Apoptosis

Unlike most neurons in the adult nervous system, olfactory receptor neurons (ORN),
found in the olfactory epithelium (OE), continually turnover in the adult rat. These
neurons project their axons to the olfactory bulb which is their central target. The
present study eliminated target neurons in the bulb using N-methyl-D-aspartate
(NMDA) to examine the effects of target loss on ORN survival and maturation. We
compared the effects of the NMDA lesion to bulbectomy, a permanent surgical
removal of the bulb, which simultaneously causes damage to ORN axons. We found
that unlike bulbectomy, large numbers of dying OE cells were not observed at any
time after the lesion. The number of immature neurons increased relative to the
control side, and the number of mature neurons also slightly increased with time
following NMDA lesion. Survival of ORNs does not seem to be significantly altered
in the absence of its target.

The excess generation of Reactive oxygen species (ROS) can damage
cell components and disrupt cellular functions. Methionine in proteins is easily
oxidized by ROS and converted to methionine sulfoxide. The enzyme peptide
Methionine Sulfoxide Reductase reduces methionine sulfoxide back to methionine.
We report here that MsrA over expression in rat cardiac myocytes prevents damage
from ROS and increases cell viability after hypoxic/reoxygenation events. The nonsteroidal
anti-inflamatory drug (NSAID) sulindac contains a methyl sulfoxide moiety
that can scavenge ROS. Sulindac can be reduced by MsrA and contribute as an
antioxidant in the cell. Our results demonstrate that 1 OOuM sulindac can reduce cell
death in rat cardiac myocytes during hypoxia/reoxygenation, and
ischemia/reperfusion in Langendorf[ perfusions. The BNIP proteins are pro-apoptotic
members of the Bcl-2 family of apoptosis regulating proteins. Hypoxia/acidosis
stabilizes BNIP-3 and increases its association with the mitochondria, causing the
release of cytochrome C and cell death. We report the retrograde perfusion
Langendorffmodel is inconclusive in mouse hearts.

Huntington's disease (HD) is an inherited neurological disorder characterized by a
selective loss of neurons in the striatum and cortex leading to involuntary movement,
dementia and eventually cell death. HD is caused by an expanded polyglutamine (PolyQ)
repeat in Huntingtin (Htt) protein. It is well known that misfolded mutant Htt could form
intracellular aggregates, trigger ER stress and ultimately lead to apoptosis. However, the
molecular link between ER stress and apoptosis in mitochondria is poorly understood. In
the present study, we identified Bim (Bcl-2 interacting mediator of cell death) as the
essential protein. We first established a cellular model of HD by over expressing the Nterminus
of wild type and mutant Htt into HEK293 cell lines. We showed that the
accumulation and aggregation of misfolded mutant Htt protein triggers ER stress and
apoptosis. The Bim protein expression level was greatly increased in mutant Htt
transfected cells and this increase was partially due to up-regulation of Bim mRNA as analyzed using quantitative RT-PCR. We further showed that Bim phosphorylation
also played an important role in regulating Bim expression. Moreover, up-regulation of
Bim facilitates the translocation of Bax to mitochondrial membrane, which lead to
cytochrome c release and apoptosis. We also silenced Bim using siRNA to further
investigate the essential role of Bim in mutant Htt induced ER stress and apoptosis.
Identifying the Bim pathway that is altered in response to the mutant Htt protein is
important for understanding the cellular processes impacted by the disease.

The lens is a crystallin tissue of the anterior part of the eye that focuses light onto the
retina. Aged-related cataract, which is the result of loss of lens transparency, is the most
common cause of blindness in the world. Being constantly exposed to UV-light, lens is
significantly affected by its UVA spectrum. UV-light exposure has been shown to result
in apoptosis of lens cells which can lead to cataract formation. This suggests the need for
molecular mechanisms to remove apoptotic debris from the lens. In the set of
experiments it was proven that integrin αvβ5-mediated pathway is involved in
phagocytosis of apoptotic cell debris in the ocular lens, thus contributing to its
homeostasis. Additionally, it was shown that exposure to UV-light plays role in cataract
formation by influencing integrin αvβ5-mediated phagocytosis function.

Prostate cancer is one of the leading causes of death in men aged 40-55. Genistein isoflavone (4', 5', 7-trihydroxyisoflavone) is a dietary phytochemical with demonstrated anti-tumor activities in a variety of cancers. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy drug, primarily used for secondary treatment of ovarian,cervical and small cell lung cancers. This study was to demonstrate the potential anticancer activities and synergy of topotecan-genistein combination in LNCaP prostate cancer cells. The potential efficacy and mechanism of topotecan/genistein-induced cell death was investigated... Results: The overall data indicated that i) both genistein and topotecan induce cellular death in LNCaP cells, ii) topotecan-genistein combination was significantly more efficacious in reducing LNCaP cell viabiligy compared to either genistein or topotecan alone, iii) in all cases, cell death was primarily through apoptosis, via the activation of the intrinsic pathway, iv) ROS levels were increased and VEGF expression was diminished significantly with the topotecan-genistein combination treatment, v) genetic analysis of topotecan-genistein treatment groups showed changes in genetic expression levels in pathway specific apoptotic genes.... Conclusion: Treatments involving topotecan-genistein combination may prove to be an attractive alternative phytotherapy of adjuvant therapy for prostate cancer.

The present study was undertaken to determine the chemotherapeutic potential of genistein and beta-lapachone and possible mechanisms of action in prostate cancer in vitro. The bioassays used included: MTT and LDH chemosensitivity-cytotoxicity assays, NQO1 detection, annexin V-FITC, TUNEL and the caspase protease (CPP32) apoptotic detection assays. The results showed that: (i) PC3 cells are sensitive to single and combination treatments in a dose and time dependent manner; (ii) there was treatment-induced dual death pathways (apoptosis and necrosis) with increasing toxicity (necrosis) at higher concentrations in single and combination treatments; (iii) combination treatment was more growth inhibitory than single treatments; (iv) the NQO1 enzyme substantially enhances the toxicity of beta-lapachone but not genistein, while genistein exerted its apoptotic inducing effects via the caspase 3 pathway. The overall results indicate that combination treatments with beta-lapachone and genistein are more efficacious in killing PC3 human prostate cancer cells than treatment with either agent alone.

The lens is an avascular organ that focuses light onto the retina where neural signals are transmitted to the brain and translated into images. Lens transparency is vital for maintaining function. The lens is formed through a transition from organelle-rich epithelial cells to organelle-free fiber cells. Lens cell differentiation, leading to the lack of organelles, provides an environment optimal for minimizing light scatter and maximizing the ability to focus light onto the retina. The process responsible for orchestrating lens cell differentiation has yet to be elucidated. In recent years, data has emerged that led our lab to hypothesize that autophagy is likely involved in lens cell maintenance, cell differentiation, and maintenance of lens transparency. As a first step towards testing this hypothesis, we used RT-PCR, western blot analysis, immunohistochemistry, confocal microscopy, and next generation RNA-Sequencing (RNA-Seq) to examine autophagy genes expressed by the lens to begin mapping their lens function.

The 23 matrix metalloproteinases (MMPs) in humans catalyze the turnover of all protein components of the extracellular matrix (ECM) and have important roles in tissue remodeling, wound healing, embryo implantation, cell migration and shedding of cell surface proteins. Excess MMP activities are associated with many diseases including arthritis, heart disease and cancer. The activities of MMPs are regulated by a family of four protein inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), that are endogenous inhibitors of matrix metalloproteinases (MMPs), ADAMs (A Disintegrin And Metalloproteinase) and ADAMTS (disintegrin-metalloproteinase with thrombospmdin motifs) .... The balance between TIMPs and active metzinicins is very important and imbalances are linked to human diseases such as arthritis, cancer, and atherosclerosis. The engineering of TIMPs to produce specific inhibitors of individual MPs could provide new therapeutic principles for disease treatment, but this requires a detailed understanding of the biophysical and structural basis of the interactions of TIMPs and MMPs and ADAMs.