scholarly journals Hydrogen Sulfide: From a Toxic Molecule to a Key Molecule of Cell Life

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 621 ◽  
Author(s):  
Angeles Aroca ◽  
Cecilia Gotor ◽  
Diane C. Bassham ◽  
Luis C. Romero

Hydrogen sulfide (H2S) has always been considered toxic, but a huge number of articles published more recently showed the beneficial biochemical properties of its endogenous production throughout all regna. In this review, the participation of H2S in many physiological and pathological processes in animals is described, and its importance as a signaling molecule in plant systems is underlined from an evolutionary point of view. H2S quantification methods are summarized and persulfidation is described as the underlying mechanism of action in plants, animals and bacteria. This review aims to highlight the importance of its crosstalk with other signaling molecules and its fine regulation for the proper function of the cell and its survival.

Information ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 272-284 ◽  
Author(s):  
Walter Kofler

1928 ◽  
Vol 55 (3) ◽  
pp. 665-735 ◽  
Author(s):  
Dorothy J. Jackson

It is well known that in many orders of typically winged insects species occur which in the adult stage are apterous or have the wings so reduced in size that flight is impossible. Sometimes the reduction of wings affects one sex only, as in the case of the females of certain moths, but in the majority of cases it is exhibited by both sexes. In many instances wing dimorphism occurs irrespective of sex, one form of the species having fully developed wings and the other greatly reduced wings. In some species the wings are polymorphic. The problem of the origin of reduced wings and of other functionless organs is one of great interest from the evolutionary point of view. Various theories have been advanced in explanation, but in the majority of cases the various aspects of the subject are too little known to warrant discussion. More experimental work is required to show how far environmental conditions on the one hand, and hereditary factors on the other, are responsible for this phenomenon. Those species which exhibit alary dimorphism afford material for the study of the inheritance of the two types of wings, but only in a few cases has this method of research been utilized.


2015 ◽  
Vol 35 (2) ◽  
pp. 167 ◽  
Author(s):  
Cristián Santibáñez Yáñéz

In this paper a tentative explanation of the competence of argumentation from an evolutionary point of view is offered. Because in contemporary argumentation theory and the informal logic approach the evolutionary perspective has been neglected, this paper gives an initial overview on the matter with the hope that core aspects of the argumentative faculty—such as argumentative normativity, the function of arguments, or fallacious moves, among others—can be seen differently afterwards. In order to specify the proposal, the main concepts considered are the notion of collective intentionality, cooperation, reputation, niche construction and, of course, basic evolutionary terms.


2017 ◽  
Vol 71 (0) ◽  
pp. 0-0
Author(s):  
Agnieszka Szczygieł ◽  
Elżbieta Pajtasz-Piasecka

Dendritic cells (DCs), as a link between innate and adaptive immunity, play a pivotal role in maintaining homeostasis of the immune system. The DC population is characterized by heterogeneity; it consists of many subpopulations which, despite their phenotypic and localization differences, play an essential function – they are professional antigen presenting cells. Due to their role, DCs can be utilized in a new cancer treatment strategy. Their main purpose is to generate an anticancer response leading to the elimination of cancer cells. The tumor microenvironment, abundant in immunosuppressive factors (e.g. IL-10, TGF-β, Arg1, IDO), impairs the proper function of DCs. For this reason, various strategies are necessary for ex vivo preparation of DC-based vaccines and for the support of in vivo DCs to fight against tumors. DC-based vaccines are combined with other forms of immunotherapy (e.g. blockade of immune checkpoint molecules, e.g. PD-1 or CTLA-4) or conventional types of therapies (e.g. chemotherapy). Despite the enormous progress that has been made in anticancer therapy in the past two decades, there are still many unresolved issues regarding the effectiveness of the DCs usage. In this paper we described, in both a mouse and a human subject, a series of DC subpopulations, differentiating in normal conditions or under the influence of cancer microenvironment. We listed factors affecting the quality of the in vivo and ex vivo generations of antitumoral responses, significant from a therapeutic point of view. Moreover, the most important strategies for the use of DCs in anticancer therapies, as well as further developments on this field, have been discussed.


2017 ◽  
Vol 6 (3) ◽  
pp. 52
Author(s):  
Sasni Amarasekara

<p>This specific study deals with a unique piece of Buddhist architecture, the Guardstone found almost in every part of ancient kingdoms in Sri Lanka spanning from Anuradhapura to Kandy period significantly. The Guardstone is an excellent piece of structure placed on either side of the first step of the flight of stairs at the entrance of ancient religious buildings or palaces in Sri Lanka. The origin of this architectural masterpiece is still to determine. Nevertheless, it is widely accepted in an evolutionary point of view that the guardstone has passed through several developmental stages from a simple slab to a highly sophisticated artifact in its dimensions, complexity and artistry. The numerous inclusions as well as exclusions from time to time to this artifact still remain uncertain as to whether they were due to secular or ecclesiastical reasons or simply due to the creators own culture influenced imagination. This study will peruse all the possible evidence that are available architecturally and to develop a logical reasoning for any identifiable characteristic and to elucidate with reasonable legitimacy as to how and why such a character is present or absent in a particular guardstone. This study in no way has any intention of rejecting or amending any proposition available at present but will pursue its best to shed light only on the attributes of a guardstone and to concentrate on the diversities of this beautiful monastic artifact that deserves serious academic study and meticulous aesthetic evaluation.</p>


2017 ◽  
pp. 65 ◽  
Author(s):  
Sergio Hernández-Verdugo ◽  
Patricia Dávila ◽  
Ken Oyama

The genus Capsicum consists of approximately 30 species of which C. annuum, C. chinense, C. frutescens, C. baccatum and C. pubescens are domesticated. Although Capsicum has been studied from the taxonomic and evolutionary point of view, using morphological, cytological and molecular characters, there are still sorne problems related to the taxonomic delimitation of the genus and its species, the nomenclature of the wild and cultivated forms, and the treatment of infraspecific variation. In order to determine the generic and specific taxonomic limits and to establish their phylogenetic and evolutionary relationships, it is necessary to undertake these studies among all the taxa of the genus Capsicum. C. annuum, C. chinense, and C. frutescens are taxa that form a taxonomic complex that can be barely differentiated and at the present it is impossible to determine whether they belong to the same or different species. The center of origin of the genus Capsicum is in South America, in the region that comprises Bolivia, northern Argentina, and central and southern Brazil. The biogeographic and archeobotanical studies indicate that during the dispersion of Capsicum along the American Continent, some of the species were domesticated independently in different places: C. annuum in Mexico; C. frutescens in Costa Rica, and possibly also in Mexico; C: chinense in the Amazonas lowlands; C. baccaturn in Bolivia, and C. pubescens in the Andes. In Mexico, C. annuwn has been cultivated throughout all the country; C. frutescens in the central and south eastern regions; C. chinense in the Yucatán Península, and C. pubescens in the high lands of the central states. In addition, there are C. ciliatum and C. lanceolatum, two species that have never been used by man. Genetic and ecological studies on wild populations are very important for the use and conservation of this genetic resource.


2016 ◽  
Vol 41 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Bo Kang ◽  
Wei Li ◽  
Wang Xi ◽  
Yinghong Yi ◽  
Yundan Ciren ◽  
...  

Background/Aims: Hydrogen sulfide (H<Sub>2</Sub>S) is a powerful inhibitor of cardiomyocytes apoptosis following ischemia/reperfusion (IR) injury, but the underlying mechanism remains unclear. Our previous study showed that microRNA-1 (miR-1) was upregulated by 2.21 fold in the IR group compared with that in the H<Sub>2</Sub>S preconditioned group. MiR-206 affected the process of cardiomyocytes hypertrophy by regulating histone deacetylase 4 (HDAC4). HDAC4 is also known to play an anti-apoptotic role in tumor cells, but its role in the myocardium has not been reported. The aim of this study was to test whether H<Sub>2</Sub>S could inhibit apoptosis of cardiomyocytes through HDAC4 regulation by miR-1 in IR. Methods: Cardiomyocytes of neonatal rats were subjected to hypoxia/reoxygenation (HR) injury with or without H<Sub>2</Sub>S pretreatment to simulate IR injury Cardiomyocytes were transfected with miR-1 mimic or HDAC4 siRNA to evaluate whether the miR-1-HDAC4 signaling pathway was involved in the protective effect of H<Sub>2</Sub>S. Results: HR increased cell apoptosis and caspase-3 cleavage, upregulated miR-1, and downregulated HDAC4. H<Sub>2</Sub>S preconditioning attenuated the apoptosis of cardiomyocytes, caspase-3 cleavage and LDH release, and enhanced cell viability In addition, H<Sub>2</Sub>S downregulated miR-1, and preserved HDAC4 expression. HDAC4 protein was down-regulated by miR-1 mimic. Transfection of cardiomyocytes with miR-1 mimic partially reduced the protective effect of H<Sub>2</Sub>S. Meanwhile, transfection of cardiomyocytes with siRNA to HDAC4 partially abrogated the protective effect of H<Sub>2</Sub>S. Conclusions: The miR-1-HDAC4 signaling pathway is involved in the protective effect of H<Sub>2</Sub>S against the apoptosis of cardiomyocytes during the IR injury process.


2020 ◽  
Vol 9 (5) ◽  
pp. 1269 ◽  
Author(s):  
Pietro Emanuele Napoli ◽  
Matteo Nioi ◽  
Ernesto d’Aloja ◽  
Maurizio Fossarello

Coronavirus disease 2019 (COVID-19) is an important health problem that was defined as a pandemic by the World Health Organization on 11 March 2020. Although great concern has been expressed about COVID-19 infection acquired through ocular transmission, its underlying mechanism has not currently been clarified. In the current work, we analyzed and elucidated the two main elements that should be taken into account to understand the “ocular route”, both from a clinical and molecular point of view. They are represented by the dynamism of the ocular surface system (e.g., the tear film turnover) and the distribution of ACE2 receptors and TMPRSS2 protein. Although it seems, at the moment, that there is a low risk of coronavirus spreading through tears, it may survive for a long time or replicate in the conjunctiva, even in absence of conjunctivitis signs, indicating that eye protection (e.g., protective goggles alone or in association with face shield) is advisable to prevent contamination from external droplets and aerosol.


2015 ◽  
Vol 35 (03) ◽  
pp. 244-251 ◽  
Author(s):  
M. Mezger ◽  
K. Göbel ◽  
P. Kraft ◽  
S. G. Meuth ◽  
C. Kleinschnitz ◽  
...  

SummaryThere is emerging evidence that platelets have an important role in inflammation beyond their involvement in hemostasis. Platelets can contribute to inflammatory reactions via crosstalk both with immune cells and endothelial cells. Inflamed vessels are characterized by the presence of activated endothelial cells. These activated endothelial cells upregulate receptors necessary for leukocyte recruitment, but also for the adhesion of platelets. Subsequently, immune cells can bind to platelets through adhesion receptors presented on the platelet surface, thus supporting leukocyte recruitment to the vessel wall. There are several neurological diseases associated with vascular inflammation including multiple sclerosis (MS) and stroke. Increased markers of platelet activation could be demonstrated in patients suffering from MS compared to healthy individuals. Reports from murine models indicate that platelets may be of importance for disease progression and severity by mediating leukocyte recruitment as one potential underlying mechanism. Blocking platelet function disease severity was considerably ameliorated. Moreover, processes of tissue remodelling may be influenced by platelet derived mediators. Whether a role of platelets for vascular inflammation can be extrapolated to further neurological diseases will have to be investigated in further in depth experimental and clinical trials.Platelets and platelet associated mechanisms may offer novel starting points to understand neurovascular diseases from a different point of view and to develop novel approaches to access the disease.


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