Matthewsadams3466
In this review, we summarize the current understanding of the role of mitochondrial Ca2+ signaling during different stages of the cell cycle and highlight the potential physiological and pathological significance of mitochondrial Ca2+ signaling.Lysosomal calcium is emerging as a modulator of autophagy and lysosomal compartment, an obligatory partner to complete the autophagic pathway. A variety of specific signals such as nutrient deprivation or oxidative stress can trigger lysosomal calcium-mediated nuclear translocation of the transcription factor EB (TFEB), a master regulator of global lysosomal function. Also, lysosomal calcium can promote the formation of autophagosome vesicles (AVs) by a mechanism that requires the production of the phosphoinositide PI3P by the VPS34 autophagic complex and the activation of the energy-sensing kinase AMPK. Additionally, lysosomal calcium plays a role in membrane fusion and fission events involved in cellular processes such as endocytic maturation, autophagosome-lysosome fusion, lysosomal exocytosis, and lysosomal reformation upon autophagy completion. Lysosomal calcium-dependent functions are defective in cellular and animal models of the non-selective cation channel TRPML1, whose mutations in humans cause the neurodegenerative lysosomal storage disease mucolipidosis type IV (MLIV). Lysosomal calcium is not only acting as a positive regulator of autophagy, but it is also responsible for turning-off this process through the reactivation of the mTOR kinase during prolonged starvation. selleck compound More recently, it has been described the role of lysosomal calcium on an elegant sequence of intracellular signaling events such as membrane repair, lysophagy, and lysosomal biogenesis upon the induction of different grades of lysosomal membrane damage. Here, we will discuss these novel findings that re-define the importance of the lysosome and lysosomal calcium signaling at regulating cellular metabolism.Hematopoiesis is based on the existence of hematopoietic stem cells (HSC) with the capacity to self-proliferate and self-renew or to differentiate into specialized cells. The hematopoietic niche is the essential microenvironment where stem cells reside and integrate various stimuli to determine their fate. Recent studies have identified niche containing high level of calcium (Ca2+) suggesting that HSCs are sensitive to Ca2+. This is a highly versatile and ubiquitous second messenger that regulates a wide variety of cellular functions. Advanced methods for measuring its concentrations, genetic experiments, cell fate tracing data, single-cell imaging, and transcriptomics studies provide information into its specific roles to integrate signaling into an array of mechanisms that determine HSC identity, lineage potential, maintenance, and self-renewal. Accumulating and contrasting evidence, are revealing Ca2+ as a previously unacknowledged feature of HSC, involved in functional maintenance, by regulating multiple actors including transcription and epigenetic factors, Ca2+-dependent kinases and mitochondrial physiology. Mitochondria are significant participants in HSC functions and their responsiveness to cellular demands is controlled to a significant extent via Ca2+ signals. Recent reports indicate that mitochondrial Ca2+ uptake also controls HSC fate. These observations reveal a physiological feature of hematopoietic stem cells that can be harnessed to improve HSC-related disease. In this review, we discuss the current knowledge Ca2+ in hematopoietic stem cell focusing on its potential involvement in proliferation, self-renewal and maintenance of HSC and discuss future research directions.Glial cells exploit calcium (Ca2+) signals to perceive the information about the activity of the nervous tissue and the tissue environment to translate this information into an array of homeostatic, signaling and defensive reactions. Astrocytes, the best studied glial cells, use several Ca2+ signaling generation pathways that include Ca2+ entry through plasma membrane, release from endoplasmic reticulum (ER) and from mitochondria. Activation of metabotropic receptors on the plasma membrane of glial cells is coupled to an enzymatic cascade in which a second messenger, InsP3 is generated thus activating intracellular Ca2+ release channels in the ER endomembrane. Astrocytes also possess store-operated Ca2+ entry and express several ligand-gated Ca2+ channels. In vivo astrocytes generate heterogeneous Ca2+ signals, which are short and frequent in distal processes, but large and relatively rare in soma. In response to neuronal activity intracellular and inter-cellular astrocytic Ca2+ waves can be produced. Astrocytic Ca2+ signals are involved in secretion, they regulate ion transport across cell membranes, and are contributing to cell morphological plasticity. Therefore, astrocytic Ca2+ signals are linked to fundamental functions of the central nervous system ranging from synaptic transmission to behavior. In oligodendrocytes, Ca2+ signals are generated by plasmalemmal Ca2+ influx, or by release from intracellular stores, or by combination of both. Microglial cells exploit Ca2+ permeable ionotropic purinergic receptors and transient receptor potential channels as well as ER Ca2+ release. In this contribution, basic morphology of glial cells, glial Ca2+ signaling toolkit, intracellular Ca2+ signals and Ca2+-regulated functions are discussed with focus on astrocytes.
Vaccination is one of the most effective public health interventions. We investigate the impact of vaccination activities for
type b, hepatitis B, human papillomavirus, Japanese encephalitis, measles,
serogroup A, rotavirus, rubella,
, and yellow fever over the years 2000-2030 across 112 countries.
Twenty-one mathematical models estimated disease burden using standardised demographic and immunisation data. Impact was attributed to the year of vaccination through vaccine-activity-stratified impact ratios.
We estimate 97 (95%CrI[80, 120]) million deaths would be averted due to vaccination activities over 2000-2030, with 50 (95%CrI[41, 62]) million deaths averted by activities between 2000 and 2019. For children under-5 born between 2000 and 2030, we estimate 52 (95%CrI[41, 69]) million more deaths would occur over their lifetimes without vaccination against these diseases.
This study represents the largest assessment of vaccine impact before COVID-19-related disruptions and provides motivation for sustaining and improving global vaccination coverage in the future.