- Metabolic requirements of the nephron. [Review]
- PNPediatr Nephrol 2018 Dec 15
- The mammalian kidney is a complex organ that has several metabolically active cell types to aid in waste filtration, salt-water balance, and electrolyte homeostasis in the body. These functions are d...
The mammalian kidney is a complex organ that has several metabolically active cell types to aid in waste filtration, salt-water balance, and electrolyte homeostasis in the body. These functions are done primarily through the nephron, which relies on strict regulation of various metabolic pathways. Any deviations in the metabolic profile of nephrons or their precursor cells called nephron progenitors can lead to renal pathologies and abnormal development. Metabolism encompasses the mechanisms by which cells generate intermediate molecules and energy in the form of adenosine triphosphate (ATP). ATP is required by all cells and is mainly generated through glycolysis, fatty acid oxidation, and oxidative phosphorylation. During kidney development, self-renewing or proliferating cells rely on glycolysis to a greater extent than the other metabolic pathways to supply energy, replenish reducing equivalents, and generate nucleotides. However, terminally differentiated cell types rely more heavily on fatty acid oxidation and oxidative phosphorylation performed in the mitochondria to fulfill energy requirements. Further, the mature nephron is comprised of distinct segments and each segment utilizes metabolic pathways to varying degrees depending on the specific function. This review will focus on major metabolic processes performed by the nephron during health and disease.
- Simultaneous detection of ATP metabolites in human plasma and urine based on palladium nanoparticle and poly(bromocresol green) composite sensor. [Journal Article]
- BBBiosens Bioelectron 2018 Dec 08; 126:758-766
- A sensitive voltammetric sensor based on palladium nanoparticles (PdNPs) and poly-bromocresol green (pBG) composite layer immobilized on amide functionalized single-walled carbon nanotubes (AmSWCNTs)...
A sensitive voltammetric sensor based on palladium nanoparticles (PdNPs) and poly-bromocresol green (pBG) composite layer immobilized on amide functionalized single-walled carbon nanotubes (AmSWCNTs) modified pyrolytic graphite (PdNPs:pBG/AmSWCNTs/PG) has been prepared for the simultaneous determination of adenosine triphosphate (ATP) catabolites, inosine (INO), hypoxanthine (HX), xanthine (XT), and uric acid (UA). The modified PdNPs:pBG/AmSWCNTs/PG was characterized by electrochemical experiments and surface analysis, which exhibited exceptional electrocatalytic effects towards the oxidation of INO, HX, XT, and UA with a significant enhanced peak current and well resolved peaks separation for all the analytes. The linear calibration curves were obtained in the concentration range of 0.001-175 µM, 0.001-200 µM, 0.001-150 µM, and 0.001-200 µM and limits of detection were found as 0.95 nM, 1.04 nM, 1.07 nM, and 0.43 nM corresponding to INO, HX, XT, and UA, respectively. The common metabolites present in the biological fluids did not interfere in the determination. The applicability of the proposed sensor was successfully demonstrated by determining INO, HX, XT, and UA in the human plasma and urine and the obtained results were validated by using HPLC.
- Uridine adenosine tetraphosphate and purinergic signaling in cardiovascular system: an update. [Review]
- PRPharmacol Res 2018 Dec 13
- Uridine adenosine tetraphosphate (Up4A), biosynthesized by activation of vascular endothelial growth factor receptor (VEGFR) 2, was initially identified as a potent endothelium-derived vasoconstricto...
Uridine adenosine tetraphosphate (Up4A), biosynthesized by activation of vascular endothelial growth factor receptor (VEGFR) 2, was initially identified as a potent endothelium-derived vasoconstrictor in perfused rat kidney. Subsequently, the effect of Up4A on vascular tone regulation was intensively investigated in arteries isolated from different vascular beds in rodents including rat pulmonary arteries, aortas, mesenteric and renal arteries as well as mouse aortas, in which Up4A produces vascular contraction. In contrast, Up4A produces vascular relaxation in porcine coronary small arteries and rat aortas. Intravenous infusion of Up4A into conscious rats or mice decreases blood pressure, and intravenous bolus injection of Up4A into anesthetized mice increases coronary blood flow, indicating an overall vasodilator influence in vivo. Although Up4A is the first dinucleotide described that contains both purine and pyrimidine moieties, its cardiovascular effects are exerted mainly through activation of purinergic receptors. These effects not only encompass regulation of vascular tone, but also endothelial angiogenesis, smooth muscle cell proliferation and migration, and vascular calcification. Furthermore, this review discusses a potential role for Up4A in cardiovascular pathophysiology, as plasma levels of Up4A are elevated in juvenile hypertensive patients and Up4A-mediated vascular purinergic signaling changes in cardiovascular disease such as hypertension, diabetes, atherosclerosis and myocardial infarction. Better understanding the vascular effect of the novel dinucleotide Up4A and the purinergic signaling mechanisms mediating its effects will enhance its potential as target for treatment of cardiovascular disease.
- The effect of ghrelin and adenosine mono phosphate kinase (AMPK) on the passive avoidance memory in male wistar rats. [Journal Article]
- NNeuropeptides 2018 Nov 27
- A newly synthesized oleanolic acid derivative inhibits the growth of osteosarcoma cells in vitro and in vivo by decreasing c-MYC-dependent glycolysis. [Journal Article]
- JCJ Cell Biochem 2018 Dec 14
- Osteosarcoma (OS) is the primary malignant bone tumor with a peak incidence in children and adolescents. However, the little molecular mechanism of pathogenesis has been known and it is urgent to dev...
Osteosarcoma (OS) is the primary malignant bone tumor with a peak incidence in children and adolescents. However, the little molecular mechanism of pathogenesis has been known and it is urgent to develop new therapeutical strategies to improve outcomes for patients. CDDO-NFM (N-formylmorpholine substituent of CDDO) is a newly synthesized triterpenoid, which is a derivative of oleanolic acid. In this study, we explored whether CDDO-NFM possesses a potential antitumor effect and revealed its molecular mechanism. We found that CDDO-NFM efficiently inhibited cell growth of OS cells and this inhibitory effect was independent of apoptosis-related and cell-cycle-related proteins. CDDO-NFM could decrease the level of glucose uptake, the generation of lactate, and the production of adenosine triphosphate to block the process of glycolysis. In vitro and in vivo cell-based assays showed that CDDO-NFM inhibited glycolysis via degradation of c-MYC rather than activating peroxisome proliferator-activated receptor gamma. Finally, CDDO-NFM could reduce tumor volume and weight with low toxicity, and down-regulate the expression of glycolysis-related enzymes in nude mice. Taken together, these results showed that CDDO-NFM might be a promising antitumor compound.
- Lichen planus: altered AIM2 and NLRP1 expression in skin lesions and defective activation in peripheral blood mononuclear cells. [Journal Article]
- CEClin Exp Dermatol 2018 Dec 14
- CONCLUSIONS: Alterations in innate immunity, such as inflammasome component expression in skin lesions and PBMCs, were observed in patients with LP. Further investigations of dysfunctional inflammasome activation and the chronic inflammatory status of LP are required.
- What's new in autoinflammation? [Review]
- PNPediatr Nephrol 2018 Dec 14
- The pathogenesis of autoinflammatory diseases has shed light on the concept of inflammation in general and on our understanding of the role of the innate immune system. The autoinflammatory diseases ...
The pathogenesis of autoinflammatory diseases has shed light on the concept of inflammation in general and on our understanding of the role of the innate immune system. The autoinflammatory diseases have a large spectrum with varying features of inflammation. The most common autoinflammatory diseases are those associated with periodic fevers. The delay in diagnosis of these four common diseases (familial Mediterranean fever, cryopyrin-associated periodic fever syndrome, mevalonate kinase deficiency, and TNF receptor-associated periodic fever syndrome) results in secondary amyloidosis of the kidney. The new work towards classification criteria for these diseases is presented. Recently a group of autoinflammatory diseases that are associated with vasculitis have also been identified. These are stimulators of interferon genes (STING)-associated vasculopathy of infancy (SAVI), which is a monogenic defect associated with excessive activity in interferon alpha and deficiency of adenosine deaminase 2, which is characterized by a polyarteritis nodosa-like picture. These monogenic diseases are now in our differential diagnosis of vasculitides. Secondary amyloidosis is a complication of autoinflammatory diseases. Understanding the inflammatory mechanisms in these diseases has led to the use of targeted biologics for this complication. It is hoped that enlightening the mechanisms underlying these monogenic autoinflammatory diseases will also teach us about the pathways in common diseases.
- Variable gender-dependent platelet responses to combined antiplatelet therapy in patients with stable coronary-artery disease. [Journal Article]
- JPJ Physiol Pharmacol 2018; 69(4)
- Antiplatelet therapy is considered as a standard procedure against atherosclerotic cardiovscular disease but this therapy has limited effect if resistance to acetylsalicylic acid or clopidogrel is pr...
Antiplatelet therapy is considered as a standard procedure against atherosclerotic cardiovscular disease but this therapy has limited effect if resistance to acetylsalicylic acid or clopidogrel is present. Important factors associated with resistance are gender; or inflammation possibly associated with membrane microparticles (MP). It was decided to challenge the hypothesis that differential responses to dual antiplatelet therapy are conditioned by gender and/or proinflammatory status. The study involved 160 patients with stable coronary heart disease (118 men, 42 women) aged 65.2 ± 7.8 years. Patients were treated long-term with acetylsalicylic acid (ASA); plus clopidogrel starting 6 days before percutaneous coronary intervention (both 75 mg/day). Response was evaluated using platelet aggregation with either arachidonic acid (the ASPI test; predominantly for ASA response) or adenosine diphosphate (the ADP test; predominantly for clopidogrel response). MP levels were measured as follows: total (MP-total); with TF expression (MP-TF); or platelet-derived microparticles (PDMP), as well as proinflammatory parameters: C-reactive protein (CRP), leukocytes (WBC) and platelet numbers (PLT). Analysis of platelet-aggregation levels with regard to gender revealed higher aggregation in women: with resistance to ASA (ASPI test: P = 0.0383, ADP test: P = 0.0027); resistance to clopidogrel (ASPI test: P = 0.0003; ADP test: P = 0.0566) and with sensitivity to both drugs with the ADP test (P = 0.0190). In women relative to men, regardless of response, significantly higher CRP (P = 0.0012), WBC (P = 0.0244) and PLT numbers (P = 0.0001) were found. In contrast, in men significantly higher concentrations of MP-TF (P = 0.0286) and triglycerides (P = 0.0296) were found in the clopidogrel-resistant group. We conclude that women have an inferior response to dual antiplatelet therapy relative to men, possibly associated with higher platelet reactivity (especially when measured with the ADP test), with a more accentuated proinflammatory status. In contrast, among the factors supporting the resistance in men can be an elevated concentration of MP-TF which, together with the coexistence of hypertriglyceridemia, may constitute an important mechanism of resistance to clopidogrel.
- Can immune biomarkers predict infections in solid organ transplant recipients? A review of current evidence. [Review]
- TRTransplant Rev (Orlando) 2018 Oct 09
- Despite improvements in graft survival, solid organ transplantation is still associated with considerable infection induced morbidity and mortality. If we were able to show that serious infection ris...
Despite improvements in graft survival, solid organ transplantation is still associated with considerable infection induced morbidity and mortality. If we were able to show that serious infection risk was associated with excessive suppression of immune capacity, we would be justified in "personalizing" the extent of immunosuppression by carefully monitored reduction to see if we can improve immune compromize without increasing the risk of rejection. Reliable biomarkers are needed to identify this patients at an increased risk of infection. This review focuses on the currently available evidence in solid organ transplant recipients for immune non-pathogen specific biomarkers to predict severe infections with the susceptibility to particular pathogens according to the component of the immune system that is suppressed. This review is categorized into immune biomarkers representative of the humoral, cellular, phagocytic, natural killer cell and complement system. Biomarkers humoral and cellular systems of the that have demonstrated an association with infections include immunoglobulins, lymphocyte number, lymphocyte subsets, intracellular concentrations of adenosine triphosphate in stimulated CD4+ cells and soluble CD30. Biomarkers of the innate immune system that have demonstrated an association with infections include natural killer cell numbers, complement and mannose binding lectin. Emerging evidence shows that quantification of viral nucleic acid (such as Epstein Barr Virus) can act as a biomarker to predict all-cause infections. Studies that show the most promise are those in which several immune biomarkers are assessed in combination. Ongoing research is required to validate non-pathogen specific immune biomarkers in multi-centre studies using standardized study designs.
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- A-to-I RNA Editing Affects lncRNAs Expression after Heat Shock. [Journal Article]
- GGenes (Basel) 2018 Dec 13; 9(12)
- Adenosine to inosine (A-to-I) RNA editing is a highly conserved regulatory process carried out by adenosine-deaminases (ADARs) on double-stranded RNA (dsRNAs). Although a considerable fraction of the...
Adenosine to inosine (A-to-I) RNA editing is a highly conserved regulatory process carried out by adenosine-deaminases (ADARs) on double-stranded RNA (dsRNAs). Although a considerable fraction of the transcriptome is edited, the function of most editing sites is unknown. Previous studies indicate changes in A-to-I RNA editing frequencies following exposure to several stress types. However, the overall effect of stress on the expression of ADAR targets is not fully understood. Here, we performed high-throughput RNA sequencing of wild-type and ADAR mutant Caenorhabditis elegans worms after heat-shock to analyze the effect of heat-shock stress on the expression pattern of genes. We found that ADAR regulation following heat-shock does not directly involve heat-shock related genes. Our analysis also revealed that long non-coding RNAs (lncRNAs) and pseudogenes, which have a tendency for secondary RNA structures, are enriched among upregulated genes following heat-shock in ADAR mutant worms. The same group of genes is downregulated in ADAR mutant worms under permissive conditions, which is likely, considering that A-to-I editing protects endogenous dsRNA from RNA-interference (RNAi). Therefore, temperature increases may destabilize dsRNA structures and protect them from RNAi degradation, despite the lack of ADAR function. These findings shed new light on the dynamics of gene expression under heat-shock in relation to ADAR function.