Angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with risk of oral precancerous lesion in betel quid chewers

To investigate whether angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is related to the risk of oral precancerous lesions (OPL) in Taiwanese subjects who chew betel quid, a total of 61 betel quid chewers having OPL were compared with 61 asymptomatic betel quid chewers matched for betel quid chewing duration and dosage. The frequency of homozygote for ACE D variant is significantly higher in the case subjects than that of the controls (44.3 vs 24.6%; P=0.0108). The adjusted odds ratio of the D homozygous for the risk of OPL is 8.10 (95% confidence interval (CI)=2.04–32.19, P=0.003). In the allelic base analysis, the D allele is also significantly associated with higher risk of OPL. When grouping the study subjects by smoking status, the association between ACE I/D polymorphism and risk of OPL was only observed in nonsmokers. Our results support the theory that genetic factors may contribute to the susceptibility of OPL and suggest that smoking and genetic factors may be differently involved in the development of OPL

Application of Direct Renin Inhibition to Chronic Kidney Disease

Chronic kidney disease has serious implications with a high risk for progressive loss of renal function, increased cardiovascular events as well as a substantial financial burden. The renin-angiotensin-aldosterone system (RAAS) is activated in chronic kidney disease, especially in diabetes and hypertension, which are the leading causes of chronic kidney disease. Angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease the rate of progression of diabetic and non-diabetic nephropathy and are recommended therapy for chronic kidney disease. Key clinical trials supporting the use of ACE inhibitors and ARBs in chronic kidney disease are discussed. Recent developments in our understanding of RAAS biology and the use of direct renin inhibition are reviewed in the context of their potential impact on the prevention and management of chronic kidney disease. Despite the clinical success of ACE inhibitors and ARBs the rates of mortality and progression to renal failure remain high in these patient populations. ACE inhibitor or ARB monotherapy, in doses commonly used in clinical practice does not result in complete suppression of the RAAS. Aliskiren, a direct renin inhibitor, offers a novel approach to inhibit the RAAS in chronic kidney disease. High dose ARB therapy or combination therapies with ACE inhibitors and ARBs have shown beneficial effects on surrogate markers of chronic kidney disease. Early data based on urinary protein excretion rates as a surrogate marker for renal function suggest a possibly novel role for aliskiren alone or in combination with ARBs in chronic kidney disease

Animal models of cardiorenal syndrome: a review

The incidence of heart failure and renal failure is increasing and is associated with poor prognosis. Moreover, these conditions do often coexist and this coexistence results in worsened outcome. Various mechanisms have been proposed as an explanation of this interrelation, including changes in hemodynamics, endothelial dysfunction, inflammation, activation of renin-angiotensin-aldosterone system, and/or sympathetic nervous system. However, the exact mechanisms initializing and maintaining this interaction are still unknown. In many experimental studies on cardiac or renal dysfunction, the function of the other organ was either not addressed or the authors failed to show any decline in its function despite histological changes. There are few studies in which the dysfunction of both heart and kidney function has been described. In this review, we discuss animal models of combined cardiorenal dysfunction. We show that translation of the results from animal studies is limited, and there is a need for new and better models of the cardiorenal interaction to improve our understanding of this syndrome. Finally, we propose several requirements that a new animal model should meet to serve as a tool for studies on the cardiorenal syndrome

Genetic polymorphisms of the RAS-cytokine pathway and chronic kidney disease

Chronic kidney disease (CKD) in children is irreversible. It is associated with renal failure progression and atherosclerotic cardiovascular (CV) abnormalities. Nearly 60% of children with CKD are affected since birth with congenital or inherited kidney disorders. Preliminary evidence primarily from adult CKD studies indicates common genetic risk factors for CKD and atherosclerotic CV disease. Although multiple physiologic pathways share common genes for CKD and CV disease, substantial evidence supports our attention to the renin angiotensin system (RAS) and the interlinked inflammatory cascade because they modulate the progressions of renal and CV disease. Gene polymorphisms in the RAS-cytokine pathway, through altered gene expression of inflammatory cytokines, are potential factors that modulate the rate of CKD progression and CV abnormalities in patients with CKD. For studying such hypotheses, the cooperative efforts among scientific groups and the availability of robust and affordable technologies to genotype thousands of single nucleotide polymorphisms (SNPs) across the genome make genome-wide association studies an attractive paradigm for studying polygenic diseases such as CKD. Although attractive, such studies should be interpreted carefully, with a fundamental understanding of their potential weaknesses. Nevertheless, whole-genome association studies for diabetic nephropathy and future studies pertaining to other types of CKD will offer further insight for the development of targeted interventions to treat CKD and associated atherosclerotic CV abnormalities in the pediatric CKD population