scholarly journals Current concepts in apoptosis: The physiological suicide program revisited

Author(s):  
Indrajit Chowdhury ◽  
Binu Tharakan ◽  
Ganapathy Bhat

AbstractApoptosis, or programmed cell death (PCD), involves a complex network of biochemical pathways that normally ensure a homeostatic balance between cellular proliferation and turnover in nearly all tissues. Apoptosis is essential for the body, as its deregulation can lead to several diseases. It plays a major role in a variety of physiological events, including embryonic development, tissue renewal, hormone-induced tissue atrophy, removal of inflammatory cells, and the evolution of granulation tissue into scar tissue. It also has an essential role in wound repair. The various cellular and biochemical mechanisms involved in apoptosis are not fully understood. However, there are two major pathways, the extrinsic pathway (receptor-mediated apoptotic pathway) and the intrinsic pathway (mitochondria-mediated apoptotic pathway), which are both well established. The key component in both is the activation of the caspase cascade. Caspases belong to the family of proteases that ultimately, by cleaving a set of proteins, cause disassembly of the cell. Although the caspase-mediated proteolytic cascade represents a central point in the apoptotic response, its initiation is tightly regulated by a variety of other factors. Among them, Bcl-2 family proteins, TNF and p53 play pivotal roles in the regulation of caspase activation and in the regulation of apoptosis. This review summarizes the established concepts in apoptosis as a physiological cell suicide program, highlighting the recent and significant advances in its study.

2021 ◽  
Vol 22 (16) ◽  
pp. 8440
Author(s):  
Geunyeong Kim ◽  
Minhwa Hong ◽  
Ayesha Kashif ◽  
Yujin Hong ◽  
Beom-Seok Park ◽  
...  

It is difficult to treat allergic diseases including asthma completely because its pathogenesis remains unclear. House dust mite (HDM) is a critical allergen and Toll-like receptor (TLR) 4 is a member of the toll-like receptor family, which plays an important role in allergic diseases. The purpose of this study was to characterize a novel allergen, Der f 38 binding to TLR4, and unveil its role as an inducer of allergy. Der f 38 expression was detected in the body and feces of Dermatophagoides farinae (DF). Electron microscopy revealed that it was located in the granule layer, the epithelium layer, and microvilli of the posterior midgut. The skin prick test showed that 60% of allergic subjects were Der f 38-positive. Der f 38 enhanced surface 203c expression in basophils of Der f 38-positive allergic subjects. By analysis of the model structure of Der p 38, the expected epitope sites are exposed on the exterior side. In animal experiments, Der f 38 triggered an infiltration of inflammatory cells. Intranasal (IN) administration of Der f 38 increased neutrophils in the lung. Intraperitoneal (IP) and IN injections of Der f 38 induced both eosinophils and neutrophils. Increased total IgE level and histopathological features were found in BALB/c mice treated with Der f 38 by IP and IN injections. TLR4 knockout (KO) BALB/c mice exhibited less inflammation and IgE level in the sera compared to wild type (WT) mice. Der f 38 directly binds to TLR4 using biolayer interferometry. Der f 38 suppressed the apoptosis of neutrophils and eosinophils by downregulating proteins in the proapoptotic pathway including caspase 9, caspase 3, and BAX and upregulating proteins in the anti-apoptotic pathway including BCL-2 and MCL-1. These findings might shed light on the pathogenic mechanisms of allergy to HDM.


Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1843
Author(s):  
Muhammad Afzal ◽  
Imran Kazmi ◽  
Fahad A. Al-Abbasi ◽  
Sultan Alshehri ◽  
Mohammed M. Ghoneim ◽  
...  

Inflammatory lung disorders (ILDs) are one of the world’s major reasons for fatalities and sickness, impacting millions of individuals of all ages and constituting a severe and pervasive health hazard. Asthma, lung cancer, bronchiectasis, pulmonary fibrosis acute respiratory distress syndrome, and COPD all include inflammation as a significant component. Microbe invasions, as well as the damage and even death of host cells, can cause and sustain inflammation. To counteract the negative consequences of irritants, the airways are equipped with cellular and host defense immunological systems that block the cellular entrance of these irritants or eliminate them from airway regions by triggering the immune system. Failure to activate the host defense system will trigger chronic inflammatory cataracts, leading to permanent lung damage. This damage makes the lungs more susceptible to various respiratory diseases. There are certain restrictions of the available therapy for lung illnesses. Vitamins are nutritional molecules that are required for optimal health but are not produced by the human body. Cholecalciferol (Vitamin D) is classified as a vitamin, although it is a hormone. Vitamin D is thought to perform a function in bone and calcium homeostasis. Recent research has found that vitamin D can perform a variety of cellular processes, including cellular proliferation; differentiation; wound repair; healing; and regulatory systems, such as the immune response, immunological, and inflammation. The actions of vitamin D on inflammatory cells are dissected in this review, as well as their clinical significance in respiratory illnesses.


2011 ◽  
Vol 20 (1) ◽  
pp. 161-173
Author(s):  
A.P. Kassatkina

Resuming published and own data, a revision of classification of Chaetognatha is presented. The family Sagittidae Claus & Grobben, 1905 is given a rank of subclass, Sagittiones, characterised, in particular, by the presence of two pairs of sac-like gelatinous structures or two pairs of fins. Besides the order Aphragmophora Tokioka, 1965, it contains the new order Biphragmosagittiformes ord. nov., which is a unique group of Chaetognatha with an unusual combination of morphological characters: the transverse muscles present in both the trunk and the tail sections of the body; the seminal vesicles simple, without internal complex compartments; the presence of two pairs of lateral fins. The only family assigned to the new order, Biphragmosagittidae fam. nov., contains two genera. Diagnoses of the two new genera, Biphragmosagitta gen. nov. (type species B. tarasovi sp. nov. and B. angusticephala sp. nov.) and Biphragmofastigata gen. nov. (type species B. fastigata sp. nov.), detailed descriptions and pictures of the three new species are presented.


Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2670
Author(s):  
Moira O’Connor ◽  
Greta Smith ◽  
Ashleigh Pantaleo ◽  
Darren Haywood ◽  
Rhys Weaver ◽  
...  

Sarcomas are a group of rare and aggressive cancers, which develop in bones and connective tissue throughout the body. Sarcomas account for only 1–2% of all cancers worldwide; however, mortality rates for sarcoma are high with approximately two in four sarcoma patients dying following a diagnosis. Delays in diagnosis, poor management of symptoms, patients’ high symptom loads and high carer burden are all associated with carer distress, which may lead to complications after bereavement. The experience of having a family member referred for palliative care is also distressing for carers, with the realisation that their family member is dying. This study aimed to explore the experiences of bereaved family carers of people diagnosed with sarcoma. A qualitative descriptive design using a social constructionist framework was adopted. Interviews were conducted with sixteen participants, and thematic analysis was used to identify patterns in the data. Four overarching themes emerged: beginning the journey; moving through treatment; transitioning to palliative care; and experiencing bereavement. The narratives were coherent and potent, and people reflected on their journeys. Interventions and supports for bereaved carers could include opportunities for counselling to support reflections, supports for developing a narrative such as writing therapy, and preparation for the death of the family member.


2021 ◽  
Vol 13 (1) ◽  
pp. 91-94
Author(s):  
Ana Carolina Pereira de Godoy ◽  
Jose Maria Pereira de Godoy ◽  
Maria de Fatima Guerreiro Godoy

Introduction: Lymphedema is a specific type of edema that affects regions of the body in a chronic, progressive manner. Aim: The aim of the present study was to describe the therapeutic evolution of more than ten years of treatment for primary congenital lymphedema using the Godoy and Godoy method. Method: Ten children with primary congenital lymphedema with more than ten years of treatment at the Godoy Clinic were evaluated. Children with a clinical diagnosis of primary congenital lymphedema in treatment for more than 10 years with the Godoy Method. Cervical stimulation is the first treatment option of the method and is performed as monotherapy. The patients were reevaluated with weekly, bi-weekly and monthly frequencies and then every three months or when the family was able to return to the clinic. Results: For cases in which cervical stimulation was not possible, grosgrain stockings as monotherapy was the second therapeutic option. Conclusion: The Godoy and Godoy Method is effective at reducing edema in cases of primary congenital lymphedema, with the maintenance of the results throughout the treatment period.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 921
Author(s):  
Futoshi Okada ◽  
Runa Izutsu ◽  
Keisuke Goto ◽  
Mitsuhiko Osaki

Inflammation-related carcinogenesis has long been known as one of the carcinogenesis patterns in humans. Common carcinogenic factors are inflammation caused by infection with pathogens or the uptake of foreign substances from the environment into the body. Inflammation-related carcinogenesis as a cause for cancer-related death worldwide accounts for approximately 20%, and the incidence varies widely by continent, country, and even region of the country and can be affected by economic status or development. Many novel approaches are currently available concerning the development of animal models to elucidate inflammation-related carcinogenesis. By learning from the oldest to the latest animal models for each organ, we sought to uncover the essential common causes of inflammation-related carcinogenesis. This review confirmed that a common etiology of organ-specific animal models that mimic human inflammation-related carcinogenesis is prolonged exudation of inflammatory cells. Genotoxicity or epigenetic modifications by inflammatory cells resulted in gene mutations or altered gene expression, respectively. Inflammatory cytokines/growth factors released from inflammatory cells promote cell proliferation and repair tissue injury, and inflammation serves as a “carcinogenic niche”, because these fundamental biological events are common to all types of carcinogenesis, not just inflammation-related carcinogenesis. Since clinical strategies are needed to prevent carcinogenesis, we propose the therapeutic apheresis of inflammatory cells as a means of eliminating fundamental cause of inflammation-related carcinogenesis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuan-chi Teng ◽  
Alfredo Leonardo Porfírio-Sousa ◽  
Giulia Magri Ribeiro ◽  
Marcela Corso Arend ◽  
Lindolfo da Silva Meirelles ◽  
...  

Abstract Background Peripheral arterial disease (PAD) affects millions of people and compromises quality of life. Critical limb ischemia (CLI), which is the most advanced stage of PAD, can cause nonhealing ulcers and strong chronic pain, and it shortens the patients’ life expectancy. Cell-based angiogenic therapies are becoming a real therapeutic approach to treat CLI. Pericytes are cells that surround vascular endothelial cells to reinforce vessel integrity and regulate local blood pressure and metabolism. In the past decade, researchers also found that pericytes may function as stem or progenitor cells in the body, showing the potential to differentiate into several cell types. We investigated the gene expression profiles of pericytes during the early stages of limb ischemia, as well as the alterations in pericyte subpopulations to better understand the behavior of pericytes under ischemic conditions. Methods In this study, we used a hindlimb ischemia model to mimic CLI in C57/BL6 mice and explore the role of pericytes in regeneration. To this end, muscle pericytes were isolated at different time points after the induction of ischemia. The phenotypes and transcriptomic profiles of the pericytes isolated at these discrete time points were assessed using flow cytometry and RNA sequencing. Results Ischemia triggered proliferation and migration and upregulated the expression of myogenesis-related transcripts in pericytes. Furthermore, the transcriptomic analysis also revealed that pericytes induce or upregulate the expression of a number of cytokines with effects on endothelial cells, leukocyte chemoattraction, or the activation of inflammatory cells. Conclusions Our findings provide a database that will improve our understanding of skeletal muscle pericyte biology under ischemic conditions, which may be useful for the development of novel pericyte-based cell and gene therapies.


2021 ◽  
Author(s):  
Hao Zhao ◽  
Jingwen Xu ◽  
Haitao Yuan ◽  
Endong Zhang ◽  
Nan Dai ◽  
...  

Inspired by the skin biofunction of protecting the body from microorganism invasion, artificially manufacturing human skin in vitro with promising antibacterial capability and cell affinity is urgently required in wound...


2014 ◽  
Vol 12 (2) ◽  
pp. 333-342 ◽  
Author(s):  
Angela M. Zanata ◽  
Priscila Camelier

Characidium samurai, a species of the family Crenuchidae apparently endemic to rio das Almas and rio Vermelho basins, Bahia, Brazil, is described. The new species is readily distinguishable from its congeners, except C. lanei, by having a dark lateral band along the head and body that is particularly broad from the rear of the head to the end of the caudal peduncle (1.5 or 2 scales wide) and by the absence of dark bars or blotches on the ventral half of the body. Characidium samurai differs from C. laneiby having the lateral band with straight borders overall (vs.lateral band with somewhat irregular borders due to blotches extending dorsally or ventrally), anal fin ii,7-8 (vs. ii,6), and 4 horizontal scale rows above the lateral line and 4 below (vs. 5/3). It further differs from congeners by a series of features, including isthmus completely covered by scales, lateral line complete with 34-37 perforated scales, 9 scales on the transversal line, 14 scale rows around the caudal peduncle, anal fin ii,7-8, and the absence of dark bars or spots on the fins, except by a faded dorsal-fin bar. The presence of pseudotympanum in four species of Characidium is discussed.


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