Calcium channel blockers suppress cytokine-induced activation of human neutrophils

Hand-foot syndrome in cancer patients on capecitabine: examining prevalence, impacts, and associated risk factors at a cancer centre in Malaysia

INTRODUCTION

Hand-foot syndrome (HFS) significantly impacts quality of life in cancer patients undergoing capecitabine treatment. This study assessed capecitabine-associated HFS prevalence, its impacts on chemotherapy treatment, and identified risk factors in multiracial Malaysian patients.

METHODS

We included adult cancer patients receiving capecitabine at Sarawak General Hospital for at least two cycles from April 1, 2021 to June 30, 2022. HFS rates, time to HFS, and proportions of HFS-related treatment modifications were determined. Characteristics between patients with and without HFS were compared and multivariable logistic regression was used to identify risk factors for all-grade HFS and grade ≥2.

RESULTS

Among 369 patients, 185 (50.1%) developed HFS, with 14.6% experiencing grade ≥2 and 21.6% (40/185) underwent treatment modifications. Risk factors for all-grade HFS include older age (OR 1.03 95%CI 1.01, 1.06), prior chemotherapy (OR 2.09 95%CI 1.22, 3.58), higher capecitabine dose (OR 2.96 95%CI 1.62, 5.38), prolonged treatment (OR 1.36 95%CI 1.21, 1.51), folic acid intake (OR 3.27 95%CI 1.45, 7.35) and lower neutrophil count (OR 0.77 95%CI 0.66, 0.89). For HFS grade ≥2, older age (OR 1.04 95%CI 1.01, 1.08), female sex (OR 2.10 95%CI 1.05, 4.18), Chinese race (OR 2.10 95%CI 1.06, 4.18), and higher capecitabine dose (OR 2.62 95%CI 1.28, 5.35) are significant risk factors. Use of calcium channel blockers were associated with reduced risks of all-grade HFS (OR 0.27, 95%CI 0.12, 0.60) and grade ≥2 (OR 0.21 95%CI 0.06, 0.78).

CONCLUSION

This study provides real-world data on capecitabine-induced HFS in Malaysian patients and identifies risk factors that may offer insights into its understanding and management.

PVB exerts anti-inflammatory effects by inhibiting the activation of MAPK and NF-κB signaling pathways and ROS generation in neutrophils

Pinaverium bromide (PVB) has been shown to protect mice against sepsis, which is predominantly attributed to PVB-mediated anti-inflammatory effects by inhibiting primed neutrophils to produce proinflammatory cytokines. However, the underlying mechanism(s) by which PVB affects neutrophils remains unknown. In this study, we report that treatment with PVB either before or after LPS stimulation attenuated IL-1β and TNF-α expression at both mRNA and protein levels in LPS-activated murine neutrophils. Further experiments revealed that PVB inhibited the phosphorylation of ERK, JNK, and IκBα in LPS-stimulated murine neutrophils. Moreover, PVB reduced reactive oxygen species (ROS) levels via regulating NADPH oxidase 2 (NOX2) activity, as represented by inhibiting p47phox translocation from the cytoplasm to the cellular membrane. Importantly, PVB significantly attenuated IL-1β, TNF-α, IL-6, CXCL1 production in both LPS-stimulated low density neutrophils (LDNs) and normal density neutrophils (NDNs) isolated from septic patients. Collectively, we demonstrated that PVB exerts anti-inflammatory effect by attenuating ROS generation and suppressing the activation of MAPK and NF-κB signaling pathways, suggesting that PVB may act as a potential therapeutic agent for sepsis by inhibiting neutrophil priming and activation.

Amlodipine Ocular Delivery Restores Ferning Patterns and Reduces Intensity of Glycosylated Peak of Carrageenan-Induced Tear Fluid: An In-Silico Flexible Docking with IL-β1

BACKGROUND

The tear ferning test can be an easy clinical procedure for the evaluation and characterization of the ocular tear film.

OBJECTIVE

The objective of this study was to examine the restoration of tear ferning patterns and reduction of glycosylation peak after amlodipine application in carrageenan-induced conjunctivitis.

METHODS

At the rabbit's upper palpebral region, carrageenan was injected for cytokine-mediated conjunctivitis. Ferning pattern and glycosylation of the tear fluid were characterized using various instrumental analyses. The effect of amlodipine was also examined after ocular instillation and flexible docking studies.

RESULTS

Optical microscopy showed a disrupted ferning of the tear collected from the inflamed eye. FTIR of the induced tear fluid exhibited peaks within 1000-1200 cm-1, which might be due to the protein glycosylation absent in the normal tear spectrogram. The glycosylation peak reduced significantly in the tear sample collected from the amlodipine-treated group. Corresponding energy dispersive analysis showed the presence of sulphur, indicating protein leakage from the lacrimal gland in the induced group. The disappearance of sulphur from the treated group indicated its remedial effect. The flexible docking studies revealed a stronger binding mode of amlodipine with Interleukin-1β (IL-1β). The reduction in the intensity of the glycosylated peak and the restoration offering are probably due to suppression of IL-1β.

CONCLUSION

This study may be helpful in obtaining primary information for drug discovery to be effective against IL-1β and proving tear fluid as a novel diagnostic biomarker.

Lomerizine attenuates LPS-induced acute lung injury by inhibiting the macrophage activation through reducing Ca2+ influx

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening lung diseases with high mortality rates, predominantly attributable to acute and severe pulmonary inflammation. Lomerizine (LMZ) is a calcium channel blocker previously used in preventing and treating migraine. Here, we found that LMZ inhibited inflammatory responses and lung pathological injury by reducing pulmonary edema, neutrophil infiltration and pro-inflammatory cytokine production in lipopolysaccharide (LPS)-induced ALI mice. In vitro experiments, upon treating with LMZ, the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α was attenuated in macrophages. The phosphorylation of p38 MAPK, ERK1/2, JNK, and NF-κB p65 was inhibited after LMZ treatment. Furthermore, LPS-induced Ca2+ influx was reduced by treating with LMZ, which correlated with inhibition of pro-inflammatory cytokine production. And L-type Ca2+ channel agonist Bay K8644 (BK) could restore cytokine generation. In conclusion, our study demonstrated that LMZ alleviates LPS-induced ALI and is a potential agent for treating ALI/ARDS.

Protein kinase C isoforms mediate the formation of neutrophil extracellular traps

Neutrophils release extracellular traps (NETs) in response to numerous pathogenic microbes as the last suicidal resource (NETosis) in the fight against infection. Apart from the host defense function, NETs play an essential role in the pathogenesis of various autoimmune, inflammatory and malignant diseases. Therefore, understanding the molecular mechanisms of NETosis is important for regulating the aberrant or excessive NET release. Protein kinase C (PKC) is a serine/threonine kinase which is involved in various neutrophil functions, however, little is known about its implication in NETosis activated by various physiological and pharmacological stimuli. Since there are conventional, novel and atypical PKC isoforms (α, βI, βII, δ, and ζ) found in human neutrophils, we investigated their impact in NETosis, oxidative burst and spreading applying pharmacological approach. Using specific inhibitors of PKC isoforms, we showed that PKCβ, PKCδ, and PKCζ are involved in the oxidative burst, spreading and NETosis activated by calcium ionophore A23187, while only PKCβ is implicated in these functions activated by phorbol 12-myristate 13-acetate (PMA). The data obtained in our study might help in the development of new drugs useful for the treatment of autoimmune and inflammatory diseases associated with NETs.

Peripheral arterial disease and hypertension

PURPOSE OF REVIEW

Hypertension (HTN) is a well known risk factor for atherosclerosis and peripheral arterial disease (PAD). PAD affects more than 250 million people globally and is associated with worse clinical outcomes. Although multiple studies have been performed to evaluate treatment of HTN in patients with PAD, blood pressure management in this high-risk cohort remains poor.

RECENT FINDINGS

There has been conflicting evidence regarding blood pressure goals in PAD with some recent studies showing adverse outcomes with low blood pressure in this patient population. Current guidelines, however, continue to recommend treatment goals in PAD patients similar to patients without PAD. To date, no single antihypertensive drug class has shown a clear benefit in PAD population over other antihypertensive drug classes.

SUMMARY

Prospective randomized trials enrolling PAD patients are required that can shed light on optimum blood pressure target and also distinguish between different antihypertensive drugs in terms of reducing adverse outcomes.

The immunomodulatory effects of antihypertensive therapy: A review

Hypertension remains the leading preventable risk factor for stroke and coronary artery disease, significantly contributing to all-cause global mortality and predisposing patients to renal and heart failure, as well as peripheral vascular disease. Due to the widespread usage of antihypertensive drugs, global mean blood pressure has remained unchanged or even slightly decreased over the past four decades. However, considering the broad spectrum of mechanisms involved in the action of antihypertensive drugs and the prevalence of their target receptors on immune cells, possible immunomodulatory effects which may exert beneficial effects of lowering blood pressure but also potentially alter immune function should be considered. In this review, we attempt to assess the consequences to immune system function of administering the five most commonly prescribed groups of antihypertensive drugs and to explain the mechanisms behind those interactions. Finally, we show potential gaps in our understanding of the effects of antihypertensive drugs on patient health. With regard to the widespread use of these drugs in the adult population worldwide, the discussed results may be of vital importance to evidence-based decision-making in daily clinical practice.

Subversion of Phytomyxae Cell Communication With Surrounding Environment to Control Soilborne Diseases; A Case Study of Cytosolic Ca2+ Signal Disruption in Zoospores of Spongospora subterranea

Ca2+ signaling regulates physiological processes including chemotaxis in eukaryotes and prokaryotes. Its inhibition has formed the basis for control of human disease but remains largely unexplored for plant disease. This study investigated the role of Ca2+ signaling on motility and chemotaxis of Spongospora subterranea zoospores, responsible for root infections leading to potato root and tuber disease. Cytosolic Ca2+ flux inhibition with Ca2+ antagonists were found to alter zoospore swimming patterns and constrain zoospore chemotaxis, root attachment and zoosporangia infection. LaCl3 and GdCl3, both Ca2+ channel blockers, at concentrations ≥ 50 μM showed complete inhibition of zoospore chemotaxis, root attachment and zoosporangia root infection. The Ca2+ chelator EGTA, showed efficient chemotaxis inhibition but had relatively less effect on root attachment. Conversely the calmodulin antagonist trifluoperazine had lesser effect on zoospore chemotaxis but showed strong inhibition of zoospore root attachment. Amiloride hydrochloride had a significant inhibitory effect on chemotaxis, root attachment, and zoosporangia root infection with dose rates ≥ 150 μM. As expected, zoospore attachment was directly associated with root infection and zoosporangia development. These results highlight the fundamental role of Ca2+ signaling in zoospore chemotaxis and disease establishment. Their efficient interruption may provide durable and practical control of Phytomyxea soilborne diseases in the field.

Pinaverium Bromide Attenuates Lipopolysaccharide-Induced Excessive Systemic Inflammation via Inhibiting Neutrophil Priming

Dominant infiltration of neutrophils is a hallmark of many inflammatory diseases, especially in septic shock. IL-1β as one of the most early released proinflammatory cytokine in neutrophil, plays a pivotal role in the progress of sepsis. In this study, we built a high-throughput-compatible drug screen assay platform based on our newly constructed reporter C57BL/6 mice, pIL1-DsRed, expressing the DsRed gene under the control of the IL-1β promoter. After screening 1200 U.S. Food and Drug Administration-approved compounds, we found that pinaverium bromide (PVB) significantly suppressed the DsRed expression of primed neutrophil and improved the survival rate of mice given LPS in an endotoxin challenge analogous to sepsis, regardless of whether PVB was administered before or after LPS. PVB also protected the liver and lung from LPS-induced damage and reduced organ-specific inflammatory responses. PVB decreased the production of IL-1β, IL-6, and CXCL1 mRNA in the lungs of LPS-treated mice and decreased the serum levels of liver transaminases (alanine aminotransferase and aspartate aminotransferase) at multiple time points and doses tested. PVB can significantly suppress primed neutrophil-specific respiratory bursts and migration as well. Lastly, PVB affected neutrophils' gene expression and phenotypic changes during neutrophil priming. PVB downregulated GM-CSF-induced expression of CD54 and dectin-2 (markers of fully primed neutrophils) at both mRNA and protein levels during late-phase neutrophil priming. In summary, we demonstrated that PVB can be used as a potential therapeutic agent for sepsis by inhibiting neutrophil priming.

Calcium Channels as Novel Therapeutic Targets for Ovarian Cancer Stem Cells

Drug resistance in epithelial ovarian cancer (EOC) is reportedly attributed to the existence of cancer stem cells (CSC), because in most cancers, CSCs still remain after chemotherapy. To overcome this limitation, novel therapeutic strategies are required to prevent cancer recurrence and chemotherapy-resistant cancers by targeting cancer stem cells (CSCs). We screened an FDA-approved compound library and found four voltage-gated calcium channel blockers (manidipine, lacidipine, benidipine, and lomerizine) that target ovarian CSCs. Four calcium channel blockers (CCBs) decreased sphere formation, viability, and proliferation, and induced apoptosis in ovarian CSCs. CCBs destroyed stemness and inhibited the AKT and ERK signaling pathway in ovarian CSCs. Among calcium channel subunit genes, three L- and T-type calcium channel genes were overexpressed in ovarian CSCs, and downregulation of calcium channel genes reduced the stem-cell-like properties of ovarian CSCs. Expressions of these three genes are negatively correlated with the survival rate of patient groups. In combination therapy with cisplatin, synergistic effect was shown in inhibiting the viability and proliferation of ovarian CSCs. Moreover, combinatorial usage of manidipine and paclitaxel showed enhanced effect in ovarian CSCs xenograft mouse models. Our results suggested that four CCBs may be potential therapeutic drugs for preventing ovarian cancer recurrence.

Meta-Analysis Evaluating Calcium Channel Blockers and the Risk of Peripheral Arterial Disease in Patients With Hypertension

Clinical studies have shown that calcium channel blockers (CCB) can mitigate the progression of atherosclerosis. Their role in the primary prevention of peripheral artery disease (PAD) is unclear. We conducted a meta-analysis of randomized control trials (RCT) to compare the impact of CCB on the incidence of PAD in patients with hypertension. A comprehensive review of the literature was performed in PubMed and Cochrane registry. Studies were included if they were RCT and had outcome data on PAD with a follow-up duration of at least 6 months. CCB formed the intervention group, whereas the control group was constituted by either placebo or active treatment with any of the other antihypertensive medications. A random-effects meta-analysis was performed, and we report odds ratio as a measure of treatment effect. Our search identified 934 trials, of which 7 RCTs with 71,971 patients fulfilled the inclusion criteria. The mean duration of follow-up was 3.8 years. In patients receiving CCB, PAD events occurred in 547 out of 27,502 patients (2%) compared with 1,263 out of 42,659 patients in the control group (3%). Based on the random-effect model, the odds for development of PAD in hypertensive patients treated with CCB compared with the control group was 0.70 (95% confidence interval of 0.58 to 0.86, p = 0.0005). In conclusion, this meta-analysis of RCTs of hypertensive patients, we found that treatment with CCB was strongly associated with a decrease in the PAD compared with other antihypertensive agents or placebo.

Azacitidine-induced hyperglycaemia

A case illustrating significant hyperglycaemia with azacitidine therapy for myelodysplastic syndrome is presented. The significance of treatment-induced hyperglycaemia with regard to increased risk of infection, and possible mechanisms of azacitidine-induced hyperglycaemia are discussed.

Anti-inflammatory and utero-relaxant effect of α-bisabolol on the pregnant human uterus

The aim of this study was to evaluate the in vitro anti-inflammatory and utero-relaxant effect of α-bisabolol on the pregnant human myometrium. Samples from the pregnant human myometrium were used in functional tests to evaluate the inhibitory effect of α-bisabolol (560, 860, 1,200 and 1,860 µM) on spontaneous myometrial contractions. The intracellular cyclic adenosine monophosphate (cAMP) levels generated in response to α-bisabolol in human myometrial homogenates were measured by ELISA. The anti-inflammatory effect of α-bisabolol was determined through the measurement of two pro-inflammatory cytokines, tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and the anti-inflammatory cytokine IL-10, in pregnant human myometrial explants stimulated with lipopolysaccharide (LPS). Forskolin was used as a positive control to evaluate the cAMP and cytokine levels. α-Bisabolol was found to induce a significant inhibition of spontaneous myometrial contractions at the highest concentration level (p<0.05). α-Bisabolol caused a concentration-dependent decrease in myometrial cAMP levels (p<0.05) and a concentration-dependent decrease in LPS-induced TNFα and IL-1β production, while IL-10 production did not increase significantly (p>0.05). The anti-inflammatory and utero-relaxant effects induced by α-bisabolol were not associated with an increase in cAMP levels in pregnant human myometrial samples. These properties place α-bisabolol as a potentially safe and effective adjuvant agent in cases of preterm birth, an area of pharmacological treatment that requires urgent improvement.

Azelnidipine Inhibits the Differentiation and Activation of THP-1 Macrophages through the L-Type Calcium Channel

Aim: Recently, calcium channel blockers (CCBs) have been reported to reduce atherosclerosis with anti-inflammatory or antiatherosclerotic effects in vivo. It is well established that monocytes and macrophages play important roles in promoting atherosclerosis. However, the effects of CCBs on macrophage activation remain unclear. The aim of this study was to evaluate the effects of azelnidipine, a dihydropyridine L-type CCB, on the activation of macrophages and to clarify the mechanisms of the effects of CCBs on atherosclerosis.

Methods: THP-1 monocytes, a human leukemic cell line, were stimulated with 50 ng/mL of phorbol-12-myristate-13-acetate (PMA) 1 h after pretreatment with 10 µM azelnidipine or dimethyl sulfoxide (DMSO), and harvested.

Results: Azelnidipine blocked the expression of intercellular adhesion molecule-1 quantified by FACS analysis. The expression levels of Apo E and MMP9, which are markers of macrophage differentiation, were inhibited by azelnidipine as evaluated by quantitative RT-PCR. The level of LOX-1 mRNA, a scavenger receptor, was also reduced significantly by pretreatment with 10 µM azelnidipine. Azelnidipine also lowered the uptake of acetylated LDL. The expression of the L-type calcium channel Cav1.2 was 10-fold higher after 24 h of PMA stimulation. A knockdown of the CACNA1C gene, which encodes Cav1.2 protein in humans, with siRNA blocked the effect of reducing adhesion by azelnidipine, indicating that the effects of azelnidipine on macrophage differentiation were expressed through the CACNA1C gene.

Conclusion: Our results suggest that azelnidipine has potent antiatherosclerotic properties by inhibition of macrophage activation through Cav1.2.

The prognostic values of leukocyte Rho kinase activity in acute ischemic stroke

Objective. It has been reported that leukocyte ROCK activity is elevated in patients after ischemic stroke, but it is unclear whether leukocyte ROCK activity is associated with clinical outcomes following acute stroke events. The objective of this study is to investigate if leukocyte ROCK activity can predict the outcomes in patients with acute ischemic stroke. Materials and Methods. We enrolled 110 patients of acute ischemic stroke and measured the leukocyte ROCK activity and plasma level of inflammatory cytokines to correlate the clinical outcomes of these patients. Results. The leukocyte ROCK activity at 48 hours after admission in acute ischemic stroke patients was higher as compared to a risk-matched population. The leukocyte ROCK activity significantly correlated with National Institute of Health Stroke Scale (NIHSS) difference between admission and 90 days after stroke event. Kaplan-Meier survival estimates showed lower stroke-free survival during follow-up period in patients with high leukocyte ROCK activity or plasma hsCRP level. Leukocyte ROCK activity independently predicted the recurrent stroke in patients with atherosclerotic stroke. Conclusions. This study shows elevated leukocyte ROCK activity in patients with ischemic stroke as compared to risk-matched subjects and is an independent predictor for recurrent stroke.

Hypericum perforatum modulates apoptosis and calcium mobilization through voltage-gated and TRPM2 calcium channels in neutrophil of patients with Behcet's disease

Behcet's disease (BD) is a chronic, inflammatory, and multisystemic condition although its pathogenesis is uncertain. Main component of St. John's wort (Hypericum perforatum, HP) is hyperforin and induces antiinflammatory and antioxidant properties. We aimed to investigate effects of HP on oxidative stress, apoptosis, and cytosolic-free Ca²⁺ [Ca²⁺](i) concentration in neutrophil of BD patients. Nine new-diagnosed active patients with BD and nine control subjects were included in the study. Disease activity was considered by clinical findings. Neutrophil samples were obtained from the patients and controls. The neutrophils from patients were divided into three subgroups and were incubated with HP, voltage-gated calcium channel (VGCC) blockers, (verapamil+dilitiazem) and non-specific TRPM2 channel blocker (2-aminoethyl diphenylborinate, 2-APB), respectively. The neutrophils were stimulated by fMLP as a Ca²⁺-concentration agonist and oxidative stress former. Caspase-3, caspase-9, apoptosis, lipid peroxidation, and [Ca²⁺](i) values were high in the patient groups, although cell viability, glutathione (GSH), and glutathione peroxidase (GSH-Px) values were low in patient group. However, the [Ca²⁺](i), caspase-3, and caspase-9 values decreased markedly in patient+HP group although GSH and GSH-Px values increased in the group. The [Ca²⁺](i) concentration was also decreased in the patient group by V+D, 2-APB, and HP incubations. In conclusion, we observed the importance of neutrophil Ca²⁺ entry, apoptosis, and oxidative stress through gating VGCC and TRPM2 channels in the neutrophils in the pathogenesis and activation of the patients with BD. HP induced protective effects on oxidative stress by modulating Ca²⁺ influx in BD patients.

Dihydropyridine calcium channel blockers inhibit non-esterified-fatty-acid-induced endothelial and rheological dysfunction

Circulating NEFAs (non-esterified fatty acids) from adipose tissue lipolysis lead to endothelial dysfunction and insulin resistance in patients with the metabolic syndrome or Type 2 diabetes mellitus. The aim of the present study was to test the hypothesis that DHP (dihydropyridine) CCBs (calcium channel blockers) prevent NEFA-induced endothelial and haemorheological dysfunction independently of their antihypertensive properties. Using a double-blind cross-over study design, nifedipine, amlodipine, diltiazem or placebo were administered to eight healthy subjects for 2 days before each study day. On the study days, the following were assessed before and after the infusion of lipid and heparin to raise serum NEFAs: endothelial function, by measuring FBF (forearm blood flow) responses to ACh (acetylcholine); leucocyte activation, by ex vivo measurement of plasma MPO (myeloperoxidase) levels, adherent leucocyte numbers and whole blood transit time through microchannels; and oxidative stress, by determining plasma levels of d-ROMs (derivatives of reactive oxygen metabolites). Effects of the CCBs on NF-κB (nuclear factor κB) p65 phospholylation stimulated by NEFAs were assessed in cultured monocytic cells in vitro. Elevated NEFAs reduced the responses to ACh and significantly increased whole blood transit time, adherent leucocyte numbers and d-ROMs. Nifedipine and amlodipine, but not diltiazem, prevented NEFA-induced endothelial dysfunction, leucocyte activation and enhancement of oxidative stress without affecting BP (blood pressure), whereas all these drugs prevented NEFA-induced p65 activation in vitro. These results suggest that DHP CCBs, independent of their antihypertensive properties in humans, prevent NEFA-induced endothelial and haemorheological dysfunction through inhibition of NEFA-induced leucocyte activation, although the sensitivity to drugs of leucocyte Ca2+ channels may differ among cells.

Drug therapy of heart failure: an immunologic view

Heart failure (HF) is a clinical syndrome manifested by signs and symptoms of low cardiac output, pulmonary, and/or systemic congestion. Immunologically, HF is defined as a state of immune activation and persistent inflammation, especially the circulatory levels of inflammatory cytokines have been found to increase. Traditional drugs used in HF have expressed immunomodulatory and/or anticytokine activities that may participate in their therapeutic efficacy in the disease. The angiotensin-converting enzyme inhibitors like captopril and enalapril as well as the angiotensin II receptor antagonist losartan indicated in HF exerted reducing effects on the inflammatory cytokines such as tumor necrosis factor-alpha and interleukin-6 at experimental and clinical levels. Aldosterone antagonists like spironolactone when administered concomitantly with losartan can attenuate angiotensin II-enhanced cytokine production in HF. Carvedilol beta-adrenergic blockers showed a wider spectrum of anti-inflammatory/anticytokine activity that proved to be associated with improvement of cardiac function and ejection fraction in patients with HF. The poor prognosis in HF despite the long experience with its treatment necessitated thinking about new drugs to be added to the traditional ones. Methotrexate and statins are examples of these drugs, especially because they exert immunologic effects. A low dose of methotrexate has been considered as a hopeful adjunct therapy in chronic HF, but large long-term clinical trials are required. Statins showed conflicting results, although they might be useful early after acute ischemic events associated with left ventricular dysfunction or failure, especially in younger patients with less advanced HF.

Colchicine modulates oxidative stress in serum and neutrophil of patients with Behçet disease through regulation of Ca²⁺ release and antioxidant system

Behçet disease (BD) is a chronic, inflammatory, and multisystemic condition with an uncertain pathogenesis. One of the major immunologic findings in BD pathogenesis is increase in activity of neutrophil. An increase in the cytosolic free Ca²⁺[Ca²⁺](i) concentration that induces Ca²⁺ signaling is an important step that participates in the neutrophil activation and reactive oxygen species production that leads to tissue damage in body cells. We aimed to investigate the effects of colchicine on oxidative stress and Ca²⁺ release in serum and neutrophil of BD patients with active and inactive periods. Twelve Behçet patients (6 active and 6 inactive) and 6 control subject were included in the study. Disease activity was considered by clinical findings. Serum and neutrophil samples were obtained from the patients and control subjects. Neutrophils from patients with active BD were divided into three subgroups and were incubated with colchicine, verapamil + diltiazem, and colchicine + verapamil + diltiazem, respectively. Erythrocyte sedimentation rate, leucocytes counts, serum C-reactive protein, neutrophil, and serum lipid peroxidation and intracellular Ca²⁺ release levels were higher in active and inactive groups than in the control group, although their levels were lower in active group than in inactive group. However, neutrophil Ca²⁺ release levels were decreased in colchicine, verapamil + diltiazem, and colchicine + verapamil + diltiazem groups group compared to active group. Serum glutathione, vitamin A, vitamin E, and β-carotene concentrations were lower in active and inactive groups than in the control group, although serum vitamin E and β-carotene concentrations were higher in the inactive group than in the active group. Neutrophil and serum glutathione peroxidase activity within the three groups did not change. In conclusion, we observed the importance of Ca²⁺ influx into the neutrophils and oxidative stress in the pathogenesis and activation of the patients with BD. Colchicine induced protective effects on oxidative stress by modulating Ca²⁺ influx in BD patients.

Nifedipine affects the course of Salmonella enterica serovar Typhimurium infection by modulating macrophage iron homeostasis

BACKGROUND

Iron overload can adversely influence the course of infection by increasing microbial replication and suppressing antimicrobial immune effector pathways. Recently, we have shown that the calcium channel blocker nifedipine can mobilize tissue iron in mouse models of iron overload. We therefore investigated whether nifedipine treatment affects the course of infection with intracellular bacteria via modulation of iron homeostasis.

METHODS

The effect of nifedipine on intramacrophage replication of bacteria and modulation of cellular iron homeostasis was investigated in the murine macrophage cell line RAW264.7, and the impact of nifedipine treatment on the course of systemic infection was investigated in C57BL/6 mice in vivo.

RESULTS

In RAW264.7 cells, nifedipine treatment significantly reduced intracellular bacterial survival of Salmonella enterica serovar Typhimurium and Chlamydophila pneumoniae. This could be attributed to the induction of the iron exporter ferroportin 1, which limited the availability of iron for intracellular Salmonella. When C57BL/6 mice were infected intraperitoneally with Salmonella and subsequently injected with nifedipine for 3 consecutive days, bacterial counts in livers and spleens were significantly reduced and survival of the mice significantly was prolonged compared with solvent-treated littermates. Nifedipine treatment increased expression of ferroportin 1 in the spleen, whereas splenic levels of the iron storage protein ferritin and serum iron concentrations were reduced.

CONCLUSIONS

Our data provide evidence for a novel mechanism whereby nifedipine enhances host resistance to intracellular pathogens via limitation of iron availability.

Safety and tolerability of fixed antihypertensive combinations in blood pressure control: focus on olmesartan medoxomil and amlodipine combination

Hypertension is a major health problem worldwide and remains underdiagnosed and undertreated. Although public awareness and control of hypertension have improved over the last decade, only one-third of hypertensive patients achieve the rather conservative blood pressure (BP) goal of <140/90 mmHg. Most hypertensive patients require more than one drug for optimum BP control. Expert panels recommend use of combination therapy with two or more medications for Stage 2 and higher hypertension and in high-risk patients. However, the use of multiple drugs reduces patient compliance. Fixed-dose combination therapy helps improve patient compliance and thus achieve the target BP. Dose titration of the individual constituent drugs is recommended before switching to an equivalent fixed-dose combination. Randomized, controlled trials have shown that the fixed-dose combination of amlodipine-olmesartan medoxomil is more effective in lowering BP than monotherapy with either of these agents, with a similar side effect profile.

Verapamil protects dopaminergic neuron damage through a novel anti-inflammatory mechanism by inhibition of microglial activation

Verapamil has been shown to be neuroprotective in several acute neurotoxicity models due to blockade of calcium entry into neurons. However, the potential use of verapamil to treat chronic neurodegenerative diseases has not been reported. Using rat primary mesencephalic neuron/glia cultures, we report that verapamil significantly inhibited LPS-induced dopaminergic neurotoxicity in both pre- and post-treatment experiments. Reconstituted culture studies revealed that the presence of microglia was essential in verapamil-elicited neuroprotection. Mechanistic studies showed that decreased production of inflammatory mediators from LPS-stimulated microglia underlay neuroprotective property of verapamil. Further studies demonstrated that microglial NADPH oxidase (PHOX), the key superoxide-producing enzyme, but not calcium channel in neurons, is the site of action for the neuroprotective effect of verapamil. This conclusion was supported by the following two observations: 1) Verapamil failed to show protective effect on LPS-induced dopaminergic neurotoxicity in PHOX-deficient (deficient in the catalytic subunit of gp91(phox)) neuron/glia cultures; 2) Ligand binding studies showed that the binding of [(3)H]Verapamil onto gp91(phox) transfected COS7 cell membranes was higher than the non-transfected control. The calcium channel-independent neuroprotective property of verapamil was further supported by the finding that R(+)-verapamil, a less active form in blocking calcium channel, showed the same potency in neuroprotection, inhibition of pro-inflammatory factors production and binding capacity to gp91(phox) membranes as R(-)-verapamil, the active isomer of calcium channel blocker. In conclusion, our results demonstrate a new indication of verapamil-mediated neuroprotection through a calcium channel-independent pathway and provide a valuable avenue for the development of therapy for inflammation-related neurodegenerative diseases.

Downregulation of programmed cell death 4 by inflammatory conditions contributes to the generation of the tumor promoting microenvironment

Ample evidence has shown key roles of inflammation in tumor promotion and carcinogenesis, and tumor-associated macrophages are known to promote tumor growth and dissemination. Programmed cell death 4 (Pdcd4) is a novel tumor suppressor, and although various studies have revealed that the functions and expression mechanisms of Pdcd4 in tumor promotion, those in regard to inflammation remain unclear. In the present study, we examined whether inflammatory stimuli regulate Pdcd4 expression. 12-O-tetradecanoylphorbol 13-acetate (TPA) suppressed expression of pdcd4 mRNA in human monocytic cell lines (U937, THP-1). Similarly, the bacterial endotoxin lipopolysaccharide (LPS) downregulated pdcd4 level in mouse RAW264.7 and peritoneal macrophages. Furthermore, conditioned medium from LPS-stimulated RAW264.7 macrophages suppressed pdcd4 mRNA in RAW264.7 macrophages, and findings obtained with recombinant tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha-specific siRNA suggested that TNF-alpha partly mediates LPS-triggered Pdcd4 downregulation via an autocrine mechanism. Specific inhibitors of phosphoinositide-3-kinase (PI3K) and c-jun N-terminus kinase (JNK) restored LPS-abolished pdcd4 mRNA. Consistently, in MCF7 mammary carcinoma cells, conditioned medium from TPA-differentiated/activated U937 cells suppressed pdcd4 mRNA. Additionally, knockdown of pdcd4 in RAW264.7 macrophages using siRNA significantly enhanced LPS-induced TNF-alpha protein production, and interferon-gamma, CC chemokine ligand (Ccl) 1, Ccl20, and interleukin-10 mRNA expression. These results suggest that Pdcd4 suppresses the induction of these inflammatory mediators. Taken together, loss of Pdcd4 in macrophages may be a critical step in establishing the inflammatory environment while that in tumor cells contributes to tumor progression.

Exogenous factors in the immunotoxicity of oral PMN

Current evidence indicates that periodontal disease is frequently due to inappropriate levels of gingival granulocyte functions. Reason of this failure may be the toxic effects of a number of local or systemic exogenous factors, capable of spreading through the gingival crevice environment, and strongly conditioning the granulocyte activities. The wide list includes bacteria and granulotoxic products, hedonistic drugs (mainly tobacco), and chemotherapeutic agents (especially antimicrobials used for preventing or reducing the accumulation of dental plaque). Almost always, their presence induces a time- and/or dose-dependent toxicity.

Vascular and cellular calcium in normal and hypertensive pregnancy

Normal pregnancy is associated with significant hemodynamic changes in the cardiovascular system in order to meet the metabolic demands of mother and fetus. These changes include increased cardiac output, decreased vascular resistance, and vascular remodeling in the uterine and systemic circulation. Preeclampsia (PE) is a major complication of pregnancy characterized by proteinuria and hypertension. Several risk factors have been implicated in the pathogenesis of PE including genetic and dietary factors. Ca2+ is an essential dietary element and an important regulator of many cellular processes including vascular function. The importance of adequate dietary Ca2+ intake during pregnancy is supported by many studies. Pregnancy-associated changes in Ca2+ metabolism and plasma Ca2+ have been observed. During pregnancy, changes in intracellular free Ca2+ concentration ([Ca2+](i)) have been described in red blood cells, platelets and immune cells. Also, during pregnancy, an increase in [Ca2+](i) in endothelial cells (EC) stimulates the production of vasodilator substances such as nitric oxide and prostacyclin. Normal pregnancy is also associated with decreased vascular smooth muscle (VSM) [Ca2+](i) and possibly the Ca2+-sensitization pathways of VSM contraction including protein kinase C, Rho-kinase, and mitogen-activated protein kinase. Ca2+-dependent matrix metalloproteinases could also promote extracellular matrix degradation and vascular remodeling during pregnancy. Disruption in the balance between dietary, plasma and vascular cell Ca2+ may be responsible for some of the manifestation of PE including procoagulation, decreased vasodilation, and increased vasoconstriction and vascular resistance. The potential benefits of Ca2+ supplements during pregnancy, and the use of modulators of vascular Ca2+ to reduce the manifestations of PE in susceptible women remain an important area for experimental and clinical research.

Long-acting nifedipine in the management of the hypertensive patient

Hypertension is a global condition affecting billions worldwide. It is a significant contributor to cardiovascular events, cardiac death and kidney disease. A number of medication classes exist to aid healthcare providers and their patients in controlling hypertension. Nifedipine, a dihydropyridine calcium channel blocker, was once one of the most widely used medications for hypertension, but safety and tolerability concerns along with the introduction of new classes of antihypertensive medications and an increasing pool of data showing mortality benefit of other classes caused nifedipine to fall out of favor. More recently, long-acting formulations were developed and made available to clinicians. These newer formulations were designed to address many of the concerns raised by earlier formulations of nifedipine. Numerous clinical trials have been conducted comparing long-acting nifedipine to many of the more commonly prescribed antihypertensive medications. This review will address the pharmacology, pharmacokinetics and the available clinical trial data on long-acting nifedipine and summarize its role in the management of hypertension.