PtdIns5P: a little phosphoinositide with big functions?

2007 ◽  
Vol 74 ◽  
pp. 117-128 ◽  
Author(s):  
Sophie Coronas ◽  
Damien Ramel ◽  
Caroline Pendaries ◽  
Frédérique Gaits-Iacovoni ◽  
Hélène Tronchère ◽  
...  

Phosphoinositides are minor constituents of cell membranes playing a critical role in the regulation of many cellular functions. Recent discoveries indicate that mutations in several phosphoinositide kinases and phosphatases generate imbalances in the levels of phosphoinositides, thereby leading to the development of human diseases. Although the roles of phosphoinositide 3-kinase products and PtdIns(4,5)P2 were largely studied these last years, the potential role of phosphatidylinositol monophosphates as direct signalling molecules is just emerging. PtdIns5P, the least characterized phosphoinositide, appears to be a new player in cell regulation. This review will summarize the current knowledge on the mechanisms of synthesis and degradation of PtdIns5P as well as its potential roles.

2020 ◽  
Vol 25 (42) ◽  
pp. 4510-4522 ◽  
Author(s):  
Biancamaria Longoni ◽  
Irene Fasciani ◽  
Shivakumar Kolachalam ◽  
Ilaria Pietrantoni ◽  
Francesco Marampon ◽  
...  

: Exosomes are extracellular vesicles produced by eukaryotic cells that are also found in most biological fluids and tissues. While they were initially thought to act as compartments for removal of cellular debris, they are now recognized as important tools for cell-to-cell communication and for the transfer of pathogens between the cells. They have attracted particular interest in neurodegenerative diseases for their potential role in transferring prion-like proteins between neurons, and in Parkinson’s disease (PD), they have been shown to spread oligomers of α-synuclein in the brain accelerating the progression of this pathology. A potential neuroprotective role of exosomes has also been equally proposed in PD as they could limit the toxicity of α-synuclein by clearing them out of the cells. Exosomes have also attracted considerable attention for use as drug vehicles. Being nonimmunogenic in nature, they provide an unprecedented opportunity to enhance the delivery of incorporated drugs to target cells. In this review, we discuss current knowledge about the potential neurotoxic and neuroprotective role of exosomes and their potential application as drug delivery systems in PD.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 909
Author(s):  
Krzysztof Kotowski ◽  
Jakub Rosik ◽  
Filip Machaj ◽  
Stanisław Supplitt ◽  
Daniel Wiczew ◽  
...  

Glycolysis is a crucial metabolic process in rapidly proliferating cells such as cancer cells. Phosphofructokinase-1 (PFK-1) is a key rate-limiting enzyme of glycolysis. Its efficiency is allosterically regulated by numerous substances occurring in the cytoplasm. However, the most potent regulator of PFK-1 is fructose-2,6-bisphosphate (F-2,6-BP), the level of which is strongly associated with 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase activity (PFK-2/FBPase-2, PFKFB). PFK-2/FBPase-2 is a bifunctional enzyme responsible for F-2,6-BP synthesis and degradation. Four isozymes of PFKFB (PFKFB1, PFKFB2, PFKFB3, and PFKFB4) have been identified. Alterations in the levels of all PFK-2/FBPase-2 isozymes have been reported in different diseases. However, most recent studies have focused on an increased expression of PFKFB3 and PFKFB4 in cancer tissues and their role in carcinogenesis. In this review, we summarize our current knowledge on all PFKFB genes and protein structures, and emphasize important differences between the isoenzymes, which likely affect their kinase/phosphatase activities. The main focus is on the latest reports in this field of cancer research, and in particular the impact of PFKFB3 and PFKFB4 on tumor progression, metastasis, angiogenesis, and autophagy. We also present the most recent achievements in the development of new drugs targeting these isozymes. Finally, we discuss potential combination therapies using PFKFB3 inhibitors, which may represent important future cancer treatment options.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Victoria Hale ◽  
Maren Weischer ◽  
Jong Y. Park

Although the causes of prostate cancer are largely unknown, previous studies support the role of genetic factors in the development of prostate cancer.CHEK2plays a critical role in DNA replication by responding to double-stranded breaks. In this review, we provide an overview of the current knowledge of the role of a genetic variant, 1100delC, ofCHEK2on prostate cancer risk and discuss the implication for potential translation of this knowledge into clinical practice. Currently, twelve articles that discussedCHEK2∗1100delC and its association with prostate cancer were identified. Of the twelve prostate cancer studies, five studies had independent data to draw conclusive evidence from. The pooled results of OR and 95% CI were 1.98 (1.23–3.18) for unselected cases and 3.39 (1.78–6.47) for familial cases, indicating thatCHEK2∗1100delC mutation is associated with increased risk of prostate cancer. Screening for CHEK2∗1100delC should be considered in men with a familial history of prostate cancer.


2021 ◽  
Vol 12 ◽  
Author(s):  
Siqi Ming ◽  
Mei Zhang ◽  
Zibin Liang ◽  
Chunna Li ◽  
Jianzhong He ◽  
...  

Mucosal associated invariant T (MAIT) cells play a critical role in Helicobacter pylori (H. pylori)-induced gastritis by promoting mucosal inflammation and aggravating mucosal injuries (1, 2). However, the underlying mechanism and key molecules involved are still uncertain. Here we identified OX40, a co-stimulatory molecule mainly expressed on T cells, as a critical regulator to promote proliferation and IL-9 production by MAIT cells and facilitate mucosal inflammation in H. pylori-positive gastritis patients. Serum examination revealed an increased level of IL-9 in gastritis patients. Meanwhile, OX40 expression was increased in mucosal MAIT cells, and its ligand OX40L was also up-regulated in mucosal dendritic cells (DCs) of gastritis patients, compared with healthy controls. Further results demonstrated that activation of the OX40/OX40L pathway promoted IL-9 production by MAIT cells, and MAIT cells displayed a highly-activated phenotype after the cross-linking of OX40 and OX40L. Moreover, the level of IL-9 produced by MAIT cells was positively correlated with inflammatory indexes in the gastric mucosa, suggesting the potential role of IL-9-producing MAIT cells in mucosal inflammation. Taken together, we elucidated that OX40/OX40L axis promoted mucosal MAIT cell proliferation and IL-9 production in H. pylori-induced gastritis, which may provide potential targeting strategies for gastritis treatment.


2003 ◽  
Vol 369 (1) ◽  
pp. 1-15 ◽  
Author(s):  
David W. LITCHFIELD

Protein kinase CK2 ('casein kinase II') has traditionally been classified as a messenger-independent protein serine/threonine kinase that is typically found in tetrameric complexes consisting of two catalytic (α and/or α′) subunits and two regulatory β subunits. Accumulated biochemical and genetic evidence indicates that CK2 has a vast array of candidate physiological targets and participates in a complex series of cellular functions, including the maintenance of cell viability. This review summarizes current knowledge of the structural and enzymic features of CK2, and discusses advances that challenge traditional views of this enzyme. For example, the recent demonstrations that individual CK2 subunits exist outside tetrameric complexes and that CK2 displays dual-specificity kinase activity raises new prospects for the precise elucidation of its regulation and cellular functions. This review also discusses a number of the mechanisms that contribute to the regulation of CK2 in cells, and will highlight emerging insights into the role of CK2 in cellular decisions of life and death. In this latter respect, recent evidence suggests that CK2 can exert an anti-apoptotic role by protecting regulatory proteins from caspase-mediated degradation. The mechanistic basis of the observation that CK2 is essential for viability may reside in part in this ability to protect cellular proteins from caspase action. Furthermore, this anti-apoptotic function of CK2 may contribute to its ability to participate in transformation and tumorigenesis.


The Healer ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 80-86
Author(s):  
Shankar Gautam ◽  
Abhishek Upadhyay ◽  
Rashmi Mutha ◽  
BINOD KUMAR SINGH ◽  
Ram Kishor Joshi

Diabetes is a clinical condition characterized by a spike in blood glucose in plasma. It is one of the 21st century's greatest public health crises and is among the top 10 causes of death worldwide. Although new drugs and therapeutics are emerging for its management but the prevalence is increasing at an alarming pace; thus, every system must contribute for effective management. An effort is made to review the efficacy and safety evaluation of the individual herbs of Darvyadi Kwatha (DK), an Ayurvedic formulation mentioned in Charaka Samhita. The constituents of the DK has some strong efficient antidiabetic/hypoglycaemic chemical principle having insulin-triggering and insulin-like behaviors which increases the activity of glucose-6-phosphate dehydrogenase (G6PD) and glucokinase and decreases glucose-6-phosphatase activity, reduce oxidative stress and prevention of glutathione reductase, superoxide dismutase, and catalase activity play a critical role in glucose homeostasis. DK also improve biochemical parameters such as SGPT, SGOT, cholesterol and triglycerides and is found to be safe in animal experiments. The various evidences clearly indicates that DK has definite hypoglycemic potential as well as anti-diabetic activity.


2018 ◽  
Vol 25 (2) ◽  
pp. 253-267 ◽  
Author(s):  
Sandra Fonseca ◽  
Dhanya Radhakrishnan ◽  
Kalika Prasad ◽  
Andrea Chini

Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits.


2019 ◽  
Vol 11 (3) ◽  
pp. 709-723 ◽  
Author(s):  
Kan Gao ◽  
Chun-long Mu ◽  
Aitak Farzi ◽  
Wei-yun Zhu

ABSTRACT The gut-brain axis (GBA) is a bilateral communication network between the gastrointestinal (GI) tract and the central nervous system. The essential amino acid tryptophan contributes to the normal growth and health of both animals and humans and, importantly, exerts modulatory functions at multiple levels of the GBA. Tryptophan is the sole precursor of serotonin, which is a key monoamine neurotransmitter participating in the modulation of central neurotransmission and enteric physiological function. In addition, tryptophan can be metabolized into kynurenine, tryptamine, and indole, thereby modulating neuroendocrine and intestinal immune responses. The gut microbial influence on tryptophan metabolism emerges as an important driving force in modulating tryptophan metabolism. Here, we focus on the potential role of tryptophan metabolism in the modulation of brain function by the gut microbiota. We start by outlining existing knowledge on tryptophan metabolism, including serotonin synthesis and degradation pathways of the host, and summarize recent advances in demonstrating the influence of the gut microbiota on tryptophan metabolism. The latest evidence revealing those mechanisms by which the gut microbiota modulates tryptophan metabolism, with subsequent effects on brain function, is reviewed. Finally, the potential modulation of intestinal tryptophan metabolism as a therapeutic option for brain and GI functional disorders is also discussed.


2019 ◽  
Vol 11 (10) ◽  
pp. 880-885 ◽  
Author(s):  
Hendrik Täuber ◽  
Stefan Hüttelmaier ◽  
Marcel Köhn

Abstract A large variety of eukaryotic small structured POLIII-derived non-coding RNAs (ncRNAs) have been described in the past. However, for only few, e.g. 7SL and H1/MRP families, cellular functions are well understood. For the vast majority of these transcripts, cellular functions remain unknown. Recent findings on the role of Y RNAs and other POLIII-derived ncRNAs suggest an evolutionarily conserved function of these ncRNAs in the assembly and function of ribonucleoprotein complexes (RNPs). These RNPs provide cellular `machineries’, which are essential for guiding the fate and function of a variety of RNAs. In this review, we summarize current knowledge on the role of POLIII-derived ncRNAs in the assembly and function of RNPs. We propose that these ncRNAs serve as scaffolding factors that `chaperone’ RNA-binding proteins (RBPs) to form functional RNPs. In addition or associated with this role, some small ncRNAs act as molecular decoys impairing the RBP-guided control of RNA fate by competing with other RNA substrates. This suggests that POLIII-derived ncRNAs serve essential and conserved roles in the assembly of larger RNPs and thus the control of gene expression by indirectly guiding the fate of mRNAs and lncRNAs.


2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Anouk Waeytens ◽  
Martine De Vos ◽  
Debby Laukens

Inflammatory bowel diseases (IBDs) are a group of chronic, relapsing, immune-mediated disorders of the intestine, including Crohn's disease and ulcerative colitis. Recent studies underscore the importance of the damaged epithelial barrier and the dysregulated innate immune system in their pathogenesis. Metallothioneins (MTs) are a family of small proteins with a high and conserved cysteine content that are rapidly upregulated in response to an inflammatory stimulus. Herein, we review the current knowledge regarding the expression and potential role of MTs in IBD. MTs exert a central position in zinc homeostasis, modulate the activation of the transcription factor nuclear factor (NF)-B, and serve as antioxidants. In addition, MTs could be involved in IBD through their antiapoptotic effects or through specific immunomodulating extracellular effects. Reports on MT expression in IBD are contradictory but clearly demonstrate a deviant MT expression supporting the idea that these aberrations in IBD require further clarification.


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