PIGA Mutations and Glycosylphosphatidylinositol Anchor Dysregulation in Polyposis-Associated Duodenal Tumorigenesis.

The pathogenesis of duodenal tumors in the inherited tumor syndromes familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumors and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIGA) in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyzes the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA. IMPLICATIONS: PIGA somatic mutation in duodenal tumors from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis.

Sex- and age-related differences in renal and cardiac injury and senescence in stroke-prone spontaneously hypertensive rats.

BACKGROUND: Sex differences play a critical role in the incidence and severity of cardiovascular diseases, whereby men are at a higher risk of developing cardiovascular disease compared to age-matched premenopausal women. Marked sex differences at the cellular and tissue level may contribute to susceptibility to cardiovascular disease and end-organ damage. In this study, we have performed an in-depth histological analysis of sex differences in hypertensive cardiac and renal injury in middle-aged stroke-prone spontaneously hypertensive rats (SHRSPs) to determine the interaction between age, sex and cell senescence. METHODS: Kidneys, hearts and urine samples were collected from 6.5- and 8-month-old (Mo) male and female SHRSPs. Urine samples were assayed for albumin and creatinine content. Kidneys and hearts were screened for a suite of cellular senescence markers (senescence-associated ß-galactosidase, p16INK4a, p21, γH2AX). Renal and cardiac fibrosis was quantified using Masson's trichrome staining, and glomerular hypertrophy and sclerosis were quantified using Periodic acid-Schiff staining. RESULTS: Marked renal and cardiac fibrosis, concomitant with albuminuria, were evident in all SHRSPs. These sequelae were differentially affected by age, sex and organ. That is, the level of fibrosis was greater in the kidney than the heart, males had greater levels of fibrosis than females in both the heart and kidney, and even a 6-week increase in age resulted in greater levels of kidney fibrosis in males. The differences in kidney fibrosis were reflected by elevated levels of cellular senescence in the kidney in males but not females. Senescent cell burden was significantly less in cardiac tissue compared to renal tissue and was not affected by age or sex. CONCLUSIONS: Our study demonstrates a clear sex pattern in age-related progression of renal and cardiac fibrosis and cellular senescence in SHRSP rats. A 6-week time frame was associated with increased indices of cardiac and renal fibrosis and cellular senescence in male SHRSPs. Female SHRSP rats were protected from renal and cardiac damage compared to age-matched males. Thus, the SHRSP is an ideal model to investigate the effects of sex and aging on organ injury over a short timeframe.

Kidney and cardiovascular diseases are some of the leading causes of death worldwide, and they affect men and women differently. Young men are generally at higher risk of developing these diseases than young women. Women also have unique risk factors for kidney and cardiovascular disease. These may include complications associated with pregnancy, such as preeclampsia, and menopause. For example, the risk of disease for women increases significantly after menopause. In addition, treatment strategies for kidney and cardiovascular diseases are often less effective in women compared to men, but the causes for this are unknown. More research is needed to understand sex differences in kidney and cardiovascular diseases, so that we can develop new drugs that are effective in women as well as men. In this study, we have examined kidney and heart damage associated with elevated blood pressure in adult male rats and adult female rats (long before the onset of menopause). We have shown that males develop significantly more scarring of their hearts and kidneys compared to females. We also identified the cells in the kidneys of male rats, but not female rats, showed signs of DNA damage and early ageing. This suggests cellular damage in young males may contribute to their more rapid progression of kidney disease compared to females. Future research examining females after menopause, when disease risk is greater, will enhance our understanding of cell damage in kidney and cardiovascular disease.

Antihypertensives and Antibiotics: Impact on Intestinal Dysfunction and Hypertension.

Gut dysfunction has emerged as a contributor to hypertension, the leading risk factor for disease globally, including stroke, heart failure, and kidney disease. This is underpinned by breakdown of the homeostatic relationship connecting intestinal epithelial function, the microbiota and immune responses. Antihypertensive medications have been shown to reverse intestinal dysfunction and gut dysbiosis. However, the mechanisms underlying this restoration of gut structure and function remain largely unknown. In this review, we examine current knowledge supporting a role for impaired intestinal epithelial permeability in hypertension, focusing on electrolyte movement, the renin-angiotensin-aldosterone system, and the restorative effects of orally administered antihypertensive medications and antibiotics. Further work is required to determine if the association between intestinal dysfunction and hypertension is causal. This is a rapidly evolving field, with intestinal dysfunction and dysbiosis representing an area that may be exploited to improve treatment of hypertension and cardiovascular disease.

Bezlotoxumab prevents extraintestinal organ damage induced by Clostridioides difficile infection.

Clostridioides difficile is the most common cause of infectious antibiotic-associated diarrhea, with disease mediated by two major toxins TcdA and TcdB. In severe cases, systemic disease complications may arise, resulting in fatal disease. Systemic disease in animal models has been described, with thymic damage an observable consequence of severe disease in mice. Using a mouse model of C. difficile infection, we examined this disease phenotype, focussing on the thymus and serum markers of systemic disease. The efficacy of bezlotoxumab, a monoclonal TcdB therapeutic, to prevent toxin mediated systemic disease complications was also examined. C. difficile infection causes toxin-dependent thymic damage and CD4+CD8+ thymocyte depletion in mice. These systemic complications coincide with changes in biochemical markers of liver and kidney function, including increased serum urea and creatinine, and hypoglycemia. Administration of bezlotoxumab during C. difficile infection prevents systemic disease and thymic atrophy, without blocking gut damage, suggesting the leakage of gut contents into circulation may influence systemic disease. As the thymus has such a crucial role in T cell production and immune system development, these findings may have important implications in relapse of C. difficile disease and impaired immunity during C. difficile infection. The prevention of thymic atrophy and reduced systemic response following bezlotoxumab treatment, without altering colonic damage, highlights the importance of systemic disease in C. difficile infection, and provides new insights into the mechanism of action for this therapeutic.Abbreviations: Acute kidney injury (AKI); Alanine Transaminase (ALT); Aspartate Aminotransferase (AST); C. difficile infection (CDI); chronic kidney disease (CKD); combined repetitive oligo-peptides (CROPS); cardiovascular disease (CVD); Double positive (DP); hematoxylin and eosin (H&E); immunohistochemical (IHC); multiple organ dysfunction syndrome (MODS); phosphate buffered saline (PBS); standard error of the mean (SEM); surface layer proteins (SLP); Single positive (SP); wild-type (WT).

Transcriptomic analysis of preovipositional embryonic arrest in a nonsquamate reptile (Chelonia mydas).

After gastrulation, oviductal hypoxia maintains turtle embryos in an arrested state prior to oviposition. Subsequent exposure to atmospheric oxygen upon oviposition initiates recommencement of embryonic development. Arrest can be artificially extended for several days after oviposition by incubation of the egg under hypoxic conditions, with development recommencing in an apparently normal fashion after subsequent exposure to normoxia. To examine the transcriptomic events associated with embryonic arrest in green sea turtles (Chelonia mydas), RNA-sequencing analysis was performed on embryos from freshly laid eggs and eggs incubated in either normoxia (oxygen tension ~159 mmHg) or hypoxia (<8 mmHg) for 36 h after oviposition (n = 5 per group). The patterns of gene expression differed markedly among the three experimental groups. Normal embryonic development in normoxia was associated with upregulation of genes involved in DNA replication, the cell cycle, and mitosis, but these genes were commonly downregulated after incubation in hypoxia. Many target genes of hypoxia inducible factors, including the gene encoding insulin-like growth factor binding protein 1 (igfbp1), were downregulated by normoxic incubation but upregulated by incubation in hypoxia. Notably, some of the transcriptomic effects of hypoxia in green turtle embryos resembled those reported to be associated with hypoxia-induced embryonic arrest in diverse taxa, including the nematode Caenorhabditis elegans and zebrafish (Danio rerio). Hypoxia-induced preovipositional embryonic arrest appears to be a unique adaptation of turtles. However, our findings accord with the proposition that the mechanisms underlying hypoxia-induced embryonic arrest per se are highly conserved across diverse taxa.

Chronic Pain as a Complication in Open Inguinal Hernia Repair: A Retrospective Study of Consenting Practice in a Single Centre.

Introduction Inguinal hernia repair is one of the most commonly performed procedures in general surgery in the United Kingdom. Chronic pain as a long-term postoperative complication of this procedure has been extensively documented in the literature. However, this complication is often undisclosed during the consenting process. This omission impairs the patients' informed decision-making process. The Montgomery v Lanarkshire Health Board case, in 2015, changed the way in which patient consent is viewed legally. This has made proper consent practices more important to surgeons undertaking procedures. Aim The objective is to assess if there has been an improvement in consenting practices by comparing consent forms from 2015 (the year of the Montgomery ruling) and 2019, specifically in regard to the risk of chronic groin pain following open inguinal hernia repair with mesh. Methods This was a retrospective review of patients who underwent open inguinal hernia repair using a prosthetic mesh in 2015 and 2019. The medical records were retrieved on the trust's electronic medical record system using the patient's hospital number. The following parameters were obtained: patient demographics, preoperative clinic letters, operation notes and consent forms. The clinic letters and consent forms were systematically reviewed for any mention of chronic groin pain. Results In 2015 and 2019, 163 and 56 open inguinal hernia repairs with mesh were performed, respectively. The median age of patients was 63 (28-88) and 64.5 (19-88) in the respective years. Throughout both years there was a predominance in male patients, and the majority of cases were performed on an elective basis. Consent for chronic pain was present in 60.7% and 62.5% of cases in 2015 and 2019, respectively (p=0.055). Conclusion Despite the importance of adequate consenting practice, we found no significant improvement in consenting practice for chronic pain following open inguinal hernia repair in the four years following the Montgomery ruling.

The effect of gestational age on mitochondrial properties of the mouse placenta.

Mitochondria are organelles within the cell that generate energy, which is essential to the developing placenta. As the placenta approaches term, organelles such as mitochondria and the endoplasmic reticulum adapt to cellular stressors (e.g. oxidative stress and fluctuations in oxygen concentration) which are likely to result in the progressive decline of tissue function, known as placental ageing. This ageing phenotype may induce cellular senescence, a process whereby the cell is no longer proliferating, yet remains metabolically active. Mitochondria, endoplasmic reticulum and senescent processes are still poorly understood in the developing placenta. Therefore, a rodent ontogeny model was used to measure genes and proteins involved in mitochondrial biogenesis, antioxidant function, electron transport chain, mitophagy, dynamics and unfolded protein response in the placenta. CD-1 mouse placental samples were collected at embryonic day (E)12.5, E14.5, E16.5 and E18.5 of pregnancy for gene and protein analysis via qPCR, protein assays and Western blotting. Mitochondrial content, SDHB (complex II) and MFN2 (mitochondrial fusion) proteins were all increased throughout pregnancy, while citrate synthase activity/mitochondrial content, Tfam, Sirt3, Mfn1, TOMM20 (mitochondrial biogenesis and dynamics); Tp53(senescence); Eif2ak3, Eif4g1(endoplasmic reticulum stress);NDUFB8, UQCRC2, ATP5A (electron transport chain sub-complexes) were decreased at E18.5, compared to E12.5. Overall, mitochondria undergo changes in response to gestational progression and pathways associated with cellular ageing to facilitate adaptions in a healthy pregnancy. This data holds great promise that mitochondrial markers across pregnancy may help to establish when a placenta is ageing inappropriately. Lay summary: Human pregnancy lasts approximately 266 days. If a baby is born early, organs may be poorly formed but if pregnancy continues past this time, stillbirth risk is increased. Gestational duration is regulated by the placenta. As the placenta approaches the end of pregnancy, it displays properties similar to tissues from aged individuals. However, it is unknown how this placental ageing contributes to pregnancy duration. This study characterised normal placental ageing by measuring properties of mitochondria in healthy placentas collected at four different gestational ages ranging from 7 days before birth to 1 day before birth of the 19-day mouse pregnancy. We found that mitochondrial number increased per cell but that a marker of mitochondrial function was reduced. Proteins that control mitochondrial number, morphology and function also changed over time. This work lays the platform to understand how placental ageing contributes to adverse pregnancy outcomes related to altered pregnancy duration.

The impact of COVID-19 pandemic on colorectal cancer patients at an NHS Foundation Trust hospital-A retrospective cohort study.

INTRODUCTION: Current NHS guidelines recommend that treatment of colorectal patients referred through the two-week wait referral system should occur within sixty two days from the date of referral. The COVID-19 pandemic which started in March 2020 has however led to significant delays in the delivery of health services, including colorectal cancer treatments. This study investigates the effects of delayed colorectal cancer treatments during the COVID pandemic on disease progression. METHODS: A retrospective chart review of 107 patients with histologically confirmed diagnosis of colorectal cancer was conducted. The occurrence of cancer upstaging after initial diagnosis was assessed and compared between patients with treatment delays and patients who received treatments within the period recommended by NHS guidelines. A logistic regression was performed to evaluate the association between treatment delays beyond 62 days and cancer upstaging. RESULTS: The median age of the cohort was 71.2 years and 64.5% of the patients were over 65 years. Treatment delays were observed in 53.3% of reviewed patients. Patients with treatment delays received cancer treatments 95.8 (31.0) days on average after referral, compared to 46.3 (11.5) days in patients who experienced no treatment delays (p-value<0.0001). 38.6% of patients with treatment delays experienced cancer upstaging by the time of treatment, compared to 20% in the non-delay group (p-value = 0.036). Patients who received treatment after sixty two days from date of referral were 3.27 times more likely to experience colorectal cancer upstaging compared to those who received timely treatments. CONCLUSION: Although an effective response to the Covid-19 pandemic requires the reallocation of healthcare resources, there is a need to ensure that treatments and health outcomes of patients with chronic diseases such as colorectal cancer continue to be prioritized and delivered in timely fashion.

Prevalence of Carcinoma in Appendectomy Specimens for Patients Presenting With Acute Appendicitis: A Single-Center Study.

Introduction Acute appendicitis is the most common general surgical emergency globally. Its etiology includes the presence of luminal obstruction by faecoliths, lymphoid hyperplasia, impacted stool, and rarely by appendiceal or caecal cancer. Malignancy related to acute appendicitis is usually seen in the older age group. Aim To identify the subset rate of patients operated for acute appendicitis who have appendiceal carcinoma and analyze the outcome of their post-operative management. Material and methods A retrospective study of a cohort of 529 patients aged > 40 diagnosed with acute appendicitis with subsequent appendectomy in the period between 1 January 2014 and 31 December 2019 at Basildon and Thurrock University Hospital, Essex, United Kingdom was conducted. We analyzed the clinical data of the cohort including demographic information, diagnosis, pre-operative imaging, histological diagnosis as well as post-operative management where indicated. Results The median age of patients was 54.5 years (range 40-92). The male to female ratio in the appendicectomy cohort was 1:1.1. About 45% were aged 40-49 years, 24.8% were aged 50-59 and 30.2% were ≥60 years. Post-operative histology revealed acute appendicitis in 82.4% of the group. In 11% of the patients, the histology revealed the presence of other benign pathology as mucocele of the appendix, acute diverticulitis, follicular hyperplasia, and fibrous obliteration. The diagnosis of appendicular malignancy was seen in 1.9%. Conclusion Incidental appendiceal cancers in the resected specimens after acute appendicitis are rare but may be associated with a poor prognosis. It is recommended to consider such diagnosis in particular when dealing with acute appendicitis in older patients with longer symptom history, and in presence of peri-appendicular mass.

Instituting a Green Zone for Elective Surgery During the Second Wave of COVID-19.

Objective Elective surgery came to a standstill during the first wave of COVID-19. The safe resumption of elective surgery with COVID-19 prevalent in the community remains a significant challenge. The aim of this study was to look into the outcomes of elective general surgery in a dedicated 'Green Zone (GZ)' during the second wave of COVID-19 in the United Kingdom. Method A 'Green Zone' pathway, meant to provide a COVID-free environment, was created. A retrospective review of prospectively collected data was done on consecutive patients who underwent an elective general surgical procedure at a single NHS trust over a six-month period (September 1, 2020, to February 28, 2021). The primary outcome was 30-day COVID-19 mortality. Secondary outcomes included 30-day non-COVID-19 mortality, readmissions, and complications. Results The study included 331 patients with a median age of 55 years (interquartile range, IQR, 41-67); 169 (51%) were females. The majority of the patients were American Society of Anaesthesiologists grade 2 (ASA 2; n=177, 53%) followed by ASA 3 (n=76, 23%). Forty-seven patients (14%) had been shielding earlier in the year. Most of the cases were day cases (n=224, 67%). There was no 30-day COVID-19 or non-COVID-19 mortality. One patient developed COVID-19 three weeks after the index operation. Thirty-day readmission and complication rate were 4% (n=14) and 6% (n=21). Most of the complications were Clavien-Dindo grade 2 (n=10, 3%) followed by an equal number of grades 1 and 3b (n=5, 1.5%). Conclusion This study has shown that a dedicated 'Green Zone' elective operating pathway is safe and feasible provided a balanced risk assessment approach is adopted.

Sotagliflozin, a Dual SGLT1/2 Inhibitor, Improves Cardiac Outcomes in a Normoglycemic Mouse Model of Cardiac Pressure Overload.

Selective SGLT2 inhibition reduces the risk of worsening heart failure and cardiovascular death in patients with existing heart failure, irrespective of diabetic status. We aimed to investigate the effects of dual SGLT1/2 inhibition, using sotagliflozin, on cardiac outcomes in normal diet (ND) and high fat diet (HFD) mice with cardiac pressure overload. Five-week-old male C57BL/6J mice were randomized to receive a HFD (60% of calories from fat) or remain on ND for 12 weeks. One week later, transverse aortic constriction (TAC) was employed to induce cardiac pressure-overload (50% increase in right:left carotid pressure versus sham surgery), resulting in left ventricular hypertrophic remodeling and cardiac fibrosis, albeit preserved ejection fraction. At 4 weeks post-TAC, mice were treated for 7 weeks by oral gavage once daily with sotagliflozin (10 mg/kg body weight) or vehicle (0.1% tween 80). In ND mice, treatment with sotagliflozin attenuated cardiac hypertrophy and histological markers of cardiac fibrosis induced by TAC. These benefits were associated with profound diuresis and glucosuria, without shifts toward whole-body fatty acid utilization, increased circulating ketones, nor increased cardiac ketolysis. In HFD mice, sotagliflozin reduced the mildly elevated glucose and insulin levels but did not attenuate cardiac injury induced by TAC. HFD mice had vacuolation of proximal tubular cells, associated with less profound sotagliflozin-induced diuresis and glucosuria, which suggests dampened drug action. We demonstrate the utility of dual SGLT1/2 inhibition in treating cardiac injury induced by pressure overload in normoglycemic mice. Its efficacy in high fat-fed mice with mild hyperglycemia and compromised renal morphology requires further study.

In Aged Females, the Enhanced Pressor Response to Angiotensin II Is Attenuated By Estrogen Replacement via an Angiotensin Type 2 Receptor-Mediated Mechanism.

[Figure: see text].

Gastric adenomas and their management in familial adenomatous polyposis.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) are at increased risk of developing gastric adenomas. There is limited understanding of their clinical course and no consensus on management. We reviewed the management of gastric adenomas in patients with FAP from two centers. METHODS: Patients with FAP and histologically confirmed gastric adenomas were identified between 1997 and 2018. Patient demographics, adenoma characteristics, and management/surveillance outcomes were collected. RESULTS: Of 726 patients with FAP, 104 (14 %; 49 female) were diagnosed with gastric adenomas at a median age of 47 years (range 19 - 80). The median size of gastric adenomas was 6 mm (range 1.5 - 50); 64 (62 %) patients had adenomas located distally to the incisura. Five patients (5 %) had gastric adenomas demonstrating high-grade dysplasia (HGD) on initial diagnosis, distributed equally within the stomach. The risk of HGD was associated with adenoma size (P = 0.04). Of adenomas > 20 mm, 33 % contained HGD. Two patients had gastric cancer at initial gastric adenoma diagnosis. A total of 63 patients (61 %) underwent endoscopic therapy for gastric adenomas. Complications occurred in three patients (5 %) and two (3 %) had recurrence, all following piecemeal resection of large (30 - 50 mm) lesions. Three patients were diagnosed with gastric cancer at median follow-up of 66 months (range 66 - 115) after initial diagnosis. CONCLUSIONS: We observed gastric adenomas in 14 % of patients with FAP. Of these, 5 % contained HGD; risk of HGD correlated with adenoma size. Endoscopic resection was feasible, with few complications and low recurrence rates, but did not completely eliminate the cancer risk.

Relaxin Attenuates Organ Fibrosis via an Angiotensin Type 2 Receptor Mechanism in Aged Hypertensive Female Rats.

Background: The antifibrotic effects of recombinant human relaxin (RLX) in the kidney are dependent on an interaction between its cognate receptor (RXFP1) and the angiotensin type 2 receptor (AT2R) in male models of disease. Whether RLX has therapeutic effects, which are also mediated via AT2R, in hypertensive adult and aged/reproductively senescent females is unknown. Thus, we determined whether treatment with RLX provides cardiorenal protection via an AT2R-dependent mechanism in adult and aged female stroke-prone spontaneously hypertensive rats (SHRSPs). Methods: In 6-month-old (6MO) and 15-month-old ([15MO]; reproductively senescent) female SHRSP, systolic BP (SBP), GFR, and proteinuria were measured before and after 4 weeks of treatment with vehicle (Veh), RLX (0.5 mg/kg per day s.c.), or RLX+PD123319 (AT2R antagonist; 3 mg/kg per day s.c.). Aortic endothelium-dependent relaxation and fibrosis of the kidney, heart, and aorta were assessed. Results: In 6MO SHRSP, RLX significantly enhanced GFR by approximately 25% (P=0.001) and reduced cardiac fibrosis (P=0.01) as compared with vehicle-treated counterparts. These effects were abolished or blunted by PD123319 coadministration. In 15MO females, RLX reduced interstitial renal (P=0.02) and aortic (P=0.003) fibrosis and lowered SBP (13±3 mm Hg; P=0.04) relative to controls. These effects were also blocked by PD123319 cotreatment (all P=0.05 versus RLX treatment alone). RLX also markedly improved vascular function by approximately 40% (P<0.001) in 15MO SHRSP, but this was not modulated by PD123319 cotreatment. Conclusions: The antifibrotic and organ-protective effects of RLX, when administered to a severe model of hypertension, conferred cardiorenal protection in adult and reproductively senescent female rats to a great extent via an AT2R-mediated mechanism.

Insulin-regulated aminopeptidase deficiency impairs cardiovascular adaptations and placental development during pregnancy.

Insulin-regulated aminopeptidase (IRAP), an enzyme that cleaves vasoactive peptides including oxytocin and vasopressin, is suggested to play a role in pregnancy and the onset of preeclampsia. Our aim was to examine the contribution of IRAP to arterial pressure regulation and placental development during pregnancy in mice. Mean arterial pressure and heart rate were measured via radiotelemetry in 12-week-old female wild-type and IRAP knockout mice. Females were time-mated with males of the same genotype. Placentae were collected at embryonic day 18.5 for histological analysis. Basal heart rate was ∼40 bpm lower in IRAP knockout females compared with wild-type females. The increase in heart rate across gestation was greater in IRAP knockout females than wild-type females. Neither basal nor gestational mean arterial pressure was different between wildtype and IRAP knockout females. Urine output and water intake of IRAP knockout mice were ∼45% less than wild-type mice at late gestation. IRAP deficiency had no effect on fetal weight. Morphological assessment of placentae revealed that IRAP deficiency was associated with reduced labyrinth surface area and accumulation of glycogen in the junctional zone. Our data demonstrate that IRAP deficiency alters maternal fluid handling and impairs placental labyrinth expansion at late gestation, indicating that IRAP contributes to the normal adaptions to pregnancy.

Serelaxin and the AT2 Receptor Agonist CGP42112 Evoked a Similar, Nonadditive, Cardiac Antifibrotic Effect in High Salt-Fed Mice That Were Refractory to Candesartan Cilexetil.

Fibrosis is involved in the majority of cardiovascular diseases and is a key contributor to end-organ dysfunction. In the current study, the antifibrotic effects of recombinant human relaxin-2 (serelaxin; RLX) and/or the AT2R agonist CGP42112 (CGP) were compared with those of the established AT1R antagonist, candesartan cilexetil (CAND), in a high salt-induced cardiac fibrosis model. High salt (HS; 5%) for 8 weeks did not increase systolic blood pressure in male FVB/N mice, but CAND treatment alone significantly reduced systolic blood pressure from HS-induced levels. HS significantly increased cardiac interstitial fibrosis, which was reduced by either RLX and/or CGP, which were not additive under the current experimental conditions, while CAND failed to reduce HS-induced cardiac fibrosis. The antifibrotic effects induced by RLX and/or CGP were associated with reduced myofibroblast differentiation. Additionally, all treatments inhibited the HS-induced elevation in tissue inhibitor of matrix metalloproteinases-1, together with trends for increased MMP-13 expression, that collectively would favor collagen degradation. Furthermore, these antifibrotic effects were associated with reduced cardiac inflammation. Collectively, these results highlight that either RXFP1 or AT2R stimulation represents novel therapeutic strategies to target fibrotic conditions, particularly in HS states that may be refractory to AT1R blockade.

Maternal hypoxia developmentally programs low podocyte endowment in male, but not female offspring.

Fetal hypoxia is a common complication of pregnancy. We have previously reported that maternal hypoxia in late gestation in mice gives rise to male offspring with reduced nephron number, while females have normal nephron number. Male offspring later develop proteinuria and renal pathology, including glomerular pathology, whereas female offspring are unaffected. Given the central role of podocyte depletion in glomerular and renal pathology, we examined whether maternal hypoxia resulted in low podocyte endowment in offspring. Pregnant CD1 mice were allocated at embryonic day 14.5 to normoxic (21% oxygen) or hypoxic (12% oxygen) conditions. At postnatal day 21, kidneys from mice were immersion fixed, and one mid-hilar slice per kidney was immunostained with antibodies directed against p57 and synaptopodin for podocyte identification. Slices were cleared and imaged with a multiphoton microscope for podometric analysis. Male hypoxic offspring had significantly lower birth weight, nephron number, and podocyte endowment than normoxic male offspring (podocyte number; normoxic 62.86 ± 2.26 podocytes per glomerulus, hypoxic 53.38 ± 2.25; p < .01, mean ± SEM). In contrast, hypoxic female offspring had low birth weight but their nephron and podocyte endowment was the same as normoxic female offspring (podocyte number; normoxic 62.38 ± 1.86 podocytes per glomerulus, hypoxic 61.81 ± 1.80; p = .88). To the best of our knowledge, this is the first report of developmentally programmed low podocyte endowment. Given the well-known association between podocyte depletion in adulthood and glomerular pathology, we postulate that podocyte endowment may place offspring at risk of renal disease in adulthood, and explain the greater vulnerability of male offspring.

Fetal growth and well-being in a study of maternal hypertension in rabbits.

Obtaining growth and physiologic data in the postnatal laboratory animal is common. However, monitoring growth in utero is far more difficult, with little data available except upon termination of pregnancy. High-resolution ultrasound was used to monitor growth, morphology, and fetal well-being in normotensive and hypertensive rabbits (21 fetuses) at day 16, 20, and 26 of the 32 day gestational period. Set protocols, comparable to those routinely assessed in humans, were devised and followed for each examination. Birth weight was greater in offspring of hypertensive as compared to normotensive mothers (p < 0.001); however, litter size was reduced. The greater birth weight was reflected in growth parameters measured throughout gestation indicating the predictive value of ultrasound. High-resolution ultrasound was a reliable and sensitive method for biometric and morphologic assessment of the fetal rabbit, demonstrating that growth trajectory of offspring of hypertensive mothers may be altered early in gestation.