scholarly journals Role of Septins in Endothelial Cells and Platelets

Author(s):  
Katharina Neubauer ◽  
Barbara Zieger

Septins are conserved cytoskeletal GTP-binding proteins identified in almost all eukaryotes except higher plants. Mammalian septins comprise 13 family members with either ubiquitous or organ- and tissue-specific expression patterns. They form filamentous oligomers and complexes with other proteins to serve as diffusions barrier and/or multi-molecular scaffolds to function in a physiologically regulated manner. Diverse septins are highly expressed in endothelial cells and platelets, which play an important role in hemostasis, a process to prevent blood loss after vascular injury. Endothelial septins are involved in cellular processes such as exocytosis and in processes concerning organismal level, like angiogenesis. Septins are additionally found in endothelial cell-cell junctions where their presence is required to maintain the integrity of the barrier function of vascular endothelial monolayers. In platelets, septins are important for activation, degranulation, adhesion, and aggregation. They have been identified as mediators of distinct platelet functions and being essential in primary and secondary hemostatic processes. Septin-knockout mouse studies show the relevance of septins in several aspects of hemostasis. This is in line with reports that dysregulation of septins is clinically relevant in human bleeding disorders. The precise function of septins in the biology of endothelial cells and platelets remains poorly understood. The following mini-review highlights the current knowledge about the role of septin cytoskeleton in regulating critical functions in these two cell types.

2016 ◽  
Vol 57 (2) ◽  
pp. 97-111 ◽  
Author(s):  
Giampaolo Trivellin ◽  
Ivana Bjelobaba ◽  
Adrian F Daly ◽  
Darwin O Larco ◽  
Leonor Palmeira ◽  
...  

We recently showed that Xq26.3 microduplications cause X-linked acrogigantism (X-LAG). X-LAG patients mainly present with growth hormone and prolactin-secreting adenomas and share a minimal duplicated region containing at least four genes. GPR101 was the only gene highly expressed in their pituitary lesions, but little is known about its expression patterns. In this work, GPR101 transcripts were characterized in human tissues by 5′-Rapid Amplification of cDNA Ends (RACE) and RNAseq, while the putative promoter was bioinformatically predicted. We investigated GPR101 mRNA and protein expression by RT-quantitative PCR (qPCR), whole-mount in situ hybridization, and immunostaining, in human, rhesus monkey, rat and zebrafish. We identified four GPR101 isoforms characterized by different 5′-untranslated regions (UTRs) and a common 6.1kb long 3′UTR. GPR101 expression was very low or absent in almost all adult human tissues examined, except for specific brain regions. Strong GPR101 staining was observed in human fetal pituitary and during adolescence, whereas very weak/absent expression was detected during childhood and adult life. In contrast to humans, adult monkey and rat pituitaries expressed GPR101, but in different cell types. Gpr101 is expressed in the brain and pituitary during rat and zebrafish development; in rat pituitary, Gpr101 is expressed only after birth and shows sexual dimorphism. This study shows that different GPR101 transcripts exist and that the brain is the major site of GPR101 expression across different species, although divergent species- and temporal-specific expression patterns are evident. These findings suggest an important role for GPR101 in brain and pituitary development and likely reflect the very different growth, development and maturation patterns among species.


2018 ◽  
Vol 115 (50) ◽  
pp. E11691-E11700 ◽  
Author(s):  
Meng Mao ◽  
Xiushuai Yang ◽  
Gordon M. Bennett

Plant sap-feeding insects (Hemiptera) rely on bacterial symbionts for nutrition absent in their diets. These bacteria experience extreme genome reduction and require genetic resources from their hosts, particularly for basic cellular processes other than nutrition synthesis. The host-derived mechanisms that complete these processes have remained poorly understood. It is also unclear how hosts meet the distinct needs of multiple bacterial partners with differentially degraded genomes. To address these questions, we investigated the cell-specific gene-expression patterns in the symbiotic organs of the aster leafhopper (ALF), Macrosteles quadrilineatus (Cicadellidae). ALF harbors two intracellular symbionts that have two of the smallest known bacterial genomes: Nasuia (112 kb) and Sulcia (190 kb). Symbionts are segregated into distinct host cell types (bacteriocytes) and vary widely in their basic cellular capabilities. ALF differentially expresses thousands of genes between the bacteriocyte types to meet the functional needs of each symbiont, including the provisioning of metabolites and support of cellular processes. For example, the host highly expresses genes in the bacteriocytes that likely complement gene losses in nucleic acid synthesis, DNA repair mechanisms, transcription, and translation. Such genes are required to function in the bacterial cytosol. Many host genes comprising these support mechanisms are derived from the evolution of novel functional traits via horizontally transferred genes, reassigned mitochondrial support genes, and gene duplications with bacteriocyte-specific expression. Comparison across other hemipteran lineages reveals that hosts generally support the incomplete symbiont cellular processes, but the origins of these support mechanisms are generally specific to the host–symbiont system.


2020 ◽  
Vol 21 (11) ◽  
pp. 3921 ◽  
Author(s):  
Takumi Okamoto ◽  
Kazunori Imaizumi ◽  
Masayuki Kaneko

Ubiquitylation plays multiple roles not only in proteasome-mediated protein degradation but also in various other cellular processes including DNA repair, signal transduction, and endocytosis. Ubiquitylation is mediated by ubiquitin ligases, which are predicted to be encoded by more than 600 genes in humans. RING finger (RNF) proteins form the majority of these ubiquitin ligases. It has also been predicted that there are 49 RNF proteins containing transmembrane regions in humans, several of which are specifically localized to membrane compartments in the secretory and endocytic pathways. Of these, RNF183, RNF186, RNF182, and RNF152 are closely related genes with high homology. These genes share a unique common feature of exhibiting tissue-specific expression patterns, such as in the kidney, nervous system, and colon. The products of these genes are also reported to be involved in various diseases such as cancers, inflammatory bowel disease, Alzheimer’s disease, and chronic kidney disease, and in various biological functions such as apoptosis, endoplasmic reticulum stress, osmotic stress, nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR), and Notch signaling. This review summarizes the current knowledge of these tissue-specific ubiquitin ligases, focusing on their physiological roles and significance in diseases.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1133
Author(s):  
Orly Weissberg ◽  
Evan Elliott

Chromodomain-helicase-DNA-binding protein 8 (CHD8) has been identified as one of the genes with the strongest association with autism. The CHD8 protein is a transcriptional regulator that is expressed in nearly all cell types and has been implicated in multiple cellular processes, including cell cycle, cell adhesion, neuronal development, myelination, and synaptogenesis. Considering the central role of CHD8 in the genetics of autism, a deeper understanding of the physiological functions of CHD8 is important to understand the development of the autism phenotype and potential therapeutic targets. Different CHD8 mutant mouse models were developed to determine autism-like phenotypes and to fully understand their mechanisms. Here, we review the current knowledge on CHD8, with an emphasis on mechanistic lessons gained from animal models that have been studied.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuetian Li ◽  
Xinyue Wang ◽  
Yu Pang ◽  
Shuangcheng Wang ◽  
Meng Luo ◽  
...  

As one of the most serious complications of radiotherapy, osteoradionecrosis (ORN) seriously affects the quality of life of patients and even leads to death. Vascular injury and immune disorders are the main causes of bone lesions. The traditional conservative treatment of ORN has a low cure rate and high recurrent. Exosomes are a type of extracellular bilayer lipid vesicles secreted by almost all cell types. It contains cytokines, proteins, mRNA, miRNA, and other bioactive cargos, which contribute to several distinct processes. The favorable biological functions of mesenchymal stem cells-derived exosomes (MSC exosomes) include angiogenesis, immunomodulation, bone regeneration, and ferroptosis regulation. Exploring the characteristic of ORN and MSC exosomes can promote bone regeneration therapies. In this review, we summarized the current knowledge of ORN and MSC exosomes and highlighted the potential application of MSC exosomes in ORN treatment.


2018 ◽  
Vol 98 (3) ◽  
pp. 1591-1625 ◽  
Author(s):  
Pier Andrea Borea ◽  
Stefania Gessi ◽  
Stefania Merighi ◽  
Fabrizio Vincenzi ◽  
Katia Varani

Adenosine is a ubiquitous endogenous autacoid whose effects are triggered through the enrollment of four G protein-coupled receptors: A1, A2A, A2B, and A3. Due to the rapid generation of adenosine from cellular metabolism, and the widespread distribution of its receptor subtypes in almost all organs and tissues, this nucleoside induces a multitude of physiopathological effects, regulating central nervous, cardiovascular, peripheral, and immune systems. It is becoming clear that the expression patterns of adenosine receptors vary among cell types, lending weight to the idea that they may be both markers of pathologies and useful targets for novel drugs. This review offers an overview of current knowledge on adenosine receptors, including their characteristic structural features, molecular interactions and cellular functions, as well as their essential roles in pain, cancer, and neurodegenerative, inflammatory, and autoimmune diseases. Finally, we highlight the latest findings on molecules capable of targeting adenosine receptors and report which stage of drug development they have reached.


2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.


2021 ◽  
Vol 22 (11) ◽  
pp. 6054
Author(s):  
Ioanna Kokkinopoulou ◽  
Paraskevi Moutsatsou

Mitochondria are membrane organelles present in almost all eukaryotic cells. In addition to their well-known role in energy production, mitochondria regulate central cellular processes, including calcium homeostasis, Reactive Oxygen Species (ROS) generation, cell death, thermogenesis, and biosynthesis of lipids, nucleic acids, and steroid hormones. Glucocorticoids (GCs) regulate the mitochondrially encoded oxidative phosphorylation gene expression and mitochondrial energy metabolism. The identification of Glucocorticoid Response Elements (GREs) in mitochondrial sequences and the detection of Glucocorticoid Receptor (GR) in mitochondria of different cell types gave support to hypothesis that mitochondrial GR directly regulates mitochondrial gene expression. Numerous studies have revealed changes in mitochondrial gene expression alongside with GR import/export in mitochondria, confirming the direct effects of GCs on mitochondrial genome. Further evidence has made clear that mitochondrial GR is involved in mitochondrial function and apoptosis-mediated processes, through interacting or altering the distribution of Bcl2 family members. Even though its exact translocation mechanisms remain unknown, data have shown that GR chaperones (Hsp70/90, Bag-1, FKBP51), the anti-apoptotic protein Bcl-2, the HDAC6- mediated deacetylation and the outer mitochondrial translocation complexes (Tom complexes) co-ordinate GR mitochondrial trafficking. A role of mitochondrial GR in stress and depression as well as in lung and hepatic inflammation has also been demonstrated.


Immuno ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 78-90
Author(s):  
Johannes Burtscher ◽  
Grégoire P. Millet

Like in other neurodegenerative diseases, protein aggregation, mitochondrial dysfunction, oxidative stress and neuroinflammation are hallmarks of Parkinson’s disease (PD). Differentiating characteristics of PD include the central role of α-synuclein in the aggregation pathology, a distinct vulnerability of the striato-nigral system with the related motor symptoms, as well as specific mitochondrial deficits. Which molecular alterations cause neurodegeneration and drive PD pathogenesis is poorly understood. Here, we summarize evidence of the involvement of three interdependent factors in PD and suggest that their interplay is likely a trigger and/or aggravator of PD-related neurodegeneration: hypoxia, acidification and inflammation. We aim to integrate the existing knowledge on the well-established role of inflammation and immunity, the emerging interest in the contribution of hypoxic insults and the rather neglected effects of brain acidification in PD pathogenesis. Their tight association as an important aspect of the disease merits detailed investigation. Consequences of related injuries are discussed in the context of aging and the interaction of different brain cell types, in particular with regard to potential consequences on the vulnerability of dopaminergic neurons in the substantia nigra. A special focus is put on the identification of current knowledge gaps and we emphasize the importance of related insights from other research fields, such as cancer research and immunometabolism, for neurodegeneration research. The highlighted interplay of hypoxia, acidification and inflammation is likely also of relevance for other neurodegenerative diseases, despite disease-specific biochemical and metabolic alterations.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 437
Author(s):  
Ting Gong ◽  
Weiyong Wang ◽  
Houqiang Xu ◽  
Yi Yang ◽  
Xiang Chen ◽  
...  

Testicular expression of taste receptor type 1 subunit 3 (T1R3), a sweet/umami taste receptor, has been implicated in spermatogenesis and steroidogenesis in mice. We explored the role of testicular T1R3 in porcine postnatal development using the Congjiang Xiang pig, a rare Chinese miniature pig breed. Based on testicular weights, morphology, and testosterone levels, four key developmental stages were identified in the pig at postnatal days 15–180 (prepuberty: 30 day; early puberty: 60 day; late puberty: 90 day; sexual maturity: 120 day). During development, testicular T1R3 exhibited stage-dependent and cell-specific expression patterns. In particular, T1R3 levels increased significantly from prepuberty to puberty (p < 0.05), and expression remained high until sexual maturity (p < 0.05), similar to results for phospholipase Cβ2 (PLCβ2). The strong expressions of T1R3/PLCβ2 were observed at the cytoplasm of elongating/elongated spermatids and Leydig cells. In the eight-stage cycle of the seminiferous epithelium in pigs, T1R3/PLCβ2 levels were higher in the spermatogenic epithelium at stages II–VI than at the other stages, and the strong expressions were detected in elongating/elongated spermatids and residual bodies. The message RNA (mRNA) levels of taste receptor type 1 subunit 1 (T1R1) in the testis showed a similar trend to levels of T1R3. These data indicate a possible role of T1R3 in the regulation of spermatid differentiation and Leydig cell function.


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