Angiotensin II mediates acinar cell apoptosis during the development of rat pancreatic fibrosis by AT1R

The magnitude of undiagnosed diabetes mellitus, prediabetes, and associated factors among adults living in Debre Tabor town, northcentral Ethiopia: A community-based cross-sectional study

Background

Diabetes mellitus (DM) is a worldwide public health problem. The burden of diabetes has been continuously increasing from day to day, especially in developing countries like Ethiopia. Globally, half of all cases of diabetes mellitus are undiagnosed. Diabetes mellitus can be easily handled if it is detected early. There is limited evidence on the magnitude of undiagnosed diabetics and prediabetes at the community level in Ethiopia, particularly in the study area.

Objective

To assess the magnitude of undiagnosed diabetes mellitus, prediabetes, and associated factors among adults living in Debre Tabor town.

Methods

A community-based cross-sectional study was conducted in Debre Tabor town from October to December 2021. A total of 407 participants were selected using a multistage sampling technique. A pretested structural questionnaire was used to collect demographic, behavioral, and clinical data. Anthropometric measurements were taken with standardized and calibrated equipment. A fasting venous blood sample was collected for blood glucose level determination. Logistic regression was used to identify risk factors. A P-value ≤0.05 was considered statistically significant.

Result

The magnitude of undiagnosed diabetes mellitus and prediabetes was found to be 4.5% (95% CI: 2.9-7.4) and 14.5% (95% CI: 11.1-18.1), respectively. Older age (AOR: 6.50, 95% CI: 1.82-23.21), abnormal body mass index (AOR: 6.84, 95% CI: 1.91-24.54), systolic hypertension (AOR: 8.74, 95% CI: 2.53-30.19), and family history of diabetes mellitus (FHDM) (AOR: 12.45, 95% CI: 3.63-42.65) were significantly associated with undiagnosed diabetes mellitus. Using saturated oil (AOR: 1.97, 95% CI: 1.09-3.55), having a high waist circumference (AOR: 2.16, 95% CI: 1.20-3.87), and being hypertensive (AOR: 2.26, 95% CI: 1.04-4.96) were all significantly associated with Prediabetes.

Conclusion

Adults in Debre Tabor town have a high prevalence of undiagnosed diabetes and prediabetes. A variety of modifiable risk factors were also identified. As a result, focusing the prevention strategy on such modifiable risk factors may help to minimize the prevalence of undiagnosed diabetes mellitus and prediabetes as well as future disease complications.

Epigenetic modifications of the renin-angiotensin system in cardiometabolic diseases

Cardiometabolic diseases (CMDs) are among the most prevalent and the highest mortality diseases. Single disease etiology such as gene mutation, polymorphisms, or environmental exposure has failed to explain the origin of CMD. This can be evident in the discrepancies in disease susceptibility among individuals exposed to the same environmental insult or who acquire the same genetic variation. Epigenetics is the intertwining of genetic and environmental factors that results in diversity in the disease course, severity, and prognosis among individuals. Environmental exposures modify the epigenome and thus provide a link for translating environmental impact on changes in gene expression and precipitation to pathological conditions. Renin-angiotensin system (RAS) is comprising genes responsible for the regulation of cardiovascular, metabolic, and glycemic functions. Epigenetic modifications of RAS genes can lead to overactivity of the system, increased sympathetic activity and autonomic dysfunction ultimately contributing to the development of CMD. In this review, we describe the three common epigenetic modulations targeting RAS components and their impact on the susceptibility to cardiometabolic dysfunction. Additionally, we highlight the therapeutic efforts of targeting these epigenetic imprints to the RAS and its effects.

C21 preserves endothelial function in the thoracic aorta from DIO mice: role for AT2, Mas and B2 receptors

Compound 21 (C21), a selective agonist of angiotensin II type 2 receptor (AT2R), induces vasodilation through NO release. Since AT2R seems to be overexpressed in obesity, we hypothesize that C21 prevents the development of obesity-related vascular alterations. The main goal of the present study was to assess the effect of C21 on thoracic aorta endothelial function in a model of diet-induced obesity (DIO) and to elucidate the potential cross-talk among AT2R, Mas receptor (MasR) and/or bradykinin type 2 receptor (B2R) in this response. Five-week-old male C57BL6J mice were fed a standard (CHOW) or a high-fat diet (HF) for 6 weeks and treated daily with C21 (1 mg/kg p.o) or vehicle, generating four groups: CHOW-C, CHOW-C21, HF-C, HF-C21. Vascular reactivity experiments were performed in thoracic aorta rings. Human endothelial cells (HECs; EA.hy926) were used to elucidate the signaling pathways, both at receptor and intracellular levels. Arteries from HF mice exhibited increased contractions to Ang II than CHOW mice, effect that was prevented by C21. PD123177, A779 and HOE-140 (AT2R, Mas and B2R antagonists) significantly enhanced Ang II-induced contractions in CHOW but not in HF-C rings, suggesting a lack of functionality of those receptors in obesity. C21 prevented those alterations and favored the formation of AT2R/MasR and MasR/B2R heterodimers. HF mice also exhibited impaired relaxations to acetylcholine (ACh) due to a reduced NO availability. C21 preserved NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways. In conclusion, C21 favors the interaction among AT2R, MasR and B2R and prevents the development of obesity-induced endothelial dysfunction by stimulating NO release through PKA/p-eNOS and AKT/p-eNOS signaling pathways.

Prevalence and factors associated with prediabetes and diabetes in fishing communities in penang, Malaysia: A cross-sectional study

Background

Diabetes is a metabolic disorder, characterized by hyperglycemic state of the body. A silent killer, which can take the lives of victims if undiagnosed at the earliest stage. Prediabetes has become an important health concern across countries due to its huge potential for the development of diabetes and other complications. The objectives of this study were to determine the prevalence of prediabetes and diabetes and its associated factors among rural fishing communities in Penang, Malaysia.

Methods

A cross-sectional study was conducted among fishing communities in Southwest District of Penang, Malaysia from August to November 2017. Blood sample (finger prick test) and physical examination were performed on sample of 168 participants consented in this study. Pre-validated Malay versions of International Physical Activity 7 (IPAQ-7) and Perceived Stress Scale (PSS) questionnaires were used to assess the level of physical activity and stress levels of the participants. Multinomial logistic regression models were fitted to identify factors associated with prediabetes and diabetes.

Results

The prevalence of diabetes and prediabetes were 19.6% (95% CI: 14.3, 26.4) and 10.12% (95% CI: 6.4, 15.7) respectively. The median physical activity (interquartile range) in MET-minutes per week for those with diabetes (1071.0 (2120.0)) and prediabetes (1314.0 (1710.0)) was generally lower as compared to non-diabetes. Majority reported moderate stress (57.3%) from PSS system. Abdominal obesity, family history of diabetes and being hypertensive were significant factors associated with diabetes; while older age, bigger waist circumference and self-perceived poor routine diet were factors associated with prediabetes.

Conclusions

The screening for prediabetes in this population gives the opportunity to implement lifestyle interventions at the earliest possible, which could prevent the development of diabetes. The identification of diabetic individuals provides an opportunity to conduct health promotion and education to ensure good metabolic control and hence reduce the risks of complications.

Health risks and interventions in prediabetes: A review

Prediabetes is a condition which appears prior to the development of diabetes in which blood glucose is abnormally high but do not reach the diagnostic threshold of type 2 diabetes mellitus. It is characterized by a cluster of metabolic abnormalities viz. dysglycemia, dyslipidemia, hypertension, physical inactivity, obesity, insulin resistance, procoagulant state, endothelial dysfunction, oxidative stress and inflammation, placing prediabetic subjects to an increased risk for diabetes and its complications. Recent studies demonstrate that complications of diabetes i.e. microvascular and macrovascular complications may manifest in some prediabetic subjects. This article reviews prediabetes-related risk factors and health issues. In addition, this article also highlights the interventions to prevent the development of diabetes in prediabetic subjects.

Prevalence of Pre-Diabetes and Its Associated Risk Factors in Rural Areas of Ningbo, China

Objective: The aims of the study were to investigate the prevalence of pre-diabetes and explore its associated risk factors in rural areas of Ningbo, China. Methods: A cross-sectional survey was conducted with 4583 adult residents in rural areas of Ningbo, China between March and May 2013. The survey used a multi-stage, stratified, cluster sampling method. Data collected included demographics and medical history, anthropometric measurements, blood pressure, blood lipid, and plasma glucose. After at least 10 h of overnight fasting, participants underwent an oral glucose tolerance test (OGTT) to identify pre-diabetes. Univariate and multivariate logistic regression analyses were used to evaluate the associated risk factors for pre-diabetes, and to estimate the effect of interaction between the factors. Results: There were 1307 survey participants having pre-diabetes (28.52%) and the age-standardized prevalence was 30.53%. Multivariate logistic regression results showed that overweight/obesity, hypertension, and higher triglycerides were the risk factors for developing pre-diabetes. There were positive interactions between overweight/obesity and triglycerides, and also between hypertension and triglycerides on the multiplicative scale, suggesting that they synergistically influenced the development of pre-diabetes. Conclusions: The rural areas in Ningbo had a high prevalence of pre-diabetes. Overweight and obesity, hypertension, and elevated triglycerides were the major risk factors. There is a need of early intervention for preventing pre-diabetes.

Mechanisms of cyclosporine-induced renal cell apoptosis: a systematic review

BACKGROUND/AIMS

Chronic cyclosporine A (CsA) nephrotoxicity (CCN) is an important cause of chronic renal dysfunction with no effective clinical intervention. To further elucidate the mechanisms of renal cell apoptosis in CCN, all relevant in vivo studies on this subject were analyzed.

METHODS

We searched for in vivo studies on the mechanisms of CsA-induced renal cell apoptosis in Medline (1966-July 2010), Embase (1980-July 2010) and ISI (1986-July 2010). The studies were evaluated for their quality according to a set of in vivo standards, data extracted according to PICOS, and then synthesized.

RESULTS

Renal cell apoptosis was an important feature of CCN and an important factor of renal dysfunction. First, CsA could upregulate Fas/Fas ligand, downregulate Bcl-2/Bcl-XL, and increase caspase-1 and caspase-3. Second, it could induce oxidative stress and damage the antioxidant defense system. Third, it could increase endoplasmic reticulum stress protein in a dose- and time-dependent manner. Fourth, CsA could impair the urine concentration and decrease the expression of hypertonicity-induced genes. Fifth, CsA-induced renal cell apoptosis was significantly decreased by blocking the angiotensin II type 1 receptor using losartan.

CONCLUSIONS

The in vivo mechanisms for CCN are more complex than those found in vitro. CsA can induce renal cell apoptosis using five pathways in vivo and activated caspases might be the ultimate intersection of these pathways and the common intracellular pathway mediating apoptosis. These data provide new potential points for intervention and need to be confirmed by further studies.

Losartan reduces trinitrobenzene sulphonic acid-induced colorectal fibrosis in rats

BACKGROUND

Intestinal fibrosis is a challenging clinical condition in several fibrostenosing enteropathies, particularly Crohn's disease. Currently, no effective preventive measures or medical therapies are available for intestinal fibrosis. Fibrosis, due to an abnormal accumulation of extracellular matrix proteins, is a chronic and progressive process mediated by cell⁄matrix⁄cytokine and growth factor interactions, but may be a reversible phenomenon. Of the several molecules regulating fibrogenesis, transforming growth factor-beta 1 (TGF-b1) appears to play a pivotal role; it is strongly induced by the local activation of angiotensin II. The levels of both TGF-b1 and angiotensin II are elevated in fibrostenosing Crohn's disease.

AIMS

To evaluate the in vivo effect of losartan - an angiotensin II receptor antagonist - on the course of chronic colitis-associated fibrosis and on TGF-b1 expression.

METHODS

Colitis was induced by intrarectal instillation of trinitrobenzene sulphonic acid (TNBS) (15 mg⁄mL) while losartan was administered orally daily by gavage (7 mg⁄kg⁄day) for 21 days. Three groups of rats were evaluated: control (n=10); TNBS treated (n=10); and TNBS + losartan treated (n=10). Inflammation and fibrosis of the colon were evaluated by macro- and microscopic score analysis. Colonic TGF-b1 levels was measured using ELISA.

RESULTS

Twenty-one days after induction, losartan significantly improved the macro- and microscopic scores of fibrosis in the colonic wall and reduced TGF-b1 concentration.

CONCLUSIONS

Prophylactic oral administration of losartan reduces the colorectal fibrosis complicating the TNBS-induced chronic colitis, an effect that appears to be mediated by a downregulation of TGF-b1 expression.

Review article: pancreatic renin-angiotensin systems in health and disease

BACKGROUND

In addition to the circulating (endocrine) renin-angiotensin system (RAS), local renin-angiotensin systems are now known to exist in diverse cells and tissues. Amongst these, pancreatic renin-angiotensin systems have recently been identified and may play roles in the physiological regulation of pancreatic function, as well as being implicated in the pathogenesis of pancreatic diseases including diabetes, pancreatitis and pancreatic cancer.

AIM

To review and summarise current knowledge of pancreatic renin-angiotensin systems.

METHODS

We performed an extensive PubMed, Medline and online review of all relevant literature.

RESULTS

Pancreatic RAS appear to play various roles in the regulation of pancreatic physiology and pathophysiology. Ang II may play a role in the development of pancreatic ductal adenocarcinoma, via stimulation of angiogenesis and prevention of chemotherapy toxicity, as well as in the initiation and propagation of acute pancreatitis (AP); whereas, RAS antagonism is capable of preventing new-onset diabetes and improving glycaemic control in diabetic patients. Current evidence for the roles of pancreatic RAS is largely based upon cell and animal models, whilst definitive evidence from human studies remains lacking.

CONCLUSIONS

The therapeutic potential for RAS antagonism, using cheap and widely available agents, and may be untapped and such roles are worthy of active investigation in diverse pancreatic disease states.

LOX-1 and angiotensin receptors, and their interplay

The renin-angiotensin system (RAS) plays an important role in regulating blood pressure, water-salt balance and the pathogenesis of cardiovascular diseases. Angiotensin II (Ang II) is the physiologically active mediator and mediates the main pathophysiological actions in RAS. Ang II exerts the effects by activating its receptors, primarily type 1 (AT1R) and type 2 (AT2R). Most of the known pathophysiological effects of Ang II are mediated by AT1R activation. The precise physiological function of AT2R is still not clear. Generally, AT2R is considered to oppose the effects of AT1R. Lectin-like oxidized low-density lipoprotein scavenger receptor-1 (LOX-1) is one of the major receptors responsible for binding, internalizing and degrading ox-LDL. The activation of LOX-1 has been known to be related to many pathophysiological events, including endothelial dysfunction and injury, fibroblast growth, and vascular smooth muscle cell hypertrophy. Many of these alterations are present in atherosclerosis, hypertension, and myocardial ischemia and remodeling. A growing body of evidence suggests the existence of a cross-talk between LOX-1 and Ang II receptors. Their interplays are embodied in the reciprocal regulation of their expression and activity. Their interplays are involved in a series of signals. Recent studies suggests that reactive oxygen species (ROS), nitric oxide (NO), protein kinase C (PKC) and mitogen activated protein kinases (MAPKs) are important signals responsible for their cross-talk. This paper reviews these aspects of dyslipidemia and RAS activation.

Distribution of a novel binding site for angiotensins II and III in mouse tissues

A novel binding site for angiotensins II and III that is unmasked by parachloromercuribenzoate has been reported in rat, mouse and human brains. Initial studies of this binding site indicate that it is not expressed in the adrenal, liver or kidney of the rat and mouse. To determine if this binding site occurs in other mouse tissues, 8 tissues were assayed for expression of this binding site by radioligand binding assay and compared with the expression of this binding site in the forebrain. Particulate fractions of homogenates of testis, epididymis, seminal vesicles, heart, spleen, pancreas, lung, skeletal muscle, and forebrain were incubated with (125)I-sarcosine(1), isoleucine(8) angiotensin II in the presence or absence of 0.3mM parachloromercuribenzoate plus 10microM losartan and 10microM PD123319 (to saturate AT(1) and AT(2) receptors). Specific (3microM angiotensin II displaceable) high affinity binding occurred in the testis>forebrain>epididymis>spleen>pancreas>lung when parachloromercuribenzoate was present. Binding could not be reliably observed in heart, skeletal muscle and seminal vesicles. High affinity binding of (125)I-sarcosine(1), isoleucine(8) angiotensin II was observed in the absence of parachloromercuribenzoate in the pancreas on occasion. This suggests that this novel angiotensin binding site may have a functional role in these tissues.

Angiotensin-converting enzyme insertion/deletion polymorphism in patients with acute and chronic pancreatitis

BACKGROUND

Reduction in angiotensin-converting enzyme (ACE) activity has been shown to attenuate pancreatic stellate cell activation and pancreatic fibrosis and suggested as a potential treatment for chronic pancreatitis. The ACE gene insertion/deletion (I/D) polymorphism in intron 16 accounts for nearly half the variation in serum ACE levels. This study determined the frequency of the I/D polymorphism in patients with acute and chronic pancreatitis.

METHODS

In total, 887 patients (346 with alcoholic, 443 with nonalcoholic, and 98 with acute pancreatitis) were enrolled, and were compared with 1294 healthy controls. Genotyping of the I/D polymorphism was performed by PCR or melting curve analyses.

RESULTS

No significant differences were found in the prevalence of the ACE-deletion genotype frequencies when patients with alcoholic (27.5%), nonalcoholic (26.4%), and acute pancreatitis (32.7%) were compared with controls (26.9%). Likewise, allele frequencies of the ACE deletion polymorphism were not significantly different in patients with alcoholic (53.8%), nonalcoholic (50.6%), and acute pancreatitis (54.1%) and controls (52.7%).

CONCLUSION

The I/D polymorphism of the ACE gene was not found to be associated with acute and chronic pancreatitis.

Protective effect of salvianolic acid B on chronic pancreatitis induced by trinitrobenzene sulfonic acid solution in rats

OBJECTIVES

To investigate the effects of salvianolic acid B (Sal-B) on pancreatic damage in experimental chronic pancreatitis.

METHODS

Chronic pancreatitis was induced by infusion of trinitrobenzene sulfonic acid into the pancreatic duct in male Sprague-Dawley rats. From the beginning of 5 weeks, the rats in group 2 were treated with Sal-B by gavage for 8 weeks. Salvianolic acid B was given at a daily dose of 10 mg/kg body weight. At the end of 12 weeks, the levels of serum biochemical indexes were measured on an automatic biochemical analyzer; serum hyaluronic acid and laminin levels were determined by radioimmunoassay; pancreatic tissue malondialdehyde (MDA) was analyzed, and the degree of pancreatic damage was determined.

RESULTS

The level of serum biochemical indexes were similar in all groups (P > 0.05 for all). Salvianolic acid B treatment did not obviously reduce hyaluronic acid and laminin concentration in blood (P > 0.05). Salvianolic acid B treatment decreased MDA concentration in pancreatic tissue (P < 0.01). Salvianolic acid B clearly improved pancreatic histological findings and prevented the activation of pancreatic stellate cells.

CONCLUSIONS

Sal-B treatment decreased MDA concentration in pancreatic tissue, attenuated morphological pancreatic damage, and prevented the activation of pancreatic stellate cells in experimental chronic pancreatitis.

The physiology of a local renin-angiotensin system in the pancreas

The systemic renin-angiotensin system (RAS) plays an important role in regulating blood pressure, electrolyte and fluid homeostasis. However, local RASs also exist in diverse tissues and organs, where they play a multitude of autocrine, paracrine and intracrine physiological roles. The existence of a local RAS is now recognized in pancreatic acinar, islet, duct, endothelial and stellate cells, the expression of which is modulated in response to physiological and pathophysiological stimuli such as hypoxia, pancreatitis, islet transplantation, hyperglycaemia, and diabetes mellitus. This pancreatic RAS has been proposed to have important endocrine and exocrine roles in the pancreas, regulating local blood flow, duct cell sodium bicarbonate secretion, acinar cell digestive enzyme secretion, islet beta-cell (pro)insulin biosynthesis, and thus, glucose-stimulated insulin release, delta-cell somatostatin secretion, and pancreatic cell proliferation and differentiation. It may further mediate oxidative stress-induced cell inflammation, apoptosis and fibrosis. Further exploration of this system would probably offer new insights into the pathogenesis of pancreatitis, diabetes, cystic fibrosis and pancreatic cancer formation. New therapeutic targets and strategies might thus be suggested.

A1166C polymorphism of angiotensin Ⅱ type 1 receptor gene and its role in pathogenesis in liver cirrhosis

AIM: To establish a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to detect A1166C polymorphism of angiotensin Ⅱ type 1 receptor (AT1R) gene.

METHODS: A1166C polymorphism was detected and analyzed in 50 anti-HBs positive healthy controls in the serum and 46 patients with liver cirrhosis after hepatitis B virus infection. A set of primers was designed according to AT1R gene. The enzyme digestion site for restriction endonuclease DdeⅠwas also designed around A1166C. A or C allele was assured based on the enzymatic result of the polymerase chain reaction products.

RESULTS: Sequencing revealed 99% homogeneity between the two homozygous strains and the AT1R gene. The anticipated mutations appeared at position A1166C. As for genotype or allele, there were no significant differences at position A1166C between the hepatitis group and the liver cirrhosis group (P > 0.05).

CONCLUSION: The established method can be applied to detect the A1166C polymorphism of AT1R gene. The mutation at A1166C site has no correlation with liver fibrosis.

Physiology of Local Renin-Angiotensin Systems

Since the first identification of renin by Tigerstedt and Bergmann in 1898, the renin-angiotensin system (RAS) has been extensively studied. The current view of the system is characterized by an increased complexity, as evidenced by the discovery of new functional components and pathways of the RAS. In recent years, the pathophysiological implications of the system have been the main focus of attention, and inhibitors of the RAS such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin (ANG) II receptor blockers have become important clinical tools in the treatment of cardiovascular and renal diseases such as hypertension, heart failure, and diabetic nephropathy. Nevertheless, the tissue RAS also plays an important role in mediating diverse physiological functions. These focus not only on the classical actions of ANG on the cardiovascular system, namely, the maintenance of cardiovascular homeostasis, but also on other functions. Recently, the research efforts studying these noncardiovascular effects of the RAS have intensified, and a large body of data are now available to support the existence of numerous organ-based RAS exerting diverse physiological effects. ANG II has direct effects at the cellular level and can influence, for example, cell growth and differentiation, but also may play a role as a mediator of apoptosis. These universal paracrine and autocrine actions may be important in many organ systems and can mediate important physiological stimuli. Transgenic overexpression and knock-out strategies of RAS genes in animals have also shown a central functional role of the RAS in prenatal development. Taken together, these findings may become increasingly important in the study of organ physiology but also for a fresh look at the implications of these findings for organ pathophysiology.

Abnormal Glucose Tolerance Contributes to the Progression of Chronic Heart Failure in Patients with Dilated Cardiomyopathy

Since 1) dilated cardiomyopathy (DCM) causes chronic heart failure (CHF), and 2) augmentation of neurohumoral factors such as angiotensin II impairs glucose metabolism, we examined the rate of abnormal glucose metabolism in patients having both DCM and CHF and whether correction of the impairment of glucose metabolism would improve the pathophysiology of CHF in DCM patients. A 75-g oral glucose tolerance test (OGTT) was performed in 56 patients with DCM-induced CHF and 168 age- and sex-matched control subjects. Among the CHF patients, 26.8% and 50.0% suffered from diabetes mellitus (DM) and impaired glucose tolerance (IGT), respectively, showing that abnormal glucose tolerance was more prevalent in DCM patients than in the control subjects (7.7% and 14.3%, respectively). In the patients with DCM-induced CHF, a correlation was observed between the brain natriuretic peptide (BNP) levels and the difference between the plasma glucose levels at the time of fasting and at 2 h of OGTT. Since neither DM nor IGT are thought to cause DCM, the abnormalities of glucose metabolism may be attributed to the progression of CHF. Furthermore, we tested whether correction of the abnormal glucose tolerance using voglibose (an alpha-glucosidase inhibitor) would improve the severity of CHF in another group of 30 patients with DCM-induced CHF and IGT. The patients treated with voglibose for 24 weeks showed decreases in left ventricular dimension, NYHA functional classification values, and plasma BNP levels, and an improvement in cardiac function. In conclusion, abnormal glucose tolerance was more prevalent among patients with DCM-induced CHF than controls, and the correction of IGT improved the pathophysiology of CHF.

Effects of angiotensin II receptor antagonist, Losartan on the apoptosis, proliferation and migration of the human pancreatic stellate cells

AIM: To investigate the effects of AT₁ (Type 1 angiotensin II receptor) antagonist (Losartan) on the apoptosis, proliferation and migration of the human pancreatic stellate cells (hPSCs).

METHODS: hPSCs were isolated from pancreatic sample of patients with pancreatic carcinoma using radioimmunoassay (RIA) technique to detect the concentration of AngII in culture media and cell homogenate. Immunocytochemistry (ICC) and in situ hybridization (ISH) methods were utilized to test AT₁ expression in hPSCs. Effects of Losartan on hPSCs proliferation, apoptosis and migration were investigated using BrdU incorporation, TUNEL, flow cytometry (FCM), and phase-contrast microscope separately when cells treated with Losartan. Immunofluorescence and Western blot were applied to quantify the expression of type I collagen in hPSCs.

RESULTS: There exists AT₁ expression in hPSCs, while no AngII was detected in culture media and cell homogenate. Losartan induces cell apoptosis in a dose- and time-dependent manner (apparently at 10^-5 mol/L), no pro-proliferative effect was observed in the same condition. Corresponding dosage of Losartan can also alleviate the motion capability and type I collagen content of hPSCs compared with AngII treatment and non-treatment control groups.

CONCLUSION: These findings suggest that paracrine not autocrine functions of AngII may have effects on hPSCs, which was mediated by AT₁ expressed on cells, while Losartan may exert anti-fibrotic effects by inhibiting hPSCs motion and partly by inducing apoptosis.