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Objectives: Certain low‐level immune‐related adverse events (irAEs) have been associated with survival benefits in patients with various solid tumors on immune checkpoint inhibitors (ICIs). We aimed to investigate the association between irAEs and response to neoadjuvant ICIs in patients with head and neck squamous cell carcinoma (HNSCC) and to identify differences in circulating cytokine levels based on irAE status. Methods: This was a retrospective cohort study including three neoadjuvant clinical trials from July 2017 to January 2022: NCT03238365 (nivolumab ± tadalafil), NCT03854032 (nivolumab ± BMS986205), NCT03618654 (durvalumab ± metformin). The presence and type of irAEs, pathologic treatment response, and survival were compared. Canonical linear discriminant analysis (LDA) was performed to identify combinations of circulating cytokines predictive of irAEs using plasma sample multiplex assay. Results: Of 113 participants meeting inclusion criteria, 32 (28.3%) developed irAEs during treatment or follow‐up. Positive p16 status was associated with irAEs (odds ratio [OR] 2.489; 95% CI 1.069–6.119; p = 0.043). irAEs were associated with pathologic treatment response (OR 3.73; 95% CI 1.34–10.35; p = 0.011) and with higher OS in the combined cohort (HR 0.319; 95% CI 0.113–0.906; p = 0.032). Patients with irAEs within the nivolumab cohort had significant elevations of select cytokines pre‐treatment. Canonical LDA identified key drivers of irAEs among all trials, which were highly predictive of future irAE status. Conclusions: irAEs are associated with response to neoadjuvant ICI therapy in HNSCC and can serve as clinical indicators for improved clinical outcomes. irAEs can be predicted by concentrations of several circulating cytokines prior to treatment. [ABSTRACT FROM AUTHOR]

Background: There is sparse literature on the effect of preoperative immunotherapy on complications after surgery for primary head and neck squamous cell carcinoma (HNSCC). The objectives are to compare complication rates in patients receiving surgery with and without neoadjuvant immune checkpoint inhibitors (nICI) for primary HNSCC and to evaluate factors associated with increased odds of surgical complications. Methods: A retrospective review of patients who underwent ablation and free flap reconstruction or transoral robotic surgery (TORS) for primary HNSCC between 2017–2021 was conducted. Complications were compared between patients who underwent surgery with or without nICI before and after propensity score matching. Regression analysis to estimate odds ratios was performed. Results: A total of 463 patients met inclusion criteria. Free flap reconstruction constituted 28.9% of patients and TORS constituted 71.1% of patients. nICI was administered in 83 of 463 (17.9%) patients. There was no statistically significant difference in surgical, medical, or overall complications between patients receiving surgery with or without nICI. In the unmatched cohort, multivariable model identified non‐White race, former/current smoking history, free flap surgery, and perineural invasion as factors significantly associated with increased complications. In the matched cohort, multivariable model identified advanced age and free flap surgery as factors significantly associated with increased complications. Plain Language Summary: It is safe to give immunotherapy before major surgery in patients who have head and neck cancer.Advanced age, non‐White race, current/former smoking, free flap surgery, and perineural invasion may be associated with increased the odds of surgical complications. In this study, neoadjuvant immune checkpoint inhibitors (nICI) did not increase the risk of overall complications after adjusting for important confounders. Definitive surgery can be conducted safely after nICI. [ABSTRACT FROM AUTHOR]

Mosquito-borne diseases (MBDs), like malaria and mosquito-borne viruses (MBVs), have caused the deaths of millions of people. Their threat resides in the variety of transmission modes that they possess, along with the wide selection of favorable hosts, such as humans, cattle, and rodents. MBDs are increasingly gaining a reputation as one of the most dangerous threats to public health in recent years. Mosquito numbers have been increasing in recent years as a result of multiple factors such as climate change and deforestation. This situation highlights the urgent need for actions to mitigate mosquito and MBD pathogen distributions. In the Middle East, many outbreaks of MBDs have been reported in the region. However, there are no reports of any endemic episodes of MBDs. The Middle East has faced many challenges over the years; however, the Syrian refugee crisis may be strongly related to the spread of infectious diseases. As mass gatherings and high-density populations are common features in the region, it is possible to understand why MBDs can spread easily. This review summarizes the state of MBDs in the Middle East, highlighting the different types of MBDs that have been reported in the region and discussing how to move forward with controlling their spread and limiting the risks they pose. According to the data reported by the electronic State Parties Self-Assessment Annual Reporting Tool (e-SPAR), the capacity to anticipate MBVs varies among Middle East countries. Therefore, the Middle East is on the frontline in the challenge to control a potential public health crisis. Consequently, the countries of the Middle East should be encouraged to improve their health and research capacities to mitigate the threat posed by MBDs. [ABSTRACT FROM AUTHOR]

Biotechnology became a paradigm-shifting science among all subfields of biology. The benefits of biotechnology have reached many practical fields, whether human health, animal, and/or agricultural. However, wherever there is a biotechnology practice, there is an associated biohazard with it, and its negative impact may reach all living entities including humans. Therefore, the cooperation of the leading institutions in this field has culminated in creating the concepts and applications of biosafety and biosecurity. The countries of the Middle East are considered biotechnology-practicing and have shown a clear acceptance to this field. But unfortunately, the Middle East region is one that is facing the most multichallenges, which would constitute real and noticeable concern at the local and international levels. Such challenges represented by wars and armed conflicts, deteriorating economic conditions, the large number of refugees, and the spread of many epidemics. Thus, limiting the region's ability to deal with the surrounding biological hazards and struggling the way to the one health concept. Therefore, this article aims to shed light on the activities of the Middle East countries in the field of biotechnology and to address potential biological threats, whether natural such as the spread of viruses, or intentional such as biological attacks and bioterrorism. The article also shows the capacity of the countries of the region in the field of biosafety and biosecurity based on available information. Accordingly, some countries are lacking the required level of preparedness to face potential biological threats. Multi-institutional and international cooperation between the concerned countries will significantly enhance the capacity of the region in biosafety and biosecurity to meet the level of biological risk. Search methodology: wide range of related keywords (based on the section) combined with the name of the region, or one country individually have been searched using available search engines and databases such as google scholar and PubMed. After scanning the content of the found results, irrelevant articles have been excluded. Figures 2, 3, 4, 6, and 7 were created by biorender.com. [ABSTRACT FROM AUTHOR]

Although brucellosis is not uncommon in Saudi Arabia, neonatal brucellosis has been infrequently reported. In this case of neonatal brucellosis, Brucella abortus was isolated by blood culture from both the mother and the neonate. Serology was positive only in the mother. [ABSTRACT FROM AUTHOR]

Gasdermin proteins have been extensively characterized for their ability to form necrotic pores in the plasma membrane, however, their interactions with other organelles have yet to be described. We recently demonstrated that some gasdermin proteins can also permeabilize the mitochondria to augment apoptotic signaling which may be important in the context of cancer and hearing loss. [ABSTRACT FROM AUTHOR]

Gasdermin-E (GSDME) is known to potentiate immunogenic cell death in many tumor types after exposure to anti-cancer agents in a caspase-3 dependent manner. This GSDME-mediated release of immunostimulatory proteins, such as HMGB1, has been shown to increase tumor immunogenicity in mouse model systems of melanoma and colon cancer, resulting in reduced tumor load and lower distal metastasis. We sought to evaluate the role of GSDME-mediated cell death in human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma (HNSCC) mouse cell lines. To test whether HNSCC exhibits a GSDME-associated anti-tumor response, two HPV+ HNSCC mouse cell lines, MTEC and TC-1, were screened for GSDME expression by Western blot and then treated with apoptotic agents (raptinal, cisplatin, etoposide, and UV). Primary outcome measures were HMGB1 release (a potent immunostimulatory factor), percent propidium iodide (%PI) uptake (an indicator of plasma membrane damage and pyroptosis) and cell morphology. Using retroviral transduction, MTEC cells were reconstituted with GSDME, and single cell clones expressing comparable levels of recombinant mouse wild type (WT) GSDME and a caspase-3-uncleavable inactive mutant (Aspartate 270/Glutamate) D270A GSDME were selected. Control MTEC transduced with empty vector (EV) were also generated. Single cell clones were tested in vitro with apoptotic agents and evaluated for HMGB1 release, %PI uptake, and cell morphology. Western blot analysis demonstrated GSDME expression in TC-1 but not MTEC cells. Following treatment with apoptotic agents, TC-1 cells demonstrated HMGB1 release and increased %PI uptake as well as a distinct secondary necrotic phenotype characterized by ballooning of the plasma membrane on morphological analysis. This was not seen in MTEC cells. To examine whether the absence of GSDME in MTEC cells correlated with reduced release of immune-stimulatory molecules, MTEC cells stably reconstituted with GSDME were treated with apoptotic agents. Unlike MTEC cells expressing the uncleavable D270A GSDME or EV control, MTEC cells expressing WT GSDME demonstrated a significant release of HMGB1 and increased %PI uptake. Morphological analysis demonstrated significant ballooning of the plasma membrane only in the WT GSDME MTEC cells. Treatment with apoptotic agents induces a GSDME-dependent pyroptotic cell death in MTEC and TC-1 cells as evidenced by HMGB1 release, increased %PI uptake, and cell morphology. As pyroptotic cell death of cancer cells induces anti-tumor immunity through the release of HMGB1 and other immunostimulatory factors, promoting GSDME-dependent pyroptosis might be a strategy to overcome treatment resistance in some HNSCC. [ABSTRACT FROM AUTHOR]

Activation of the NLRP3 inflammasome by diverse stimuli requires a priming signal from TLRs and an activation signal from purinergic receptors or pore-forming toxins. In this study, we demonstrate, through detailed analysis of NLRP3 activation in macrophages deficient in key downstream TLR signaling molecules, that MyD88 is required for an immediate early phase, whereas Toll/IL-1R domain-containing adapter inducing IFN-β is required for a subsequent intermediate phase of posttranslational NLRP3 activation. Both IL-1R-associated kinase (IRAK) 1 and IRAK4 are critical for rapid activation of NLRP3 through the MyD88 pathway, but only IRAK1 is partially required in the Toll/IL-1R domain-containing adapter inducing IFN-β pathway. IRAK1 and IRAK4 are also required for rapid activation of NLRP3 by Listeria monocytogenes, as deletion of IRAK1 or IRAK4 led to defective inflammasome activation. These findings define the pathways that lead to rapid NLRP3 activation and identify IRAK1 as a critical mediator of a transcription-independent, inflammasome-dependent early warning response to pathogenic infection. [ABSTRACT FROM AUTHOR]

The NLRP3 inflammasome is a key component of the innate immune response to pathogenic infection and tissue damage. It is also involved in the pathogenesis of a number of human diseases, including gouty arthritis, silicosis, atherosclerosis, and type 2 diabetes. The assembly of the NLRP3 inflammasome requires a priming signal derived from pattern recognition or cytokine receptors, followed by a second signal derived from extracellular ATP, pore-forming toxins, or crystalline materials. How these two signals activate the NLRP3 inflammasome is not yet clear. Here, we show that in mouse macrophages, signaling by the pattern recognition receptor TLR4 through MyD88 can rapidly and non-transcriptionally prime NLRP3 by stimulating its deubiquitination. This process is dependent on mitochondrial reactive oxygen species production and can be inhibited by antioxidants. We further show that signaling by ATP can also induce deubiquitination of NLRP3 by a mechanism that is not sensitive to antioxidants. Pharmacological inhibition of NLRP3 deubiquitination completely blocked NLRP3 activation in both mouse and human cells, indicating that deubiquitination of NLRP3 is required for its activation. Our findings suggest that NLRP3 is activated by a two-step deubiquitination mechanism initiated by Toll-like receptor signaling and mitochondrial reactive oxygen species and further potentiated by ATP, which could explain how NLRP3 is activated by diverse danger signals. [ABSTRACT FROM AUTHOR]

Infection with Listeria monocytogenes can cause meningitis and septicemia in newborn, elderly, or immunocompromised individuals. Pregnant women are particularly susceptible to Listeria, leading to a potentially fatal infection. Cytosolic Listeria activates the proinflammatory caspase-1 and induces the processing and secretion of interleukins IL-1β and IL-18 as well as caspase-1-dependent pyroptosis. This study elucidates the role of various inflammasome components of host macrophages in the proinflammatory response to infection with Listeria. Here, we have used macrophages from AIM2-, NLRC4-, NLRP3-, and ASC-deficient mice to demonstrate that AIM2, NLRC4, and NLRP3 inflammasomes as well as the adaptor protein ASC all contribute to activation of caspase-1 in Listeria-infected macrophages. We show that Listeria DNA, which escapes into the cytosol of infected macrophages, triggers AIM2 oligomerization, caspase-1 activation, and pyroptosis. Interestingly, we found that flagellin-deficient Listeria, like Francisella tularensis, is recognized primarily by the AIM2 inflammasome, as no caspase-1 activation or cell death was observed in AIM2-deficient macrophages infected with this Listeria mutant. We further show that prior priming of NLRC4-deficient macrophages with LPS is sufficient for Listeria-induced caspase-1 activation in these macrophages, suggesting that TLR4 signaling is important for activation of the AIM2 and NLRP3 inflammasomes by Listeria in the absence of NLRC4. Taken together, our results indicate that Listeria infection is sensed by multiple inflammasomes that collectively orchestrate a robust caspase-1 activation and proinflammatory response. [ABSTRACT FROM AUTHOR]

Francisella tularensis, the causative agent of tularemia, infects host macrophages, which triggers production of the proinflammatory cytokines interleukin 1β (IL-1β) and IL-18. We elucidate here how host macrophages recognize F. tularensis and elicit this proinflammatory response. Using mice deficient in the DNA-sensing inflammasome component AIM2, we demonstrate here that AIM2 is required for sensing F. tularensis. AIM2-deficient mice were extremely susceptible to F. tularensis infection, with greater mortality and bacterial burden than that of wild-type mice. Caspase-1 activation, IL-1β secretion and cell death were absent in Aim2−/− macrophages in response to F. tularensis infection or the presence of cytoplasmic DNA. Our study identifies AIM2 as a crucial sensor of F. tularensis infection and provides genetic proof of its critical role in host innate immunity to intracellular pathogens. [ABSTRACT FROM AUTHOR]

Activation of the inflammasome generates the pro-inflammatory cytokines interleukin-1β and -18, which are important mediators of inflammation. Abnormal activation of the inflammasome leads to many inflammatory diseases, including gout, silicosis, neurodegeneration, and genetically inherited periodic fever syndromes. Therefore, identification of small molecule inhibitors that target the inflammasome is an important step toward developing effective therapeutics for the treatment of inflammation. Here, we show that the herbal NF-κB inhibitory compound parthenolide inhibits the activity of multiple inflammasomes in macrophages by directly inhibiting the protease activity of caspase-1. Additional investigations of other NF-KB inhibitors revealed that the synthetic 1κB kinase-β inhibitor Bay 11-7082 and structurally related vinyl sulfone compounds selectively inhibit NLRP3 inflammasome activity in macrophages independent of their inhibitory effect on NF-κB activity. In vitro assays of the effect of parthenolide and Bay 11-7082 on the ATPase activity of NLRP3 demonstrated that both compounds inhibit the ATPase activity of NLRP3, suggesting that the inhibitory effect of these compounds on inflammasome activity could be mediated in part through their effect on the ATPase activity of NLRP3. Our results thus elucidate the molecular mechanism for the therapeutic anti-inflammatory activity of parthenolide and identify vinyl sulfones as a new class of potential therapeutics that target the NLRP3 inflammasome. [ABSTRACT FROM AUTHOR]

Host- and pathogen-associated cytoplasmic double-stranded DNA triggers the activation of a NALP3 (also known as cryopyrin and NLRP3)-independent inflammasome, which activates caspase-1 leading to maturation of pro-interleukin-1β and inflammation. The nature of the cytoplasmic-DNA-sensing inflammasome is currently unknown. Here we show that AIM2 (absent in melanoma 2), an interferon-inducible HIN-200 family member that contains an amino-terminal pyrin domain and a carboxy-terminal oligonucleotide/oligosaccharide-binding domain, senses cytoplasmic DNA by means of its oligonucleotide/oligosaccharide-binding domain and interacts with ASC (apoptosis-associated speck-like protein containing a CARD) through its pyrin domain to activate caspase-1. The interaction of AIM2 with ASC also leads to the formation of the ASC pyroptosome, which induces pyroptotic cell death in cells containing caspase-1. Knockdown of AIM2 by short interfering RNA reduced inflammasome/pyroptosome activation by cytoplasmic DNA in human and mouse macrophages, whereas stable expression of AIM2 in the non-responsive human embryonic kidney 293T cell line conferred responsiveness to cytoplasmic DNA. Our results show that cytoplasmic DNA triggers formation of the AIM2 inflammasome by inducing AIM2 oligomerization. This study identifies AIM2 as an important inflammasome component that senses potentially dangerous cytoplasmic DNA, leading to activation of the ASC pyroptosome and caspase-1. [ABSTRACT FROM AUTHOR]

Summary: The molecular mechanism by which mutations in the cytoskeleton-organizing protein PSTPIP1 cause the autoinflammatory PAPA syndrome is still elusive. Here, we demonstrate that PSTPIP1 requires the familial Mediterranean fever protein pyrin to assemble the ASC pyroptosome, a molecular platform that recruits and activates caspase-1. We provide evidence that pyrin is a cytosolic receptor for PSTPIP1. Pyrin exists as a homotrimer in an autoinhibited state due to intramolecular interactions between its pyrin domain (PYD) and B-box. Ligation by PSTPIP1, which is also a homotrimer, activates pyrin by unmasking its PYD, thereby allowing it to interact with ASC and facilitate ASC oligomerization into an active ASC pyroptosome. Because of their high binding affinity to pyrin''s B-box, PAPA-associated PSTPIP1 mutants were found to be more effective than WT PSTPIP1 in inducing pyrin activation. Therefore, constitutive ligation and activation of pyrin by mutant PSTPIP1 proteins explain the autoinflammatory phenotype seen in PAPA syndrome. [Copyright &y& Elsevier]

Pyroptosis is a caspase-1-dependent inflammatory form of cell death. The adapter protein ASC binds directly to caspase-1 and is critical for caspase-1 activation in response to a broad range of stimuli. To elucidate the mechanism of activation of caspase-1 by ASC and its exact role in macrophage pyroptosis, we performed time-lapse confocal bioimaging analysis on human THP-1 macrophages stably expressing an ASC–GFP fusion protein. We show that stimulation of these cells with several proinflammatory stimuli trigger the formation of a large supramolecular assembly of ASC, termed here pyroptosome. Only one distinct pyroptosome in each stimulated cell is formed, which rapidly recruits and activates caspase-1 resulting in pyroptosis and the release of the intracellular proinflammatory cytokines. The pyroptosome is largely composed of oligomerized ASC dimers. Dimerization of ASC is driven by subphysiological concentrations of potassium as in vitro incubation of purified recombinant ASC in the presence of subphysiological concentrations of potassium induces the assembly of a functional pyroptosome. Furthermore, stimulation of potassium efflux in THP-1 cells with potassium-depleting agents induces formation of the pyroptosome, while increasing potassium concentrations in the culture medium or pharmacological inhibition of this efflux inhibits its assembly. Our results establish that macrophage pyroptosis is mediated by a unique pyroptosome, distinct from the inflammasome.Cell Death and Differentiation (2007) 14, 1590–1604; doi:10.1038/sj.cdd.4402194; published online 29 June 2007 [ABSTRACT FROM AUTHOR]

The innate immune system depends on molecules collectively known as pattern recognition receptors (PRRs) to survey the extracellular space and the cytoplasm for the presence of dangerous pathogens, pathogen-derived molecules, or even self-derived molecular danger signals, which arise from tissue damage. Absent in melanoma 2 (AIM2) is a newly discovered PRR involved in the sensing of dangerous cytosolic DNA produced by infection with DNA viruses. Remarkably, recent studies in AIM2-deficient mice showed that AIM2 is uniquely involved in sensing infection with the intracellular bacteria Francisella tularensis and subsequently triggering caspase-1-mediated pro-inflammatory cytokine production and macrophage cell death, which activate other components of the immune system and eliminate the infected macrophages. Here, we provide an overview of our current understanding of the role of AIM2 in innate immunity against F. tularensis in particular, and how infection of macrophages with this pathogen is thought to activate AIM2. [ABSTRACT FROM AUTHOR]

Background: The One Health concept (OHC) seeks to improve the health of plants, animals, and humans because improving animal and plant health will increase the capacity for improving human health. Many risks such as plant and animal biotechnology applications have the potential to generate new diseases that can be transmitted to humans. In this way, the health of humans, animals, and plants is interrelated and depends on one another. However, it has been difficult to apply the OHC in some countries, such as those in the Middle East. The absence of financial support in the region is a major hindrance to applying this concept in the region. The application of the OHC requires the support of specialists who can advocate the government for support in launching OHC-related projects. Here, we discuss the OHC in the context of antimicrobial resistance, zoonotic diseases, and biosafety/biosecurity, which are important public health issues. Furthermore, we describe the current status of the OHC in the Middle East and recent research conducted related to this concept. There has been recent international solidarity in the application of the OHC to reduce risks that threaten the health of organisms. Several countries jointly launched the Global Health Security Agenda in 2014 with the aim of realizing a world that is free of infectious disease-related health risks. However, no previous review articles have examined the applications of the OHC in the Middle East region. This article discusses the OHC in terms of its needs and current applications in the Middle East. Methodology: The following keywords were used in the search: "One Health," "Middle East," "medicinal plants," "viruses," "rabies," "MERS," and "antimicrobial resistance." Related papers were obtained by searching for these keywords using available search engines, such as PubMed, Google Scholar, and Google search, as well as international organization websites. Conclusion: The concept of One Health is relatively new and has not been applied in most countries, possibly because the value of this concept for improving human health is not well understood. The key principle defining this concept and its importance is the interdependency of plants, animals, and human health. By applying the OHC, humans can benefit from healthy plants and animals by enhancing their growing conditions, medications, and environments. This would in turn improve general human health by allowing the safe extraction of therapeutics and food resources. [ABSTRACT FROM AUTHOR]

Investigates the individual roles of multiple interleukin 1beta-converting enzyme-related proteases in apoptosis. Cleavage of recombinant and nuclear lamin A by Mch2alpha; Inability of CPP32 to cleave to lamin A; Inhibition of the cleavage of lamin A by Mch2alpha and by cell-free model system for apoptosis; Identification of active IRPs of aspartic acid.

Describes the identification and cloning of two aspartate-specific cysteine proteases named Mch4 and Mch5. Structure of both proteases; Indication of possible role of these two proteases in the Fas-apoptotic pathway due to the presence of FADD-like domains.

Mitochondrial dysfunction is primarily responsible for neurodegeneration in Parkinson's disease. The Parkinson's-disease-associated kinase PINK1 has been identified as an important regulator of the activity of the mitochondria-associated stress-protective protease HtrA2. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) is the major cause of bronchiolitis among children under 5 years of age worldwide, accounting for a prevalence of 25%--88% in Saudi Arabia. Although no effective treatment for the virus exists, passive immunoprophylaxis reduced RSV hospitalizations in high-risk children. With recent advances in immunization, the Saudi Initiative of Bronchiolitis Diagnosis, Management, and Prevention panel screened recent relevant international guidelines, locally published data, and expert consensus to update guidelines for RSV prevention, taking into consideration the resources, timing, varying health profiles, and RSV burden in Saudi Arabia. The panel updated its recommendations to include immunization of infants, mothers, and older adults. Practical guidelines were prepared to facilitate the administration of the short-acting and newly developed long-acting RSV monoclonal antibodies (mAb) during the regular follow-ups of high-risk infants in specialized clinics. In addition, long-acting mAb was highlighted as all-infant protection in the routine immunization calendar. [ABSTRACT FROM AUTHOR]

NALP proteins, also known as NLRPs, belong to the CATERPILLER protein family involved, like Toll-like receptors, in the recognition of microbial molecules and the subsequent activation of inflammatory and immune responses. Current advances in the function of NALPs support the recently proposed model of a disease continuum bridging autoimmune and autoinflammatory disorders. Among these diseases, hereditary periodic fevers (HPFs) are Mendelian disorders associated with sequence variations in very few genes; these variations are mostly missense mutations whose deleterious effect, which is particularly difficult to assess, is often questionable. The growing number of identified sporadic cases of periodic fever syndrome, together with the lack of discriminatory clinical criteria, has greatly hampered the identification of new disease-causing genes, a step that is, however, essential for appropriate management of these disorders. Using a candidate gene approach, we identified nonambiguous mutations in NALP12 (i.e., nonsense and splice site) in two families with periodic fever syndromes. As shown by means of functional studies, these two NALP12 mutations have a deleterious effect on NF-κB signaling. Overall, these data identify a group of HPFs defined by molecular defects in NALP12, opening up new ways to manage these disorders. The identification of these first NALP12 mutations in patients with autoinflammatory disorder also clearly demonstrates the crucial role of NALP12 in inflammatory signaling pathways, thereby assigning a precise function to this particular member of an emerging family of proteins whose putative biological properties are currently inferred essentially through in vitro means. [ABSTRACT FROM AUTHOR]

The pigmentation of oral soft tissues is predominantly an aesthetic problem because lifestyle, media, and social influences impact people's perception of beauty, which in turn affects their self-esteem as well as their relationships. The melanin pigmentation of the gingiva has become a real concern in the Gulf region, especially for younger people and females, who seek aesthetic solutions to remove the pigmentation. The pigmentation caused by melanin can be removed by surgical blades, diamond burs, chemicals, and lasers, among other methods. A systematic literature review from 2012 to 2022 was performed using databases such as PubMed, Medline, and Sciencedirect. The keywords used were "Diode laser", "Erbium laser", and "Melanin pigmentation". PRISMA flowchart was used to describe the selection process of searched articles. Findings revealed that 6 out of 8 studies listed superior characteristics and treatment outcomes of diode lasers as compared to Erbium lasers. It can be concluded that the diode laser is the better option to treat gingival melanin pigmentation as compared to the Erbium lasers. [ABSTRACT FROM AUTHOR]

The intermembrane space of mitochondria is home to several potentially lethal proteins, including pro-apoptotic caspases. The observation that caspase-9 moves from mitochondria into the nucleus on the induction of apoptosis provides this caspase with a possible new role. [ABSTRACT FROM AUTHOR]

Th2 cytokine IL-4 has been previously shown to suppress the production of proinflammatory cytokines in monocytes. However, the underlying molecular mechanism by which IL-4 signaling antagonizes proinflammatory responses is poorly characterized. In particular, whether IL-4 can modulate inflammasome signaling remains unknown. Here, we provide evidence that IL-4 suppresses NLRP3-dependent caspase-1 activation and the subsequent IL-1β secretion but does not inhibit absent in melanoma 2 (AIM2)- or NLRC4 (NOD-like receptor family, CARD domain-containing 4)-dependent caspase-1 activation in THP-1 and mouse bone marrow-derived macrophages. Upon lipopolysaccharide (LPS) or LPS/ATP stimulation, IL-4 markedly inhibited the assembly of NLRP3 inflammasome, including NLRP3-dependent ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain) oligomerization, NLRP3-ASC interaction and NLRP3 speck-like oligomeric structure formation. The negative regulation of NLRP3 inflammasome by IL-4 was not due to the impaired mRNA or protein production of NLRP3 and proinflammatory cytokines. Supporting this observation, IL-4 attenuated NLRP3 inflammasome activation even in reconstituted NLRP3-expressing macrophages in which NLRP3 expression is not transcriptionally regulated by TLR-NF-κB signaling. Furthermore, the IL-4-mediated suppression of NLRP3 inflammasome was independent of STAT6-dependent transcription and mitochondrial reactive oxygen species (ROS). Instead, IL-4 inhibited subcellular redistribution of NLRP3 into mitochondria and microtubule polymerization upon NLRP3-activating stimulation. Our results collectively suggest that IL-4 could suppress NLRP3 inflammasome activation in a transcription-independent manner, thus providing an endogenous regulatory machinery to prevent excessive inflammasome activation. [ABSTRACT FROM AUTHOR]

Caspase-1 activation is a central event in innate immune responses to many pathogenic infections and tissue damage. The NLRP3 inflammasome, a multiprotein scaffolding complex that assembles in response to two distinct steps, priming and activation, is required for caspase-1 activation. However, the detailed mechanisms of these steps remain poorly characterized. To investigate the process of LPS-mediated NLRP3 inflammasome priming, we used constitutively present pro-IL-18 as the caspase-1-specific substrate to allow study of the early events. We analyzed human monocyte caspase-1 activity in response to LPS priming, followed by activation with ATP. Within minutes of endotoxin priming, the NLRP3 inflammasome is licensed for ATP-induced release of processed IL-18, apoptosis-associated speck-forming complex containing CARD, and active caspase-1, independent of new mRNA or protein synthesis. Moreover, extracellular signal-regulated kinase 1 (ERK1) phosphorylation is central to the priming process. ERK inhibition and small interfering RNA-mediated ERK1 knockdown profoundly impair priming. In addition, proteasome inhibition prevents ERK phosphorylation and blocks priming. Scavenging reactive oxygen species with diphenylene iodonium also blocks both priming and ERK phosphorylation. These findings suggest that ERK1-mediated posttranslational modifications license the NLRP3 inflammasome to respond to the second signal ATP by inducing posttranslational events that are independent of new production of pro-IL-1β and NOD-like receptor components. [ABSTRACT FROM AUTHOR]

Head and Neck cancer (HNC) diagnosis and treatment have the potential to significantly affect patient relationships. We aimed to understand the effects of a HNC diagnosis on patient and partner perceived intimacy at diagnosis and after treatment. Additionally, we sought to understand if the diagnosis of HPV related HNC influenced patients' and partners' levels of perceived intimacy. A prospective, survey-based study was conducted using two cohorts of HNC patients and partners: HPV-positive and HPV-negative. Respondents completed a survey of questions adapted from the HPV Impact Profile, the Dyadic Adjustment Scale, and the Miller Social Intimacy Scale at two time points. Within 2 months of diagnosis prior to treatment and again after 3-6 months post treatment. Responses were then scored as: loss of intimacy (0-48), stable relationship (49-71), improvement in intimacy (72-120). Respondents were also asked whether changes in perceived intimacy were due to HPV or effects of cancer treatment. Survey responses were considered discordant if patient and partner scores equated to different levels of perceived intimacy. 25 patient-partner pairs completed the first survey. 68% of couples demonstrated concordant responses with 16 couples reporting increased intimacy, one couple reporting stable intimacy and none reporting decreased intimacy. 32% of patient-partner pairs showed some discordance in responses with 7 couples in which one partner reported stability and the other reported increase in intimacy and one couple in which one partner reported an increase and the other reported a decrease in intimacy. 15 patient-partner pairs completed the second survey 3-6 months post HNC treatment. 73% of patient-partner pairs demonstrated concordant responses with 8 couples reporting increased intimacy, two couples reporting stable intimacy and one couple reporting decreased intimacy. 27% of patient-partner pairs showed some discordance in responses, with four couples in which one partner reported an increase and the other reported stable intimacy. Overall scores were not significantly different between patients and partners at either timepoint (p=0.31, p=0.63). Mean scores were similar between HPV+ and HPV- groups at both timepoints (p=0.35, p=0.22); however, the patient and partner who reported loss of intimacy cited presence of HPV in diagnosis as a reason for the decline. The majority of patients and partners surveyed reported either stable or increased intimacy both at diagnosis and after treatment. Further, most patients and partners agreed about their perceived level of intimacy. The simultaneous diagnosis of HPV related malignancy did not significantly affect intimacy scores; however, individuals who experienced a loss of intimacy reported that HPV was at the core of the decline. [ABSTRACT FROM AUTHOR]

NLRP3 assembles an inflammasome complex that activates caspase-1 upon sensing various danger signals derived from pathogenic infection, tissue damage, and environmental toxins. How NLRP3 senses these various stimuli is still poorly understood, but mitochondria and mitochondrial reactive oxygen species have been proposed to play a critical role in NLRP3 activation. In this article, we provide evidence that the mitochondrial antiviral signaling protein MAVS associates with NLRP3 and facilitates its oligomerization leading to caspase-1 activation. In reconstituted 293T cells, full-length MAVS promoted NLRP3-dependent caspase-1 activation, whereas a C-terminal transmembrane domain-truncated mutant of MAVS (MAVS-ΔTM) did not. MAVS, but not MAVSΔTM, interacted with NLRP3 and triggered the oligomerization of NLRP3, suggesting that mitochondrial localization of MAVS and intact MAVS signaling are essential for activating the NLRP3 inflammasome. Supporting this, activation of MAVS signaling by Sendai virus infection promoted NLRP3-dependent caspase-1 activation, whereas knocking down MAVS expression clearly attenuated the activation of NLRP3 inflammasome by Sendai virus in THP-1 and mouse macrophages. Taken together, our results suggest that MAVS facilitates the recruitment of NLRP3 to the mitochondria and may enhance its oligomerization and activation by bringing it in close proximity to mitochondrial reactive oxygen species. [ABSTRACT FROM AUTHOR]

Abstract: Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), an essential component of the inflammasome complex, is frequently silenced by epigenetic methylation in many tumor cells. Here, we demonstrate that restoration of ASC expression in human colorectal cancer DLD-1 cells, in which ASC is silenced by aberrant methylation, potentiated cell death mediated by DNA damaging agent. Contrarily, ASC knockdown in HT-29 cells rendered cells less susceptible to etoposide toxicity. The increased susceptibility of ASC-expressing DLD-1 cells to genotoxic stress was independent of inflammasome or caspase activation, but partially dependent on mitochondrial ROS production and JNK activation. Thus, our data suggest that ASC expression in cancer cells is an important factor in determining their susceptibility to chemotherapy. [Copyright &y& Elsevier]

Human pyrin with gain-of-function mutations in its B30.2/ SPRY domain causes the autoinflammatory disease familial Mediterranean fever by assembling an ASC-dependent inflammasome that activates caspase-1. Wild-type human pyrin can also form an inflammasome complex with ASC after engagement by autoinflammatory PSTPIP1 mutants. How the pyrin inflammasome is activated in the absence of disease-associated mutations is not yet known. We report here that ribotoxic stress triggers the assembly of the human pyrin inflammasome, leading to ASC oligomerization and caspase-1 activation in THP-1 macrophages and in a 293T cell line stably reconstituted with components of the pyrin inflammasome. Knockdown of pyrin and selective inhibition of p38 MAPK greatly attenuated caspase-1 activation by ribotoxic stress, whereas expression of the conditional mutant ΔMEKK3:ER* allowed the activation of caspase-1 without ribotoxic stress. Disruption of microtubules by colchicine also inhibited pyrin inflammasome activation by ribotoxic stress. Together, our results indicate that ribotoxic stress activates the human pyrin inflammasome through a mechanism that requires p38 MAPK signaling and microtubule stability. [ABSTRACT FROM AUTHOR]

mnd2 mice die prematurely as a result of neurodegeneration 30-40 days after birth due to loss of the enzymatic activity of the mitochondrial quality control protease HtrA2/Omi. Here, we show that transgenic expression of human HtrA2/Omi in the central nervous system of mnd2 mice rescues them from neurodegeneration and prevents their premature death. Interestingly, adult transgenic mnd2 mice develop accelerated aging phenotypes, such as premature weight loss, hair loss, reduced fertility, curvature of the spine, heart enlargement, increased autophagy, and death by 12-17 months of age. These mice also have elevated levels of clonally expanded mitochondrial DNA (mtDNA) deletions in their tissues. Our results provide direct genetic evidence linking mitochondrial protein quality control to mtDNA deletions and aging in mammals. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a Gram-positive, extracellular bacterium that is responsible for significant mortality and morbidity worldwide. Pneumolysin (PLY), a cytolysin produced by all clinical isolates of the pneumococcus, is one of the most important virulence factors of this pathogen. We have previously reported that PLY is an essential factor for activation of caspase-1 and consequent secretion of IL-1β and IL-18 in macrophages infected with S. pneumoniae. However, the host molecular factors involved in caspase-1 activation are still unclear. To further elucidate the mechanism of caspase-1 activation in macrophages infected with S. pneumoniae, we examined the involvement of inflammasomes in inducing this cellular response. Our study revealed that apoptosis-associated specklike protein containing a caspase recruitment domain (ASC), an adaptor protein for inflammasome receptors such as nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) and absent in melanoma 2 (AIM2), is essentially required for the induction of caspase-1 activation by S. pneumoniae. Caspase-1 activation was partially impaired in NLRP3-/- macrophages, whereas knockdown and knockout of AIM2 resulted in a clear decrease in caspase-1 activation in response to S. pneumoniae. These results suggest that ASC inflammasomes, including AIM2 and NLRP3, are critical for caspase-1 activation induced by S. pneumoniae. Furthermore, ASC-/- mice were more susceptible than wild-type mice to S. pneumoniae, with impaired secretion of IL-1β and IL-18 into the bronchoalveolar lavage after intranasal infection, suggesting that ASC inflammasomes contribute to the protection of host from infection with PLY-producing S. pneumoniae. [ABSTRACT FROM AUTHOR]

The article presents a study in gaining insight to the pathophysiology of an atypical form of an autoinflammatory disorder and assess the functional consequences of a missense mutation in the leucine-rich repeat (LRR) domain of cryopyrin (NLRP3). It states that NLRP3 belongs to the NOD-like receptor (NLR) involved in the recognition of microbial molecules that triggers inflammatory and immune response. It notes that functional consequences of LRR adds importance of in vitro assays.

Mitochondrial proteins such as cytochrome c, Smac/DIABLO and Omi/HtrA2 play important roles in the cell death pathways of mammalian cells. In Drosophila, the role of mitochondria in cell death is less clear. Here, we report the identification and characterization of the Drosophila ortholog of human Omi/HtrA2. We show that Drosophila Omi/HtrA2 is imported into the mitochondria where it undergoes proteolytic maturation to yield two isoforms, dOmi-L and dOmi-S. dOmi-L contains a canonical N-terminal IAP-binding motif (AVVS), whereas dOmi-S contains a distinct N-terminal motif (SKMT). DIAP1 was able to bind to both isoforms via its BIR1 and BIR2 domains. This resulted in cleavage of the linker region of DIAP1 between the BIR1 and BIR2 domains and further degradation of the BIR1 domain by the proteolytic activity of dOmi. The binding of DIAP1 to dOmi also resulted in DIAP1-mediated polyubiquitination of dOmi, suggesting that DIAP1 could target dOmi for proteasomal degradation. Consistent with this, expression of DIAP1 in Drosophila eye discs protected them from dOmi-induced eye ablation, indicating that DIAP1 plays an important role in protecting cells from the potentially lethal effects of dOmi. The ability of IAPs to bind to and ubiquitinate mitochondrial proteins such as dOmi may be a key conserved function to counterbalance the lethal effects of these proteins if accidentally released into the cytosol.Cell Death and Differentiation (2008) 15, 1073–1083; doi:10.1038/cdd.2008.19; published online 15 February 2008 [ABSTRACT FROM AUTHOR]

Mutations in cryopyrin and pyrin proteins are responsible for several autoinflammatory disorders in humans, suggesting that these proteins play important roles in regulating inflammation. Using a HEK293 cell-based reconstitution system that stably expresses ASC and procaspase-1 we demonstrated that neither cryopyrin nor pyrin or their corresponding disease-associated mutants could significantly activate NF-κB in this system. However, both cryopyrin and two disease-associated cryopyrin mutants induced ASC oligomerization and ASC-dependent caspase-1 activation, with the disease-associated mutants being more potent than the wild-type (WT) cryopyrin, because of increased self-oligomerization. Contrary to the proposed anti-inflammatory activity of WT pyrin, our results demonstrated that pyrin, like cryopyrin, can also assemble an inflammasome complex with ASC and procaspase-1 leading to ASC oligomerization, caspase-1 activation and interleukin-1β processing. Thus, we propose that pyrin could function as a proinflammatory molecule.Cell Death and Differentiation (2006) 13, 236–249. doi:10.1038/sj.cdd.4401734; published online 22 July 2005 [ABSTRACT FROM AUTHOR]

Adequate nutrition in early life is proposed to shape a child's future health by launching the growth trajectory in the proper direction, which helps to avoid negative metabolic programming effects. Protein intake during infancy and early childhood is of great importance, as it plays a key role in infant metabolic programming and the future risk of obesity. Breastfeeding provides the best nutrition in early life, with many benefits tailored for the baby, including the appropriate quantity and quality of proteins. Considering the high prevalence of childhood, and subsequent adult, obesity in the region, a virtual Middle East expert consensus meeting was held to discuss an effective approach for managing childhood obesity. Leading pediatric experts from Bahrain, Egypt, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates participated in the meeting. The experts discussed, debated, and agreed on certain directions, including the importance of educating parents, endorsing breastfeeding, and ensuring optimum quantity and quality intake of proteins in early life. This expert consensus may serve as the starting point for healthcare professionals in the region who are interested in shaping a healthy future for the generations to come. [ABSTRACT FROM AUTHOR]

In yeast, Tim50 along with Tim23 regulate translocation of presequence-containing proteins across the mitochondrial inner membrane. Here, we describe the identification and characterization of a novel human mitochondrial inner membrane protein homologous to the yeast Tim50. We demonstrate that human Tim50 possesses phosphatase activity and is present in a complex with human Tim23. Down-regulation of human Tim50 expression by RNA interference increases the sensitivity of human cell lines to death stimuli by accelerating the release of cytochrome c from the mitochondria. Furthermore, injection of Tim50-specific morpholino antisense oligonucleotides during early zebrafish embryonic development causes neurodegeneration, dysmorphic hearts, and reduced motility as a result of increased cell death. These observations indicate that loss of Tim50 in vertebrates causes mitochondrial membrane permeabilization and dysfunction followed by cytoplasmic release of cytochrome c along with other mitochondrial inducers of cell death. Thus Tim50 is important for both mitochondrial function and early neuronal development. [ABSTRACT FROM AUTHOR]

The mouse mutant mnd2 (motor neuron degeneration 2) exhibits muscle wasting, neurodegeneration, involution of the spleen and thymus, and death by 40 days of age. Degeneration of striatal neurons, with astrogliosis and microglia activation, begins at around 3 weeks of age, and other neurons are affected at later stages. Here we have identified the mnd2 mutation as the missense mutation Ser276Cys in the protease domain of the nuclear-encoded mitochondrial serine protease Omi (also known as HtrA2 or Prss25). Protease activity of Omi is greatly reduced in tissues of mnd2 mice but is restored in mice rescued by a bacterial artificial chromosome transgene containing the wild-type Omi gene. Deletion of the PDZ domain partially restores protease activity to the inactive recombinant Omi protein carrying the Ser276Cys mutation, suggesting that the mutation impairs substrate access or binding to the active site pocket. Loss of Omi protease activity increases the susceptibility of mitochondria to induction of the permeability transition, and increases the sensitivity of mouse embryonic fibroblasts to stress-induced cell death. The neurodegeneration and juvenile lethality in mnd2 mice result from this defect in mitochondrial Omi protease. [ABSTRACT FROM AUTHOR]

Smac/Diablo and HtrA2/Omi are inhibitors of apoptosis (IAP)-binding proteins released from the mitochondria of human cells during apoptosis and regulate apoptosis by liberating caspases from IAP inhibition. Here we describe the identification of a proteolytically processed isoform of the polypeptide chain-releasing factor GSPT1/eRF3 protein, which functions in translation, as a new IAP-binding protein. In common with other IAP-binding proteins, the processed GSPT1 protein harbors a conserved N-terminal IAP-binding motif (AKPF). Additionally, processed GSPT1 interacts biochemically with lAPs and could promote caspase activation, IAP ubiquitination and apoptosis. The IAP-binding motif of the processed GSPT1 is absolutely required for these activities. Our findings are consistent with a model whereby processing of GSPT1 into the IAP-binding isoform could potentiate apoptosis by liberating caspases from IAP inhibition, or target IAPs and the processed GSPT1 for proteasome-mediated degradation. [ABSTRACT FROM AUTHOR]

The mature serine protease Omi/HtrA2 is released from the mitochondria into the cytosol during apoptosis. Suppression of Omi/HtrA2 by RNA interference in human cell lines reduces cell death in response to TRAIL and etoposide. In contrast, ectopic expression of mature wildtype Omi/HtrA2, but not an active site murant, induces potent caspase activation and apoptosis. In vitro assays demonstrated that Omi/HtrA2 could degrade inhibitor of apoptosis proteins (IAPs). Consistent with this observation, increased expression of Omi/ HtrA2 in cells increases degradation of XIAP, while suppression of Omi/HtrA2 by RNA interference has an opposite effect. Combined, our data demonstrate that IAPs are substrates for Omi/HtrA2, and their degradation could be a mechanism by which the mitochondrially released Omi/HtrA2 activates caspases during apoptosis. [ABSTRACT FROM AUTHOR]

Death effector domain-containing proteins are involved in important cellular processes such as death-receptor induced apoptosis, NF-κB activation and ERK activation. Here we report the identification of a novel nuclear DED-containing protein, FLAME-3. FLAME-3 shares significant sequence (46.6% identical) and structural homology to another DEDcontaining protein, DEDD. FLAME-3 interacts with DEDD and c-FLIP (FLAME-1) but not with the other DED-containing proteins FADD, caspase-8 or caspase-10. FLAME-3 translocates to, and sequesters c-FLIP in the nucleus upon overexpression in human cell lines. Using the yeast twohybrid system to identify DEDD-interacting proteins, the TFIIIC102 subunit of human transcription factor TFIIIC was identified as a DEDD- and FLAME-3-specific interacting protein. Co-expression of either DEDD or FLAME-3 with hTFIIIC102 in MCF-7 cells induces the translocation from the cytoplasm and sequestration of hTFIIIC102 in the nucleus, indicating that DEDD and FLAME-3 form strong heterocomplexes with hTFIIIC102 and might be important regulators of the activity of the hTFIIIC transcriptional complex. Consistent with this, overexpression of DEDD or FLAME-3 in 293 cells inhibited the expression of a luciferase-reporter gene under the control of the NF-κB promoter. Our data provide the first direct evidence for the involvement of DED-containing proteins in the regulation of components of the general transcription machinery in the nucleus. [ABSTRACT FROM AUTHOR]

Inhibitors of apoptosis proteins (IAPs) interact with caspases and inhibit their protease activity, whereas the IAP-inhibitory proteins Smac/DIABLO in mammals and Reaper, Hid, and Grim in flies relieve IAP-mediated inhibition to induce cell death. Here we describe the functional characterization of the novel Drosophila cell death protein Sickle (Skl), which binds to IAPs and neutralizes their apoptotic inhibitory activity. Skl exhibits no sequence homology to Reaper, Hid, Grim, or Smac/DIABLO, except within the 4 residue N-terminal IAP binding motif. Skl interacts with Drosophila and mammalian IAPs and can promote caspase activation in the presence of IAPs. Consistent with these findings, expression of Skl in Drosophila and mammalian cell lines or in Drosophila embryos induces apoptosis. Skl can also synergize with Grim to induce cell death in the Drosophila eye imaginal disc. Based on biochemical and structural data, the N terminus of Skl, like that of the mammalian Smac/DIABLO, is absolutely required for its apoptotic and caspase-promoting activities and its ability to interact with IAPs. These findings point to conservation in the structure and function of the IAP-inhibitory proteins across species and suggest the existence of other family members. [Copyright &y& Elsevier]

Bax translocation from cytosol to mitochondria is believed to be a crucial step for triggering cytochrome c release from mitochondria. However, it is unclear whether Bax translocation is associated with Bax induction by DNA damaging agents. The induction of Bax in response to DNA damaging agents has been considered to be linked with p53. In this study, we used the p53 negative human chronic myeloid leukaemia K562 cell line. Bax up-regulation occurred at the whole cell level after DNA damage induced by etoposide. However, after incubation with etoposide, Bax failed to translocate to mitochondria and as a result, the apoptotic process was blocked. A Bax stable transfectant, the K/Bax cell line, expressed more Bax protein in the cytosol, mitochondria and nuclei. This Bax overexpression induced cytochrome c release, a reduction of cytochrome c oxidase activity and mitochondrial membrane potential (ΔΨm). However, Bax-induced apoptosis was blocked downstream of mitochondria in K562 cells. The increased levels of mitochondrial Bax sensitized cells to etoposide-induced activation of caspases-2, -3 and -9 and apoptosis. However, after transient transfection with the Apaf-1 gene, K/Bax cells were sensitized to etoposide-induced caspase activation and apoptosis to a larger extent compared with Bax or Apaf-1 transfection alone. We therefore conclude that two mechanisms contribute to the resistance of K562 cells to etoposide-induced apoptosis; firstly failure of Bax targeting to mitochondria and, secondly, deficiency of Apaf-1. Uncoupling of Bax translocation from Bax induction can occur in response to etoposide-induced DNA damage. Oncogene (2001) 20, 4817–4826. [ABSTRACT FROM AUTHOR]

Presents a study showing that X-linked inhibitor-of-apoptosis protein (XIAP) associates with the active caspase-9-Apaf-1 holoenzyme complex through binding to the amino terminus of the linker peptide on the small subunit of caspase-9, which becomes exposed after proteolytic processing of procaspase-9 at Asp 315. Finding of a mechanism in which binding to the BIR3 domain by two conserved peptides, one from Smac and one from caspase-9, has opposing effects on caspase activity and apoptosis.

Presents research which determined the crystal structure of the caspase-recruitment domain of Apaf-1 alone and in complex with the prodomain of procaspase-9. Role of caspase-9-mediated apoptosis in the development and homeostasis of organisms; Derivation of mature caspase-9; Effects of the mutation of residues in procaspase-9 or Apaf-1; Inhibition by wild-type prodomains of caspase-9; Analysis of homologues from Caenorhabditis elegans.

N-TosyI-L-phenylalanyl chloromethyl ketone (TPCK), a chymotrypsin-like serine protease inhibitor, affected apoptosis in human monocytic THP.1 cells differently dependent on both the concentration used and the apoptotic stimulus. TPCK (50-75 μM) induced both biochemical and ultrastructural changes characteristic of apoptosis, including proteolysis of poly (ADP-ribose) polymerase (PARP) and lamins together with formation of large kilobase pair fragments of DNA, particularly of 30-50 and 200-300 kilobase pairs in length but without internucleosomal cleavage of DNA. The induction of apoptosis by TPCK also involved the processing of CPP32 and Mch 3 to their catalytically active subunits. Benzyloxycarbonyl-VaI-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD.FMK), an ICE-like protease inhibitor, completely prevented all the biochemical and morphological changes induced by TPCK demonstrating the involvement of ICE-like proteases in the execution phase of apoptosis. Lower concentrations of TPCK (5-20 μM) prevented internucleosomal cleavage of DNA induced by other apoptotic stimuli. TPCK (10 μM) inhibited cell death induced by etoposide but potentiated that induced by cycloheximide demonstrating that it differentially affected apoptosis in THP.1 cells dependent on the stimulus used. These results are consistent with at least three distinct TPCK targets, one being important for cell survival, the second in facilitating internucleosomal cleavage of DNA and the third in the modulation of apoptosis induced by different apoptotic stimuli. [ABSTRACT FROM AUTHOR]

Background: Since the outbreak of Covid-19, several studies have demonstrated that healthcare workers (HCWs) are at risk of developing mental health disorders. Objective: To survey Saudi healthcare workers exposed to Covid-19 patients for most commonly reported mental health disorders. Study type, settings & duration: A descriptive cross-sectional study carried out at King Fahd Armed Forces Hospital Jeddah, Kingdom of Saudi Arabia (KSA) during June 2020. Methodology: The population comprised of healthcare workers (physicians, nurses and paramedical staff). The mental health disorders explored were depression, anxiety, insomnia and post traumatic stress disorder (PTSD). Data analysis was performed using SPSS statistical software version 22.0 (IBM Corp). Results: The most frequent mental health disorder reported in the present study was anxiety (68.6%) followed by insomnia (30.3%), PTSD (15.7%) and clinically significant depression (11.1%). Frontline healthcare workers demonstrated significantly higher risk of developing anxiety and PTSD after adjustment for other factors (OR of 1.9, 95% CI: 1.13-3.15, p =0.015), and (OR of 2.7, 95% CI: 1.22-6.01, p =0.014) respectively. Conclusion: Frontline HCWs demonstrated approximately two-fold increased risk of developing anxiety and approximately three-fold risk of developing post-traumatic stress disorders after adjustment for other variables. We suggest launching a large scale health education program and screening for Saudi HCWs engaged in the management of Covid-19 patients. [ABSTRACT FROM AUTHOR]