Role Of Caspases Research Articles

The Role of Caspases in Melanoma Pathogenesis.

Melanoma (malignant melanoma, MM) is an aggressive malignant skin cancer with an increasing incidence rate. The complete pathogenesis of MM in not clear. Due to DNA damage, mutations, dysregulation of growth factors, inactivation of tumor suppressor genes, and activation of oncogenes, excessive uncontrolled growth of abnormal melanocytes occurs in melanomas. Caspases are a group of proteolytic enzymes that participate in several processes important in regulating mechanisms at the cellular level. They play a role in cell homeostasis and programmed cell death (apoptosis) and in the regulation of non-apoptotic cell death processes. Dysregulation of caspase activation plays a role in the etiology of cancers, including melanoma. Caspases can initiate and execute apoptosis and are involved in regulating cell death and controlling tumor growth. These enzymes also inhibit tumor growth by cleaving and inactivating proteins that are involved in cell proliferation and angiogenesis. Moreover, caspases are involved in the activation of immune processes through the processing and presentation of tumor antigens, which facilitates recognition of the tumor by the immune system. The role of caspases in melanoma is complex, and they may inhibit melanoma growth and progression. This work aims to review the current knowledge of the role of individual caspases in melanoma pathogenesis.

Caspase-8 activity mediates TNFα production and restricts Coxiella burnetii replication during murine macrophage infection.

Coxiella burnetii is an obligate intracellular bacteria that causes the global zoonotic disease Q Fever. Treatment options for chronic infection are limited, and the development of novel therapeutic strategies requires a greater understanding of how C. burnetii interacts with immune signaling. Cell death responses are known to be manipulated by C. burnetii, but the role of caspase-8, a central regulator of multiple cell death pathways, has not been investigated. In this research, we studied bacterial manipulation of caspase-8 signaling and the significance of caspase-8 to C. burnetii infection, examining bacterial replication, cell death induction, and cytokine signaling. We measured caspase, RIPK, and MLKL activation in C. burnetii-infected tumor necrosis factor alpha (TNFα)/cycloheximide-treated THP-1 macrophage-like cells and TNFα/ZVAD-treated L929 cells to assess apoptosis and necroptosis signaling. Additionally, we measured C. burnetii replication, cell death, and TNFα induction over 12 days in RIPK1-kinase-dead, RIPK3-kinase-dead, or RIPK3-kinase-dead-caspase-8-/- bone marrow-derived macrophages (BMDMs) to understand the significance of caspase-8 and RIPK1/3 during infection. We found that caspase-8 is inhibited by C. burnetii, coinciding with inhibition of apoptosis and increased susceptibility to necroptosis. Furthermore, C. burnetii replication was increased in BMDMs lacking caspase-8, but not in those lacking RIPK1/3 kinase activity, corresponding with decreased TNFα production and reduced cell death. As TNFα is associated with the control of C. burnetii, this lack of a TNFα response may allow for the unchecked bacterial growth we saw in caspase-8-/- BMDMs. This research identifies and explores caspase-8 as a key regulator of C. burnetii infection, opening novel therapeutic doors.

Role of caspase-6 in the formation of severe chronic heart failure in patients infected with the human immunodeficiency virus

Caspases are a group of cysteine proteases that play a leading role in the processes of apoptosis. There is evidence that apoptosis of cardiomyocytes is the morphological basis for the formation of chronic heart failure (CHF). The aim of the study was to study the role of caspase-6 in the blood serum of patients with severe CHF infected with the human immunodeficiency virus (HIV). In 2019–2022, on the basis of a large hospital, a one-stage screening clinical study was performed with the inclusion of 240 patients infected with HIV, 160 of them (66.6 %) were diagnosed with CHF. Inclusion criteria for the study were the presence of confirmed CHF, the presence of HIV infection, stabilization of the condition due to the disease that required hospitalization, and the patient's consent to participate in the study. The criteria for exclusion from the study were social deprivation and refusal to sign informed voluntary consent, acute decompensation of CHF, acute heart failure, and oncology. The criterion for severe CHF was an increase in the level of NT-proBNP in blood plasma ≥ 1500 pg/ml. According to the results of the study, a direct close relationship was revealed between the formation of severe CHF and the content of caspase-6 in the blood serum, which may indicate an intensification of the processes of cardiomyocyte apoptosis. When the content of caspase-6 is equal to 148.35 pg/ml and above, there is a high risk of developing severe CHF with NT-pro BNP ≥ 1500 pg/ml, the chances of developing the following complications increase – CHF with low left ventricular ejection fraction (LVEF) < 40 % – 11.77 times, left ventricular hypertrophy (LVH) – 1.31 times, cachexia with a body mass index (BMI) < 18 – 18.91 times, valvular heart disease – 2.32 times, arterial hypotension - 5.96 times. In patients with CHF and HIV infection, the patterns obtained allow us to state the role of the effector enzyme apoptosis-caspase-6 as a prognostic factor for the development of such complications as LVEF < 40 %, cachexia, arterial hypotension, valvular heart disease and LVH.

Caspase-2 protects against ferroptotic cell death

Caspase-2, one of the most evolutionarily conserved members of the caspase family, is an important regulator of the cellular response to oxidative stress. Given that ferroptosis is suppressed by antioxidant defense pathways, such as that involving selenoenzyme glutathione peroxidase 4 (GPX4), we hypothesized that caspase-2 may play a role in regulating ferroptosis. This study provides the first demonstration of an important and unprecedented function of caspase-2 in protecting cancer cells from undergoing ferroptotic cell death. Specifically, we show that depletion of caspase-2 leads to the downregulation of stress response genes including SESN2, HMOX1, SLC7A11, and sensitizes mutant-p53 cancer cells to cell death induced by various ferroptosis-inducing compounds. Importantly, the canonical catalytic activity of caspase-2 is not required for its role and suggests that caspase-2 regulates ferroptosis via non-proteolytic interaction with other proteins. Using an unbiased BioID proteomics screen, we identified novel caspase-2 interacting proteins (including heat shock proteins and co-chaperones) that regulate cellular responses to stress. Finally, we demonstrate that caspase-2 limits chaperone-mediated autophagic degradation of GPX4 to promote the survival of mutant-p53 cancer cells. In conclusion, we document a novel role for caspase-2 as a negative regulator of ferroptosis in cells with mutant p53. Our results provide evidence for a novel function of caspase-2 in cell death regulation and open potential new avenues to exploit ferroptosis in cancer therapy.

The key role of vitamin C in the treatment of pulmonary hypertension of meat-type chickens: role of caspase-3

Ascites is a prominent example of the pathophysiological interaction between the heart and lungs in broilers. Previous experiments have shown that the amount of apoptosis increases in heart failure and pulmonary hypertension. In the current study, the effect of vitamin C on apoptosis was investigated by measuring the expression of the CASP3 gene in the heart and lungs of chickens with ascites. For this purpose, 90 one-day-old meat-type chickens were divided into three groups (sham (basal diet), control (basal diet +1.5 mg/kg of triiodothyronine (T3)), and treatment group (basal diet + 1.5 mg/kg of T3 + 1200 ppm of vitamin C)) and bred for 49 days. On the 21st and 49th days after rearing, 15 chickens from each group were selected randomly, and the right ventricle/ total ventricle weight ratio (RV/TV), as well as the expression level of CASP3 genes in the lung and right ventricle of all groups were measured and compared. The amount of mRNA related to CASP3 gene at the age of 21 and 49 days demonstrated a meaningful decrease in the treatment group compared to the control group (P<0.05). This significant difference indicates the reduction of apoptosis in the group treated with vitamin C. Also, RV/TV as an index of the induction of this syndrome improved in the treatment group at the age of 21 and 49 days (P<0.05). Finally, according to the current study's findings, vitamin C has ameliorating effects in treating ascites in meat-type chickens.

The Role of Caspase-11 and Pyroptosis in the Regulation of Inflammation in Peri-Implantitis.

Peri-implantitis is an important cause of oral implant failure. In the past, TLR4 and TLR2 in the Toll-like family were generally considered as the key immune recognition receptors regulating peri-implantitis. However, under the guidance of this theory, there are still some unexplainable peri-implantitis symptoms. With the discovery of novel intracellular LPS receptor Caspase-11, a new understanding of inflammatory signaling and immune regulation in the development of peri-implantitis has been gained. However, the regulatory role of Caspase-11 in peri-implantitis and its crosstalk with the TLR4 pathway remain unclear. The therapeutic effect of drugs targeting Caspase-11 on peri-implantitis is still in its early stages. In view of this situation, this paper reviews the possible role of Caspase-11 in peri-implant inflammation, elaborated the entry process of LPS and the activation mechanism of Caspase-11, and analyzes the differences in Caspase-11 between commonly studied animals, mice and humans. The current research hotspots and challenges are also analyzed to provide new insights and ideas for researchers.

Caspase-1 affects chronic restraint stress-induced depression-like behaviors by modifying GABAergic dysfunction in the hippocampus

Major depression disorder (MDD) is one of the most common psychiatric disorders and one of the leading causes of disability in worldwide. Both inflammation and GABAergic dysfunction have been implicated in the pathophysiology of MDD. Caspase-1, a classic inflammatory caspase, regulates AMPARs-mediated glutamatergic neurotransmission. However, the role of caspase-1 in chronic stress-induced GABAergic dysfunction remains largely unknown. In this study, we found that serum and hippocampal caspase-1-IL-1β levels increased significantly in chronic restraint stress (CRS) mice, and a significant negative correlation occurred between levels of caspase-1 and depression-like behaviors. Furthermore, CRS significantly decreased GAD67 mRNA levels and GABAergic neurotransmission accompanied by the reduction of GABA concentration, reduced the amplitude and frequency of mIPSCs inhibitory postsynaptic currents (mIPSCs) and the decreased surface expression of GABAARs γ2 subunit in the hippocampus. Genetic deficiency of caspase-1 not only blocked CRS-induced depression-like behaviors, but also alleviated CRS-induced impairments in GABAergic neurotransmission. Finally, reexpression of caspase-1 in the hippocampus of Caspase-1−/− mice increased susceptibility to stress-induced anxiety- and depression-like behaviors through inhibiting GAD67 expression and GABAARs-mediated synaptic transmission. Our study suggests that CRS dysregulates GABAergic neurotransmission via increasing the levels of caspase-1-mediated neuroinflammation in the hippocampus, ultimately leading to depression-like behaviors. This work illustrates that targeting caspase-1 may provide potential therapeutic benefits to stress-related GABAergic dysfunction in the pathogenesis of MDD.

Role of Caspase-11 in house dust mites-mediated lung inflammation

Abstract Asthma is a long-term recurring inflammatory lung disorder characterized by mucus hypersecretion, cellular infiltration, chronic airway inflammation and bronchial hyper-responsiveness. House dust mites (HDM), such as Dermatophagoides pteronyssinus, are an unsurpassed cause of atopic sensitization and the major causes of allergic asthma worldwide. The multiprotein complexness of the canonical and noncanonical inflammasomes assemble in response to pathogen or danger-associated molecular patterns (PAMPs or DAMPs). We have shown that caspase-11 expression is induced in vitro in response to HDM. Treatment with TH2 cytokines such as IL-4 and IL-13 mediates caspase-11 expression. Additionally, caspase-11−/−macrophages show reduced release of IL-6, IL-12, and KC, and express lower levels of costimulatory molecules (e.g., CD40, CD86 and MHCII) in response to HDM stimulation. Notably, similar level of IgE responses and similar degree of hypothermia in response to nasal HDM challenge were seen in WT and caspase-11−/−mice following HDM sensitization. However, altered inflammatory responses and reduced neutrophilia in bronchiolar alveolar lavage fluid (BALF) and in representative histopathological lung tissues were seen in the caspase-11−/−mice. Therefore, caspase-11 is a regulator of airway inflammation in response to HDM exposure.

Abstract LB035: The role of nucleophosmin1 mediated caspase2 activation in acute myeloid leukemia cell death and cell survival

Abstract Nucleophosmin 1 (NPM1) mutation is the primary genetic lesion in adult acute myeloid leukemia (AML). Typically, a nucleolar protein, NPM1 mutations cause cytoplasmic delocalization of NPM1(NPM1c+), triggering leukemogenesis. Interestingly, NPM1c+ mutation confers enhanced chemosensitivity. However, the mechanism underlying NPM1c+ mutation-induced oncogenesis or chemosensitivity remains unclear. We previously reported that, in response to genotoxic stimuli, NPM1 forms a platform for caspase-2 activation in the nucleolus. Caspase-2 is a pro-apoptotic protein and a known tumor suppressor. Our results indicate that nucleolar caspase-2 activation is specific to NPM1wt cells. In the NPM1c+ cells, caspase-2 activation is exclusively cytosolic, suggesting that caspase-2 is activated in the same sub-cellular compartment as NPM1 localization. Loss of caspase-2 rescued the increased sensitivity of NPM1c+ cells to apoptotic cell death. This is accompanied by reduced cleavage of the apoptotic substrate, caspase-3. Notably, caspase-2 deficient NPM1wt cells showed no significant difference in the percentage of apoptotic cell death or endogenous substrate cleavage compared to its caspase-2 wild-type counterpart. This suggests that caspase-2 may contribute to the chemosensitivity of NPM1c+ cells. Strikingly, in unstimulated cells, loss of caspase-2 leads to prolonged G1 arrest and progressive loss of cell viability. Immunophenotyping of NPM1c+ cells revealed a remarkable increase in the CD14+population representing monocyte/macrophage-like features, suggesting that loss of caspase-2 results in terminal differentiation. Exogenous expression of NPM1c+ in caspase-2 deficient NPM1wt cells impaired viability, confirming that NPM1c+ cells require caspase-2 for its growth and proliferation. Transcriptomic analysis revealed that loss of caspase-2 significantly downregulates pathways involved in stem cell pluripotency. In particular, FGF2, IGFR, WNT, LIF, and one of the core members of the self-renewal transcription factor, OCT 4, were downregulated in the absence of caspase-2 in NPM1c+ cells. This reveals a novel role for caspase-2 in maintaining NPM1c+ AML stemness. Taken together, our study shows that NPM1c+ mediated caspase-2 activation regulates AML cell death and survival cascades, a key determinant of chemosensitivity and leukemogenesis. Citation Format: Dharaniya Sakthivel, Alexandra Brown-Suedel, Francesca Keane, F. Kenneth McSherry, Chloe I. Charendoff, Kevin Dunne, Dexter Robichaux, Jonathan M. Flanagan, Lisa Bouchier-Hayes. The role of nucleophosmin1 mediated caspase2 activation in acute myeloid leukemia cell death and cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB035.

Abstract 3651: The role of caspase-1 in basal-like breast cancer and the tumor microenvironment

Abstract Introduction: Breast cancer is the most common malignancy in women world-wide. Basal-like breast cancer (BLBC) is an aggressive subtype with poor prognosis for which there are no known targeted therapies. Understanding what drives complex cell-cell interactions within the tumor microenvironment (TME) is critical to developing new strategies. BLBC has previously been shown to have high expression of the inflammatory cytokine IL1β, which then promotes the recruitment of pro-tumoral tumor-associated macrophages (TAMs) to the TME. Here we report that BLBC is uniquely capable of IL1β secretion due to elevated expression of caspase-1, a key component of the inflammasome required for IL1β maturation. Methods: Using publicly available gene expression data sets, the association between caspase-1, breast cancer subtype and estrogen receptor (ER) co-expression was examined. These associations were further assessed in vitro by exposing luminal (T47D/MCF7) or BLBC (MDA-MB231) cell lines to siER knockdown or ER overexpression. Using both a CRISPR/Cas9 generated caspase-1 knockout (KO) BLBC mouse line as well as pharmacological inhibition with the caspase-1 inhibitor VX-765, the effect of caspase-1 on tumor growth was studied in syngeneic immunocompetent mice. Immune infiltrates were assessed via flow cytometry of the excised murine tumors as well as immunohistochemistry. To prove these results were IL1β specific, caspase-1 KO tumor allografts containing self-cleaving IL1β were used for comparison. Finally, to determine potential synergy between caspase-1 and immune checkpoint inhibition, wild type and caspase-1 KO allografts were simultaneously treated with anti-PD1 immunotherapy. Tumor growth and immune infiltrates were analyzed between the treatment groups as stated above. Results: Caspase-1 was found to be associated with the basal-like subtype and have an inverse relationship with ER expression. In vitro, inhibition of ER increased caspase-1 expression, whereas ER overexpression decreased caspase-1. Caspase-1 KO or pharmacological inhibition resulted in a significant decrease in tumor growth and TAM infiltration, and these findings were rescued back to wild type levels with the addition of a self-cleaving IL1β. Finally, caspase-1 inhibition reversed resistance to anti-PD1 immunotherapy in murine allografts, resulting in significant deceleration of tumor growth when used in combination. Summary: The lack of ER in BLBC promotes caspase-1 expression, allowing IL1β maturation, macrophage recruitment and tumor progression. Genetic or pharmacologic inhibition of caspase-1 inhibits TAM recruitment and reverses resistance to immune checkpoint inhibition in BLBC. Conclusions: Our data provides new insights into the biology of BLBC and identifies the combination of caspase-1/IL1β inhibition and immunotherapy as a novel therapeutic strategy to combat this disease. Citation Format: Wanda Marini, Weiyue Zheng, Kiichi Murakami, Pamela S. Ohashi, Michael Reedijk. The role of caspase-1 in basal-like breast cancer and the tumor microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3651.

Overexpression of CASP1 triggers acute promyelocytic leukemia cell pyroptosis and differentiation

Caspase-1 (CASP1)-mediated classical pyroptosis plays a key role in cancer development and management, however, the role of CASP1 and its regulation has not yet been documented for acute promyelocytic leukemia (APL). Here, we found that CASP1/GSDMD had lower expression in patients with APL and most other subtypes of primary de novo acute myeloid leukemia (AML) and was increased in all-trans-retinoic acid (ATRA)-treated APL cells. We showed that ATRA increases and activates CASP1 to trigger the pyroptosis and differentiation of APL cells. Mechanistically, ATRA could induce CASP1 expression via the IFNγ/STAT1 pathway in APL cells. In conclusion, ATRA-induced activation of CASP1 may serve as a suppressor in APL progression, as it triggers pyroptotic cell death and differentiation.

New Insights of Early Brain Injury after Subarachnoid Hemorrhage: A Focus on the Caspase Family.

Spontaneous subarachnoid hemorrhage (SAH), primarily caused by ruptured intracranial aneurysms, remains a prominent clinical challenge with a high rate of mortality and morbidity worldwide. Accumulating clinical trials aiming at the prevention of cerebral vasospasm (CVS) have failed to improve the clinical outcome of patients with SAH. Therefore, a growing number of studies have shifted focus to the pathophysiological changes that occur during the periods of early brain injury (EBI). New pharmacological agents aiming to alleviate EBI have become a promising direction to improve outcomes after SAH. Caspases belong to a family of cysteine proteases with diverse functions involved in maintaining metabolism, autophagy, tissue differentiation, regeneration, and neural development. Increasing evidence shows that caspases play a critical role in brain pathology after SAH. Therefore, caspase regulation could be a potential target for SAH treatment. Herein, we provide an overview pertaining to the current knowledge on the role of caspases in EBI after SAH, and we discuss the promising therapeutic value of caspase-related agents after SAH.

Preventive effect of quercetin-Loaded nanophytosome against autistic-like damage in maternal separation model: The possible role of Caspase-3, Bax/Bcl-2 and Nrf2

The autism is an abnormality in the neuronal advance which starts before age 3 recognized by defective behaviors. This study aimed to make quercetin-loaded nanophytosomes (QNP) on behavioral deficits, cerebellar oxidative stress and apoptosis in an autistic-like model caused by maternal separation (MS). The newborn rats are randomly categorized into seven groups, including control, positive control, disease, and diseases treated with quercetin (10 and 40 mg/kg) and QNP (10 and 40 mg/kg). Pups exposed to MS for 3 h per day from postnatal days (PND) 1–9 showed behavioral impairment in adult rats compared to control group. The oral administration of quercetin and QNP was constantly started after the lactation period (21 postnatal days) for three weeks. Autistic-like behaviors, antioxidant parameters, and Nrf2, Bax/Bcl-2, and Caspase-3 expressions were surveyed in the cerebellum. Quercetin (40 mg/kg) treated improved some behavioral disorders. Also, the improvement of oxidative stress parameters, Nrf2 and apoptotic factors gene expression was observed in the cerebellum of quercetin (40 mg/kg) treated (p < 0.01). QNP treatment (10 and 40 mg/kg) significantly ameliorated anxiety-like behaviors, line crossing, and grooming index (p < 0.001), lipid peroxidation (p < 0.001), and increased catalase (CAT) (p < 0.001), superoxide dismutase (SOD) (p < 0.001), glutathione peroxidase (GPx) (p < 0.001) activity, and glutathione (GSH) levels (p < 0.05). Moreover, QNP significantly reduced Caspase-3 and Bax expression (p < 0.001), but increased Bcl-2, and Nrf2 expressions (p < 0.001). These findings indicated that QNP due to its high bioavailability was more effective than quercetin can be reduced autistic-like behavior, oxidative and apoptotic damages in the model of MS rats.

The Role of Caspases in Alzheimer's Disease: Pathophysiology Implications and Pharmacologic Modulation.

Alzheimer's disease (AD) is the most common neurodegenerative disorder worldwide. Although the main cause of the onset and development of AD is not known yet, neuronal death due to pathologic changes such as amyloid-β (Aβ) deposition, tau aggregation, neuroinflammation, oxidative stress, and calcium dyshomeostasis are considered to be the main cause. At the present, there is no cure for this insidious disorder. However, accurate identification of molecular changes in AD can help provide new therapeutic goals. Caspases are a group of proteases which are known because of their role in cellular apoptosis. In addition, different caspases are involved in other cellular responses to the environment, such as induction of inflammation. Emerging evidence suggest that these proteases play a central role in AD pathophysiology due to their role in the processing of amyloid-β protein precursor, tau cleavage, and neuroinflammation. Therefore, it seems that targeting caspases may be a suitable therapeutic option to slow the progression of AD. This review focuses on the role of caspases in AD pathophysiology and introduce results from studies targeted caspases in different models of AD.

Isofraxidin enhances hyperthermia‑induced apoptosis via redox modification in acute monocytic leukemia U937 cells.

The cell‑killing potential of most chemotherapeutic agents is enhanced by a temperature elevation. Isofraxidin (IF) is a coumarin compound widely found in plants, such as the Umbelliferae or Chloranthaceae families. IF induces anticancer effects in lung and colorectal cancer. To the best of our knowledge, the combined effects of hyperthermia (HT) and IF on heat‑induced apoptosis have not been reported. Acute monocytic leukemia U937 cells were exposed to HT with or without IF pre‑treatment. Apoptosis was measured by Annexin V‑FITC/PI double staining assay using flow cytometry and cell viability was observed by cell counting kit assay, DNA fragmentation. The mechanism involved in the combination was explored by measuring changes in the mitochondrial membrane potential, (MMP), intracellular ROS generation, expression of apoptosis related protein, and intracellular calcium ion level. It was demonstrated that IF enhanced HT‑induced apoptosis in U937 cells. The results demonstrated that combined treatment enhanced mitochondrial membrane potential loss and transient superoxide generation increased protein expression levels of caspase‑3, caspase‑8 and phosphorylated‑JNK and intracellular calcium levels. Moreover, the role of caspases and JNK was confirmed using a pan caspase inhibitor (zVAD‑FMK) and JNK inhibitor (SP600125) in U937 cells. Collectively, the data demonstrated that IF enhanced HT‑induced apoptosis via a reactive oxygen species mediated mitochondria/caspase‑dependent pathway in U937 cells.

Role of caspase-8 in stem cell transplantation alleviates rat cerebral cortex apoptosis after cardiopulmonary resuscitation

To explore the effects and the possible mechanism of bone marrow mesenchymal stem cell (BMMSC) transplantation on apoptosis in rats cerebral cortex after cardiac arrest/cardiopulmonary resuscitation (CA/CPR). The BMMSC of 2 Sprague-Dawley (SD) rats aged 4-5weeks was extracted, and the 3rd passage was used in experimental study. Eighteen Sprague-Dawley (SD) rats were divided into sham group, model group (CA/CPR group) and intervention group (BMMSC group) according to random number table method, with 6 rats in each group. CPR was performed 6 minutes after asphyxia induced CA. In sham group, CA was not induced except performing general surgical procedure. At 1 hour after return of spontaneous circulation (ROSC), 0.5 mL phosphate buffered saline (PBS) was injected through tail vein in CA/CPR group. 2×109/L green fluorescence protein (GFP)-labeled BMMSC was injected through tail vein 1 hour after ROSC in BMMSC group. Neurological deficit score (NDS) were assessed in every group at 72 hours after CPR. Serum S100 calcium binding protein B (S100B) levels were assayed by enzyme linked immunosorbent assay (ELISA). Distribution of BMMSC in brain was observed under a fluorescent microscope. Apoptosis rate in cerebral cortex was assayed by TdT-mediated dUTP nick-end labeling (TUNEL). Western blotting was performed to measure the expression levels of active aspartic acid specific cysteine proteinase (caspase-8 and caspase-9) in cerebral cortex. At 3 days after CPR, compared with sham group, the apoptosis of cerebral cortex cells was increased and brain damage was obvious, NDS score was decreased significantly (56.6±5.5 vs. 80.0±0.0, P < 0.05), and serum S100B was increased markedly (ng/L: 45.1±4.7 vs. 19.1±1.4, P < 0.05), apoptosis rate of cerebral cortex cells increased significantly [(52.9±11.8)% vs. (10.1±1.5)%, P < 0.05], the level of active caspase-8 expression in cerebral cortex was significantly higher (caspase-8/GAPDH: 0.689±0.047 vs. 0.330±0.108, P < 0.05), and there was no significant difference in active caspase-9 protein expression (caspase-9/GAPDH: 0.428±0.014 vs. 0.426±0.021, P > 0.05) in CA/CPR group. After BMMSC transplantation, GFP-labeled BMMSC were primarily detected in cerebral cortex, compared with CA/CPR group, the apoptosis of cerebral cortex cells and brain injury were significantly improved in BMMSC group, NDS score increased significantly (70.6±2.1 vs. 56.6±5.5, P < 0.05), serum S100B levels in BMMSC group were lower (ng/L: 32.0±3.2 vs. 45.1±4.7, P < 0.05), apoptosis rate of cerebral cortex cells decreased significantly [(31.1±3.4)% vs. (52.9±11.8)%, P < 0.05], and the active caspase-8 expression in cerebral cortex in BMMSC group was significantly decreased (caspase-8/GAPDH: 0.427±0.067 vs. 0.689±0.047, P < 0.05). The active caspase-9 expression in cerebral cortex in BMMSC group and CA/CPR group were not significantly different (caspase-9/GAPDH: 0.431±0.022 vs. 0.428±0.014, P > 0.05). BMMSC transplantation can alleviate rat brain damage after CA/CPR possibly by inhibiting the death receptor mediated apoptotic pathway to inhibit the apoptosis of brain cells.

Methanolic Moringa oleifera leaf extract protects against epithelial barrier damage and enteric bacterial translocation in intestinal I/R: Possible role of caspase 3.

Background: Activation of caspase 3 has been implicated in the pathogenesis of I/R injury in various organs, but there is a paucity of data on its role in IIRI. Also, no reports were found on the beneficial role of methanolic Moringa oleifera leaf extract (MMOLE) in IIRI. This study investigated the involvement of caspase 3 in IIRI, and the impact of MMOLE in IIRI. Methods: Male Wistar rats were randomized into five groups; the sham-operated group that was sham-operated and received 0.5 ml of distilled water for 7 days prior to sham surgery, and the IIRI, febuxostat (FEB) +IIRI, low dose MMOLE (LDMO)+IIRI, and high dose MMOLE (HDMO)+IIRI groups that underwent I/R and also received 0.5 ml of distilled water, 10 mg/kg of febuxostat, 200 mg/kg of MMOLE, and 400 mg/kg of MMOLE respectively for 7 days prior to I/R. Markers of hepatic function, oxidative stress, and inflammation as well as enteric bacterial translocation and histoarchitecture integrity of intestinal and hepatic tissues were evaluated. The bioactive components of MMOLE were also determined by GC-MS. Results: As revealed by GC-MS, the active bioactive components of MMOLE were thiosemicarbazone, hydrazine, 1,3-dioxolane, octanoic acid, 1,3-benzenediamine, 9-octadecenoic acid, oleic acid, nonadecanoic acid, 3-undecanone, phosphonic acid, and cyclopentanecarboxylic acid. MMOLE alleviated IIRI-induced rise in intestinal and hepatic injury markers, malondialdehyde, TNF-α, IL-6, and myeloperoxidase activities. MMOLE improved IIRI-induced suppression of reduced glutathione, thiol and non-thiol proteins, and superoxide dismutase, catalase and glutathione peroxidase activities. These were associated with suppression of IIRI-induced caspase 3 activity and bacterial translocation. Histopathological evaluation revealed that MMOLE attenuated IIRI-induced alterations in intestinal and hepatic histoarchitecture integrity. MMOLE also militated against increased absolute and relative intestinal and hepatic weight, intestinal and hepatic injuries, epithelial mucosal barrier dysfunction, and enteric bacterial translocation associated with IIRI by downregulating oxidative stress-mediated activation of caspase 3. Conclusion: IIRI is associated with a rise in caspase 3 activity. Also, MMOLE confers protection against IIRI, possibly due to its constituent bioactive molecules, especially hydrazine, 9-octadecenoic acid, 1,3-dioxolane, oleic acid, and nonadecanoic acid.

Role of Caspases and Gasdermin A during HSV-1 Infection in Mice.

Herpes simplex virus type 1 (HSV-1) infection can manifest locally as mucocutaneous lesions or keratitis and can also spread to the central nervous system to cause encephalitis. HSV-1 establishes a lifelong latent infection and neither cure nor vaccine is currently available. The innate immune response is the first line of defense against infection. Caspases and gasdermins are important components of innate immunity. Caspases are a family of cysteine proteases, most of which mediate regulated cell death. Gasdermins are a family of pore-forming proteins that trigger lytic cell death. To determine whether caspases or gasdermins contribute to innate immune defenses against HSV-1, we screened mice deficient in specific cell death genes. Our results indicate a modest role for caspase-6 in defense against HSV-1. Further, Asc–/–Casp1/11–/– mice also had a modest increased susceptibility to HSV-1 infection. Caspase-7, -8, and -14 did not have a notable role in controlling HSV-1 infection. We generated Gsdma1-Gsdma2-Gsdma3 triple knockout mice, which also had normal susceptibility to HSV-1. We confirmed that the previously published importance of RIPK3 during systemic HSV-1 infection also holds true during skin infection. Overall, our data highlight that as a successful pathogen, HSV-1 has multiple ways to evade host innate immune responses.

Caspase-11/4 is involved in bacteria-mediated periodontitis by promoting the release of interleukin-1 β and tumor necrosis factor-α

ObjectiveThis study investigated the main mechanism and role of caspase-11/4 as a pattern recognition receptor (PRR) in periodontitis through caspase-11 inhibition. DesignClinical tissue samples were collected from patients with periodontitis and healthy volunteers and evaluated through hematoxylin–eosin (HE) staining, immunohistochemical (IHC) staining, and real-time quantitative PCR (RT-qPCR). In the rat periodontitis model, both these staining procedures, RT-qPCR, and western blotting were used to evaluate the histological, mRNA, and protein levels of caspase-11, interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). In vitro, the role of caspase-11, inhibited by siRNA, was investigated by analyzing the mRNA and protein levels of IL-1β and TNF-α in Porphylinomonas gingivalis (P. gingivalis) lipopolysaccharide (LPS)-stimulated Raw264.7 macrophages. ResultsHistological and molecular biological results of clinical and experimental animal periodontitis samples indicated that caspase-11/4 mRNA and protein levels significantly increased in inflammatory tissues. Caspase-11 is mainly distributed in leukocytes, which are labeled by CD45 in the submucosa. In vitro results further confirmed that the expression of caspase-11/4, IL-1β, and TNF-α significantly increased in LPS-stimulated macrophages, and these changes were significantly attenuated by inhibiting caspase-11/4 expression. ConclusionsThe function of caspase-11 in rat periodontitis models is similar to that of caspase-4 in human clinical periodontitis. IL-1β and TNF-α release in periodontitis depends on the recognition of P. gingivalis LPS by caspase-11/4.

Involvement of Caspase-3 Pathway in Anti-cancer Properties of Genistein in AGS Gastric Cancer Cell Line is Still Enigmatic

Background: Genistein is an isoflavone that has been reported to have various anti-cancer properties. Objectives: This study aimed to reveal whether or not the anti-cancer properties of genistein in AGS gastric cancer cell line were mediated through caspase-3 enzyme. Methods: AGS gastric cancer cells were treated with different concentrations of genistein for 12, 24, and 48 hours and, then, the viability of the cells and IC50 were determined. To determine the effect of genistein on AGS cell migration potency, the wound healing assay was performed. The genistein-induced apoptosis in AGS gastric cells was evaluated by flow cytometry. Caspase-3 gene (CASP3) expression level and its enzyme activity level were determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and colorimetric techniques, respectively. Results: The IC50 value was calculated as 70 µM concentration for 24 hours of incubation with genistein. Genistein significantly reduced AGS cell migration compared to the untreated control cells (P&lt;0.001). Genistein increased the early and late apoptosis of the cells (P&lt;0.001) and upregulated the caspase-3 gene expression (P&lt;0.001), but did not significantly enhance the caspase-3 enzyme activity in treated cells. Conclusion: Genistein exhibited anti-cancer effects on AGS cells to some extent by reducing cellular migration, increasing apoptosis, and upregulating CASP3 gene expression; however, it did not alter the caspse-3 activity. Therefore, it was recommended that more studies should be carried out to delineate the role of caspase-3 in health benefits attributed to the genistein.