scholarly journals Circadian Rhythms, the Mesolimbic Dopaminergic Circuit, and Drug Addiction

2007 ◽  
Vol 7 ◽  
pp. 194-202 ◽  
Author(s):  
Colleen A. McClung
Keyword(s):  
Circadian Rhythms ◽  
Drug Addiction ◽  
Molecular Mechanisms ◽  
Dopaminergic System ◽  
Treatment Options ◽  
Drug Induced ◽  
Circadian Genes ◽  
Dopaminergic Transmission ◽  
Central Pacemaker

Drug addiction is a devastating disease that affects millions of individuals worldwide. Through better understanding of the genetic variations that create a vulnerability for addiction and the molecular mechanisms that underlie the progression of addiction, better treatment options can be created for those that suffer from this condition. Recent studies point to a link between abnormal or disrupted circadian rhythms and the development of addiction. In addition, studies suggest a role for specific genes that make up the molecular clock in the regulation of drug sensitivity, sensitization, and reward. The influence of circadian genes and rhythms on drug-induced behaviors may be mediated through the mesolimbic dopaminergic system. This system has long been implicated in the development of addiction, and recent evidence supports a regulatory role for the brain's central pacemaker and circadian gene expression in the regulation of dopaminergic transmission. This review highlights the association between circadian genes and drug addiction, and the possible role of the mesolimbic dopaminergic system in this association.

scholarly journals Cellular and mitochondrial mechanisms of atrial fibrillation

2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Fleur E. Mason ◽  
Julius Ryan D. Pronto ◽  
Khaled Alhussini ◽  
Christoph Maack ◽  
Niels Voigt
Keyword(s):  
Atrial Fibrillation ◽  
Nicotinamide Adenine Dinucleotide ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Specific Treatment ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Mitochondrial Activity ◽  
Atp Production

AbstractThe molecular mechanisms underlying atrial fibrillation (AF), the most common form of arrhythmia, are poorly understood and therefore target-specific treatment options remain an unmet clinical need. Excitation–contraction coupling in cardiac myocytes requires high amounts of adenosine triphosphate (ATP), which is replenished by oxidative phosphorylation in mitochondria. Calcium (Ca2+) is a key regulator of mitochondrial function by stimulating the Krebs cycle, which produces nicotinamide adenine dinucleotide for ATP production at the electron transport chain and nicotinamide adenine dinucleotide phosphate for the elimination of reactive oxygen species (ROS). While it is now well established that mitochondrial dysfunction plays an important role in the pathophysiology of heart failure, this has been less investigated in atrial myocytes in AF. Considering the high prevalence of AF, investigating the role of mitochondria in this disease may guide the path towards new therapeutic targets. In this review, we discuss the importance of mitochondrial Ca2+ handling in regulating ATP production and mitochondrial ROS emission and how alterations, particularly in these aspects of mitochondrial activity, may play a role in AF. In addition to describing research advances, we highlight areas in which further studies are required to elucidate the role of mitochondria in AF.

scholarly journals Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

2021 ◽  
Vol 11 ◽  
Author(s):  
Codruţa Şoica ◽  
Mirela Voicu ◽  
Roxana Ghiulai ◽  
Cristina Dehelean ◽  
Roxana Racoviceanu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Treatment Options ◽  
Active Role ◽  
Structural Features ◽  
Sex Hormone ◽  
Ongoing Research ◽  
New Treatment ◽  
Highly Correlated

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

scholarly journals Role of Enzymes in Causing Neurological Disorders

2021 ◽  
Vol 12 (1) ◽  
pp. 466-476
Author(s):  
Vysakh Visweswaran ◽  
Roshni PR
Keyword(s):  
Neurological Disorders ◽  
Drug Targets ◽  
Molecular Mechanisms ◽  
Neurological Diseases ◽  
Treatment Options ◽  
Direct Result ◽  
Permanent Disability ◽  
Genetic Abnormalities ◽  
Underlying Pathology

Diseases of the nervous system are always associated with poor prognosis and limited treatment options. The fragile nature of the neurons and their inability to replicate means that neurological disorders are associated with a permanent disability. Pharmacotherapy of neurological diseases requires understanding the molecular mechanisms involved in the disease pathology. In most of the cases a faulty cellular biochemical pathway is involved, resulting from a defective enzyme. This article focusses on role of enzymes in various neurological disorders. To review pertinent literature and summarise the role of enzymes in the underlying pathology of various neurological disorders. A comprehensive literature search was conducted using PubMed, SCOPUS, J-GATE and Google Scholar and relevant papers were collected using the keywords enzymes, Alzheimer's disease, redox, thiamine, depression, neurotransmitters, epileptogenesis. The literature review highlighted the role of enzymes in major neurological disorders and their potential to be used as drug targets and biomarkers. Identifying defective enzymes gives us new molecular targets to focus on for developing more effective pharmacotherapeutic options. They can be also considered as potential biomarkers. An abnormal enzyme is most often a direct result of an underlying genetic abnormality. Identifying and screening for these genetic abnormalities can be used in early identification and prevention of disease in individuals who have a genetic predisposition. The modern advances in genetic engineering shows a lot of promise in correcting these abnormalities and development of revolutionary cures although ethical concerns remain. 

scholarly journals Emerging roles of the Hedgehog signalling pathway in inflammatory bowel disease

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhuo Xie ◽  
Mudan Zhang ◽  
Gaoshi Zhou ◽  
Lihui Lin ◽  
Jing Han ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Critical Role ◽  
Signalling Pathway ◽  
Hedgehog Signalling Pathway ◽  
Inflammatory Bowel ◽  
Effective Drugs

AbstractThe Hedgehog (Hh) signalling pathway plays a critical role in the growth and patterning during embryonic development and maintenance of adult tissue homeostasis. Emerging data indicate that Hh signalling is implicated in the pathogenesis of inflammatory bowel disease (IBD). Current therapeutic treatments for IBD require optimisation, and novel effective drugs are warranted. Targeting the Hh signalling pathway may pave the way for successful IBD treatment. In this review, we introduce the molecular mechanisms underlying the Hh signalling pathway and its role in maintaining intestinal homeostasis. Then, we present interactions between the Hh signalling and other pathways involved in IBD and colitis-associated colorectal cancer (CAC), such as the Wnt and nuclear factor-kappa B (NF-κB) pathways. Furthermore, we summarise the latest research on Hh signalling associated with the occurrence and progression of IBD and CAC. Finally, we discuss the future directions for research on the role of Hh signalling in IBD pathogenesis and provide viewpoints on novel treatment options for IBD by targeting Hh signalling. An in-depth understanding of the complex role of Hh signalling in IBD pathogenesis will contribute to the development of new effective therapies for IBD patients.

scholarly journals The Role of Na/K-ATPase Signaling in Oxidative Stress Related to Aging: Implications in Obesity and Cardiovascular Disease

2018 ◽  
Vol 19 (7) ◽  
pp. 2139 ◽  
Author(s):  
David Bartlett ◽  
Richard Miller ◽  
Scott Thiesfeldt ◽  
Hari Lakhani ◽  
Joseph Shapiro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiovascular Disease ◽  
Patient Outcomes ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Cellular Mechanisms ◽  
General Decline ◽  
Pumping Function ◽  
Improve Patient

Aging has been associated with a series of pathophysiological processes causing general decline in the overall health of the afflicted population. The cumulative line of evidence suggests an important role of oxidative stress in the development and progression of the aging process and metabolic abnormalities, exacerbating adipocyte dysfunction, cardiovascular diseases, and associated complications at the same time. In recent years, robust have established the implication of Na/K-ATPase signaling in causing oxidative stress and alterations in cellular mechanisms, in addition to its distinct pumping function. Understanding the underlying molecular mechanisms and exploring the possible sources of pro-oxidants may allow for developing therapeutic targets in these processes and formulate novel intervention strategies for patients susceptible to aging and associated complications, such as obesity and cardiovascular disease. The attenuation of oxidative stress with targeted treatment options can improve patient outcomes and significantly reduce economic burden.

scholarly journals The Role of Histone Acetylation-/Methylation-Mediated Apoptotic Gene Regulation in Hepatocellular Carcinoma

2020 ◽  
Vol 21 (23) ◽  
pp. 8894
Author(s):  
Pradeep Kumar Rajan ◽  
Utibe-Abasi Udoh ◽  
Juan D. Sanabria ◽  
Moumita Banerjee ◽  
Gary Smith ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Histone Modification ◽  
Molecular Mechanisms ◽  
Treatment Options ◽  
Epigenetic Alterations ◽  
Therapeutic Approaches ◽  
Nuclear Changes ◽  
New Perspective ◽  
Effective Diagnosis

Epigenetics, an inheritable phenomenon, which influences the expression of gene without altering the DNA sequence, offers a new perspective on the pathogenesis of hepatocellular carcinoma (HCC). Nonalcoholic steatohepatitis (NASH) is projected to account for a significant share of HCC incidence due to the growing prevalence of various metabolic disorders. One of the major molecular mechanisms involved in epigenetic regulation, post-translational histone modification seems to coordinate various aspects of NASH which will further progress to HCC. Mounting evidence suggests that the orchestrated events of cellular and nuclear changes during apoptosis can be regulated by histone modifications. This review focuses on the current advances in the study of acetylation-/methylation-mediated histone modification in apoptosis and the implication of these epigenetic regulations in HCC. The reversibility of epigenetic alterations and the agents that can target these alterations offers novel therapeutic approaches and strategies for drug development. Further molecular mechanistic studies are required to enhance information governing these epigenetic modulators, which will facilitate the design of more effective diagnosis and treatment options.

scholarly journals Role of MexZ and PA5471 in transcriptional regulation of mexXY in Pseudomonas aeruginosa

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3312-3321 ◽  
Author(s):  
Masaki Yamamoto ◽  
Atsuhisa Ueda ◽  
Makoto Kudo ◽  
Yasuhiro Matsuo ◽  
Jun Fukushima ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcriptional Regulation ◽  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Mobility Shift ◽  
Drug Induced ◽  
Drug Efflux Pump ◽  
Mobility Shift Assay

MexXY, a drug efflux pump in Pseudomonas aeruginosa, confers resistance to aminoglycoside antibiotics. We recently reported that MexZ binds to the promoter region of the mexXY operon. Electrophoretic mobility shift assay (EMSA) using recombinant MexZ and oligonucleotide probes prepared from the intergenic region between mexZ and mexX revealed that MexZ binds to a 20 bp palindromic sequence. Culture of P. aeruginosa in the presence of tetracycline induced higher levels of MexX and MexZ, as measured by immunoblotting and EMSA, than in the absence of antibiotics. When MexZ was expressed by a mexZ expression plasmid, the plasmid-borne MexZ repressed drug-induced MexX production, further confirming that MexZ acts as a repressor of the mexXY operon. PA5471 protein has been reported to be essential for drug-induced MexXY production. Similarly to that report, we observed that plasmid-borne PA5471 induced both MexX and MexZ production in PAO1 cells. Interestingly, interaction between MexZ and PA5471 was observed in a yeast two-hybrid assay. Furthermore, EMSA and in vitro transcription assays revealed that interaction between PA5471 and MexZ reduced MexZ DNA-binding ability, leading to mexXY transcription. These findings contribute to the understanding of the molecular mechanisms underlying the transcriptional regulation of mexZ and mexXY by drug-induced PA5471 expression.

Pathophysiology of Liver Fibrosis

2015 ◽  
Vol 33 (4) ◽  
pp. 492-497 ◽  
Author(s):  
Massimo Pinzani
Keyword(s):  
Wound Healing ◽  
Liver Fibrosis ◽  
Tissue Damage ◽  
Molecular Mechanisms ◽  
Epigenetic Modification ◽  
Relative Concentration ◽  
Portal Tract ◽  
Drug Induced ◽  
Chronic Activation

Progressive accumulation of fibrillar extracellular matrix (ECM) in the liver is the consequence of reiterated liver tissue damage due to infective (mostly hepatitis B and C viruses), toxic/drug-induced, metabolic and autoimmune causes, and the relative chronic activation of the wound-healing reaction. The process may result in clinically evident liver cirrhosis and hepatic failure. Although cirrhosis is the common result of progressive fibrogenesis, there are distinct patterns of fibrotic development related to the underlying disorders causing the fibrosis. These different patterns of fibrogenic evolution are related to different factors and particularly: (1) the topographic localization of tissue damage, (2) the relative concentration of profibrogenic factors and (3) the prevalent profibrogenic mechanism(s). The mechanisms responsible for the fibrogenic evolution of chronic liver diseases can be summarized in three main groups: chronic activation of the wound-healing reaction, oxidative stress-related molecular mechanisms, and the derangement of the so-called ‘epithelial-mesenchymal' interaction leading to the generation of reactive cholangiocytes and peribiliary fibrosis. Most of the knowledge on the cell and molecular biology of hepatic fibrosis derives from in vitro studies employing culture of activated hepatic stellate cells isolated from rat, mouse or human liver. It is now evident that other ECM-producing cells, i.e. fibroblasts and myofibroblasts of the portal tract and circulating ‘fibrocytes', are likely to contribute to liver fibrosis. More recently, the attention is progressively shifting to the profibrotic microenvironment of the liver with increasing interest for the role of immune cells and specific subsets of macrophages regulating the progression or the regression of fibrosis, the role of intestinal microbiota and the influence of tissue stiffness. Other major areas of development include the role of tissue hypoxia and the establishment of an anaerobic proinflammatory environment and the influence of epigenetic modification in conditioning the progression of fibrosis.

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