Relationship between plasma plasminogen activator inhibitor-1 and hypertension in American Indians: findings from the Strong Heart Study

Differential associations between kidney and vascular health biomarkers in young adults stratified by blood pressure status: The African Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension study

OBJECTIVE

Hypertension and kidney disease share common pathophysiological pathways involved in endothelial dysfunction including increased oxidative stress and chronic inflammation. The precise early-stage mechanisms associated with nephron-specific kidney injury remain unclear. We aimed to explore associations of kidney function biomarkers with markers representing these mechanisms in young adults stratified by blood pressure status [according to 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines].

METHODS

We cross-sectionally analysed 1055 adults. Kidney biomarkers included estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (uACR), alpha-1 microglobulin (uA1M), neutrophil gelatinase-associated lipocalin (uNGAL), uromodulin (uUMOD) and CKD273 classifier. Markers of oxidative stress [gamma-glutamyl transferase (GGT); malondialdehyde (MDA)], inflammation [interleukin 6 (IL-6); C-reactive protein (CRP); fibrinogen] and endothelial function [soluble intercellular adhesion molecule-1; soluble vascular cell adhesion molecule-1 (sVCAM-1); von Willebrand factor antigen (vWFag); monocyte chemoattractant protein-1 (MCP-1); plasminogen activator inhibitor-1 activity (PAI-1act); urinary nitrate-to-nitrite ratio] were analysed.

RESULTS

Individuals in the hypertensive group (mean age 24.8 years; 73.2% men; 39% Black) had higher GGT, CRP, IL-6, MCP-1 and PAI-1act levels (all P ≤ 0.024) compared to their normotensive counterparts. In individuals with hypertension, eGFR associated negatively and uNGAL positively with IL-6, while uA1M associated positively with PAI-1act (all P ≤ 0.047). In the same group, UMOD associated positively with fibrinogen and CKD273 classifier negatively with MCP-1 (all P ≤ 0.021). In contrast, eGFR associated positively with MDA and negatively with GGT, CKD273 classifier associated positively with GGT, sVCAM-1 and vWFag, and uACR associated negatively with CRP (all P ≤ 0.033) in normotensives.

CONCLUSION

In young adults, mechanisms linked to early nephron-specific kidney injury biomarkers differ according to blood pressure status.

An encompassing review of meta-analyses and systematic reviews of the effect of oats on all-cause mortality, cardiovascular risk, diabetes risk, body weight/adiposity and gut health

The ability of oats to reduce blood cholesterol is well established but there is increasing evidence that its health benefits extend well beyond that. The purpose of this review was to critically evaluate the state of the science of oats in relation to all-cause mortality, cardiovascular and diabetes risk and the effects of oats on blood lipids, blood glucose, blood pressure, weight management and gut health from meta-analyses and systematic reviews. Limited epidemiological data indicated a possible beneficial effect of oats on all-cause mortality and incident diabetes when high versus low oat consumers were compared, but its effect on cardiovascular events was not adequately discerned. Observational data also showed an inverse association between oat intake and blood cholesterol, blood pressure, body weight and obesity variables in different populations. Randomized controlled oat intervention studies demonstrated a significant reduction in postprandial blood glucose in both diabetic and non-diabetic subjects, fasting blood glucose in diabetic subjects, blood pressure in prehypertensive individuals, and body weight and adiposity in overweight individuals. Increased fecal bulk was observed but clinical data for a potential gut barrier effect is lacking. The mechanism of action of each health effect was reviewed. While beta-glucan viscosity was once considered the only mode of action, it is evident that the fermentation products of beta-glucan and the associated gut microbial changes, as well as other components in oats (i.e., avenanthramides etc.) also play an important role.

Low Cortisone as a Novel Predictor of the Low-Renin Phenotype

A large proportion of patients with low-renin hypertension (LRH) correspond to primary aldosteronism (PA). However, some of these subjects have low to normal aldosterone. Since low renin is driven by excessive mineralocorticoids or glucocorticoids acting on mineralocorticoid receptors (MRs), we hypothesize that a low-cortisone condition, associated classically with 11βHSD2 deficiency, is a proxy of chronic MR activation by cortisol, which can also lead to low renin, elevated blood pressure, and renal and vascular alterations.

Objective

To evaluate low cortisone as a predictor of low renin activity and its association with parameters of kidney and vascular damage.

Methods

A cross-sectional study was carried out in 206 adult subjects. The subjects were classified according to low plasma renin activity (<1 ng/mL × hours) and low cortisone (<25th percentile).

Results

Plasma renin activity was associated with aldosterone (r = 0.36; P < .001) and cortisone (r = 0.22; P = .001). A binary logistic regression analysis showed that serum cortisone per ug/dL increase predicted the low-renin phenotype (OR 0.4, 95% CI 0.21-0.78). The receiver operating characteristic curves for cortisone showed an area under the curve of 0.6 to discriminate subjects with low renin activity from controls. The low-cortisone subjects showed higher albuminuria and PAI-1 and lower sodium excretion. The association study also showed that urinary cortisone was correlated with blood pressure and serum potassium (P < .05).

Conclusion

This is the first study showing that low cortisone is a predictor of a low-renin condition. Low cortisone also predicted surrogate markers of vascular and renal damage. Since the aldosterone to renin ratio is used in the screening of PA, low cortisone values should be considered additionally to avoid false positives in the aldosterone-renin ratio calculation.

Past, Present, and Future Perspectives of Plasminogen Activator Inhibitor 1 (PAI-1)

Plasminogen activator inhibitor 1 (PAI-1), a SERPIN inhibitor, is primarily known for its regulation of fibrinolysis. However, it is now known that this inhibitor functions and contributes to many (patho)physiological processes including inflammation, wound healing, cell adhesion, and tumor progression.This review discusses the past, present, and future roles of PAI-1, with a particular focus on the discovery of this inhibitor in the 1970s and subsequent characterization in health and disease. Throughout the past few decades diverse functions of this serpin have unraveled and it is now considered an important player in many disease processes. PAI-1 is expressed by numerous cell types, including megakaryocytes and platelets, adipocytes, endothelial cells, hepatocytes, and smooth muscle cells. In the circulation PAI-1 exists in two pools, within plasma itself and in platelet α-granules. Platelet PAI-1 is secreted following activation with retention of the inhibitor on the activated platelet membrane. Furthermore, these anucleate cells contain PAI-1 messenger ribonucleic acid to allow de novo synthesis.Outside of the traditional role of PAI-1 in fibrinolysis, this serpin has also been identified to play important roles in metabolic syndrome, obesity, diabetes, and most recently, acute respiratory distress syndrome, including coronavirus disease 2019 disease. This review highlights the complexity of PAI-1 and the requirement to ascertain a better understanding on how this complex serpin functions in (patho)physiological processes.

Fatty liver index predicts the development of hypertension in a Japanese general population with and without dysglycemia

Fatty liver has been suggested to be associated with the development of hypertension. However, whether this association is related to glycemia has not been elucidated. Therefore, we investigated whether the fatty liver index (FLI) predicts the development of hypertension among individuals with and without dysglycemia in a general Japanese population. A total of 3114 participants (1036 males and 2078 females) without hypertension who underwent a Specific Health Checkup in the fiscal year 2013 were followed up until 2018. The participants were divided into six groups based on FLI tertiles (low, moderate, or high) and whether they had dysglycemia. We estimated the hazard ratios (HRs) of each group by sex using the Cox proportional hazard model. Models were adjusted for age, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, smoking, and alcohol consumption and further adjusted for systolic blood pressure (SBP). During the mean follow-up period of 2.8 years, 160 of the 3114 participants developed hypertension. Using the low FLI group with normoglycemia as a reference, the HR for incident hypertension was increased in the high FLI group with and without dysglycemia in both sexes after adjusting for confounders, except SBP (HR [95% confidence interval]: male: 1.52 (1.06-2.17) in normoglycemia and 2.05 (1.43-2.92) in dysglycemia, and female: 1.86 (1.43-2.42) in normoglycemia and 2.98 (2.19-4.07) in dysglycemia). Furthermore, in females, this association was observed after adjusting for SBP. We concluded that FLI was independently associated with an increased risk of incident hypertension in individuals with and without dysglycemia.

Elevated Blood Pressure (≥120/80 mmHg) Is Associated with Elevated Serum Plasminogen Activator Inhibitor-1, Low Birth Weight, and Family History of Diabetes in Young Normal Weight Japanese Women

Objective: We examined whether elevated blood pressure (BP) (≥120/80 mmHg) was associated with several anthropometric, metabolic, and clinical variables, including the family history of type 2 diabetes (FHD) and low birth weight, in young normal weight Japanese women. Methods: BP, body composition, and fasting glucose, insulin, lipids, lipoproteins, apolipoproteins, and adipokines were measured in 332 young Japanese women. They received a questionnaire on birth weight and FHD. Results: The prevalence of low birth weight was 2.4% and that of positive FHD was 22.9%. Homeostasis model assessment-insulin resistance averaged <1.5 and did not differ cross-sectionally between 32 women with elevated BP and 300 women with normal BP although mean body mass index was higher in the former than in the latter (21.7 ± 2.9 kg/m² vs. 20.8 ± 2.2 kg/m², P = 0.02). Women with elevated BP had higher fat mass index (P = 0.02) and trunk fat percentage (P = 0.04). They had lower high-density lipoprotein (HDL) cholesterol and apolipoprotein A1 (both P = 0.01) while fasting triglycerides and apolipoprotein B did not differ. In addition, they had higher plasminogen activator inhibitor-1 (PAI-1) (P = 0.001). Furthermore, the prevalence of low birth weight (9.4% vs. 1.7%, P = 0.03) and positive FHD (40.6% vs. 20.0%, P = 0.01) was higher in women with elevated BP. Multivariable logistic regression analyses revealed that elevated BP was independently associated with PAI-1 [odds ratio (OR); 1.05, 95% confidence interval (CI): 1.02-1.08, P = 0.001], low birth weight (OR: 12.3, 95% CI: 2.3-67.3, P = 0.04), and FHD (OR: 3.0, 95% CI: 1.3-7.9, P = 0.01). Conclusion: Elevated BP was associated with positive FHD, low birth weight, and elevated serum PAI-1 in young normal weight Japanese women.

Pharmacological inhibition of PAI-1 alleviates cardiopulmonary pathologies induced by exposure to air pollutants PM2.5

Numerous studies have established that acute or chronic exposure to environmental pollutants like particulate matter (PM) leads to the development of accelerated aging related pathologies including pulmonary and cardiovascular diseases, and thus air pollution is one of the major global threats to human health. Air pollutant particulate matter 2.5 (PM_2.5)-induced cellular dysfunction impairs tissue homeostasis and causes vascular and cardiopulmonary damage. To test a hypothesis that elevated plasminogen activator inhibitor-1 (PAI-1) levels play a pivotal role in air pollutant-induced cardiopulmonary pathologies, we examined the efficacy of a drug-like novel inhibitor of PAI-1, TM5614, in treating PM_2.5-induced vascular and cardiopulmonary pathologies. Results from biochemical, histological, and immunohistochemical studies revealed that PM_2.5 increases the circulating levels of PAI-1 and thrombin and that TM5614 treatment completely abrogates these effects in plasma. PM_2.5 significantly augments the levels of pro-inflammatory cytokine interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF), and this also can be reversed by TM5614, indicating its efficacy in amelioration of PM_2.5-induced increases in inflammatory and pro-thrombotic factors. TM5614 reduces PM_2.5-induced increased levels of inflammatory markers cluster of differentiation 107 b (Mac3) and phospho-signal transducer and activator of transcription-3 (pSTAT3), adhesion molecule vascular cell adhesion molecule 1 (VCAM1), and apoptotic marker cleaved caspase 3. Longer exposure to PM_2.5 induces pulmonary and cardiac thrombosis, but TM5614 significantly ameliorates PM_2.5-induced vascular thrombosis. TM5614 also reduces PM_2.5-induced increased blood pressure and heart weight. In vitro cell culture studies revealed that PM_2.5 induces the levels of PAI-1, type I collagen, fibronectin (Millipore), and sterol regulatory element binding protein-1 and 2 (SREBP-1 and SREBP-2), transcription factors that mediate profibrogenic signaling, in cardiac fibroblasts. TM5614 abrogated that stimulation, indicating that it may block PM_2.5-induced PAI-1 and profibrogenic signaling through suppression of SREBP-1 and 2. Furthermore, TM5614 blocked PM_2.5-mediated suppression of nuclear factor erythroid related factor 2 (Nrf2), a major antioxidant regulator, in cardiac fibroblasts. Pharmacological inhibition of PAI-1 with TM5614 is a promising therapeutic approach to control air pollutant PM_2.5-induced cardiopulmonary and vascular pathologies.

A Serpin With a Finger in Many PAIs: PAI-1's Central Function in Thromboinflammation and Cardiovascular Disease

Plasminogen activator inhibitor 1 (PAI-1) is a member of the serine protease inhibitor (serpin) superfamily. PAI-1 is the principal inhibitor of the plasminogen activators, tissue plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA). Turbulence in the levels of PAI-1 tilts the balance of the hemostatic system resulting in bleeding or thrombotic complications. Not surprisingly, there is strong evidence that documents the role of PAI-1 in cardiovascular disease. The more recent uncovering of the coalition between the hemostatic and inflammatory pathways has exposed a distinct role for PAI-1. The storm of proinflammatory cytokines liberated during inflammation, including IL-6 and TNF-α, directly influence PAI-1 synthesis and increase circulating levels of this serpin. Consequently, elevated levels of PAI-1 are commonplace during infection and are frequently associated with a hypofibrinolytic state and thrombotic complications. Elevated PAI-1 levels are also a feature of metabolic syndrome, which is defined by a cluster of abnormalities including obesity, type 2 diabetes, hypertension, and elevated triglyceride. Metabolic syndrome is in itself defined as a proinflammatory state associated with elevated levels of cytokines. In addition, insulin has a direct impact on PAI-1 synthesis bridging these pathways. This review describes the key physiological functions of PAI-1 and how these become perturbed during disease processes. We focus on the direct relationship between PAI-1 and inflammation and the repercussion in terms of an ensuing hypofibrinolytic state and thromboembolic complications. Collectively, these observations strengthen the utility of PAI-1 as a viable drug target for the treatment of various diseases.

Dietary Fiber: An Opportunity for a Global Control of Hyperlipidemia

Dietary fiber has a long history in the intervention study of hyperlipidemia. In this review, current understandings of structures, sources, and natures of various kinds of dietary fibers (DFs) were analyzed first. Available evidences for the use of different varieties of DFs in the lipid-lowering action both in vitro and in vivo were subsequently classified, including both soluble ones, such as glucans, pectins, and gums, and insoluble ones, including arabinooxylans and chitosans, in order to draw a primary conclusion of their dose and molecular weight relationship with lipid-lowering effect. Their potential mechanisms, especially the related molecular mechanism of protective action in the treatment and prevention of hyperlipidemia, were summarized at last. Five major mechanisms are believed to be responsible for the antihyperlipidemic benefits of DFs, including low levels of energy, bulking effect, viscosity, binding capacity, and fermentation thus ameliorating the symptoms of hyperlipidemia. From the molecular level, DFs could possibly affect the activities of HMG-CoA reductase, LDL receptors, CYP7A1, and MAPK signaling pathway as well as other lipid metabolism-related target genes. In summary, dietary fibers could be used as alternative supplements to exert certain lipid-lowering effects on humans. However, more clinical evidence is needed to strengthen this proposal and its fully underlying mechanism still requires more investigation.

Contribution of RAGE axis activation to the association between metabolic syndrome and cancer

Far beyond the compelling proofs supporting that the metabolic syndrome represents a risk factor for diabetes and cardiovascular diseases, a growing body of evidence suggests that it is also a risk factor for different types of cancer. However, the involved molecular mechanisms underlying this association are not fully understood, and they have been mainly focused on the individual contributions of each component of the metabolic syndrome such as obesity, hyperglycemia, and high blood pressure to the development of cancer. The Receptor for Advanced Glycation End-products (RAGE) axis activation has emerged as an important contributor to the pathophysiology of many clinical entities, by fueling a chronic inflammatory milieu, and thus supporting an optimal microenvironment to promote tumor growth and progression. In the present review, we intend to highlight that RAGE axis activation is a crosswise element on the potential mechanistic contributions of some relevant components of metabolic syndrome into the association with cancer.

The association of PAI-1 with 24 h blood pressure in young healthy adults is influenced by smoking and alcohol use: The African-PREDICT study

BACKGROUND AND AIMS

The association between plasminogen activator inhibitor-1 (PAI-1) and blood pressure is well established, but it is debatable whether raised PAI-1 levels precede or result from raised blood pressure. Furthermore, it is unclear whether this association already exists in the absence of overt hypertension and to what degree it is influenced by health behaviours. Our aim was to investigate the association of 24 h blood pressure with PAI-1 activity (PAI-1_act) in a young, healthy cohort, and to assess the influence of alcohol consumption and smoking on these associations.

METHODS AND RESULTS

Healthy black and white men and women (aged 20-30 years, n = 1156) were cross-sectionally analysed. Statistical analysis was performed first split by ethnicity and sex and then by alcohol consumption and smoking. Regression analyses adjusted for age revealed positive associations of 24 h blood pressure with PAI-1_act in most groups (p < 0.05). In multivariate-adjusted analyses, significance was lost in all groups except black men, who also had higher monocyte chemoattractant protein-1 (MCP-1) and von Willebrand factor antigen (vWF_ag) compared to white men (both p < 0.001). Analyses in black men, split by self-reported alcohol use and smoking, revealed 24 h blood pressure-PAI-1_act associations only in alcohol users (24 h SBP [B = 4.22, p < 0.001], DBP [B = 2.04, p = 0.015] and PP [B = 2.18, p = 0.013]) and smokers (24 h SBP [B = 6.10, p < 0.001] and PP [B = 4.33, p = 0.001]).

CONCLUSION

Our findings support a positive association between 24 h blood pressure and PAI-1, particularly in individuals with higher MCP-1 and vWF_ag levels. Furthermore, smoking and alcohol consumption play an important role in modifying the association between blood pressure and PAI-1.

An aberrant STAT pathway is central to COVID-19

COVID-19 is caused by SARS-CoV-2 infection and characterized by diverse clinical symptoms. Type I interferon (IFN-I) production is impaired and severe cases lead to ARDS and widespread coagulopathy. We propose that COVID-19 pathophysiology is initiated by SARS-CoV-2 gene products, the NSP1 and ORF6 proteins, leading to a catastrophic cascade of failures. These viral components induce signal transducer and activator of transcription 1 (STAT1) dysfunction and compensatory hyperactivation of STAT3. In SARS-CoV-2-infected cells, a positive feedback loop established between STAT3 and plasminogen activator inhibitor-1 (PAI-1) may lead to an escalating cycle of activation in common with the interdependent signaling networks affected in COVID-19. Specifically, PAI-1 upregulation leads to coagulopathy characterized by intravascular thrombi. Overproduced PAI-1 binds to TLR4 on macrophages, inducing the secretion of proinflammatory cytokines and chemokines. The recruitment and subsequent activation of innate immune cells within an infected lung drives the destruction of lung architecture, which leads to the infection of regional endothelial cells and produces a hypoxic environment that further stimulates PAI-1 production. Acute lung injury also activates EGFR and leads to the phosphorylation of STAT3. COVID-19 patients' autopsies frequently exhibit diffuse alveolar damage (DAD) and increased hyaluronan (HA) production which also leads to higher levels of PAI-1. COVID-19 risk factors are consistent with this scenario, as PAI-1 levels are increased in hypertension, obesity, diabetes, cardiovascular diseases, and old age. We discuss the possibility of using various approved drugs, or drugs currently in clinical development, to treat COVID-19. This perspective suggests to enhance STAT1 activity and/or inhibit STAT3 functions for COVID-19 treatment. This might derail the escalating STAT3/PAI-1 cycle central to COVID-19.

An aberrant STAT pathway is central to COVID-19

COVID-19 is caused by SARS-CoV-2 infection and characterized by diverse clinical symptoms. Type I interferon (IFN-I) production is impaired and severe cases lead to ARDS and widespread coagulopathy. We propose that COVID-19 pathophysiology is initiated by SARS-CoV-2 gene products, the NSP1 and ORF6 proteins, leading to a catastrophic cascade of failures. These viral components induce signal transducer and activator of transcription 1 (STAT1) dysfunction and compensatory hyperactivation of STAT3. In SARS-CoV-2-infected cells, a positive feedback loop established between STAT3 and plasminogen activator inhibitor-1 (PAI-1) may lead to an escalating cycle of activation in common with the interdependent signaling networks affected in COVID-19. Specifically, PAI-1 upregulation leads to coagulopathy characterized by intravascular thrombi. Overproduced PAI-1 binds to TLR4 on macrophages, inducing the secretion of proinflammatory cytokines and chemokines. The recruitment and subsequent activation of innate immune cells within an infected lung drives the destruction of lung architecture, which leads to the infection of regional endothelial cells and produces a hypoxic environment that further stimulates PAI-1 production. Acute lung injury also activates EGFR and leads to the phosphorylation of STAT3. COVID-19 patients' autopsies frequently exhibit diffuse alveolar damage (DAD) and increased hyaluronan (HA) production which also leads to higher levels of PAI-1. COVID-19 risk factors are consistent with this scenario, as PAI-1 levels are increased in hypertension, obesity, diabetes, cardiovascular diseases, and old age. We discuss the possibility of using various approved drugs, or drugs currently in clinical development, to treat COVID-19. This perspective suggests to enhance STAT1 activity and/or inhibit STAT3 functions for COVID-19 treatment. This might derail the escalating STAT3/PAI-1 cycle central to COVID-19.

Plasminogen activator inhibitor-1 activity and the 4G/5G polymorphism are prospectively associated with blood pressure and hypertension status

OBJECTIVES

Plasminogen activator inhibitor-1 (PAI-1) has consistently shown positive associations with blood pressure (BP). Whether elevations in PAI-1 levels precede or result from raised BP is still under debate and data on prospective studies are limited. Hence, we investigated the prospective associations of PAI-1 and the 4G/5G polymorphism with brachial and central BP and pulse pressure (PP) over a 10-year period.

METHODS

Black South Africans aged 30 years and older were included. Baseline data collection commenced in 2005 (n = 2010) with follow-up data collection in 2010 (n = 1288) and 2015 (n = 926). Plasma PAI-1 activity (PAI-1act), 4G/5G polymorphism genotyping, waist circumference and BP measurements were performed and analysed using sequential regression and mixed models.

RESULTS

In multivariable adjusted analyses, PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension in the total group [1.04 (1.01; 1.08) and 1.82 (1.07; 3.12) respectively]. Furthermore, PAI-1act was prospectively associated with brachial SBP (r = 0.0815) and PP (r = 0.0832) in the total group, and with central PP in women (r = 0.1125; all P < 0.05). Addition of waist circumference to the models either decreased or nullified the contribution of PAI-1act to BP and hypertension development.

CONCLUSION

PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension. Furthermore, PAI-1act associated prospectively with both brachial and central BP. These associations were mediated in part by central adiposity. The study supports the hypothesis that PAI-1 also contributes to hypertension development rather than solely being a consequence thereof.

miR-34a targets PAI-1 to regulate urinary microalbumin and renal function in hypertensive mice

Background

The aim of the study is to investigate the effects of miR-34a targeted at PAI-1 on urinary microalbumin and renal function in hypertensive mice.

Methods

Twenty specific-pathogen-free (SPF) BPN/3J mice were selected in normal group, and 120 SPF BPH/2J mice were evenly divided into model group, negative control group, miR-34a mimic group, miR-34a inhibitor group, Si-PAI-1 group, and miR-34a inhibitor + Si-PAI-1 group. qRT-PCR was used to detect the expression of miR-34a and PAI-1 mRNA. The protein expressions of PAI-1, angiotensin-converting enzyme (ACE) and ACE2 were detected by Western blot. Serum levels of AngII and Ang1-7 were detected by ELISA.

Results

miR-34a negatively regulated the expression of PAI-1. Compared with the normal group, mice in the other groups had significantly lower body weight, increased systolic blood pressure and 24-h urinary microalbumin content, decreased miR-34a expression, superoxide dismutase (SOD) and nitric oxide (NO) content, and ACE2 protein expression, and increased PAI-1 expression, serum creatinine (Scr), blood urea nitrogen (BUN) malondialdehyde (MDA), AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the model group, mice in the miR-34a mimic group and Si-PAI-1 group had no significant changes in body weight (all P > 0.05), while they had significantly lower systolic blood pressure and 24-h urinary microalbumin content, increased SOD and NO levels and ACE2 protein expression, and decreased PAI-1 expression, Scr, BUN, MDA, AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the miR-34a inhibitor group, symptoms in miR-34a inhibitor + Si-PAI-1 group were significantly improved (all P < 0.05).

Conclusions

miR-34a can inhibit the expression of PAI-1, thereby reducing urinary microalbumin content in hypertensive mice and protecting their renal function.

Therapeutics targeting the fibrinolytic system

The function of the fibrinolytic system was first identified to dissolve fibrin to maintain vascular patency. Connections between the fibrinolytic system and many other physiological and pathological processes have been well established. Dysregulation of the fibrinolytic system is closely associated with multiple pathological conditions, including thrombosis, inflammation, cancer progression, and neuropathies. Thus, molecules in the fibrinolytic system are potent therapeutic and diagnostic targets. This review summarizes the currently used agents targeting this system and the development of novel therapeutic strategies in experimental studies. Future directions for the development of modulators of the fibrinolytic system are also discussed.

The fibrinolytic system was originally identified to dissolve blood clots, and is shown to have important roles in other pathological processes, including cancer progression, inflammation, and thrombosis. Molecules or therapeutics targeting fibrinolytic system have been successfully used in the clinical treatments of cancer and thrombotic diseases. The clinical studies and experimental models targeting fibrinolytic system are reviewed by Haili Lin at Sanming First Hosipital, Mingdong Huang at Fuzhou University in China, and Peng Xu at A*STAR in Singapore to demonstrate fibrinolytic system as novel therapeutic targets. As an example, the inhibition of fibrinolytic system protein can be used to suppress cancer prolifieration and metastasis. This review also discusses the potential therapeutic effects of inhibitiors of fibrinolytic system on inflammatory disorders.

Proteomic Analysis of Longitudinal Changes in Blood Pressure

Hypertension is the leading risk factor for premature death worldwide. The identification of modifiable causes of hypertension remains an imperative task. We aimed to investigate associations between 79 proteins implicated in cardiovascular disease and longitudinal blood pressure (BP) changes in three Swedish prospective cohorts. In a discovery phase, we investigated associations between baseline circulating protein levels assessed with a proximity extension assay and BP stage progression at follow-up 5 years later among persons without BP-lowering drugs at baseline in two independent community-based cohorts from the Prospective Investigation of the Vasculature in Uppsala Seniors study (PIVUS) and the Uppsala Longitudinal Study of Adult Men (ULSAM). We used an independent cohort, the Malmö Diet and Cancer Study (MDC), for replication. The primary outcome of BP stage progression was defined as per the 2017 AHA/ACC (American Heart Association/ American College of Cardiology) Guideline BP categories. We also investigated associations of protein levels with changes in BP on a continuous scale, and meta-analyzed all three cohorts. Levels of renin were associated with BP stage progression with a 5% false discovery rate (FDR) in the ULSAM (n = 238) and PIVUS (n = 566) cohorts, but we could not replicate this association in the MDC cohort (n = 2659). The association in the discovery cohorts was modest, with an odds ratio for BP stage progression over 5 years of 1.33 (95% confidence interval 1.14 to 1.56) per standard deviation of baseline renin. In conclusion, we could not find any novel robust associations with longitudinal BP increase in a proximity extension assay-based proteomics investigation in three cohorts.

Differential gene regulation in human small airway epithelial cells grown in monoculture versus coculture with human microvascular endothelial cells following multiwalled carbon nanotube exposure

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Coculture gene expression may have opposite direction of changes than monoculture.

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Cells grow and treated in monoculture may exaggerate toxicological responses.

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Coculture of cells may provide a more in-depth assessment of toxicological responses.

Concurrent with rising production of carbon-based engineered nanomaterials is a potential increase in respiratory and cardiovascular diseases due to exposure to nanomaterials in the workplace atmosphere. While single-cell models of pulmonary exposure are often used to determine the potential toxicity of nanomaterials in vitro, previous studies have shown that coculture cell models better represent the cellular response and crosstalk that occurs in vivo. This study identified differential gene regulation in human small airway epithelial cells (SAECs) grown either in monoculture or in coculture with human microvascular endothelial cells following exposure of the SAECs to multiwalled carbon nanotubes (MWCNTs). SAEC genes that either changed their regulation direction from upregulated in monoculture to downregulated in coculture (or vice versa) or had a more than a two-fold changed in the same regulation direction were identified. Genes that changed regulation direction were most often involved in the processes of cellular growth and proliferation and cellular immune response and inflammation. Genes that had a more than a two-fold change in regulation in the same direction were most often involved in the inflammatory response. The direction and fold-change of this differential gene regulation suggests that toxicity testing in monoculture may exaggerate cellular responses to MWCNTs, and coculture of cells may provide a more in-depth assessment of toxicological responses.

Bioinformatic analysis reveals novel hub genes and pathways associated with hypertensive nephropathy

AIM

Hypertensive nephropathy (HTN) is one of the leading causes of end-stage renal disease and is closely associated with inflammation and tubule-interstitial fibrosis. The molecular mechanism underlying HTN remains unclear. This study used bioinformatic analysis to identify the novel gene targets for HTN.

METHODS

We downloaded the microarray data of GSE99325 and GSE32591 from Gene Expression Omnibus. The dataset comprised 20 HTN and 15 normal samples. The differentially expressed genes (DEG) were identified, and then gene ontology (GO) enrichment was performed, and a GO tree was constructed by using clusterProfiler and ClueGO. In addition, a protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes database and visualized by Cytoscape. The novel hub genes were validated in in vitro experiments.

RESULTS

A total of 267 genes (117 up-regulated and 150 down-regulated genes) were identified as DEG. GO analysis and the GO tree indicated that the DEG were mainly associated with steroid hormone response and the extracellular matrix. Based on the protein-protein interaction network, we screened out several novel hub genes. Considering the findings and the literature review, we focused on and validated the dual specificity phosphatase 1, tissue inhibitor of matrix metalloproteinases 1, fos proto-oncogene and jun proto-oncogenes, which may play significant roles in the pathogenesis of HTN. These findings were consistent with the bioinformatic results for the in vitro validation.

CONCLUSION

This study identified for the first time novel hub genes with microarray data in HTN by using bioinformatic analysis and provided novel evidence and clues for future works.