ROLE OF ENDOGENOUS PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-?? (PPAR-??) LIGANDS IN THE DEVELOPMENT OF GUT ISCHEMIA AND REPERFUSION IN MICE

Shock ◽  
2006 ◽  
Vol 25 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Carmelo Mui?? ◽  
Emanuela Mazzon ◽  
Concetta Crisafulli ◽  
Rosanna Di Paola ◽  
Tiziana Genovese ◽  
...  
PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Yuji Naito ◽  
Tomohisa Takagi ◽  
Toshikazu Yoshikawa

Peroxisome proliferator-activated receptor (PPAR) is a nuclear receptor that is known to play a central role in lipid metabolism and insulin sensitivity as well as inflammation and cell proliferation. According to the results obtained from studies on several animal models of gastrointestinal inflammation, PPAR has been implicated in the regulation of the immune response, particularly inflammation control, and has gained importance as a potential therapeutic target in the management of gastrointestinal inflammation. In the present paper, we present the current knowledge on the role of PPAR ligands in the gastrointestinal tract.


2020 ◽  
Vol 27 ◽  
Author(s):  
Suvadeep Mal ◽  
Ashish Ranjan Dwivedi ◽  
Vijay Kumar ◽  
Naveen Kumar ◽  
Bhupinder Kumar ◽  
...  

: Peroxisome proliferator-activated receptor (PPAR), a ligand dependant transcription factor, is a member of nuclear receptor superfamily. PPAR exists in three isoforms i.e. PPAR alpha (PPARα), PPAR beta (PPARβ), and PPAR gamma (PPARγ). These are multi-functional transcription factor and help in regulating inflammation, diabetes type 2, lipid concentration in the body, metastasis, and tumor growth or angiogenesis. Activation of PPARγ causes inhibition of growth of cultured human breast, gastric, lung, prostate, and other cancer cells. PPARγ is mainly involved in fatty acid storage, glucose metabolism, and homeostasis and adipogenesis regulation. A large number of natural and synthetic ligands bind to PPARγ and modulate its activity. Ligands such as thiazolidinedione, troglitazone, rosiglitazone, pioglitazone effectively bind to PPARγ however, most of these were found to display severe side effects such as hepatotoxicity, weight gain, cardiovascular complications and bladder tumor. Now the focus is shifted towards the development of dual-acting or pan PPAR ligands. The current review article describes the functions and role of PPARγ in various disease states. In addition, recently reported PPARγ ligands and pan PPAR ligands were discussed in detail. It is envisaged that the present review article may help in the development of potent PPAR ligands with no or minimal side effects.


Author(s):  
Rana A. Alaaeddine ◽  
Perihan A. Elzahhar ◽  
Ibrahim AlZaim ◽  
Wassim Abou-Kheir ◽  
Ahmed S.F. Belal ◽  
...  

: Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro-and anti-tumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarize the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 734
Author(s):  
Pietro Antonuccio ◽  
Herbert Ryan Marini ◽  
Antonio Micali ◽  
Carmelo Romeo ◽  
Roberta Granese ◽  
...  

Varicocele is an age-related disease with no current medical treatments positively impacting infertility. Toll-like receptor 4 (TLR4) expression is present in normal testis with an involvement in the immunological reactions. The role of peroxisome proliferator-activated receptor-α (PPAR-α), a nuclear receptor, in fertility is still unclear. N-Palmitoylethanolamide (PEA), an emerging nutraceutical compound present in plants and animal foods, is an endogenous PPAR-α agonist with well-demonstrated anti-inflammatory and analgesics characteristics. In this model of mice varicocele, PPAR-α and TLR4 receptors’ roles were investigated through the administration of ultra-micronized PEA (PEA-um). Male wild-type (WT), PPAR-α knockout (KO), and TLR4 KO mice were used. A group underwent sham operation and administration of vehicle or PEA-um (10 mg/kg i.p.) for 21 days. Another group (WT, PPAR-α KO, and TLR4 KO) underwent surgical varicocele and was treated with vehicle or PEA-um (10 mg/kg i.p.) for 21 days. At the end of treatments, all animals were euthanized. Both operated and contralateral testes were processed for histological and morphometric assessment, for PPAR-α, TLR4, occludin, and claudin-11 immunohistochemistry and for PPAR-α, TLR4, transforming growth factor-beta3 (TGF-β3), phospho-extracellular signal-Regulated-Kinase (p-ERK) 1/2, and nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) Western blot analysis. Collectively, our data showed that administration of PEA-um revealed a key role of PPAR-α and TLR4 in varicocele pathophysiology, unmasking new nutraceutical therapeutic targets for future varicocele research and supporting surgical management of male infertility.


2021 ◽  
Vol 11 (15) ◽  
pp. 7120
Author(s):  
Mirko Pesce ◽  
Irene La Fratta ◽  
Teresa Paolucci ◽  
Alfredo Grilli ◽  
Antonia Patruno ◽  
...  

The beneficial effects of exercise on the brain are well known. In general, exercise offers an effective way to improve cognitive function in all ages, particularly in the elderly, who are considered the most vulnerable to neurodegenerative disorders. In this regard, myokines, hormones secreted by muscle in response to exercise, have recently gained attention as beneficial mediators. Irisin is a novel exercise-induced myokine, that modulates several bodily processes, such as glucose homeostasis, and reduces systemic inflammation. Irisin is cleaved from fibronectin type III domain containing 5 (FNDC5), a transmembrane precursor protein expressed in muscle under the control of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). The FNDC5/irisin system is also expressed in the hippocampus, where it stimulates the expression of the neurotrophin brain-derived neurotrophic factor in this area that is associated with learning and memory. In this review, we aimed to discuss the role of irisin as a key mediator of the beneficial effects of exercise on synaptic plasticity and memory in the elderly, suggesting its roles within the main promoters of the beneficial effects of exercise on the brain.


2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Jaou-Chen Huang

Peroxisome proliferator-activated receptorδ(PPARδ, also known as PPARβ) has ubiquitous distribution and extensive biological functions. The reproductive function of PPARδwas first revealed in the uterus at the implantation site. Since then, PPARδand its ligand have been discovered in all reproductive tissues, including the gametes and the preimplantation embryos. PPARδin preimplantation embryos is normally activated by oviduct-derived PPARδligand. PPARδactivation is associated with an increase in embryonic cell proliferation and a decrease in programmed cell death (apoptosis). On the other hand, the role of PPARδand its ligand in gamete formation and function is less well understood. This review will summarize the reproductive functions of PPARδand project its potential applications in assisted reproductive technology.


Endocrinology ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 3525-3538 ◽  
Author(s):  
Hong Guo ◽  
Merlijn Bazuine ◽  
Daozhong Jin ◽  
Merry M. Huang ◽  
Samuel W. Cushman ◽  
...  

Lipocalin 2 (Lcn2) has previously been characterized as an adipokine/cytokine playing a role in glucose and lipid homeostasis. In this study, we investigate the role of Lcn2 in adipose tissue remodeling during high-fat diet (HFD)-induced obesity. We find that Lcn2 protein is highly abundant selectively in inguinal adipose tissue. During 16 weeks of HFD feeding, the inguinal fat depot expanded continuously, whereas the expansion of the epididymal fat depot was reduced in both wild-type (WT) and Lcn2−/− mice. Interestingly, the depot-specific effect of HFD on fat mass was exacerbated and appeared more pronounced and faster in Lcn2−/− mice than in WT mice. In Lcn2−/− mice, adipocyte hypertrophy in both inguinal and epididymal adipose tissue was more profoundly induced by age and HFD when compared with WT mice. The expression of peroxisome proliferator-activated receptor-γ protein was significantly down-regulated, whereas the gene expression of extracellular matrix proteins was up-regulated selectively in epididymal adipocytes of Lcn2−/− mice. Consistent with these observations, collagen deposition was selectively higher in the epididymal, but not in the inguinal adipose depot of Lcn2−/− mice. Administration of the peroxisome proliferator-activated receptor-γ agonist rosiglitazone (Rosi) restored adipogenic gene expression. However, Lcn2 deficiency did not alter the responsiveness of adipose tissue to Rosi effects on the extracellular matrix expression. Rosi treatment led to the further enlargement of adipocytes with improved metabolic activity in Lcn2−/− mice, which may be associated with a more pronounced effect of Rosi treatment in reducing TGF-β in Lcn2−/− adipose tissue. Consistent with these in vivo observations, Lcn2 deficiency reduces the adipocyte differentiation capacity of stromal-vascular cells isolated from HFD-fed mice in these cells. Herein Rosi treatment was again able to stimulate adipocyte differentiation to a similar extent in WT and Lcn2−/− inguinal and epididymal stromal-vascular cells. Thus, combined, our data indicate that Lcn2 has a depot-specific role in HFD-induced adipose tissue remodeling.


2013 ◽  
Vol 65 (2) ◽  
pp. 447-453
Author(s):  
N. Lukic ◽  
A. Stankovic ◽  
E. Dincic ◽  
M. Bundalo ◽  
Z. Krsmanovic ◽  
...  

The function of peroxisome proliferator-activated receptor ? (PPAR?) in immune regulation, as well as in antiinflammatory and anti-proliferative actions towards T lymphocytes, has been reported. A potential role of PPARs in multiple sclerosis (MS) was suggested. The aim of this study was to investigate if there is an association of PPAR?-2 Pro12Ala polymorphism with MS in 361 patients from Serbia. The genotype and allele frequencies of Pro12Ala polymorphism were not significantly different between controls and patients, or between females and males. In contrast to controls, we detected a rare Ala/Ala genotype in patients with MS. We found that there is a significant association of Ala/Ala genotype with older age at onset (ANOVA, p=0.07; LSD post-hoc, Ala/Ala vs. Pro/Ala, p=0.03, Ala/Ala vs. Pro/Pro p=0.02). It would be useful to validate our results in other populations, as well as to perform follow-up of the disease progression in regard to PPAR? genotypes.


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