semen. MATERIALS AND METHODS In this experimental study, split pooled ejaculates (n=4), possessing more than 70% visual sperm motility were divided in two aliquots and diluted in Bioxcell® and tris-citric ...

Rapid repair of plasma membrane wounds is critical for cellular survival. Muscle fibers are particularly susceptible to injury, and defective sarcolemma resealing causes muscular dystrophy. Caveolae accumulate in dystrophic muscle fibers and caveolin and cavin mutations cause muscle pathology, but the underlying mechanism is unknown. Here we show that muscle fibers and other cell types repair m...

WCB is a protein that locates between the inner face of the plasma membrane and the sub-pellicular corset of microtubules in Trypanosoma brucei. We provide the molecular identity of WCB and bioinformatic analysis suggests that it possesses a C2 domain implicated in membrane/protein interactions and a highly charged region possessing characteristics of a putative tubulin-binding domain. Function...

Endothelial barrier dysfunction underlies chronic inflammatory diseases. In searching for new proteins essential to the human endothelial inflammatory response, we have found that the endosomal GTPase RhoB is up-regulated in response to inflammatory cytokines and expressed in the endothelium of some chronically inflamed tissues. We show that although RhoB and the related RhoA and RhoC play addi...

in the present study, the fertilizing potential of semen recovered from slaughtered bulls epididymis was evaluated after cryopreservation, by conventional techniques and flow cytometry methods. the cauda epididymal was dissected and sperm were recovered and evaluated for volume, sperm concentration, and membrane and acrosome integrity using a flow cytometer. sperm fertility potential was tested...