Vaccination against the angiotensin type 1 receptor for the prevention of L-NAME-induced nephropathy

Recent Advances in the Biomedical Applications of Functionalized Nanogels

Nanomaterials have been extensively used in several applications in the past few decades related to biomedicine and healthcare. Among them, nanogels (NGs) have emerged as an important nanoplatform with the properties of both hydrogels and nanoparticles for the controlled/sustained delivery of chemo drugs, nucleic acids, or other bioactive molecules for therapeutic or diagnostic purposes. In the recent past, significant research efforts have been invested in synthesizing NGs through various synthetic methodologies such as free radical polymerization, reversible addition-fragmentation chain-transfer method (RAFT) and atom transfer radical polymerization (ATRP), as well as emulsion techniques. With further polymeric functionalizations using activated esters, thiol-ene/yne processes, imines/oximes formation, cycloadditions, nucleophilic addition reactions of isocyanates, ring-opening, and multicomponent reactions were used to obtain functionalized NGs for targeted delivery of drug and other compounds. NGs are particularly intriguing for use in the areas of diagnosis, analytics, and biomedicine due to their nanodimensionality, material characteristics, physiological stability, tunable multi-functionality, and biocompatibility. Numerous NGs with a wide range of functionalities and various external/internal stimuli-responsive modalities have been possible with novel synthetic reliable methodologies. Such continuous development of innovative, intelligent materials with novel characteristics is crucial for nanomedicine for next-generation biomedical applications. This paper reviews the synthesis and various functionalization strategies of NGs with a focus on the recent advances in different biomedical applications of these surface modified/functionalized single-/dual-/multi-responsive NGs, with various active targeting moieties, in the fields of cancer theranostics, immunotherapy, antimicrobial/antiviral, antigen presentation for the vaccine, sensing, wound healing, thrombolysis, tissue engineering, and regenerative medicine.

Therapeutic vaccine for chronic diseases after the COVID-19 Era

There is currently a respiratory disease outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After rapid development, RNA vaccines and adenoviral vector vaccines were approved within a year, which has demonstrated the strong impact of preventing infectious diseases using gene therapy technology. Furthermore, intensive immunological analysis has been performed to evaluate the efficiency and safety of these vaccines, potentially allowing for rapid progress in vaccine technology. After the coronavirus disease 2019 (COVID-19) era, the novel vaccine technology developed will expand to other vaccines. We have been developing vaccines for chronic diseases, such as hypertension, for >10 years. Regarding the development of vaccines against self-antigens (i.e., angiotensin II), the vaccine should efficiently induce a blocking antibody response against the self-antigen without activating cytotoxic T cells. Therefore, the epitope vaccine approach has been proposed to induce antibody production in response to a combination of a B cell epitope and exogenous T cell epitopes through major histocompatibility complex molecules. When these vaccines are established as therapeutic options for hypertension, their administration regimen, which might be a few times per year, will replace daily medication use. Thus, therapeutic vaccines for hypertension may be a novel option to control the progression of cerebrovascular diseases. Hopefully, the accumulation of immunological findings and vaccine technology advances due to COVID-19 will provide a novel concept for vaccines for chronic diseases.

Vaccines against components of the renin-angiotensin system

Even though effective drugs for treating hypertension are available, a great percentage of patients have inadequate control of their blood pressure. Unwanted side effects and inappropriate oral drug adherence are important factors that contribute to the global problem of uncontrolled hypertension. Vaccination could provide a revolutionary therapy with long-lasting effects, increasing patient compliance and therefore better control of high blood pressure. Nowadays, current immunization approaches against hypertension target renin, angiotensin I, angiotensin II, and angiotensin II type 1 receptor, key elements of the renin–angiotensin system. This article reviews the different vaccination attempts with proteins and peptides against the different molecules of the renin–angiotensin system in the last two decades, safety issues, and other novel prospects biomarkers in hypertension, and summarizes the potential of this immunomodulatory approach in clinical practice.

Future Directions of Therapeutic Vaccines for Chronic Diseases

Vaccines are well-known therapies for infectious disease and cancer; however, recently, we and others have developed vaccines for other chronic diseases, such as hypertension, diabetes and dyslipidemia. Although we have many treatment options for hypertension, including angiotensin II type 1 receptor blockers, calcium-channel blockers, and diuretics, a substantial portion of the hypertensive population has uncontrolled blood pressure due to poor medication adherence. When these vaccines are established in the future as therapeutic options for chronic diseases, their administration regimen, such as several times per year, will replace daily medication use. Thus, therapeutic vaccines might be a novel option to control the progression of cardiovascular diseases. Importantly, regarding the development of vaccines against self-antigens (i.e., angiotensin II), the vaccine should efficiently induce a blocking antibody response against the self-antigen without provoking cytotoxic T cells. Therefore, to address the safety and efficiency of therapeutic vaccines, we have developed an original B-cell vaccine to induce antibody production and used carrier proteins, which include exogenous T-cell epitopes through the major histocompatibility complex. In this review, we will introduce the challenges in developing therapeutic vaccines for chronic diseases and describe the therapeutic potential for cardiovascular diseases.

Endothelin: 30 Years From Discovery to Therapy

Discovered in 1987 as a potent endothelial cell-derived vasoconstrictor peptide, endothelin-1 (ET-1), the predominant member of the endothelin peptide family, is now recognized as a multifunctional peptide with cytokine-like activity contributing to almost all aspects of physiology and cell function. More than 30 000 scientific articles on endothelin were published over the past 3 decades, leading to the development and subsequent regulatory approval of a new class of therapeutics-the endothelin receptor antagonists (ERAs). This article reviews the history of the discovery of endothelin and its role in genetics, physiology, and disease. Here, we summarize the main clinical trials using ERAs and discuss the role of endothelin in cardiovascular diseases such as arterial hypertension, preecclampsia, coronary atherosclerosis, myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) caused by spontaneous coronary artery dissection (SCAD), Takotsubo syndrome, and heart failure. We also discuss how endothelins contributes to diabetic kidney disease and focal segmental glomerulosclerosis, pulmonary arterial hypertension, as well as cancer, immune disorders, and allograft rejection (which all involve ET_A autoantibodies), and neurological diseases. The application of ERAs, dual endothelin receptor/angiotensin receptor antagonists (DARAs), selective ET_B agonists, novel biologics such as receptor-targeting antibodies, or immunization against ET_A receptors holds the potential to slow the progression or even reverse chronic noncommunicable diseases. Future clinical studies will show whether targeting endothelin receptors can prevent or reduce disability from disease and improve clinical outcome, quality of life, and survival in patients.

Vaccine Development against the Renin-Angiotensin System for the Treatment of Hypertension

Hypertension is a global public health issue and the most important preventable cause of cardiovascular diseases. Despite the clinical availability of many antihypertensive drugs, many hypertensive patients have poor medication adherence and blood pressure control due, at least partially, to the asymptomatic and chronic characteristics of hypertension. Immunotherapeutic approaches have the potential to improve medication adherence in hypertension because they induce prolonged therapeutic effects and need a low frequency of administration. The first attempts to reduce blood pressure by using vaccines targeting the renin-angiotensin system were made more than half a century ago; however, at the time, a poor understanding of immunology and the mechanisms of hypertension and a lack of optimal vaccine technologies such as suitable antigen design, proper adjuvants, and effective antigen delivery systems meant that attempts to develop antihypertensive vaccines failed. Recent advances in immunology and vaccinology have provided potential therapeutic immunologic approaches to treat not only infectious diseases but also cancers and other noncommunicable diseases. One important biotechnology that has had a major impact on modern vaccinology is virus-like particle technology, which can efficiently deliver vaccine antigens without the need for artificial adjuvants. A human clinical trial that indicated the effectiveness and safety of a virus-like particle-based antiangiotensin II vaccine marked a turning point in the field of therapeutic antihypertensive vaccines. Here, we review the history of the development of immunotherapies for the treatment of hypertension and discuss the current perspectives in the field.

Intranasal vaccination against angiotensin II type 1 receptor and pneumococcal surface protein A attenuates hypertension and pneumococcal infection in rodents

OBJECTIVES

To combat global increases in the prevalence of lifestyle-related diseases and concomitant infectious diseases, we aimed to develop an innovative intranasal vaccine that simultaneously targets both hypertension and pneumonia, is not given by invasive injection, and offers prolonged therapeutic effect and reduced frequency of administration.

METHODS

Angiotensin II type 1 receptor-pneumococcal surface protein A (AT1R-PspA) vaccine, consisting of a cationic nanometer-sized hydrogel incorporating AT1R partial peptide conjugated with PspA and cyclic diguanylate monophosphate adjuvant, was created and given intranasally to spontaneously hypertensive rats (SHRs). Antigen-specific antibodies and blood pressure were examined to evaluate immune responses and the antihypertensive effect of the vaccine. To examine the protective effect of antibodies induced by vaccination on pneumococcal infection, sera obtained from immunized SHRs were incubated with a lethal dose of Streptococcus pneumoniae and then administered to mice.

RESULTS

Five doses of AT1R-PspA nasal-vaccine-induced AT1R-specific serum IgG antibody production and attenuated the development of hypertension in SHRs in the long term. Both in-vitro and in-vivo studies revealed that responses to angiotensin II were suppressed in vaccinated rats. Mice passively immunized with sera obtained from AT1R-PspA-vaccinated SHRs were protected from lethal pneumococcal infection.

CONCLUSION

Intranasal immunization with AT1R-PspA vaccine has the potential to simultaneously attenuate the development of hypertension and protect from lethal pneumococcal infection.

Nicousamide attenuates renal dysfunction and glomerular injury in remnant kidneys by inhibiting TGF-β1 internalisation and renin activity

Nicousamide has been shown to exert renal protective effects against diabetic nephropathy and has moved to a phase II clinical trial in China for diabetic nephropathy indication. To expand its clinical indications, 5/6-nephrectomised rats were used to mimic glomerular and vascular sclerosis and tubulointerstitial scarring, with subsequent progression towards end-stage renal disease. Adult Wistar rats underwent 5/6 nephrectomy to induce the development of chronic kidney disease, with a sham operation performed as a control. The nephrectomised animals were treated orally with either saline, nicousamide (7.5,15, or 45 mg/kg), benazepril (4 mg/kg), or losartan (10 mg/kg) daily for 20 weeks. At 8, 16, and 20 weeks of treatment, blood pressure was measured in each animal, and blood and urine samples were collected for biochemical analysis, while kidney remnants were collected for histological examination. Levels of fibronectin and transforming growth factor beta 1 (TGF-β1) were measured in kidneys by immunohistochemistry. Renin activity in the plasma was measured by an enzyme-linked immunosorbent assay. The results showed that nicousamide treatment significantly reduced systemic hypertension, proteinuria, and blood urea nitrogen (P < 0.05), effectively alleviated glomerular sclerosis scores and tubulointerstitial injuries in a dose-dependent manner (P < 0.01), and markedly decreased fibronectin and TGF-β1 levels in kidney tissues of the 5/6-nephrectomised animals. In vitro studies suggested that nicousamide could moderately inhibit the renin activity and strongly block the TGF-β1 internalisation into fibroblast cells. In summary, nicousamide may protect from renal failure through dual targeting, which involves a TGF-β1-dependent mechanism and inhibition of renin activity.

Pre-emptive medicine for hypertension and its prospects

Pre-emptive medicine is a novel medical concept proposed in Japan that aims to precisely predict the onset and progression of diseases and to provide therapeutic interventions during early stages, before symptoms appear. The concept of pre-emptive medicine considers the time-course of a disease in each individual and seeks medical interventions to prevent disease progression. Suitable and promising targets for pre-emptive medicine are non-communicable diseases, including hypertension. Recent advances in genomic analysis, information technology, and artificial intelligence should make this medical concept feasible in the near future. In this review, we focused on pre-emptive medicine for hypertension, referring to concrete plans for the future direction of this research. The ultimate goal of pre-emptive medicine is to completely prevent the onset and progression of hypertension by precisely predicting the elevation of blood pressure and performing interventions to avoid it. The diagnostic processes of hypertension, from the standpoint of pre-emptive medicine, should include the detection of abnormal blood pressure regulation as the earliest manifestation of the disease, the depiction of the present status of hypertension in an individual ("nowcasting"), and a prediction of the future trajectory of the disease ("forecasting"). Novel therapeutic strategies for hypertension, from the standpoint of pre-emptive medicine, should aim for the regression of hypertension through early treatments and the remission of hypertension through intermittent intensive therapies. An efficient modification of lifestyle and therapies, according to the progression of hypertension, should be required. If pre-emptive medicine for hypertension becomes established, it would greatly contribute to the extension of a healthy lifespan, which cannot yet be satisfactorily achieved.

Therapeutic Vaccines for Hypertension: a New Option for Clinical Practice

PURPOSE OF REVIEW

Vaccines are commonly used as preventive methods, primarily against infectious diseases. The goal of our study is to develop the therapeutic vaccine for hypertension.

RECENT FINDINGS

We and others recently reported that an angiotensin II (AngII) vaccine for hypertension successfully attenuated elevated blood pressures in an animal model without any immunogenic side effects. In this system, an immunogenic molecule (i.e., KLH) with adjuvants provides an antigen that supports the activation of helper T cells. In addition, pretreatment with the AngII vaccine exerts neuroprotective effects in a cerebral ischemia model and cardioprotective effects in a myocardial infarction model. In the early phase of clinical trial, the administration of an AngII vaccine (AngQb-Cyt006) successfully decreased blood pressure in hypertensive patients with the increase of anti-AngII antibody titer. Increasing the effectiveness of drug adherence interventions in the clinical setting may have a large impact on the health of the population, which can be improved by using successful therapeutic vaccines. In this review, we describe the concept of therapeutic vaccines for hypertension and future directions for therapeutic vaccines.

Nanogel-based nasal vaccines for infectious and lifestyle-related diseases

Because the mucosa is the major entry route for most pathogens, the development of mucosal vaccines is a rational approach for protecting against these undesired agents. Mucosal administration of vaccine antigen is useful for non-infectious chronic diseases as well, because of its advantages over injection routes, including comparable efficacy in the induction of systemic immune responses, less pain, and no risk of adverse events at the injection site. However, because it is difficult to effectively induce and regulate antigen-specific mucosal and systemic immune responses when antigen alone is mucosally administered, an appropriate form of mucosal delivery vehicle must be used. Antigen delivery systems involving nanogels, which act as artificial chaperones and mucosal adhesives, are a promising approach to overcoming this problem. Here, we introduce current perspectives regarding the development of nanogel-based nasal vaccines for both infectious and lifestyle-related diseases.

Design of therapeutic vaccines as a novel antibody therapy for cardiovascular diseases

Vaccines are primarily used worldwide as a preventive medicine for infectious diseases and have recently been applied to cancer. We and others have developed therapeutic vaccines designed for cardiovascular diseases that are notably different from previous vaccines. In the case of cancer vaccines, a specific protein in cancer cells is a target antigen, and the activation of cytotoxic T cells (CTL) is required to kill and remove the antigen-presenting cancer cells. Our therapeutic vaccines work against hypertension by targeting angiotensin II (Ang II) as the antigen, which is an endogenous hormone. Therapeutic vaccines must avoid CTL activation and induce the blocking antibodies for Ang II. The goal of our therapeutic vaccine for cardiovascular diseases is to induce the specific antibody response toward the target protein without inducing T-cell or antibody-mediated inflammation through the careful selection of the target antigen, carrier protein and adjuvants. The goal of our therapeutic vaccine is similar to that of antibody therapy. Recently, multiple antibody-based drugs have been developed for cancer, immune-related diseases, and dyslipidemia, which are efficient but expensive. If the effect of a therapeutic vaccine is nearly equivalent to antibody therapy as an alternative approach, the lower medical cost and improvement in drug adherence can be advantages of therapeutic vaccines. In this review, we will describe our concept of therapeutic vaccines for cardiovascular diseases and the future directions of therapeutic vaccines as novel antibody therapies.

Vaccination against type 1 angiotensin receptor prevents streptozotocin-induced diabetic nephropathy

Abstract

Recently, our group has developed a therapeutic hypertensive vaccine against angiotensin (Ang) II type 1 receptor (AT1R) named ATRQβ-001. To explore its potential effectiveness on streptozotocin-induced diabetic nephropathy, male Sprague Dawley rats were randomly divided into two groups: a control and a diabetic model. After 1 week, the diabetic rats were divided into four subgroups (each with 15 rats) for 14-week treatments with saline, olmesartan, ATRQβ-001, and Qβ virus-like particle (VLP), respectively. In addition to lower blood pressure, ATRQβ-001 vaccination ameliorated biochemical parameter changes of renal dysfunction, mesangial expansion, and fibrosis through inhibiting oxidative stress, macrophage infiltration, and proinflammatory factor expression. Furthermore, ATRQβ-001 vaccination suppressed renal Ang II-AT1R activation and abrogated the downregulation of angiotensin-converting enzyme 2-Ang (1–7), similar to olmesartan treatment, while no obvious feedback activation of circulating or local renin-angiotensin system (RAS) was only observed in vaccine group. In rat mesangial cells, the anti-ATR-001 antibody inhibited high glucose-induced transforming growth factor-β1 (TGF)-β1/Smad3 signal pathway. Additionally, no significant immune-mediated damage was detected in vaccinated animals. In conclusion, the ATRQβ-001 vaccine ameliorated streptozotocin-induced diabetic renal injury via modulating two RAS axes and inhibiting TGF-β1/Smad3 signal pathway, providing a novel, safe, and promising method to treat diabetic nephropathy.

Key messages

Overactivation of RAS plays a crucial role in the development of the DN.

Our aim was to verify the effectiveness of ATRQβ-001 vaccine in STZ-induced DN.

The ATRQβ-001 modulated two RAS axes and inhibited TGF-β1/Smad3 signal pathway.

The vaccine therapy may provide a novel, safe, and promising method to treat DN.

Electronic supplementary material

The online version of this article (doi:10.1007/s00109-015-1343-6) contains supplementary material, which is available to authorized users.

Swimming training prevents alterations in acetylcholinesterase and butyrylcholinesterase activities in hypertensive rats

BACKGROUND

Cholinergic enzyme activities are altered in hypertension, reflecting a low-grade inflammation. Regular physical exercise exerts anti-inflammatory effects and has been described as a coadjutant in the treatment of hypertension. In this study, we investigated the effect of 6 weeks of swimming training on cholinergic enzyme activities (acetylcholinesterase and butyrylcholinesterase) in Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats.

METHODS

The rats were divided into 4 groups: control (n = 10), exercise (n = 10), L-NAME (n = 10), and exercise L-NAME (n = 10). The animals were trained 5 times per week in an adapted swimming system for 60 minutes with a gradual increase of the workload up to 5% of animal's body weight. Enzyme activities were measured spectrophotometrically in lymphocytes, whole blood, and serum.

RESULTS

A significant rise in acetylcholinesterase activity was observed in lymphocytes and whole blood as well as in serum butyrylcholinesterase activity in the L-NAME group when compared with the other groups (P < 0.05), and the increase in cholinesterase activities was positively correlated with the rise in blood pressure (r = 0.5721, r = 0.6121, and r = 0.5811, respectively). Swimming training was efficient in preventing these alterations in the exercise L-NAME group, which displayed values similar to those of the control group. Exercise training demonstrated a significant hypotensive effect in hypertensive rats.

CONCLUSIONS

Exercise training was shown to prevent increased cholinesterase related to inflammatory processes in hypertensive rats, providing a new insight about protective exercise mechanisms to avoid hypertension-related inflammation.

Effects of angiotensin-converting enzyme inhibitory peptide LAP on vascular remodeling

The aim of this article is to study the efficiency of an angiotensin-converting enzyme (ACE)-inhibitory peptide LAP on the blood pressure (BP) and the vascular remodeling in spontaneously hypertensive rats (SHRs). Ten-week-old male SHRs were divided into four groups with 10 animals in each group and treated for 2 months: blank, pseudo-experimental (NS), enalapril (ENA), and LAP. The alterations of BP, plasma angiotensin II (AngII) levels, and morphological changes of left common carotid artery and the third level of superior mesenteric artery were investigated. After 2 weeks of treatment, LAP and ENA significantly decreased BP and the antihypertensive effects lasted till the end of experiment. After 2 months, LAP and ENA also significantly lowered plasma AngII levels. LAP and enalapril significantly lowered vascular medial thickness, media thickness/lumen diameter, medial cross-sectional area, and mean nuclear area of smooth muscle cells in left common carotid artery. When compared to the blank group, LAP and ENA significantly lowered the percentages of collagen fibers in the vascular area of left common carotid artery with 24.84 ± 0.53, 23.36 ± 0.99 versus 31.82 ± 0.57 (blank), respectively, and those of the third level of superior mesenteric artery with 15.82 ± 0.60, 15.15 ± 0.71 versus 23.42 ± 0.72, respectively. LAP had a beneficial effect on BP and vascular remodeling in SHRs. These findings suggest the potential therapeutic value of LAP in the treatment of hypertension.

Renal-protective effect of nicousamide on hypertensive nephropathy in spontaneously hypertensive rats

Previous studies have demonstrated that a novel coumarin-aspirin derivative, nicousamide, has a significant renal-protective effect on diabetic nephropathy. The present study aimed to investigate the beneficial effect of nicousamide on hypertensive nephropathy, as well as the underlying mechanisms in spontaneously hypertensive rats (SHRs). SHRs were treated orally with saline, nicousamide at 15, 30 and 45 mg/kg, and losartan (10 mg/kg) daily for 17 weeks, during which blood pressure (BP) was measured every four weeks. At the end of the 17-week treatment, blood and urine samples were collected for biochemical analysis and kidney tissues were obtained for histopathological and reverse transcription-polymerase chain reaction (RT-PCR) analyses. The concentration of angiotensin (Ang) II in plasma was also examined. Results showed that nicousamide effectively attenuated the progression of hypertensive nephropathy by decreasing urinary albumin excretion (UAE) and blood urea nitrogen (BUN). This could significantly decrease BP (less effectively compared to losartan) and the incidence of glomerulosclerosis and glomerular arteriosclerosis, adequately alleviating tubular impairment. Nicousamide markedly reduced the plasma Ang II level in SHRs and reduced mRNA expression of angiotensin-converting enzyme (ACE) and chymase in the kidneys of SHRs. Thus, nicousamide may retard the progression of hypertensive nephropathy. Although the underlying mechanisms have yet to be fully elucidated, this may involve blocking of the renin-Ang system.