Q-VD-OPh, a pancaspase inhibitor, reduces trauma-induced apoptosis and improvesthe recovery of hind-limb function in rats after spinal cord injury

Background. Various caspases have been implicatedin the development of secondary damage after spinalcord injury (SCI). Anticaspase therapy that targets onlyone caspase has been investigated in a variety of in vitroand in vivo studies. This study examined the neuroprotectiveeffects of Q-VD-OPh, a pan-caspase inhibitor, ina rat model of SCI.Methods. Thirty Wistar albino rats were divided into3 groups of 10 each: the sham-operated controls (group1), the trauma-created controls (group 2), and the QVD-OPh–treated rats (group 3). An SCI (a trauma of40 g-cm) was produced at the thoracic level (T8-T10) bythe weight-drop technique. The response to injury andthe neuroprotective effects of Q-VD-OPh were investigatedby histopathologic examination and terminaldeoxynucleotidyl transferase dUTP nick-end labeling(TUNEL) 24 hours and 5 days after trauma. The inclinedplane technique of Rivlin and Tator and a modifiedversion of Tarlov’s grading scale were used to assess thefunctional status of the rats 24 hours, 3 days, and 5 daysafter injury.Results. Twenty-four hours after trauma, lightmicroscopic examination of a specimen taken fromgroup 2 rats revealed hemorrhage, necrosis, vascularthrombi, and edema. Group 3 tissue samples showedsimilar features at that time. Twenty-four hours aftertrauma, the mean apoptotic cell number was 4.47 ± 0.35cells in group 2 and 1.58 ± 0.33 in group 3. Five daysafter injury, the mean apoptotic cell count was 4.35 ±0.47 in group 2 and 1.25 ± 0.34 in group 3. Thus thenumber of TUNEL-positive cells in an injured spinalcord was greatly reduced by treatment with Q-VDOPh.The neurologic function scores (both the inclinedplane performance and motor grading scores) were significantlybetter in the Q-VD-OPh–treated (AU)

Introducción. En el desarrollo de daño secundario tras lesión medular están implicadas diversas caspasas.La terapia anti-caspasas ha utilizado como diana una sola caspasa que ha sido investigada en una gran variedad de estudios tanto in-vitro como in-vivo. Estos estudios han examinado el efecto neuroprotector delQ-VD-PPh, un inhibidor pan-caspasa, en un modelo delesión medular en rata. Material y métodos. Se dividieron 30 ratas Wistar entres grupos de 10 ratas cada uno: una lesión medulartraumática (con un trauma de 40 g-cm) se realizó anivel torácico grupo control (grupo 1), grupo traumacontrol (grupo 2) y el grupo de ratas tratadas con QVD-OPh (grupo 3) se realizó a nivel torácico (T8-T10) mediante la técnica de caída de peso. La respuesta a la lesión y los efectos neuroprotectores de Q-VD-OPh se valoraron mediante el examen histopatológico y la técnica de TUNEL 24 horas y 5 días tras el traumatismo. Se usó la prueba del plano inclinado de Rivlin y Tatory una versión modificada de la escala de Tarlov paravalorar el resultado funcional de las ratas 24 horas, 3 días y 5 días tras la lesión. Resultado. Veinticuatro horas tras la lesión, el estudio histopatológico de las secciones obtenidas del grupo 2 revelaron hemorragia, necrosis, trombos vasculares y edema. Las secciones obtenidos del grupo 3 mostraron hallazgos similares en ese momento. 24 horas tras lalesión el número de células apoptóticas fue 4.47 ± 0.35en el grupo 2 y 1.58 ± 0.33 en el grupo 3. Cinco días trasla lesión el número medio de células apoptóticas fue de4.35 ± 0.47 en el grupo 2 y de 1.25 ± 0.34 en el grupo 3. De esta forma el número de células TUNEL positivas enla médula dañada se redujo de forma considerable conel tratamiento con Q-VD-OPh (AU)

Evaluación histológica e inmunohistoquímica secuencial de marcadores de proliferación y apoptosis durante el tratamiento de la psoriasis con anti-factor de necrosis tumoral; (infliximab) / Sequential Histological and ImmunohistochemicalAssessment of Proliferation and ApoptoticMarkers During Treatment of Psoriasiswith Antitumor Necrosis Factor α (Infliximab)

Introducción y objetivos. La psoriasis es una enfermedad inflamatoria cutánea de naturaleza inmunológica mediada por citoquinas de tipo Th1. El tratamiento con anticuerpos anti-factor de necrosis tumoral α (TNF-α) (infliximab) ha proporcionado respuestas clínicas significativas; sin embargo, los mecanismos implicadosen la curación no están bien aclarados. El objetivo del presente trabajo es evaluar las variaciones de la histología y en la expresión de marcadores de proliferación y apoptosis, en biopsias cutáneas secuenciales de pacientes con psoriasis tratados con in fliximab. Material y métodos. Se estudiaron biopsias de piel (sana y lesionada) de 3 pacientes afectados de psoriasis generalizada moderada-grave (índice de área y gravedad de la soriasis [PASI]: 35 de media) tratados con infusiones por vía intravenosa de infliximab (5 mg/kg) en las semanas 0, 2 y 6. Las biopsias se realizaron en los días 0, 14 y 28, y fueron procesadas para estudio histológico convencional e inmunohistoquímico con marcadores de apoptosis–TP53, BCL-2 y anticaspasas 3 y 8– y de proliferación celular –Ki67–. Resultados. El tratamiento con infliximab se asoció con una significativa mejoría clínica en los 3 pacientes (PASI medio: 21,6 a los 14 días y 13,9 a las 6 semanas), que se correlacionó con la desaparición progresiva de las lesiones histológicas, con disminución de la proliferación epidérmica. Sin embargo, no observamos imágenes de apoptosis ni obtuvimos positividad con los anticuerpos anticaspasas. La expresión de TP53 disminuyó a las2 semanas del inicio del tratamiento, siendo similar a la piel normal a los 28 días. Conclusiones. La respuesta clínica e histológica de la psoriasis con infliximab no se asoció a un incremento significativo en los marcadores de apoptosis evaluados (AU)

Background and objectives. Psoriasis is an inflammatory skin disease of immunologic nature that is mediated by T-helper-1 cytokines. Clinical response to treatment with antitumor necrosis factor (TNF) –α antibodies (infliximab) has been significant; however, the mechanisms for clearance of lesions have not been elucidated. The aim of the present study was to assess variations in the histology and expression of proliferation and apoptotic markers in sequential skin biopsies of patients with psoriasis treated with infliximab. Material and methods. We studied skin biopsies (of lesioned and healthy skin) from 3 patients with extensive moderate-to-severe psoriasis (mean psoriasis area and severity index [PASI] score, 35) treated with intravenous infliximab infusions (5 mg/kg) at weeks 0, 2, and 6. Biopsies were taken on days 0, 14, and 28, and were processed for conventional histological and immunohistochemical study. The apoptotic markers used were TP53, B-cell lymphoma 2 protein, anticaspase 3, and anticaspase 8. The cell proliferation marker used was Ki67. Results. Treatment with infliximab was associated with a significant clinical improvement in 3 patients (mean PASI score, 21.6 at 14 days and 13.9 at 6 weeks), which correlated with the progressive disappearance of histological lesions with a decrease in epidermal proliferation. However, apoptosis was not observed, and the samples tested negative for anticaspase antibodies. Expression of TP53 decreased 2 weeks after starting treatment, and was similar to that in normal skin at 28 days. Conclusions. Clinical and histological response of psoriasis to infliximab was not associated with a significant increase in the apoptotic markers assessed (AU)

Envelhecer e morrer / To age and to die

Após breve consideração sobre a origem da vida, os autores questionaram o porquê de se envelhecer e evoluir para o fim. A morte celular programada (apoptose) é discutida, com seu substrato bioquímico (proteases, família, BCL-2, mediadores-chaves na ativação das caspases, inibidores da apoptose). Expõem 18 teorias que procuram explicar o envelhecimento. Relatam, de forma objetiva, as conseqüências da ação do tempo sobre os diversos órgãos e sistemas. Concluem questionando a relação de causalidade entre as teorias expostas e os achados físicos observados no processo de envelhecimento.

After some consideration on the origin of life, the authors question the reason to age and to go to an end. The programmed cellular death (apoptosis) is discussed with its biochemical substratum (proteases, BCL-2 family, key-mediators in the activation of caspases, inhibitors of apoptosis). Eighteen theories that try to explain aging are presented. The consequences of the actin of time on the variios organs and systems will be objectivelly reported. The authors conclude by questioning the relation of causality between the theories displayed and the physical findings observed in the aging process.

Human Telomerase Reverse Transcriptase (hTERT): A Target Molecule for the Treatment of Cisplatin-resistant Tumors / 대한진단검사의학회지

BACKGROUND: Human telomerase reverse transcriptase (hTERT) is a catalytic enzyme that is required for telomerase activity (TA) and cancer progression. Telomerase inhibition or inactivation increases cellular sensitivity to UV irradiation, DNA-damaging agents, the tyrosine kinase inhibitor, imatinib, and pharmacological inhibitors, such as BIBR1532. hTERT is associated with apoptosis. Some patients show drug-resistance during anti-cancer drug treatment and the cancer cell acquire anti-apoptotic mechanism. Therefore, we attempted to study correlation between hTERT and drug-resistance. METHODS: To study the correlation between protein level and activity of hTERT and drug-resistance, Western blotting and telomerase repeat amplification protocol (TRAP) assays were performed. To investigate whether hTERT contributes to drug resistance in tumor cells, we transiently decreased hTERT levels using small interfering RNA (siRNA) in T24/R2 cells. RESULTS: hTERT knockdown increased Bax translocation into the mitochondria and cytochrome C release into the cytosol. Caspase inhibitors, especially Z-VAD-FMK, rescued this phenomenon, suggesting that the stability or expression of hTERT might be regulated by caspase activity. CONCLUSIONS: These data suggest that hTERT might be a target molecule for drug-resistant tumor therapy.

FLIP as an Anti-Cancer Therapeutic Target

Suppression of apoptosis is one of the hallmarks of carcinogenesis. Tumor cells endure apoptotic pressure by overexpressing several antiapoptotic proteins, and FLICE inhibitory protein (FLIP) is one of the important antiapoptotic proteins that have been shown to be overexpressed in various primary tumor cells. FLIP has two death-effector domains in tandem, mimicking the prodomain of procaspase-8. It is recruited to Fadd in death-inducing signaling complex, thereby preventing the activation of procaspase-8. To date, three isoforms of human cytosolic FLIP (c-FLIP) and six viral homologs (v-FLIP) have been identified. Recently, the crystal structure of v-FLIP MC159 was determined for the first time as an atomic-detail FLIP structure, which revealed that two death effector domains are packed tightly against each other mainly through conserved hydrophobic interactions. The overexpression of c-FLIP in tumor cells has been shown to be the determinant of the tumor's resistance to death ligands such as FasL and TRAIL. It has also been shown that the down-regulation of c-FLIP results in sensitizing resistant tumor cells. Therefore, the agents directly targeting c-FLIP at mRNA and protein levels are expected to be developed in near future and tested for the potential as a new class of anti-cancer drugs.

Neuronal loss in primary long-term cortical culture involves neurodegeneration-like cell death via calpain and p35 processing, but not developmental apoptosis or aging

Primary neuronal culture is a powerful tool to study neuronal development, aging, and degeneration. However, cultured neurons show signs of cell death after 2 or 3 weeks. Although the mechanism underlying this phenomenon has not been elucidated, several preventive methods have been identified. Here we show that the neuronal loss in primary cortical culture involves calpain activation and subsequent neuronal cell death. Neuronal loss during cultivation showed destruction of neurites and synapses, and a decrease in neuron numbers. micro-Calpain and micro-calpain were initially activated and accumulated by increased RNA expression. This neuronal death exhibited neurodegenerative features, such as conversion of p35 to p25, which is important in the developmental process and in the pathogenesis of Alzheimer's disease. But, postnatal and aged rat cortex did not show calpain activation and prolonged processing of p35 to p25, in contrast to the long-term culture of cortical neurons. In addition, the inhibition of calpains by ALLM or ALLN blocked the conversion of p35 to p25, indicating that the calpain activity is essential for the neurodegenerative features of cell death. Taken together, this study shows that the neuronal loss in primary cortical cultures involves neurodegeneration-like cell death through the activation of calpains and the subsequent processing of p35 to p25, but not developmental apoptosis or aging. Our results suggest that the long term primary culture of cortical neurons represent a valuable model of neurodegeneration, such as Alzheimer's disease.

Prostaglandin A2 Induces Caspase-independent Apoptosis in Hepatocellular Carcinoma Cells / 대한간학회지

BACKGROUND/AIMS: Prostaglandin (PG) A2 has been reported to inhibit the growth of hepatocellular carcinoma cells via activation of apoptosis, although the molecular mechanisms involved have not been clarified, yet. To investigate the mechanism of the PGA2-induced apoptosis, we analyzed the activation of caspases during the apoptosis of hepatoma cell lines. METHODS: Induction of apoptosis by PGA2 in hepatoma cell lines, Hep 3B and Hep G2, was assessed by DAPI staining of nuclei and agarose gel electrophoresis of genomic DNA. The involvement of caspases was analyzed by immunoblot analysis of poly ADP-ribose polymerase (PARP) and by checking the effect of caspase inhibitors on PGA2-induced apoptosis. RESULTS: PGA2 inhibited the growth of Hep 3B and Hep G2 cells, accompanying nuclear condensation and fragmentation, and genomic DNA laddering, which are the hallmarks of apoptosis. The PARP was not cleaved during the apoptosis of Hep 3B and Hep G2 cells and caspase inhibitors such as z-VAD-Fmk and z-DEVD-Fmk exerted no effect on the PGA2-induced apoptosis. CONCLUSIONS: These results suggest that PGA2 induces apoptosis in Hep 3B and Hep G2 cells via caspase-independent pathway.

Norcantharidin Induces Human Melanoma A375-S2 Cell Apoptosis through Mitochondrial and Caspase Pathways

Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris. To examine the pathway of NCTD-induced A375-S2 cell death, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide (MTT) assay, photomicroscopical observation, DNA agarose gel electrophoresis, caspase activity assay and Western blot analysis were carried out. A375-S2 cells treated with NCTD exhibited several typical characteristics of apoptosis. The inhibitory effect of NCTD on human melanoma, A375-S2 cells, was partially reversed by the inhibitors of pan-caspase, caspase-3 and caspase-9. The activities of caspase-3 and -9 were significantly increased after treatment with NCTD at different time. The expression of inhibitor of caspase-activated DNase was decreased in a time-dependent manner, simultaneously, the ratio of Bcl-2/Bax or Bcl-xL/Bax was decreased and the expression ratio of proteins could be reversed by caspase-3 inhibitor. The expression of cytochrome c in cytosol was increased after NCTD treatment and caspase- 3 inhibitor had no significant effect on the up-regulation of cytochrom c. These results suggest that NCTD induced A375-S2 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of NCTD-induced A375-S2 cell apoptosis.

Pseudolaric acid B induces apoptosis via activation of c-Jun N-terminal kinase and caspase-3 in HeLa cells

Pseudolaric acid B was isolated from Pseudolarix kaempferi Gordon (Pinaceae) and was evaluated for the anti-cancer effect in HeLa cells. We observed that pseudolaric acid B inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. HeLa cells treated with pseudolaric acid B showed typical characteristics of apoptosis including the morphological changes and DNA fragmentation. JNK inhibitor, SP600125, markedly inhibited pseudolaric acid B-induced cell death. In addition, Bcl-2 expression was down-regulated while Bax protein level was up-regulated. Caspase-3 inhibitor, z-DEVD-fmk, partially blocked pseudolaric acid B-induced cell death, and the expression of two classical caspase substrates, PARP and ICAD, were both decreased in a time- dependent manner, indicative of downstream caspase activation.

Nuevas estrategias terapéuticas basadas en apoptosis y virus / Viruses and apoptosis-based therapeutic agents in human diseases

En éste trabajo se presentan los mecanismos y las moléculas que participan de la apoptosis en células de mamífero. Se discute la función de la mitocondria, se relacionan los distintos controles del sistema con patologías humanas y se presentan algunos virus neurotrópicos donde existe una importante conexión con la apoptosis. Asimismo, se indican algunos factores participantes del proceso que tienen una veta promisoria en el tratamiento de enfermedades donde la desregulación de la muerte celular programada es la causa de la patología en cuestión (AU)

Macrophage colony-stimulating factor promotes the survival of osteoclast precursors by up-regulating Bcl-XL

Macrophage colony-stimulating factor (M-CSF) is known as one of the factors essential for osteoclast development. In the present study, we examined effects of M-CSF on the apoptotic pathway of osteoclast precursors and their underlying molecular mechanisms. Osteoclast precursors underwent apoptosis in the absence of M-CSF, even in the presence of receptor activator of NF-kB ligand (RANKL). Active caspase-3 and -9 were detected in the osteoclast precursors and treatments of precursors with their specific inhibitors (Z- DEVD-FMK and Z-LEHD-FMK) decreased the apoptosis. M-CSF decreased apoptosis in a dose-dependent manner with decreasing in active caspases-3 and -9 levels and up-regulating Bcl-XL. Those effects of M-CSF on inhibiting apoptosis of osteoclasts precursor by regulating anti-apoptotic signals was more effective when combined with RANKL. These results demonstrate that M-CSF acts as a survival factor for the osteoclast precursors. Furthermore, it is believed that the apoptosis of osteoclast precursors may be involved in the activation of caspase-9 and that M-CSF may promote their survival through Bcl-XL-induced inhibition of caspase-9 activation.