Discovery Category Highlights

Pathogenesis, Newly Recognized Etiologies, and Management of Idiopathic Anaphylaxis

Abstract: Idiopathic anaphylaxis (IA) is a life-threatening allergic disease and the most common diagnosis given to patients following an anaphylactic event. The inability of the healthcare provider and the patient to identify the trigger for anaphylaxis makes standard allergen avoidance measures ineffectual. IA is diagnosed after other causes of anaphylaxis have been excluded. Mast cell activation syndromes (MCAS), mastocytosis, IgE to galactose-alpha-1,3-galactose (α-gal), and certain medications have recently been recognized as causes of anaphylaxis that were previously labeled idiopathic. This review will describe the epidemiology and proposed theories of pathogenesis for IA, its diagnostic approach, its clinical management, and examine newly recognized disorders that were previously labeled as idiopathic anaphylaxis. ... Read more

Unwinding the Role of Senataxin in Neurodegeneration

Abstract: Interest in senataxin biology began in 2004 when mutations were first identified in what was then a novel protein. Dominantly inherited mutations were documented in rare juvenile-onset, motor neuron disease pedigrees in a familial form of amyotrophic lateral sclerosis (ALS4), while recessive mutations were found to cause a severe early-onset ataxia with oculomotor apraxia (AOA2) that is actually the second most common recessive ataxia after Freidreich's ataxia. From earlier studies of sen1p, the yeast ortholog of senataxin, a range of important RNA processing functions have been attributed to this protein. Like sen1p, senataxin contains a helicase domain to interact with RNA and an amino-terminal domain for critical protein interactions. Senataxin also joins a group of important proteins responsible for maintaining RNA transcriptome homeostasis, including FUS, TDP-43, and SMN that can all cause familial forms of motor neuron disease (MND). Independent of this association, senataxin is gaining attention for its role in maintaining genomic stability. Senataxin has been shown to resolve R-Loop structures, which form when nascent RNA hybridizes to DNA, displacing the non-transcribed strand. But in cycling cells, senataxin is also found at nuclear foci during the S/G2 cell-cycle phase, and may function at sites of specific collision between components of the replisome and transcription machinery. Which of these important processes is most critical to prevent neurodegeneration remains unknown, but our evolving understanding of these processes will be crucial not only for understanding senataxin's role in neurological disease, but also in a number of fundamentally important cellular functions. ... Read more

T Cell Chemokine Receptor Patterns as Pathogenic Signatures in Autoimmunity

Abstract: Autoimmune diseases arise from aberrant activation of immune cells directed against endogenous autoantigens expressed throughout the human body. While the initiating triggers remain poorly understood, the self-perpetuating phase of these diseases is directly linked to the ongoing recruitment of inflammatory cells that traffic to the affected anatomical sites. T lymphocytes are prominent drivers of many autoimmune diseases and the targeted trafficking of these cells to infiltrate the affected organs is often a common denominator. The regulation of T cell trafficking involves the coordinated expression of specific patterns of chemokines and the reciprocal expression of cognate chemokine receptors on T cell membranes. Thereby, chemokines direct the specific trafficking of a wide array of responsive activated immune cells. Specific patterns of chemokine receptor expression can correlate with disease activity in an autoimmune disease, confirming the importance of further characterizing the T cells that infiltrate specific sites of autoimmunity. Herein, we will review our current understanding of the roles of chemokines in two common autoimmune diseases: rheumatoid arthritis and multiple sclerosis. We also discuss the implications for chemokine receptor signatures in autoimmune pathogenesis, and how these may provide novel targets for therapeutic intervention. ... Read more

Targeted Therapy for Genetic Cancer Syndromes: Fanconi Anemia, Medullary Thyroid Cancer, Tuberous Sclerosis, and RASopathies

Abstract: With the advent of genomics-based treatment in recent years, the use of targeted therapies in the treatment of various malignancies has increased exponentially. Though much data is available regarding the efficacy of targeted therapies for common malignancies, genetic cancer syndromes remain a somewhat unexplored topic with comparatively less published literature. This review seeks to characterize targeted therapy options for the following genetic cancer syndromes: Fanconi anemia, inherited medullary thyroid cancer, tuberous sclerosis, and RASopathies. By understanding the pathophysiology of these conditions as well as available molecularly targeted therapies, oncologists, in collaboration with geneticists and genetic counsellors, can begin to develop effective clinical management options and therapy regimens for the patients with these genetic syndromes that they may encounter in their practice. ... Read more

Targeted Therapy for Genetic Cancer Syndromes: Von Hippel-Lindau Disease, Cowden Syndrome, and Proteus Syndrome

Abstract: Von Hippel-Lindau disease, Cowden syndrome, and Proteus syndrome are cancer syndromes which affect multiple organs and lead to significant decline in quality of life in affected patients. These syndromes are rare and typically affect the adolescent and young adult population, resulting in greater cumulative years of life lost. Improved understanding of the underpinnings of the genetic pathways underlying these syndromes and the rapid evolution of targeted therapies in general have made it possible to develop therapeutic options for these patients and other genetic cancer syndromes. Targeted therapies especially antiangiogenics and inhibitors of the PIK3CA/AKT/mTOR signaling pathway have shown activity in selected group of patients affected by these syndromes or in patients harboring specific sporadic mutations which are otherwise characteristic of these syndromes. Unfortunately due to the rare nature, patients with these syndromes are not the focus of clinical trials and unique results seen in these patients can easily go unnoticed. Most of the data suggesting benefits of targeted therapies are either case reports or small case series. Thus, a literature review was indicated. In this review we explore the use of molecularly targeted therapy options in Von Hippel-Lindau disease, Cowden syndrome, and Proteus syndrome. ... Read more

The Impact of Anti-HBV Treatment on the Occurrence and Recurrence of Hepatocellular Carcinoma: Focus on Asian Studies

Abstract: Chronic hepatitis B (CHB) virus infection can cause persistent hepatic inflammation and cirrhosis, which may lead to hepatocellular carcinoma (HCC). CHB is considered the dominant cause of HCC in Asia because of the endemic status of hepatitis B virus (HBV) infection. A persistently high viral load, long duration of infection, and cirrhosis are the major risk factors for developing HCC in CHB patients. Antiviral therapies using interferon (IFN) and nucleos(t)ide analogues (NAs) could suppress viral replication, reduce liver injury, and preserve liver function, thereby lowering the risk of developing HCC. Recurrence of HCC after therapy is closely related to high levels of HBV DNA at the initial stage. Western studies have found that persistent antiviral treatments on CHB patients could not only reduce their risk of developing HCC, but also prevent or delay HCC recurrence after liver transplantation, hepatic resection, or radiation therapies. This review will focus on Asian clinical studies, where there is a higher prevalence of CHB and HCC. The outcomes of antiviral therapies on HCC in these Asian studies were compared to those in the Western studies. ... Read more

The Guts of Obesity: Progress and Challenges in Linking Gut Microbes to Obesity

Abstract: The sharp rise in prevalence of obesity in recent decades has been suggestively labeled as an "epidemic," and the lack of fully explanatory causal factors has challenged existing understandings of obesity's etiology from a purely energetic standpoint. Much recent attention has been focused on the microbial members of the human gut for insights into their role in potentially causing or promoting obesity. The human gut is home to trillions of microbes, among which hundreds of distinct species of bacteria interact to form the human gut microbiome, and numerous studies in humans and animal models have linked shifts in the gut microbiome to obesity. In this review we explore contemporary understandings of the relationship between obesity and the microbiome from a high-level ecological and functional perspective, along with a survey of recently proposed interventions. We highlight areas of consensus and areas for further study in the field. ... Read more

Epigenetics in Atherosclerosis: a Clinical Perspective

Abstract: Significant progress has been made in understanding in the pathogenesis of atherosclerosis. Nevertheless, atherosclerosis remains a great threat to human health worldwide. Epigenetic mechanisms, which involve DNA methylation, histone modification, and microRNA, have significantly enhanced our understanding of the pathological process of atherosclerosis. More importantly, epigenetic processes (in contrast to genetic alterations) are reversible and thus provide a potential therapeutic target in atherosclerosis treatment. Both in vitro and in vivo studies using drugs targeting enzymes involved in epigenetic modifications have shown considerable promise in atherosclerosis treatment. This review aims to present an overview of current epigenetic mechanisms involved in the pathogenesis of atherosclerosis, and discuss points in these processes where therapeutic interventions likely bear fruition. ... Read more

GKN1 Inhibits Cell Invasion in Gastric Cancer by Inactivating the NF-kappaB Pathway

Abstract: Metastasis is a relatively early event and a major cause of death in gastric cancer (GC) patients. Gastrokine 1 (GKN1) is a stomach-specific protein that is normally expressed in gastric mucosa but not in primary tumors or cell lines. We and others have demonstrated that GKN1 inhibits cell growth; however, its role in metastasis is not clear. In this study, we explored the role of GKN1 in cell invasion. Immunohistochemistry (IHC) was used to measure the expression of GKN1 in precancerous lesions and in GCs. The cell invasion assay was employed to examine the effect of GKN1 on cell invasion. The molecular mechanism of GKN1 in inhibiting GC cell invasion in vitro was explored by western blotting. We noted a gradual decrease in GKN1 expression from normal mucosa to dysplastic gastric tissue to GC, and that low GKN1 expression was associated with metastasis (P=0.003). We showed that GKN1 inhibits cell invasion by downregulating MMP2 expression through the NF-κB pathway. These results provide molecular evidence that GKN1 inhibits metastasis in GC cells, and indicate that GKN1 is a potential novel therapeutic target for gastric cancer. ... Read more

Viral Expression Cassette Elements to Enhance Transgene Target Specificity and Expression in Gene Therapy

Abstract: Over the last five years, the number of clinical trials involving AAV (adeno-associated virus) and lentiviral vectors continue to increase by about 150 trials each year. For continued success, AAV and lentiviral expression cassettes need to be designed to meet each disease's specific needs. This review discusses how viral vector expression cassettes can be engineered with elements to enhance target specificity and increase transgene expression. The key differences relating to target specificity between ubiquitous and tissue-specific promoters are discussed, as well as how endogenous miRNAs and their target sequences have been used to restrict transgene expression. Specifically, relevant studies indicating how cis-acting elements such as introns, WPRE, polyadenylation signals, and the CMV enhancer are highlighted to show their utility for enhancing transgene expression in gene therapy applications. All discussion bears in mind that expression cassettes have space constraints. In conclusion, this review can serve as a menu of vector genome design elements and their cost in terms of space to thoughtfully engineer viral vectors for gene therapy. ... Read more

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