Low-dose hydralazine reduces albuminuria and glomerulosclerosis in a mouse model of obesity-related chronic kidney disease.

AIM: To determine, using a mouse model of obesity, whether low-dose hydralazine prevents obesity-related chronic kidney disease (CKD). METHODS: From 8 weeks of age, male C57BL/6 mice received a high-fat diet (HFD) or chow, with or without low-dose hydralazine (25 mg/L) in drinking water, for 24 weeks. Biometric and metabolic variables, renal function and structural changes, renal global DNA methylation, DNA methylation profile and markers of renal fibrosis, injury, inflammation and oxidative stress were assessed. RESULTS: The HFD-fed mice developed obesity, with glucose intolerance, hyperinsulinaemia and dyslipidaemia. Obesity increased albuminuria and glomerulosclerosis, which were significantly ameliorated by low-dose hydralazine in the absence of a blood pressure-lowering effect. Obesity increased renal global DNA methylation and this was attenuated by low-dose hydralazine. HFD-induced changes in methylation of individual loci were also significantly reversed by low-dose hydralazine. Obese mice demonstrated increased markers of kidney fibrosis, inflammation and oxidative stress, but these markers were not significantly improved by hydralazine. CONCLUSION: Low-dose hydralazine ameliorated HFD-induced albuminuria and glomerulosclerosis, independent of alterations in biometric and metabolic variables or blood pressure regulation. Although the precise mechanism of renoprotection in obesity is unclear, an epigenetic basis may be implicated. These data support repurposing hydralazine as a novel therapy to prevent CKD progression in obese patients.

Blood DNA Methylation Predicts Diabetic Kidney Disease Progression in High Fat Diet-Fed Mice.

Diabetic kidney disease (DKD) progresses at different rates among patients with type 2 diabetes mellitus (T2D). Early identification of patients with a higher risk of DKD progression is essential to improve prognosis. Epigenetic modifications, particularly DNA methylation, have been independently implicated in T2D and chronic kidney disease. The current study aimed to determine changes in blood DNA methylation that reflects and predicts DKD progression. C57BL/6 mice were fed a high-fat diet (HFD) from weaning and subclassified into two groups, HFD-1 and HFD-2, according to urinary kidney injury marker KIM-1/creatinine ratios (low vs. high) and histological abnormalities (mild-moderate vs. advanced). DNA methylation profiles were determined by reduced representative bisulfide sequencing (RRBS). Our results confirmed early and established DKD at week 9 and week 32, respectively. At week 32, advanced kidney injury was associated with dysregulation of methylation and demethylation enzymes in the kidney. Blood RRBS revealed 579 and 203 differentially methylated sites (DMS) between HFD-1 and HFD-2 animals at week 32 and week 9, respectively, among which 11 were common. The DMS in blood and kidney at week 32 were both related to organ development, neurogenesis, cell junction, and Wnt signalling, while the DMS in blood at week 9 suggested a specific enrichment of kidney development processes. In conclusion, our data strongly support the implication of early blood DNA methylation modifications and DKD progression in T2D that could be used to improve the disease's prognostication.

Novel Role of Gestational Hydralazine in Limiting Maternal and Dietary Obesity-Related Chronic Kidney Disease.

BACKGROUND: Maternal obesity is a risk factor for chronic kidney disease (CKD) in offspring, underpinning the theory of the developmental origins of health and disease. DNA methylation has been implicated in the programming of adult chronic disease by maternal obesity, therefore, DNA demethylating agents may mitigate offspring risk of disease. In rodent models, low-dose hydralazine has previously been shown to reduce renal fibrosis via DNA demethylation. We used mouse models of maternal obesity and offspring obesity to determine whether administration of low-dose hydralazine during gestation can prevent fetal programming of CKD in offspring. METHODS: Female C57BL/6 mice received high fat diet (HFD) or chow prior to mating, during gestation and lactation. During gestation, dams received subcutaneous hydralazine (5 mg/kg) or saline thrice-weekly. Male offspring weaned to HFD or chow, which continued until endpoint at 32 weeks. Biometric and metabolic parameters, renal global DNA methylation, renal functional and structural changes, and renal markers of fibrosis, inflammation and oxidative stress were assessed at endpoint. RESULTS: Offspring exposed to maternal obesity or diet-induced obesity had significantly increased renal global DNA methylation, together with other adverse renal effects including albuminuria, glomerulosclerosis, renal fibrosis, and oxidative stress. Offspring exposed to gestational hydralazine had significantly reduced renal global DNA methylation. In obese offspring of obese mothers, gestational hydralazine significantly decreased albuminuria, glomerulosclerosis, and serum creatinine. Obese offspring of hydralazine-treated lean mothers displayed reduced markers of renal fibrosis and oxidative stress. CONCLUSION: Gestational hydralazine decreased renal global DNA methylation and exerted renoprotective effects in offspring. This supports a potential therapeutic effect of hydralazine in preventing maternal obesity or dietary obesity-related CKD, through an epigenetic mechanism.

Lysyl oxidase inhibitors attenuate cyclosporin A-induced nephropathy in mouse.

Calcineurin inhibitors, such as Cyclosporin (CsA), are the mainstay of anti-rejection therapy in solid organ transplants but can paradoxically induce progressive nephropathy characterised by renal dysfunction and interstitial fibrosis. Lysyl oxidases (LOXs), a group of enzymes that catalyse extracellular matrix (ECM) crosslinking, were shown to implicate in tissue scarring. It is hypothesized that inhibition of these enzymes may render therapeutic effects against CsA-induced nephropathy. In this study, 6-to-8 weeks old C57BL/6 J mice were administered saline or CsA (30 mg/kg/day s.c) for 16 weeks. At 8 weeks, CsA-treated animals were divided into 5 groups respectively treated with: (1) vehicle, (2) PXS-5505 (Pan-LOX inhibitor), (3) PXS-5382 (LOX-like 2 inhibitor), (4) PXS-5505 for 4 weeks then PXS-5382 for 4 weeks (sequential therapy), and (5) Telmisartan (standard therapy). Our results indicate that CsA administration significantly increased the levels of blood urea nitrogen, glomerular and tubular injury, tubulointerstitial fibrosis, inflammation and oxidative stress in mouse kidney. These changes were associated with upregulated mRNA expression of LOX and LOXL2. Administration of Pan-LOX or LOXL2 inhibitors or the sequential therapy suppressed the expression of ECM proteins (α-SMA, FN and COL1A), matrix metalloproteases (MMP)2 and 9, inflammatory markers (TNFα and MCP-1) and TGF-ß1-Smad3 signalling. Among all regimens including telmisartan, only Pan-LOX inhibitor PXS-5505 was able to attenuate uraemia. Collectively, our study suggests that Pan-LOX and LOXL2 inhibition can attenuate progressive nephropathy due to CsA administration.

Low-dose hydralazine during gestation reduces renal fibrosis in rodent offspring exposed to maternal high fat diet.

BACKGROUND: Maternal high fat diet (HFD) promotes chronic kidney disease (CKD) in offspring. This is in accordance with the theory of fetal programming, which suggests adverse conditions occurring in utero predispose offspring to chronic conditions later in life. DNA methylation has been proposed as a key mechanism by which fetal programming occurs and is implicated in CKD progression. DNA demethylating drugs may interrupt the fetal programming of CKD by maternal obesity. Hydralazine, an antihypertensive agent, demethylates DNA at low doses which do not reduce blood pressure. We used a mouse model of maternal obesity to determine whether gestational administration of low-dose hydralazine to mothers can prevent CKD in offspring. METHODS: C57BL/6 dams received HFD or chow from 6 weeks prior to mating and were administered subcutaneous hydralazine (5mg/kg) or saline thrice weekly during gestation. Male offspring were weaned to chow and were sacrificed at either postnatal week 9 or week 32. Biometric and metabolic parameters, renal global DNA methylation, renal structural and functional changes and markers of fibrosis, oxidative stress and inflammation were measured in offspring at weeks 9 and 32. RESULTS: In week 9 offspring, maternal HFD consumption did not significantly alter anthropometric or metabolic parameters, or renal global DNA methylation. Week 32 offspring had increased renal global DNA methylation, together with albuminuria, glomerulosclerosis, renal fibrosis and oxidative stress. Administration of low-dose hydralazine to obese mothers during gestation reduced renal global DNA methylation and renal fibrotic markers in week 32 offspring. CONCLUSION: Gestational hydralazine reduced renal global DNA methylation in offspring of obese mothers and attenuated maternal obesity-induced renal fibrosis. These data support the use of low-dose hydralazine as a demethylating agent to prevent CKD arising in offspring due to maternal HFD consumption.

Comorbidities Rather Than Age Are Associated With the Use of Immunomodulators in Elderly-onset Inflammatory Bowel Disease.

BACKGROUND AND AIM: The use of immunomodulators (IMs) is often avoided in elderly patients with inflammatory bowel disease (IBD) due to concerns about complications. Our aim is to compare the use of IMs in elderly and younger patients with Crohn's disease (CD) or ulcerative colitis (UC) and identify markers that predict their use. METHODS: In this retrospective cohort study, patients diagnosed with IBD from 1970 to 2009 were recruited from the "Sydney IBD Cohort." Patients diagnosed at age 60 years old or older and between 16 and old 40 years were classified as "elderly-onset" and "young-onset" respectively. RESULTS: A total of 255 elderly-onset patients (115 CD, 140 UC) and 1244 young-onset patients (657 CD, 587 UC) were recruited. Most elderly-onset patients had colonic CD (61.4%), whereas young-onset patients had predominantly ileocolonic CD (42.8%, P < 0.0001). Left-sided UC was the most common disease localization for both elderly-onset (52.1%) and young-onset patients (42.2%, P = 0.013). The cumulative probability of IM exposure at 5 years post-diagnosis was significantly less in elderly-onset patients compared with young-onset patients for CD (20.0% vs 33.4%, P = 0.0002) and UC (7.8% vs 13.4%, P = 0.0007). Age at diagnosis was not associated with the time to IMs introduction. Charlson Comorbidity Index was shown to delay IM introduction in CD (hazard ratio [HR] 0.863; 95% CI, 0.787-0.946; P = 0.002) and UC (HR 0.807; 95% CI, 0.711-0.917; P = 0.001). Early IM use was associated with reduced need for abdominal and perianal surgery in CD (HR 0.177; 95% CI, 0.089-0.351; P < 0.0001). CONCLUSIONS: Comorbidity and not age at diagnosis is associated with IM introduction. Early IM is associated with reduced surgery in both young- and elderly-onset CD but not UC.

Exercise-induced brain-derived neurotrophic factor expression: Therapeutic implications for Alzheimer's dementia.

Emerging evidence indicates that moderate intensity aerobic exercise is positively correlated with cognitive function and memory. However, the exact mechanisms underlying such improvements remain unclear. Recent research in animal models allows proposition of a pathway in which brain-derived neurotrophic factor (BDNF) is a key mediator. This perspective draws upon evidence from animal and human studies to highlight such a mechanism whereby exercise drives synthesis and accumulation of neuroactive metabolites such as myokines and ketone bodies in the periphery and in the hippocampus to enhance BDNF expression. BDNF is a neurotrophin with well-established properties of promoting neuronal survival and synaptic integrity, while its influence on energy transduction may provide the crucial link between inherent vascular and metabolic benefits of exercise with enhanced brain function. Indeed, BDNF mRNA and protein is robustly elevated in rats following periods of voluntary exercise. This was also correlated with improved spatial memory, while such benefits were abolished upon inhibition of BDNF signaling. Similarly, both BDNF and cardiovascular fitness arising from aerobic exercise have been positively associated with hippocampal volume and function in humans. We postulate that exercise will attenuate cortical atrophy and synaptic loss inherent to neurodegenerative disorders - many of which also exhibit aberrant down-regulation of BDNF. Thus, the proposed link between BDNF, exercise and cognition may have critical therapeutic implications for the prevention and amelioration of memory loss and cognitive impairment in Alzheimer's disease and associated dementias.

Primary sclerosing cholangitis as an independent risk factor for colorectal cancer in the context of inflammatory bowel disease: a review of the literature.

To examine and evaluate recent evidence regarding the epidemiology, pathogenesis and management of colorectal cancer (CRC) development in inflammatory bowel disease (IBD)-primary sclerosing cholangitis (PSC) patients. Using the PubMed database, a literature search was conducted for relevant articles in English from the past 10 years. Relevant studies investigating PSC as a risk factor for CRC in IBD in the context of incidence and prevalence, pathogenesis, prevention and prognosis were included in this review. Recent evidence increasingly points to PSC as a significant risk factor in the development of CRC in patients with concomitant IBD. PSC may be an important risk factor for CRC in different populations worldwide. The mechanism for this increase in risk is still unclear. The efficacy of UDCA as a chemopreventive agent remains controversial. Liver transplantation does not halt the development of CRC, although there is not enough evidence to suggest that it is associated with increased incidence of CRC. While routine colonoscopic surveillance should be performed in patients with concurrent PSC and IBD, more high-level evidence is required to support the benefits of the procedure. While many new developments have taken place in the last decade, the pathogenesis and optimal management of CRC development in IBD-PSC patients remain unclear.

Early use of thiopurines or methotrexate reduces major abdominal and perianal surgery in Crohn's disease.

BACKGROUND: Earlier introduction of immunomodulators (IM) thiopurine or methotrexate is advocated to improve Crohn's disease (CD) outcomes, but whether abdominal surgery can be prevented remains controversial. METHODS: A specialist-referred cohort of CD was recruited from 1970 to 2009. Early IM use was defined as commencement of azathioprine or methotrexate within 3 years of CD diagnosis and adherence of at least 6 months. Propensity score matching was conducted to correct for confounders influencing early IM introduction. Outcomes of interest were rates of initial and recurrent major abdominal surgery for CD and their predictive factors. RESULTS: A total of 1035 consecutive patients with CD (13,061 patient-years) were recruited. The risk of first and recurrent major abdominal surgery at 1, 5, and 10 years were 17.5%, 28.4%, and 39.5% and 5.9%, 19.0%, and 33.3%, respectively. Early IM use increased over time from 1.3% to 55.3% (P < 0.0001) and was a significant independent predictor of lower rates of initial abdominal surgery (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.35-0.69), recurrent abdominal surgery (HR, 0.44; 95% CI, 0.25-0.79) and perianal surgery (HR, 0.30; 95% CI, 0.16-0.56). Using propensity score matching, early IM significantly reduced surgical rates (HR, 0.54; 95% CI, 0.37-0.79). Number needed to treat to prevent a surgical event at 5 years from diagnosis and after initial surgery was 6.99 (95% CI, 5.34-11.95) and 8.59 (95% CI, 6.26-23.93), respectively. CONCLUSIONS: Early IM use with thiopurines or methotrexate was significantly associated with the reduced need for abdominal and perianal surgery in CD.