ABSTRACT
Aim To investigate the antinociception, tolerance and withdrawal abstinence of δ/μ/κ opioid receptor triple agonist KUST201 ( DPI-125 ) in rats. Methods Male Sprague-Dawley rats were used to de-termine the time course of analgesic effects and ED50 effects of co-administration of naltrindole were assessed as well. In withdrawal experiments, KUST201 was ad-ministrated twice daily for 3 d with increasing doses each day. On the 4th day, the rats were given a single dose, challenged with naloxone 3 h later, and signs of abstinence were monitored. Results The ED50 values of KUST201 were 0. 34 mg·kg-1 in tail-pinch test and 0. 68 mg · kg-1 in hot-plate test. The antinociception actions of KUST201 started to decrease 1 h after ad-ministration, and disappeared after 2 h. In chronic tol-erance experiments, the antinociception actions started to decrease on d 3 , and completely disappeared on d 7 . Naltrindole could reduce the antinociceptive action of KUST201. In withdrawal experiments, abstinence scores increased significantly in the dose range between 2~8 times of tail-pinch ED50 . Conclusion Compared with previously reported δ/μ/κ triple agonist DPI-3290 , KUST201 exhibits similar antinociceptive effects in rats. The chronic tolerance to KUST201 actions de-velops less quickly, but the abstinence scores of KUST201 are slightly higher. The activation of δ-opi-oid receptor can synergistically enhance the antinoci-ception mediated by μ-receptor.
ABSTRACT
Tumor is a system-biology illness.Treatment of this intractable disease by any single medicine has not been realistic.In this review, we analyze the anti-tumor network of Tumor Necrosis Factor-related Apoptosis-indu-cing Ligand ( TRAIL ) by a system-biology technology and try to providecin individualized treatment strategy for TRAIL based therapy .
ABSTRACT
Alzheimer′s disease ( AD) is a type of neurodegener-ative disease. Recent studies indicate that neuronal degeneration and loss triggered by tau, APP and Aβare the probable risks for AD. Neurofibrillary tangles are formed after tau truncated by ac-tivated caspases and subsequently induced tau aggregates, which causes neuronal degeneration and loss. In addition, caspases are crucial components in the biological functioning in the apoptosis pathways. Apoptosis pathway involves activation of upstream ini-tiator caspase-8 and downstream executor caspase-3/-6/-7. After the actions of β- and γ-secretase, APP transforms into sAPPβand Aβ40/42 . Aggregated Aβ42 can activate apoptosis pathway through DR4/5 interaction. C-APP is truncated into C31 frag-ments by caspases and cell apoptosis is facilitated. N-APP, a product of sAPPβhydrolysis, can promote the abnormal develop-ment of neurons mediated by DR6. Caspase activates γ-secre-tase-activating protein to regulate activity ofγ-secretase, and the production of C31 and Aβ40/42 , which, then, causes the occur-rence of AD. This brief review summarizes the specific roles of caspases and the concerning apoptosis pathways on the mecha-nisms of neuronal degeneration and loss, and how they impact the occurrence of AD in the hope of uncovering additional poten-tial therapeutic targets that can be employed in drug development and clinical therapy for AD.
ABSTRACT
Many tumor cells are resistant to cell apoptosis through the expression of antiapoptotic proteins. c-FLIP is a ma-jor resistance protein of antiapoptosis. In human cells, there are three types of c-FLIP, c-FLIPL , c-FLIPS and c-FLIPR . The c-FLIP binds to FADD to prevent the formation of procaspase-8-DISC and the subsequent activation of caspase cascade. Further-more, c-FLIPL and c-FLIPS have multifunctional roles in various cellular signaling pathways, as well as up-regulating several cyto-protective signaling. Studies show that upregulation of c-FLIP has been found in various tumors, and its downregulation has been shown to restore apoptosis triggered by various chemothera-peutic agents, like the transcriptional regulating agents, trichos-tatin-A, camptothecin, cisplatin, doxorubicin, etc. or other new biotechnologies, such as the specific siRNA. Therefore, c-FLIPS are important targets of cancer therapy. This review summarizes the results on the role of c-FLIP in cancer chemotherapy of tradi-tional antitumor agents and siRNA, and to provide new ideas and rationales of searching for the antiapoptosis effective compounds that can specifically antagonize c-FLIP.