Effect of interleukin 8 and ICAM-1 on calcium-dependent outflow of K+ in erythrocytes from subjects with essential hypertension

Relationship between Cytokines and Metabolic Syndrome Components: Role of Pancreatic-Derived Factor, Interleukin-37, and Tumor Necrosis Factor-α in Metabolic Syndrome Patients

The metabolic syndrome (MetS) is a serious public health issue that affects people all over the world. Notably, insulin resistance, prothrombotic activity, and inflammatory state are associated with MetS. This study aims to explore the relationship between cytokines and tumor necrosis factor-α (TNF-α), pancreatic-derived factor (PANDER), and interleukin (IL-)-37 and the accumulation of MetS components. Eligible participants were divided into four groups as follows: group 1, patients with dyslipidemia; group 2, patients with dyslipidemia and obesity; group 3, patients with dyslipidemia, obesity, and hypertension; and group 4, patients with dyslipidemia, obesity, hypertension, and hyperglycemia. This study exhibited that serum levels of TNF-α and PANDER were significantly elevated (P < 0.001) in the MetS groups, while IL-37 level and IL-37 mRNA expression were significantly decreased (P < 0.001) relative to healthy controls. Moreover, this study has revealed significant correlations (P < 0.001) between MetS components and TNF-α, PANDER, and IL-37 levels in MetS patients. The aforementioned results suggested the association between the proinflammatory cytokine (TNF-α and PANDER) and anti-inflammatory cytokine (IL-37) with the accumulation of MetS components. Hence, the overall outcome indicated that PANDER and IL-37 may be considered novel biomarkers associated with increased risk of MetS and can be used as a promising therapeutic target in preventing, ameliorating, and treating metabolic disorders.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01079-z.

A new immune disease: systemic hypertension

Systemic hypertension is the most common medical comorbidity affecting the adult population globally, with multiple associated outcomes including cerebrovascular diseases, cardiovascular diseases, vascular calcification, chronic kidney disease, metabolic syndrome and mortality. Despite advancements in the therapeutic field approximately one in every five adult patients with hypertension is classified as having treatment-resistant hypertension, indicating the need for studies to provide better understanding of the underlying pathophysiology and the need for more therapeutic targets. Recent pre-clinical studies have demonstrated the role of the innate and adaptive immune system including various cell types and cytokines in the pathophysiology of hypertension. Moreover, pre-clinical studies have indicated the potential beneficial effects of immunosuppressant medications in the control of hypertension. Nevertheless, it is unclear whether such pathophysiological mechanisms and therapeutic alternatives are applicable to human subjects, while this area of research is undoubtedly a rapidly growing field.

CXCL1-CXCR2 signalling mediates hypertensive retinopathy by inducing macrophage infiltration

Inflammation plays an important role in hypertensive retinal vascular injury and subsequent retinopathy. Monocyte chemotaxis via CXCL1-CXCR2 binding has been implicated in various cardiovascular diseases, but the function of CXCL1-CXCR2 signalling involved in retinopathy, which was investigated as angiotensin II (Ang II)-induced retinopathy, is unclear. In our study, we established a hypertensive retinopathy (HR) model by Ang II infusion (3000 ng/min/kg) for 3 weeks. To determine the involvement of CXCR2 signalling, we used CXCR2 knockout (KO) mice or C57BL/6J wild-type (WT) mice as experimental subjects. The mice were treated with a CXCL1 neutralizing antibody or SB225002 (the specific CXCR2 inhibitor). Our results showed that after Ang II treatment, the mRNA levels of CXCL1 and CXCR2 and the number of CXCR2⁺ inflammatory cells were significantly elevated. Conversely, unlike in the IgG control group, the CXCL1 neutralizing antibody greatly reduced the increase in central retinal thickness induced by Ang II infusion, arteriolar remodelling, superoxide production, and retinal dysfunction in WT mice. Furthermore, Ang II infusion induced arteriolar remodelling, infiltration of Iba1⁺ macrophages, the production of oxidative stress, and retinal dysfunction, but the symptoms were ameliorated in CXCR2 KO mice and SB225002-treated mice. These protective effects were related to the reduction in the number of CXCR2⁺ immune cells, particularly macrophages, and the decrease in proinflammatory cytokine (IL-1β, IL-6, TNF-ɑ, and MCP-1) expression in Ang II-treated retinas. Notably, serum CXCL1 levels and the number of CXCR2⁺ monocytes/neutrophils were higher in HR patients than in healthy controls. In conclusion, this study provides new evidence that the CXCL1-CXCR2 axis plays a vital role in the pathogenesis of hypertensive retinopathy, and selective blockade of CXCL1-CXCR2 activation may be a potential treatment for HR.

Exploring the Relationship of Perivascular Adipose Tissue Inflammation and the Development of Vascular Pathologies

Initially thought to only provide mechanical support for the underlying blood vessels, perivascular adipose tissue (PVAT) has now emerged as a regulator of vascular function. A healthy PVAT exerts anticontractile and anti-inflammatory actions on the underlying vasculature via the release of adipocytokines such as adiponectin, nitric oxide, and omentin. However, dysfunctional PVAT produces more proinflammatory adipocytokines such as leptin, resistin, interleukin- (IL-) 6, IL-1β, and tumor necrosis factor-alpha, thus inducing an inflammatory response that contributes to the pathogenesis of vascular diseases. In this review, current knowledge on the role of PVAT inflammation in the development of vascular pathologies such as atherosclerosis and hypertension was discussed.

Sulfatase 1 mediates IL-10-induced dimethylarginine dimethylaminohydrolase-1 expression and antiproliferative effects in vascular smooth muscle cells of spontaneously hypertensive rats

The extracellular sulfatases (exSulfs) sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2) are well-known regulators of cell signaling and metabolism. In addition, exSulfs mediate the up- or downregulatory effects of cytokines on angiotensin II (Ang II)-induced expression of hypertensive mediators in vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHRs). Previously, we demonstrated that interleukin-10 (IL-10)-induced dimethylarginine dimethylaminohydrolase-1 (DDAH-1) expression was mediated by Ang II subtype 2 receptor (AT2 R) and AMP-activated protein kinase (AMPK) activation, and that IL-10-mediated inhibition of Ang II-induced proliferation of SHRs VSMC was partially associated with DDAH-1. In this study, we examined the effects of exSulfs on IL-10-induced DDAH-1 expression, abrogation of Ang II-induced DDAH-1 downregulation, and inhibition of Ang II-induced proliferation of SHRs VSMC. IL-10-induced DDAH-1 expression and abrogation of Ang II-induced DDAH-1 downregulation were attenuated in Sulf1 siRNA-transfected SHRs VSMC. However, Sulf2 did not affect IL-10-induced DDAH-1 expression and abrogation of Ang II-induced DDAH-1 downregulation. Downregulation of Sulf1 inhibited IL-10-induced AT2 R expression and the synergistic effects of IL-10 on Ang II-induced AT2 R expression. Additionally, Sulf1 downregulation inhibited IL-10-induced AMPK activity and abrogation of Ang II-induced decrease in AMPK activity. Moreover, the IL-10-mediated inhibition of Ang II-induced proliferation was not detected in Sulf1 siRNA-transfected SHRs VSMC; IL-10-mediated inhibition of Ang II-induced VSMC proliferation was mediated via the AT2 R pathway and AMPK activation. Specifically, IL-10-induced DDAH-1 expression, abrogation of Ang II-induced DDAH-1 downregulation, and inhibition of Ang II-induced proliferation, which is mediated by the AT2 R pathway and AMPK activation, are mainly mediated by Sulf1 activity in SHRs VSMC. These results suggest that Sulf1, and not Sulf2, mediates the IL-10-induced inhibition of Ang II-induced hypertensive effects in SHRs VSMC.

Arterial Hypertension and Interleukins: Potential Therapeutic Target or Future Diagnostic Marker?

Hypertension as a multifactorial pathology is one of the most important cardiovascular risk factors, affecting up to 30-40% of the general population. Complex immune responses are involved in the inflammatory mechanism of hypertension, with evidence pointing to increased inflammatory mediators even in prehypertensive patients. Increased vascular permeability, thrombogenesis, and fibrosis, effects that are associated with sustained hypertension, could be attributed to chronic inflammation. Chronic inflammation triggers endothelial dysfunction via increased production of ROS through proinflammatory cytokines. Increased serum level of proinflammatory cytokines such as IL-1β, IL-6, IL-8, IL-17, IL-23, TGFβ, and TNFα in hypertensive patients has been associated with either increased blood pressure values and/or end-organ damage. Moreover, some cytokines (i.e., IL-6) seem to determine a hypertensive response to angiotensin II, regardless of blood pressure values. Understanding hypertension as an inflammatory-based pathology gives way to new therapeutic targets. As such, conventional cardiovascular drugs (statins, calcium channels blockers, and ACEIs/ARBs) have shown additional anti-inflammatory effects that could be linked to their blood pressure lowering properties. Moreover, anti-inflammatory drugs (mycophenolate mofetil) have been shown to decrease blood pressure in hypertensive patients or prevent its development in normotensive individuals. Further research is needed to evaluate whether drugs targeting hypertensive-linked proinflammatory cytokines, such as monoclonal antibodies, could become a new therapeutic option in treating arterial hypertension.

The study of soluble intercellular adhesion molecule-1 and ghrelin in adolescents with family history of type 2 diabetes

The purpose of this study was to observe both the changes of soluble intercellular adhesion molecule-1 (sICAM-1) and ghrelin in adolescents with family history of type 2 diabetes (FHD) and the relationship between sICAM-1 and ghrelin. This case-control study included 63 adolescents (boys/girls 29/34, age 14.1 ± 0.7 years) without FHD (FHD-) and 67 adolescents (boys/girls 33/34, age 14.0 ± 0.8 years) with FHD (FHD+). Anthropometric measurements, including height, weight, waist circumference (WC), and blood pressure, were obtained. Blood samples were collected, and fasting plasma glucose (FPG), serum lipids, true insulin, sICAM-1, and ghrelin were assayed. The results showed that the age and gender were similar in two groups (P > 0.05). Body mass index (BMI), WC, FPG, fasting insulin, HOMA-IR, and sICAM-1 were all significantly higher in the FHD+ group than in the FHD- group (P < 0.05). Ghrelin was significantly lower in the FHD+ group than in the FHD- group (P < 0.05). sICAM-1 was positively correlated with WC (r = 0.178, P = 0.043), fasting insulin (r = 0.195, P = 0.026), HOMA-IR (r = 0.197, P = 0.024), and ghrelin (r = 0.290, P = 0.001). After multivariate analysis, the ghrelin (β = 0.788, 95 % CI: 0.416-1.159, P = 0.000) and HOMA-IR (β = 0.106, 95 % CI: 0.045-0.167, P = 0.001) maintained an independent association with sICAM-1. These findings led to the conclusion that endothelial dysfunction and decline of ghrelin were found in adolescents with family history of diabetes. The decline of ghrelin maybe a protection mechanism for endothelial function in adolescents with family history of diabetes and should be examined in future studies.

Association between human metapneumovirus seroprevalence and hypertension in elderly subjects in a long-term care facility

Recently, relations between hypertension and infections caused by several pathogens have been reported. However, few studies have examined the relationship between human metapneumovirus (hMPV) and hypertension in elderly inpatients. To assess the association between anti-hMPV-immunoglobulin G (IgG) titer and the prevalence of hypertension, we conducted a case-control study in a Japanese long-term care facility (LTCF). The participants included 84 hypertensive patients aged 65 years, and 84 age- and sex-matched normotensive controls (38 males and 46 females in each group; cases, 79.9±8.4 (s.d.) years; controls, 80.1±8.3 years). Data on underling chronic clinical conditions were collected. Titers were measured using an immunofluorescence assay kit. The significance of risk factor differences was analyzed using univariate and multivariate comparisons of cases and controls. All serum samples were positive for hMPV, and IgG titers ranged from 40-fold to more than 5120-fold. There were no significant sex- or age-related differences in log(2) (anti-hMPV-IgG titer/10) among the subjects. Compared with normotensive subjects, hypertensive patients presented significantly higher log(2) (anti-hMPV-IgG titer/10) values (P<0.001). After adjustment with multiple logistic analysis, the odds ratio for log(2) (anti-hMPV-IgG titer/10) was 1.42 (95% confidence interval 1.16-1.75, P=0.001) relative to normotensive subjects. In all subjects, stepwise multiple regression analysis revealed that both hypertension and a poor nutritional state independently contributed to increased log(2) (anti-hMPV-IgG titer/10). These observations suggest that an increased anti-hMPV-IgG titer was closely related to hypertension in elderly subjects in a Japanese LTCF.

Downregulation of Angiotensin II-Induced 12-Lipoxygenase Expression and Cell Proliferation in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats by CCL5

Angiotensin II (Ang II) plays an important role in vascular hypertension. The role of the chemokine CCL5 on Ang II-induced activities in vascular smooth muscle cells (VSMCs) has not been studied. In this study, we elucidated the effect of CCL5 on Ang II-induced 12-lipoxygenase (LO) expression and cell proliferation in spontaneously hypertensive rats (SHR) VSMCs. CCL5 decreased Ang II-induced 12-LO mRNA expression and protein production, and it increased Ang II type 2 (AT(2)) receptor expression in SHR VSMCs. The inhibitory effect of CCL5 on Ang II-induced 12-LO mRNA expression was mediated through the AT(2) receptor. Although treatment of CCL5 alone induced SHR VSMCs proliferation, CCL5 inhibited Ang II-induced VSMCs proliferation and PD123,319, an AT(2) receptor antagonist, blocked the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation. Phosphorylation of p38 was detected in VSMCs treated with Ang II or CCL5 alone. But, decrease of p38 phosphorylation was detected in VSMCs treated with Ang II and CCL5 simultaneously (Ang II/CCL5) and PD123,319 increased p38 phosphorylation in VSMCs treated with Ang II/CCL5. Therefore, these results suggest that the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation is mediated by the AT(2) receptor via p38 inactivation, and CCL5 may play a beneficial role in Ang II-induced vascular hypertension.

IL-8/CXCL8 Upregulates 12-Lipoxygenase Expression in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats

Background

We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC.

Methods

Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 (AT₁) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [³H]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings.

Results

Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the AT₁ receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an AT₁ receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor.

Conclusion

These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.

15-Deoxy-Delta-Prostaglandin J(2) Upregulates the Expression of LPS-Induced IL-8/CXCL8 mRNA in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats

Background

15d-PGJ₂ has been known to act as an anti-inflammatory agent and has anti-hypertensive effects. As a result of these properties, we examined the effect of 15d-PGJ₂ on the LPS-induced IL-8/CXCL8 mRNA expression in VSMCs from SHR.

Methods

Effect and action mechanism of 15d-PGJ₂ on the expression of LPS-induced IL-8/CXCL8 mRNA in VSMCs from SHR and WKY were examined by using real-time polymerase chain reaction, electrophoretic mobility shift assay for NF-κB avtivity, Western blotting analysis for ERK and p38 phosphorylation and flow cytometry for NAD(P)H oxidase activity.

Results

15d-PGJ₂ decreased the expression of LPS-induced IL-8/CXCL8 mRNA in WKY VSMCs, but increased the expression of LPS-induced IL-8/CXCL8 mRNA in SHR VSMCs. The upregulatory effect of 15d-PGJ₂ in SHR VSMCs was mediated through PPARγ, and dependent on NF-κB activation and ERK phosphorylation. However, inhibition of the p38 signaling pathway augmented the upregulatory effect of 15d-PGJ₂ on LPS-induced IL-8/CXCL8 mRNA. A NAD(P)H oxidase inhibitor inhibited the upregulatory effect of 15d-PGJ₂ on LPS-induced IL-8/CXCL8 mRNA expression in SHR VSMCs, and an increase in NAD(P)H oxidase activity was detected in SHR VSMCs treated with 15d-PGJ₂/LPS.

Conclusion

Our results indicate that the upregulatory effect of 15d-PGJ₂ on LPS-induced IL-8/CXCL8 expression in SHR VSMCs is mediated through the PPARγ and ERK pathway, and may be related to NAD(P)H oxidase activity. However, p38 inactivation may also play an important role in 15d-PGJ₂/LPS-induced IL-8/CXCL8 expression in SHR VSMCs.

Nutrient intake and immune function of elderly subjects

OBJECTIVE

Food intake, aging, and immune function share complex influences. Therefore, the purpose of this study was to examine relationships between nutrient intakes from food and dietary supplements and a biomarker of immune function.

DESIGN

Data were collected from participants in a cross-sectional study as well as baseline data from a longitudinal study (n=89). Subjects completed 24-hour food recalls, including supplement intake. Polyclonal mitogen phytohemmagluttin (PHA) was the immune function stimulator used. Height and weight were used to calculate body mass index.

STATISTICAL ANALYSES PERFORMED

Descriptive, bivariate correlation, Spearman's rho for nonparametric data, t tests, and stepwise regression with nutrient intakes as independent variables and T-cell proliferation as dependent variables.

RESULTS

Significant positive correlations (P< or =0.05) were found between PHA-induced proliferation and intake of docosahexaenoic acid (DHA), eicosahexaenoic acid (EPA), sodium, and selenium, although intakes of DHA plus EPA were inadequate when compared to recommended intakes. A significant negative correlation with total vitamin A, with many vitamin A levels being above the upper limit of safety. Regression analyses found these nutrients to be variables significant in explaining the variance in PHA (P=0.005).

CONCLUSIONS

Selenium, sodium, DHA, EPA, and vitamin A intake from diet and supplements were associated with PHA-induced proliferative responses. Clients may be counseled to have adequate selenium, EPA, DHA intake, and vitamin A, but avoid excess vitamin A.

Upregulation of interleukin-8/CXCL8 in vascular smooth muscle cells from spontaneously hypertensive rats

Chemokines promote vascular inflammation and play a pathogenic role in the development and maintenance of hypertension. In the present study, the expression of the chemokine interleukin-8/CXCL8 (IL-8/CXCL8) was investigated in cultured vascular smooth muscle cells (VSMC) obtained from the thoracic aorta of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). IL-8/CXCL8 expression in thoracic aorta tissue and VSMC in SHR were significantly higher than in WKY. However, the expression of CXCR1 mRNA in VSMC from WKY was higher than that in VSMC from SHR. Angiotensin II (Ang II) induced a higher level of IL-8/CXCL8 mRNA expression in VSMC from SHR than in VSMC from WKY. The time course of Ang II-induced IL-8/CXCL8 expression in VSMC from SHR correlated with those of Ang II-induced CXCL1 and Ang II type 1 (AT1) receptor expression, and the expression of IL-8/CXCL8 by Ang II was inhibited by the AT1 receptor antagonist losartan. The effect of Ang II on IL-8/CXCL8 expression was not dependent on nuclear factor-kappaB (NF-kappaB) activation, but was mediated by an extracellular signal-regulated kinase (ERK) signaling pathway. Although Ang II directly induced IL-8/CXCL8 expression, expression of Ang II-induced IL-8/CXCL8 decreased in VSMC transfected with heme oxygenase-1. These results suggest that IL-8/CXCL8 plays an important role in the pathogenesis of Ang II-induced hypertension and vascular lesions in SHR.

Comparative analysis of the maternal and umbilical interleukin-8 levels in normal pregnancies and in pregnancies complicated by preeclampsia with intrauterine normal growth and intrauterine growth retardation

OBJECTIVES

The aim of this study was to determine the maternal and umbilical cord serum levels of interleukin-8 (IL-8) in pregnancies complicated by preeclampsia with intrauterine normal growth and intrauterine growth retardation (IUGR), and in normotensive pregnancies.

PATIENTS AND METHODS

The study was carried out on 15 patients with singleton pregnancies complicated by preeclampsia with appropriate for gestational age weight infants and 12 pregnant patients with preeclampsia complicated by IUGR. The control group consisted of 10 healthy normotensive delivering patients with singleton uncomplicated pregnancies. Maternal and umbilical serum IL-8 concentrations were estimated using the ELISA method.

RESULTS

There were no statistically significant differences in patient profiles between the groups. Systolic and diastolic blood pressure and mean arterial blood pressure were higher in the study groups in comparison with the control group. Lower birth weight and lower gestational age at birth were observed in the group of patients with preeclampsia complicated by IUGR. Increased maternal and umbilical serum levels of IL-8 were found in both preeclamptic patient groups in comparison with the control group. The umbilical cord blood concentrations of IL-8 in all groups of patients tended to be higher in comparison with the maternal blood.

CONCLUSIONS

It seems that these higher IL-8 concentrations may be associated with apoptosis, inflammation, neutrophil activation, endothelial cell damage and dysfunction, and increased endothelial permeability. They may also participate in an attempt to compensate for the imbalanced apoptosis and vascular resistance. Our findings suggest a possible significant role of IL-8 in the pathogenesis and sequelae of preeclampsia, especially in preeclamptic pregnancies complicated by IUGR.

Erythrocyte signal transduction pathways, their oxygenation dependence and functional significance

Erythrocytes play a key role in human and vertebrate metabolism. Tissue O2 supply is regulated by both hemoglobin (Hb)-O2 affinity and erythrocyte rheology, a key determinant of tissue perfusion. Oxygenation-deoxygenation transitions of Hb may lead to re-organization of the cytoskeleton and signalling pathways activation/deactivation in an O2-dependent manner. Deoxygenated Hb binds to the cytoplasmic domain of the anion exchanger band 3, which is anchored to the cytoskeleton, and is considered a major mechanism underlying the oxygenation-dependence of several erythrocyte functions. This work discusses the multiple modes of Hb-cytoskeleton interactions. In addition, it reviews the effects of Mg2+, 2,3-diphosphoglycerate, NO, shear stress and Ca2+, all factors accompanying the oxygenation-deoxygenation cycle in circulating red cells. Due to the extensive literature on the subject, the data discussed here, pertain mainly to human erythrocytes whose O2 affinity is modulated by 2,3-diphosphoglycerate, ectothermic vertebrate erythrocytes that use ATP, and to bird erythrocytes that use inositol pentaphosphate.