1. Deling Yin M.D., Ph.D. Associate Professor Department of Internal Medicine College of Medicine East Tennessee State University Johnson City, TN 37614 Role of Cell Apoptosis in Drug Abuse and Human Diseases

2. Apoptosis Apoptosis is an active process that results in membrane blebbing, DNA fragmentation. It is gene-directed process responsible for a number of membrane receptors and cytoplamic proteins. Apoptosis plays a fundamental role in a variety of physiological process and its deregulation contributes to many diseases, including AIDS and autoimmune diseases. Growing evidence demonstrated that HIV-1/AIDS and opioid drugs are capable to induce apoptosis of immune cells, but the mechanism is not clear.

3. Apoptosis Programmed Cell Death

4. Flow cytometry is a powerful tool to determine the number of apoptotic cells. DNA content Two years ago, Dr. Junying Yuan’s group reported for the first time that “necroptosis” contributes to delayed mouse ischemic brain injury in vivo (Nature Chemical Biology. 2005. 1, 112- 119). “Necroptosis” is from necrosis and apoptosis.

16. Absence of trophic factor: Caspase activation

18. Opioids (e.g. morphine) are an old class of drugs derived from the poppy of opium plant Papaver somniferum. Opioids Opioids have been used for centuries as pain relievers. Opioids have effects on perception of pain, consciousness, and motor control.

19. Long-term use of opioid leads to tolerance, dependence, and addiction and their mechanisms remain to be elucidated. Previous research suggested that the abnormal gene expression in brain, impairment of neuronal cells and changes in the plasticity of neuron may play important roles in the development of opioid addiction. 30% of HIV-1 infected individuals are drug abuse, and most of these individuals abuse opioids. Opioids induce specific signal transduction processes through specific opioid receptors. Although the last 30 years extraordinary progress have been marked in efforts to deal with the interactions of opioid abuse and HIV-1/AIDS, we still lack fundamental knowledge of the cause of addiction, and certainly lack definitive treatments and cures for many patients.

20. Opioids Receptors Opioid receptors belong to G protein-coupled receptors (GPCRs) Morphine, heroin, and many related synthetic opioids produce their major effects through specific cell surface opioid receptors. Opioid receptors and their agonists and antagonists µ қδ Allother Agonists DAMGO Endormorphine-1 Endormorphine-2 U69593 Dynorphine A U-50,488H RU51599 Phenylacetamine Methylpiperidine DADLE DPDPE DSLET SNC 80 SNC 121 Morphine Etorphine Codeine Enkephalin Endorphine Dynorphine Nociceptin (orphanin FQ) (ORL1) Antagonists CTAP Beta- Funaltrexamine Naloxonazine DIPPA Nor- binaltorphimine DALCE ICI-154,129 Natrindole TIPP BNTXmaleate Natrexone Naloxone Diprenorphine Nocistatin Note: µ-receptor is the main receptor for morphine, heroin and other opioids

21. Mu-Opioid Receptor Mediated Signaling

22. HIV-1/AIDS and Apoptosis HIV-1 is a retrovirus. Continuous HIV-1 replication leads to the destruction Of immune cells, profound immune dysfunction, and finally, progression to AIDS. Disease progression during HIV-1 infection correlates with both elevated levels of apoptosis and increased virus load. However, the molecular mechanisms of the HIV-1-assocaite loss of CD4+ T cells in HIV-1 Infected individuals. Gp120, the HIV-1 envelope glycoprotein, stimulates pro-apoptotic signaling. Further understanding of the regulation of apoptosis in HIV-1 disease Will lead to the development of novel immune-based therapies for HIV-1 Infection and AIDS treatment.

23. Opioid Drug Abuse and HIV-1 Interactions Injection drug users comprise over 30% of the HIV-1-infected population, and many of subjects abuse opioids Opioid drugs (e.g. morphine, heroin) are major risk factors and are the fastest growing means for spread of HIV-1 infection. A few studies have demonstrated that morphine significantly increase Gp120-induced cell apoptosis through the p38 mitogen-activated protein kinase (MAPK) signaling pathway. However, the molecular mechanism by which gp120 affects the immune response, particularly in the opioid-addicted individual, remains to be defined.

24. Mechanisms of HIV-1 Gp120-Induced Apoptosis

26. β-Arrestin-Mediated Signaling Lefkowitz RJ et al. Science. 2005;308:512-517

27. Beta-Arrestin-Mediated Signaling in the Heart

28. Critical involvement of beta-arr 1 in experimental autoimmune encephalomyelitis (for multiple sclerosis) Nat Immunol. 2007 Aug;8(8):817-24

29. Beta-Arr2 Deficiency Promotes Lung Tumor Growth, Lung Metastasis, and Mortality J. Immunol. 2008;180;5699-5706.

30. Model of β-arrestin Mediated Migration and Metastasis