Catestatin as a Target for Treatment of Inflammatory Diseases

Vasostatin-1 restores autistic disorders in an idiopathic autism model (BTBR T+ Itpr3tf/J mice) by decreasing hippocampal neuroinflammation

Chromogranin A (CgA), a ∼ 49 kDa acidic secretory protein, is ubiquitously distributed in endocrine and neuroendocrine cells and neurons. As a propeptide, CgA is proteolytically cleaved to generate several peptides of biological importance, including pancreastatin (PST: hCgA250-301), Vasostatin 1 (VS1: hCgA1-76), and catestatin (CST: CgA 352-372). VS1 represents the most conserved fragment of CgA. A 20 amino acid domain within VS1 (CgA 47-66) exhibits potent antimicrobial and anti-inflammatory activities. Autism is known to be associated with inflammation. Therefore, we seek to test the hypothesis that VS1 modulates autism behaviors by reducing inflammation in the hippocampus. Treatment of C57BL/6 (B6) and BTBR (a mouse model of idiopathic autism) mice with VS1 revealed the following: BTBR mice showed a significant decrease in chamber time in the presence of a stranger or a novel object. Treatment with VS1 significantly increased chamber time in both cases, underscoring a crucial role for VS1 in improving behavioral deficits in BTBR mice. In contrast to chamber time, sniffing time in BTBR mice in the presence of a stranger was less compared to B6 control mice. VS1 did not improve this latter parameter. Surprisingly, sniffing time in BTBR mice in the presence of a novel object was comparable with B6 mice. Proinflammatory cytokines such as IL-6 and IL-1b, as well as other inflammatory markers, were elevated in BTBR mice, which were dramatically reduced after supplementation with VS1. Interestingly, even Beclin-1/p62, pAKT/AKT, and p-p70-S6K/p70-S6K ratios were notably reduced by VS1. We conclude that VS1 plays a crucial role in restoring autistic spectrum disorders (ASD) plausibly by attenuating neuroinflammation.

The physiological anti-hypertensive peptide catestatin and its common human variant Gly364Ser: differential cardiovascular effects in a rat model of hypertension

Catestatin (CST), a 21-amino acids physiological peptide, has emerged as a key modulator of cardiovascular functions due to its anti-hypertensive and cardioprotective properties. However, the ramifications of the most common human variant of CST (viz., Gly364Ser) on cardiovascular pathophysiology remain partially understood. In this study, hypertension was induced in uninephrectomized rats by treatment with deoxycorticosterone-acetate and sodium chloride (DOCA-salt). The DOCA-salt-induced hypertensive (DSHR) animals were then intraperitoneally administered with either CST wild-type (CST-WT) or 364Ser variant (CST-Ser) peptide. CST-Ser was profoundly less effective than CST-WT in rescuing the elevated systolic blood pressure [from ∼211 mmHg to ∼176 mmHg, p < 0.0001 (CST-Ser) versus ∼116 mmHg, p < 0.0001 (CST-WT)] and heart rate [from ∼356 bpm to ∼314 bpm, p = 0.66 (CST-Ser) versus ∼276 bpm, p = 0.02 (CST-WT)]. CST-Ser also showed diminished effects in lowering diastolic blood pressure and mean arterial pressure in the DSHR animals. Furthermore, CST-Ser was inefficient/markedly less potent in rescuing the impaired contractile and diastolic function in DSHR animals [improvements in the contractility index by ∼22 s-1 (CST-Ser), p = 0.15 versus by ∼84 s-1 (CST-WT), p < 0.0001 and decrease in end-diastolic pressure by ∼4 mmHg (CST-Ser), p = 0.015 versus by ∼14 mmHg (CST-WT), p < 0.0001]. Moreover, CST-Ser exerted less potent anti-inflammatory effects on the DSHR hearts than CST-WT. These findings are in concordance with the elevated systolic/diastolic blood pressure observed in Ser variant carriers from various human populations. This study provides compelling evidence for the diminished anti-hypertensive and cardioprotective effects of the CST-Gly364Ser variant.

Serum Catestatin Levels in Patients with Acne Vulgaris: Single-Center Prospective Study

Introduction

Recent studies showed that antimicrobial peptides have an essential role in the pathogenesis of acne vulgaris. This study aims to investigate serum catestatin levels in acne vulgaris patients and focuses on the change in serum levels after systemic isotretinoin therapy.

Methods

This prospective study includes 101 acne vulgaris patients and 28 healthy controls. Serum catestatin levels were measured and compared between acne vulgaris and control group patients. Also, serum catestatin levels were measured again at the 24th week of isotretinoin therapy.

Results

The serum catestatin levels in patients with acne vulgaris were statistically higher than in the control group (p < 0.001). In addition, serum catestatin levels were associated with the severity of acne vulgaris. A significant decrease in serum catestatin levels was detected after 24 weeks of systemic isotretinoin treatment.

Conclusion

Catestatin was found to be significantly higher in the serum of patients with acne vulgaris compared to the control group. Although, the demonstration that catestatin levels decrease with isotretinoin treatment may indicate that it may have an important role in the pathogenesis of acne and could be used as a biomarker, future studies are needed to establish the role of catestatin in the pathogenesis of acne vulgaris.

Antimicrobial neuropeptides and their therapeutic potential in vertebrate brain infectious disease

The defense mechanisms of the vertebrate brain against infections are at the forefront of immunological studies. Unlike other body parts, the brain not only fends off pathogenic infections but also minimizes the risk of self-damage from immune cell induced inflammation. Some neuropeptides produced by either nerve or immune cells share remarkable similarities with antimicrobial peptides (AMPs) in terms of size, structure, amino acid composition, amphiphilicity, and net cationic charge. These similarities extend to a wide range of antibacterial activities demonstrated in vitro, effectively protecting nerve tissue from microbial threats. This review systematically examines 12 neuropeptides, pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal peptide (VIP), α-melanocyte stimulating hormone (α-MSH), orexin-B (ORXB), ghrelin, substance P (SP), adrenomedullin (AM), calcitonin-gene related peptide (CGRP), urocortin-II (UCN II), neuropeptide Y (NPY), NDA-1, and catestatin (CST), identified for their antimicrobial properties, summarizing their structural features, antimicrobial effectiveness, and action mechanisms. Importantly, the majority of these antimicrobial neuropeptides (9 out of 12) also possess significant anti-inflammatory properties, potentially playing a key role in preserving immune tolerance in various disorders. However, the connection between this anti-inflammatory property and the brain's infection defense strategy has rarely been explored. Our review suggests that the combined antimicrobial and anti-inflammatory actions of neuropeptides could be integral to the brain's defense strategy against pathogens, marking an exciting direction for future research.

A Narrative Review: Immunometabolic Interactions of Host-Gut Microbiota and Botanical Active Ingredients in Gastrointestinal Cancers

The gastrointestinal tract is where the majority of gut microbiota settles; therefore, the composition of the gut microbiota and the changes in metabolites, as well as their modulatory effects on the immune system, have a very important impact on the development of gastrointestinal diseases. The purpose of this article was to review the role of the gut microbiota in the host environment and immunometabolic system and to summarize the beneficial effects of botanical active ingredients on gastrointestinal cancer, so as to provide prospective insights for the prevention and treatment of gastrointestinal diseases. A literature search was performed on the PubMed database with the keywords "gastrointestinal cancer", "gut microbiota", "immunometabolism", "SCFAs", "bile acids", "polyamines", "tryptophan", "bacteriocins", "immune cells", "energy metabolism", "polyphenols", "polysaccharides", "alkaloids", and "triterpenes". The changes in the composition of the gut microbiota influenced gastrointestinal disorders, whereas their metabolites, such as SCFAs, bacteriocins, and botanical metabolites, could impede gastrointestinal cancers and polyamine-, tryptophan-, and bile acid-induced carcinogenic mechanisms. GPRCs, HDACs, FXRs, and AHRs were important receptor signals for the gut microbial metabolites in influencing the development of gastrointestinal cancer. Botanical active ingredients exerted positive effects on gastrointestinal cancer by influencing the composition of gut microbes and modulating immune metabolism. Gastrointestinal cancer could be ameliorated by altering the gut microbial environment, administering botanical active ingredients for treatment, and stimulating or blocking the immune metabolism signaling molecules. Despite extensive and growing research on the microbiota, it appeared to represent more of an indicator of the gut health status associated with adequate fiber intake than an autonomous causative factor in the prevention of gastrointestinal diseases. This study detailed the pathogenesis of gastrointestinal cancers and the botanical active ingredients used for their treatment in the hope of providing inspiration for research into simpler, safer, and more effective treatment pathways or therapeutic agents in the field.

Protective effects of the bioactive peptide from maggots against skin flap ischemia‒reperfusion injury in rats

Ischemia‒reperfusion (I/R) injury is a frequently observed complication after flap surgery, and it affects skin flap survival and patient prognosis. Currently, there are no proven safe and effective treatment options to treat skin flap I/R injury. Herein, the potential efficacies of the bioactive peptide from maggots (BPM), as well as its underlying mechanisms, were explored in a rat model of skin flap I/R injury and LPS- or H2O2-elicited RAW 264.7 cells. We demonstrated that BPM significantly ameliorated the area of flap survival, and histological changes in skin tissue in vivo. Furthermore, BPM could markedly restore or enhance Nrf2 and HO-1 levels, and suppress the expression of pro-inflammatory cytokines, including TLR4, p-IκB, NFκB p65, p-p65, IL-6, and TNF-α in I/R-injured skin flaps. In addition, BPM treatment exhibited excellent biocompatibility with an adequate safety profile, while it exhibited superior ROS-scavenging ability and the upregulation of antioxidant enzymes in vitro. Mechanistically, the above benefits related to BPM involved the activation of Nrf2/HO-1 and suppression of TLR4/NF-κB pathway. Taken together, this study may provide a scientific basis for the potential therapeutic effect of BPM in the prevention of skin flap I/R injury and other related diseases.

Distinct membrane perturbation effects of Catestatin and its CST-364 S variant: Insights from molecular simulations and anisotropy measurements

Catestatin (CST), a versatile 21 amino acid long cationic peptide, is stored in chromaffin granules and exocytosed upon fusion with the plasma membrane. CST, produced by chromaffin cells and neutrophils, is derived from the processing of chromogranin A and induced in the skin after injury. It involves catecholamine inhibition, blood pressure control, inflammation, and innate immunity. It is thought that calcium influx is triggered by CST permeating within neutrophils. It is unknown whether CST can disturb the immediate environment enough to penetrate the cell membrane passively. We used molecular dynamics simulations to examine the behaviour of human CST in its wild-type state (CST WT) and one of its naturally occurring variants, CST-364 S, which has a high allelic frequency in the human population. Both peptides were incorporated into the model eukaryotic cell membrane known as the POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine) lipid bilayer. The molecular modelling and simulations results show that CST WT and CST-364 S have different propensities for membrane disruption. It was shown that CST-364 S has higher membrane permeability than CST WT. In addition, we have used fluorescence anisotropy and leakage assay to study the interaction of peptides with PC membranes. Both peptides interacted with POPC and DOPC membranes, while CST-364 S penetrated the membrane more deeply via disorganizing the membrane interface, which supports our previous findings. According to this study, there is a good possibility that the peptides will passively permeate the cell membrane, distort, and pass through it.

Transcriptome and proteome profile of jejunum in chickens challenged with Salmonella Typhimurium revealed the effects of dietary bilberry anthocyanin on immune function

Introduction

The present study investigated the effects of bilberry anthocyanin (BA) on immune function when alleviating Salmonella Typhimurium (S. Typhimurium) infection in chickens.

Methods

A total of 180 newly hatched yellow-feathered male chicks were assigned to three groups (CON, SI, and SI + BA). Birds in CON and SI were fed a basal diet, and those in SI + BA were supplemented with 100 mg/kg BA for 18 days. Birds in SI and SI + BA received 0.5 ml suspension of S. Typhimurium (2 × 109 CFU/ml) by oral gavage at 14 and 16 days of age, and those in CON received equal volumes of sterile PBS.

Results

At day 18, (1) dietary BA alleviated weight loss of chickens caused by S. Typhimurium infection (P < 0.01). (2) Supplementation with BA reduced the relative weight of the bursa of Fabricius (P < 0.01) and jejunal villus height (P < 0.05) and increased the number of goblet cells (P < 0.01) and the expression of MUC2 (P < 0.05) in jejunal mucosa, compared with birds in SI. (3) Supplementation with BA decreased (P < 0.05) the concentration of immunoglobulins and cytokines in plasma (IgA, IL-1β, IL-8, and IFN-β) and jejunal mucosa (IgG, IgM, sIgA, IL-1β, IL-6, IL-8, TNF-α, IFN-β, and IFN-γ) of S. Typhimurium-infected chickens. (4) BA regulated a variety of biological processes, especially the defense response to bacteria and humoral immune response, and suppressed cytokine-cytokine receptor interaction and intestinal immune network for IgA production pathways by downregulating 6 immune-related proteins.

Conclusion

In summary, the impaired growth performance and disruption of jejunal morphology caused by S. Typhimurium were alleviated by dietary BA by affecting the expression of immune-related genes and proteins, and signaling pathways are related to immune response associated with immune cytokine receptors and production in jejunum.

Chromogranin A and its derived peptides: potential regulators of cholesterol homeostasis

Chromogranin A (CHGA), a member of the granin family of proteins, has been an attractive therapeutic target and candidate biomarker for several cardiovascular, neurological, and inflammatory disorders. The prominence of CHGA stems from the pleiotropic roles of several bioactive peptides (e.g., catestatin, pancreastatin, vasostatins) generated by its proteolytic cleavage and by their wide anatomical distribution. These peptides are emerging as novel modulators of cardiometabolic diseases that are often linked to high blood cholesterol levels. However, their impact on cholesterol homeostasis is poorly understood. The dynamic nature of cholesterol and its multitudinous roles in almost every aspect of normal body function makes it an integral component of metabolic physiology. A tightly regulated coordination of cholesterol homeostasis is imperative for proper functioning of cellular and metabolic processes. The deregulation of cholesterol levels can result in several pathophysiological states. Although studies till date suggest regulatory roles for CHGA and its derived peptides on cholesterol levels, the mechanisms by which this is achieved still remain unclear. This review aims to aggregate and consolidate the available evidence linking CHGA with cholesterol homeostasis in health and disease. In addition, we also look at common molecular regulatory factors (viz., transcription factors and microRNAs) which could govern the expression of CHGA and genes involved in cholesterol homeostasis under basal and pathological conditions. In order to gain further insights into the pathways mediating cholesterol regulation by CHGA/its derived peptides, a few prospective signaling pathways are explored, which could act as primers for future studies.

Mechanisms of ag85a/b DNA vaccine conferred immunotherapy and recovery from Mycobacterium tuberculosis-induced injury

Our previous research developed a novel tuberculosis (TB) DNA vaccine ag85a/b that showed a significant therapeutic effect on the mouse tuberculosis model by intramuscular injection (IM) and electroporation (EP). However, the action mechanisms between these two vaccine immunization methods remain unclear. In a previous study, 96 Mycobacterium tuberculosis (MTB) H37 Rv-infected BALB/c mice were treated with phosphate-buffered saline, 10, 50, 100, and 200 μg ag85a/b DNA vaccine delivered by IM and EP three times at 2-week intervals, respectively. In this study, peripheral blood mononuclear cells (PBMCs) from three mice in each group were isolated to extract total RNA. The gene expression profiles were analyzed using gene microarray technology to obtain differentially expressed (DE) genes. Finally, DE genes were validated by real-time reverse transcription-quantitive polymerase chain reaction and the GEO database. After MTB infection, most of the upregulated DE genes were related to the digestion and absorption of nutrients or neuroendocrine (such as Iapp, Scg2, Chga, Amy2a5), and most of the downregulated DE genes were related to cellular structural and functional proteins, especially the structure and function proteins of the alveolar epithelial cell (such as Sftpc, Sftpd, Pdpn). Most of the abnormally upregulated or downregulated DE genes in the TB model group were recovered in the 100 and 200 μg ag85a/b DNA IM groups and four DNA EP groups. The pancreatic secretion pathway downregulated and the Rap1 signal pathway upregulated had particularly significant changes during the immunotherapy of the ag85a/b DNA vaccine on the mouse TB model. The action targets and mechanisms of IM and EP are highly consistent. Tuberculosis infection causes rapid catabolism and slow anabolism in mice. For the first time, we found that the effective dose of the ag85a/b DNA vaccine immunized whether by IM or EP could significantly up-regulate immune-related pathways and recover the metabolic disorder and the injury caused by MTB.

Selected Serum Biomarkers (Leptin, Chromogranin A, CA19-9, CEA) in Patients with Pancreatic Neuroendocrine Neoplasm and Associations with Metabolic Syndrome

Metabolic abnormalities are well-known risk factors for many cancers, even though no clearly established link with pancreatic neuroendocrine neoplasms (PanNENs) has yet been investigated. This research aimed to assess the serum levels of leptin, chromogranin A (CgA), carbohydrate antigen 19-9 (CA19-9), and carcinoembryonic antigen (CEA) in patients with PanNENs and to search for associations between PanNENs, these selected serum biomarkers, and metabolic abnormalities in the form of metabolic syndrome (MS). Second, we aimed to investigate whether MS increases the risk of PanNENs. The serum concentrations of biomarkers, metabolic parameters (glucose, cholesterol, triglycerides), and anthropometric measurements (weight, height, BMI) were assessed in 106 patients with PanNENs and 40 healthy volunteers. Patients with PanNENs showed higher serum concentrations of CA19-9, CEA, and CgA in comparison to controls (p < 0.001, p = 0.042, and p = 0.025, respectively). Statistically significant differences in CEA levels were found in PanNENs patients with MS (p = 0.043). PanNENs patients with a BMI ≥ 25 kg/m² and who were female exhibited significantly higher leptin levels (p < 0.001 and p = 0.013, respectively). Additionally, this study reflects the importance of determining markers. Future research should focus on understanding the impact of metabolic disturbances on PanNENs and accounting for the relationship between PanNENs and MS, such as other malignancies.

Reduction in CgA-Derived CST Protein Level in HTR-8/SVneo and BeWo Trophoblastic Cell Lines Caused by the Preeclamptic Environment

One of the most dangerous complications of pregnancy is preeclampsia (PE), a disease associated with a high risk of maternal and fetal mortality and morbidity. Although its etiology remains unknown, the placenta is believed to be at the center of ongoing changes. One of the hormones produced by the placenta is chromogranin A (CgA). Thus far, its role in pregnancy and pregnancy-related disorders is enigmatic, yet it is known that both CgA and its derived peptide catestatin (CST) are involved in the majority of the processes that are disturbed in PE, such as blood pressure regulation or apoptosis. Therefore, in this study, the influence of the preeclamptic environment on the production of CgA using two cell lines, HTR-8/SVneo and BeWo, was investigated. Furthermore, the capacity of trophoblastic cells to secrete CST to the environment was tested, as well as the correlation between CST and apoptosis. This study provided the first evidence that CgA and CST proteins are produced by trophoblastic cell lines and that the PE environment has an impact on CST protein production. Furthermore, a strong negative correlation between CST protein level and apoptosis induction was found. Hence, both CgA and its derived peptide CST may play roles in the complex process of PE pathogenesis.

Selected Serum Markers Associated with Pathogenesis and Clinical Course of Type 1 Diabetes in Pediatric Patients-The Effect of Disease Duration

Biochemical abnormalities in the course of type 1 diabetes (T1D) may cause the production/activation of various proteins and peptides influencing treatment and causing a risk of complications. The aim of this study was to assess concentrations of selected serum substances involved in the pathogenesis and course of T1D and to correlate their concentrations with the duration of T1D. The study included patients with T1D (n = 156) at the age of 3-17, who were divided according to the duration of the disease into those newly diagnosed (n = 30), diagnosed after 3-5 (n = 77), 6-7 (n = 25), and over 7 (n = 24) years from the onset of T1D, and age-matched healthy controls (n = 30). Concentrations of amylin (IAPP), proamylin (proIAPP), catestatin (CST), chromogranin A (ChgA), nerve growth factor (NFG), platelet-activating factor (PAF), uromodulin (UMOD), and intestinal fatty acid binding protein (I-FABP) were measured in sera using immunoenzymatic tests. There were significant differences in concentrations of all the substances except UMOD and NGF between T1D patients and healthy children. The duration of the disease affected concentrations of CST, ChgA, PAF, and NGF, i.e., proteins/peptides which could have an impact on the course of T1D and the development of complications. In long-term patients, a decrease in concentrations of CST and ChgA, and an increase in PAF concentrations were found. In the case of NGF, a decrease was observed after the initial high values, followed by an increase over 7 years after T1D diagnosis. Concluding, the results show that concentrations of selected serum indicators may change in the course of T1D. Further studies are needed to establish whether these indicators could be used in the context of predicting long-term complications.

Chromogranin A: An Endocrine Factor of Pregnancy

Pregnancy is a state of physiological and hormonal changes. One of the endocrine factors involved in these processes is chromogranin A, an acidic protein produced, among others, by the placenta. Although it has been previously linked to pregnancy, no existing articles have ever managed to clarify the role of this protein regarding this subject. Therefore, the aim of the present study is to gather knowledge of chromogranin A's function with reference to gestation and parturition, clarify elusive information, and, most importantly, to formulate hypotheses for the future studies to verify.

Serum Catestatin Concentrations Are Increased in Patients with Atrial Fibrillation

The autonomic nervous system is crucial in initiating and maintaining atrial fibrillation (AF). Catestatin is a multipurpose peptide that regulates cardiovascular systems and reduces harmful, excessive activity of the sympathetic nervous system by blocking the release of catecholamines. We aimed to determine whether serum catestatin concentrations are associated with AF severity, duration indices, and various clinical and laboratory indicators in these individuals to better define the clinical value of catestatin in patients with AF. The present single center study enrolled 73 participants with AF and 72 healthy age-matched controls. Serum catestatin concentrations were markedly higher in AF patients than controls (14.11 (10.21-26.02) ng/mL vs. 10.93 (5.70-20.01) ng/mL, p = 0.013). Furthermore, patients with a more severe form of AF had significantly higher serum catestatin (17.56 (12.80-40.35) vs. 10.98 (8.38-20.91) ng/mL, p = 0.001). Patients with higher CHA₂DS₂-VASc scores (17.58 (11.89-37.87) vs. 13.02 (8.47-22.75) ng/mL, p = 0.034) and higher NT-proBNP levels (17.58 (IQR 13.91-34.62) vs. 13.23 (IQR 9.04-22.61), p = 0.036) had significantly higher serum catestatin concentrations. Finally, AF duration correlated negatively with serum catestatin levels (r = -0.348, p = 0.003). The results of the present study implicate the promising role of catestatin in the intricate pathophysiology of AF, which should be explored in future research.

Serum Catestatin Level as a Stratification Assessment Tool in Non-Critical COVID-19 Patients

Introduction: Catestatin (CST) is a peptide with immunomodulatory, anti-inflammatory, and anti-microbial activities. There are only a few studies that have investigated plasma CST levels in COVID-19 patients (mostly in ICU patients). In our work, the aim was to demonstrate serum CST levels and their correlation with clinical outcomes in a group of severe COVID-19 patients admitted to the non-ICU department. Methods: The subjects were 32 patients (25 females, 7 males) admitted to the non-ICU unit for COVID-19 patients. Results: CST levels in our cohort were higher (8.91 ± 7.00) than previously reported CST levels in control subjects. We found a significant positive correlation between serum CST levels and C-reactive protein (r = 0.423, p = 0.008), D-dimers (r = 0.395, p = 0.013), hsTNT (high-sensitivity troponin T) (r = 0.603, p < 0.001), proBNP (N-terminal pro-brain natriuretic peptide) (r = 0.569, p < 0.001), and hospitalization days (r = 0.388, p = 0.014). There was a difference between groups of participants with SOFA <3 (n = 18) and SOFA >=3 (n = 14) in catestatin serum levels (7.25 ± 3.66 vs. 11.05 ± 9.52 ng/mL), but the difference was statistically insignificant (p = 0.065). Conclusion: We considered plasma CST level at hospital admission as a possible tool for early risk assessment in non-critical COVID-19 patients. This study is an attempt to clarify the complex pathophysiological mechanisms present in the development of severe forms of SARS-CoV2 infection.

Chronic catestatin treatment reduces atrial fibrillation susceptibility via improving calcium handling in post-infarction heart failure rats

BACKGROUND

Abnormal Ca²⁺ handling is a pivotal element of atrial fibrillation (AF) substrates. Catestatin (CST) modulates intracellular Ca²⁺ handling in cardiomyocytes (CMs). We investigated the effects of CST administration on atrial Ca²⁺ handling and AF susceptibility in rats with post-infarction heart failure (HF).

METHODS

Myocardial infarction (MI) was established by ligation of the left anterior descending coronary artery in rats. Two-week later, rats with post-infarction HF were randomly treated with saline (MI group) or CST (MI + CST group) for 4-week. Cellular Ca²⁺ imaging was performed by incubating atrial CMs with Fura-2 AM. An in vitro electrophysiological study was performed to assess the vulnerability to action potential duration (APD) alternans and AF. Ca²⁺ handling proteins expression was determined using western blotting.

RESULTS

In atrial CMs, compared with the sham group, the sarcoplasmic reticulum (SR) Ca²⁺ load, Ca²⁺ transient (CaT) amplitude, and threshold for Ca²⁺ alternans were significantly decreased, but the diastolic intracellular Ca²⁺ level, SR Ca²⁺ leakage, and spontaneous Ca²⁺ events were markedly increased in the MI group. However, CST attenuated these Ca²⁺-handling abnormalities induced by post-infarction HF. Moreover, vulnerability to atrial APD alternans and AF was significantly increased in isolated hearts from the MI group compared to the sham group, whereas all effects were prevented by CST. CST treatment also preserved SR Ca²⁺-ATPase protein expression but decreased the protein levels of phosphorylated-ryanodine receptor 2 and phosphorylated-Ca²⁺/calmodulin-dependent protein kinase II in atria from post-infarction HF rats.

CONCLUSION

Chronic CST treatment reduces AF vulnerability in rats with MI-induced HF by improving Ca²⁺ handling.

Review on Molecular Mechanism of Hypertensive Nephropathy

Hypertension, a prevalent chronic ailment, has the potential to impair kidney function, and thereby resulting in hypertensive nephropathy. The escalating incidence of hypertensive nephropathy attributed to the aging population in urban areas, has emerged as a prominent cause of end-stage renal disease. Nevertheless, the intricate pathogenesis of hypertensive nephropathy poses considerable obstacles in terms of precise clinical diagnosis and treatment. This paper aims to consolidate the research findings on the pathogenesis of hypertensive nephropathy by focusing on the perspective of molecular biology.

Role of Chromogranin A in the Diagnosis and Follow-up of Neuroendocrine Tumors: Real-World Experience

OBJECTIVE

The aim of this study was to assess the utility of serum chromogranin A (CgA) along the clinical pathway of patients with neuroendocrine tumors (NETs).

METHODS

A retrospective review of medical records was conducted of patients with NET who had at least 1 measurement of CgA between January 2015 and April 2021 at a large metropolitan Australian hospital. Chromogranin A was classified as increased or decreased if there was at least a 25% change in sequential levels and was compared with disease response by anatomical or functional imaging if within 6 weeks (considered concurrent).

RESULTS

Of 102 patients with NETs, 67 had at least 1 serum CgA level: 50 had been ordered during diagnostic workup, of which 33 were elevated (sensitivity: 66%; 95% confidence interval, 51%-79%). Of 129 CgA results concurrent with imaging, the sensitivity for detecting progressive disease was 28% (95% confidence interval, 15%-44%).

CONCLUSIONS

Our findings support previous concerns that CgA adds little value in clinical decision-making.

Catestatin selects for colonization of antimicrobial-resistant gut bacterial communities

The gut microbiota is in continuous interaction with the innermost layer of the gut, namely the epithelium. One of the various functions of the gut epithelium, is to keep the microbes at bay to avoid overstimulation of the underlying mucosa immune cells. To do so, the gut epithelia secrete a variety of antimicrobial peptides, such as chromogranin A (CgA) peptide catestatin (CST: hCgA352-372). As a defense mechanism, gut microbes have evolved antimicrobial resistance mechanisms to counteract the killing effect of the secreted peptides. To this end, we treated wild-type mice and CST knockout (CST-KO) mice (where only the 63 nucleotides encoding CST have been deleted) with CST for 15 consecutive days. CST treatment was associated with a shift in the diversity and composition of the microbiota in the CST-KO mice. This effect was less prominent in WT mice. Levels of the microbiota-produced short-chain fatty acids, in particular, butyrate and acetate were significantly increased in CST-treated CST-KO mice but not the WT group. Both CST-treated CST-KO and WT mice showed a significant increase in microbiota-harboring phosphoethanolamine transferase-encoding genes, which facilitate their antimicrobial resistance. Finally, we show that CST was degraded by Escherichia coli via an omptin-protease and that the abundance of this gene was significantly higher in metagenomic datasets collected from patients with Crohn's disease but not with ulcerative colitis. Overall, this study illustrates how the endogenous antimicrobial peptide, CST, shapes the microbiota composition in the gut and primes further research to uncover the role of bacterial resistance to CST in disease states such as inflammatory bowel disease.

Role of Catestatin in the Cardiovascular System and Metabolic Disorders

Catestatin is a multifunctional peptide that is involved in the regulation of the cardiovascular and immune systems as well as metabolic homeostatis. It mitigates detrimental, excessive activity of the sympathetic nervous system by inhibiting catecholamine secretion. Based on in vitro and in vivo studies, catestatin was shown to reduce adipose tissue, inhibit inflammatory response, prevent macrophage-driven atherosclerosis, and regulate cytokine production and release. Clinical studies indicate that catestatin may influence the processes leading to hypertension, affect the course of coronary artery diseases and heart failure. This review presents up-to-date research on catestatin with a particular emphasis on cardiovascular diseases based on a literature search.

Catestatin induces glycogenesis by stimulating the phosphoinositide 3-kinase-AKT pathway

AIM

Defects in hepatic glycogen synthesis contribute to post-prandial hyperglycaemia in type 2 diabetic patients. Chromogranin A (CgA) peptide Catestatin (CST: hCgA352-372 ) improves glucose tolerance in insulin-resistant mice. Here, we seek to determine whether CST induces hepatic glycogen synthesis.

METHODS

We determined liver glycogen, glucose-6-phosphate (G6P), uridine diphosphate glucose (UDPG) and glycogen synthase (GYS2) activities; plasma insulin, glucagon, noradrenaline and adrenaline levels in wild-type (WT) as well as in CST knockout (CST-KO) mice; glycogen synthesis and glycogenolysis in primary hepatocytes. We also analysed phosphorylation signals of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphatidylinositol-dependent kinase-1 (PDK-1), GYS2, glycogen synthase kinase-3β (GSK-3β), AKT (a kinase in AKR mouse that produces Thymoma)/PKB (protein kinase B) and mammalian/mechanistic target of rapamycin (mTOR) by immunoblotting.

RESULTS

CST stimulated glycogen accumulation in fed and fasted liver and in primary hepatocytes. CST reduced plasma noradrenaline and adrenaline levels. CST also directly stimulated glycogenesis and inhibited noradrenaline and adrenaline-induced glycogenolysis in hepatocytes. In addition, CST elevated the levels of UDPG and increased GYS2 activity. CST-KO mice had decreased liver glycogen that was restored by treatment with CST, reinforcing the crucial role of CST in hepatic glycogenesis. CST improved insulin signals downstream of IR and IRS-1 by enhancing phospho-AKT signals through the stimulation of PDK-1 and mTORC2 (mTOR Complex 2, rapamycin-insensitive complex) activities.

CONCLUSIONS

CST directly promotes the glycogenic pathway by (a) reducing glucose production, (b) increasing glycogen synthesis from UDPG, (c) reducing glycogenolysis and (d) enhancing downstream insulin signalling.

Serum catestatin levels in patients with rheumatoid arthritis

Catestatin (CST) is an important peptide that influences various inflammatory diseases. Our goal was to investigate CST concentrations in patients with RA compared to healthy subjects. This cross-sectional observational study included 80 patients with RA and 80 healthy control subjects. Demographic characteristics and laboratory parameters were recorded. Serum CST levels were determined by an enzyme-linked immunosorbent assay (ELISA). Serum CST levels were significantly higher in RA patients than in the control group (10.53 ± 3.90 vs 5.24 ± 2.37 ng/mL, p < 0.001). In RA patients, there was a statistically significant correlation between CST and patient age (r = 0.418, p < 0.001) and both DAS28 (r = 0.469, p < 0.001) and HAQ scores (r = 0.483, p < 0.001). There was a statistically significant correlation between serum CST levels and RA duration (r = 0.583, p < 0.001). Multiple linear regression analysis showed that serum CST levels retained a significant association with RA duration (β ± SE, 0.13 ± 0.04, p = 0.002) and DAS28 score (0.94 ± 0.45, p = 0.039) after model adjustment for age, body mass index (BMI) and HAQ score, with serum CST levels as a dependent variable. These findings imply that CST is possibly associated with RA complex pathophysiology and disease activity. However, future larger multicentric longitudinal studies are necessary to define the role of CST in RA.

Ginsenoside Rg1 ameliorated experimental colitis by regulating the balance of M1/M2 macrophage polarization and the homeostasis of intestinal flora

Aberrant M1/M2 macrophage polarization and dysbiosis are involved in the pathogenesis of ulcerative colitis (UC). Ginsenoside Rg1 exhibits optimal immunomodulatory and anti-inflammatory effects in treating UC of humans and animals, but the action mechanism through the regulation of M1/M2 macrophage polarization and intestinal flora composition remain unclear. Here, experimental colitis was induced in BALB/c mice using dextran sulfate sodium, and Rock1 inhibitor Y27632 was used to explore the action mechanism of ginsenoside Rg1. Following treatment with ginsenoside Rg1 (200 mg/kg/day) and Y27632 (10 mg/kg/day) for 14 consecutive days, the rate of change in mouse body weight, mouse final weight, colonic weight, colonic length, colonic weight index and pathological damage scores of colitis mice were effectively improved, accompanied by less ulcer formation and inflammatory cell infiltration, lower levels of interleukin (IL)-6, IL-33, chemokine (C-C motif) ligand 2 (CCL-2), tumor necrosis factor alpha (TNF-α), and higher IL-4 and IL-10. Importantly, ginsenoside Rg1 and Y27632 significantly down-regulated CD11b+F4/80+, CD11b+F4/80+Tim-1+ and CD11b+F4/80+TLR4+ macrophages, and CD11b+F4/80+iNOS+ M1 macrophages, and significantly up-regulated CD11b+F4/80+CD206+ and CD11b+F4/80+CD163+ M2 macrophages in colitis mice; concomitantly, ginsenoside Rg1 improved the diversity of colonic microbiota and regulated Lachnospiraceae, Staphylococcus, Bacteroide and Ruminococcaceae_UCG_014 at genus level in colitis mice, but the flora regulated by Y27632 was not identical to it. Moreover, ginsenoside Rg1 and Y27632 down-regulated the protein levels of Rock1, RhoA and Nogo-B in colitis mice. These results suggested that ginsenoside Rg1 and Y27632 ameliorated colitis by regulating M1/M2 macrophage polarization and microbiota composition, associated with inhibition of the Nogo-B/RhoA signaling pathway.

The Catestatin-Derived Peptides Are New Actors to Fight the Development of Oral Candidosis

Resistance to antifungal therapy of Candida albicans and non-albicans Candida strains, frequently associated with oral candidosis, is on the rise. In this context, host-defense peptides have emerged as new promising candidates to overcome antifungal resistance. Thus, the aim of this study was to assess the effectiveness against Candida species of different Catestatin-derived peptides, as well as the combined effect with serum albumin. Among Catestatin-derived peptides, the most active against sensitive and resistant strains of C. albicans, C. tropicalis and C. glabrata was the D-isomer of Cateslytin (D-bCtl) whereas the efficiency of the L-isomer (L-bCtl) significantly decreases against C. glabrata strains. Images obtained by transmission electron microscopy clearly demonstrated fungal membrane lysis and the leakage of the intracellular material induced by the L-bCtl and D-bCtl peptides. The possible synergistic effect of albumin on Catestatin-derived peptides activity was investigated too. Our finding showed that bovine serum albumin (BSA) when combined with the L- isomer of Catestatin (L-bCts) had a synergistic effect against Candida albicans especially at low concentrations of BSA; however, no synergistic effect was detected when BSA interacted with L-bCtl, suggesting the importance of the C-terminal end of L-bCts (GPGLQL) for the interaction with BSA. In this context in vitro D-bCtl, as well as the combination of BSA with L-bCts are potential candidates for the development of new antifungal drugs for the treatment of oral candidosis due to Candida and non-Candida albicans, without detrimental side effects.

Prognostic differences of catestatin among young and elderly patients with acute myocardial infarction

BACKGROUND

Previous studies have reported inconsistent findings regarding the association between catestatin and outcomes of acute myocardial infarction (AMI). This study aims to investigate the prognostic value of catestatin for long-term outcomes in patients with AMI.

METHODS

One hundred and sixty-five patients with AMI were enrolled in this series. The plasma catestatin levels at baseline and clinical data were collected. All patients were followed up for four years to investigate whether there were major adverse cardiovascular events (MACEs), including cardiovascular death, recurrent AMI, rehospitalization for heart failure, and revascularization.

RESULTS

There were 24 patients who had MACEs during the follow-up period. The MACEs group had significantly lower plasma catestatin levels (0.74±0.49 ng/mL vs. 1.10±0.79 ng/mL, P=0.033) and were older (59.0±11.4 years old vs. 53.2±12.8 years old, P=0.036). The rate of MACEs was significantly higher in the elderly group (≥60 years old) than in the young group (<60 years old) (23.8% [15/63] vs. 8.8% [9/102], P=0.008). The catestatin level was significantly lower in the MACEs group than that in the non-MACEs group (0.76±0.50 ng/mL vs. 1.31±0.77 ng/mL, P=0.012), and catestatin was significantly associated with MACEs (Kaplan Meier, P=0.007) among the elderly group, but not in the young group (Kaplan Meier, P=0.893). In the Cox proportional hazards regression, high catestatin was one of the independent factors for predicting MACEs after adjustment for other risk factors (hazard ratio 0.19, 95% confidence interval 0.06-0.62, P=0.006) among elderly patients.

CONCLUSIONS

Elderly AMI patients with lower plasma catestatin levels are more likely to develop MACEs. Catestatin may be a novel marker for the long-term prognosis of AMI, especially in elderly patients.

Putative regulation of macrophage-mediated inflammation by catestatin

Catestatin (CST) is a bioactive cleavage product of the neuroendocrine prohormone chromogranin A (CgA). Recent findings show that CST can exert anti-inflammatory and antiadrenergic effects by suppressing the inflammatory actions of mammalian macrophages. However, recent findings also suggest that macrophages themselves are major CST producers. Here, we hypothesize that macrophages produce CST in an inflammation-dependent manner and thereby might self-regulate inflammation in an autocrine fashion. CST is associated with pathological conditions hallmarked by chronic inflammation, including autoimmune, cardiovascular, and metabolic disorders. Since intraperitoneal injection of CST in mouse models of diabetes and inflammatory bowel disease has been reported to be beneficial for mitigating disease, we posit that CST should be further investigated as a candidate target for treating certain inflammatory diseases.

The anti-inflammatory peptide Catestatin blocks chemotaxis

Increased levels of the anti‐inflammatory peptide Catestatin (CST), a cleavage product of the pro‐hormone chromogranin A, correlate with less severe outcomes in hypertension, colitis, and diabetes. However, it is unknown how CST reduces the infiltration of monocytes and macrophages (Mϕs) in inflamed tissues. Here, it is reported that CST blocks leukocyte migration toward inflammatory chemokines. By in vitro and in vivo migration assays, it is shown that although CST itself is chemotactic, it blocks migration of monocytes and neutrophils to inflammatory attracting factor CC‐chemokine ligand 2 (CCL2) and C‐X‐C motif chemokine ligand 2 (CXCL2). Moreover, it directs CX₃CR1⁺ Mϕs away from pancreatic islets. These findings suggest that the anti‐inflammatory actions of CST are partly caused by its regulation of chemotaxis.

Chromogranin A Deficiency Confers Protection From Autoimmune Diabetes via Multiple Mechanisms

Recognition of β-cell antigens by autoreactive T cells is a critical step in the initiation of autoimmune type1 diabetes. A complete protection from diabetes development in NOD mice harboring a point mutation in the insulin B-chain 9-23 epitope points to a dominant role of insulin in diabetogenesis. Generation of NOD mice lacking the chromogranin A protein (NOD.ChgA^-/-) completely nullified the autoreactivity of the BDC2.5 T cell and conferred protection from diabetes onset. These results raised the issue concerning the dominant antigen that drives the autoimmune process. Here we revisited the NOD.ChgA^-/- mice and found that their lack of diabetes development may not be solely explained by the absence of chromogranin A reactivity. NOD.ChgA^-/- mice displayed reduced presentation of insulin peptides in the islets and periphery, which corresponded to impaired T-cell priming. Diabetes development in these mice was restored by antibody treatment targeting regulatory T cells or inhibiting transforming growth factor-β and programmed death-1 pathways. Therefore, the global deficiency of chromogranin A impairs recognition of the major diabetogenic antigen insulin, leading to broadly impaired autoimmune responses controlled by multiple regulatory mechanisms.

Chromogranin A demonstrates higher expression in preeclamptic placentas than in normal pregnancy

BACKGROUND

Although preeclampsia has long been recognized as a condition affecting late pregnancy, little is known of its pathogenesis or treatment. The placenta releases a number of hormones and molecules that influence the course of pregnancy, one of which is chromogranin A, a soluble protein secreted mainly from the chromaffin cells of the adrenal medulla. Its role in pregnancy and pregnancy-related disorders remains unclear. Therefore, the main aim of the proposed study is to determine whether chromogranin A is related with the occurrence of preeclampsia.

METHODS

Placental samples were collected from 102 preeclamptic patients and 103 healthy controls, and Chromogranin A gene (CHGA) expression was measured using real-time RT-PCR, The RT-PCR results were verified on the protein level using ELISA. The normal distribution of the data was tested using the Shapiro-Wilk test. The clinical and personal characteristics of the groups were compared using the Student's t-test for normally-distributed data, and the χ2 test for categorical variables. The Mann-Whitney U test was used for non-normally distributed data. As the log- transformation was not suitable for the given outcomes, the Box- Cox Transformation was used to normalize data from ELISA tests and CHGA expression. Values of P < .05 were considered statistically significant.

RESULTS

Chromogranin A gene expression was found to be significantly higher in the study group than in controls. Protein analyses showed that although the CgA concentration in placental samples did not differ significantly, the catestatin (CST) level was significantly lower in samples obtained from women with preeclampsia, according to the controls.

CONCLUSIONS FOR PRACTICE

This study for the first time reveals that chromogranin A gene expression level is associated with preeclampsia. Moreover, the depletion in catestatin level, which plays a protective role in hypertension development, might be a marker of developing preeclampsia. Further studies may unravel role of Chromogranin A in the discussed disease.

Catestatin in innate immunity and Cateslytin-derived peptides against superbugs

Chromogranin A (CgA) is the precursor of several antimicrobial peptides, such as Catestatin (Cts, bovine CgA344-364), initially described as a potent inhibitor of catecholamines. This peptide displays direct antimicrobial activities and contributes to immune system regulation. The aim of the present study is to investigate a designed peptide based on Cts to fight infections against superbugs and more particularly Staphylococcus aureus. In addition to Cateslytin (Ctl, bovine CgA344-358), the active domain of Catestatin, several peptides including dimers, D-isomer and the new designed peptide DOPA-K-DOPA-K-DOPA-TLRGGE-RSMRLSFRARGYGFR (Dopa5T-Ctl) were prepared and tested. Cateslytin is resistant to bacterial degradation and does not induce bacterial resistance. The interaction of Catestatin with immune dermal cells (dendritic cells DC1a, dermal macrophages CD14 and macrophages) was analyzed by using confocal microscopy and cytokine release assay. The dimers and D-isomer of Ctl were tested against a large variety of bacteria showing the potent antibacterial activity of the D-isomer. The peptide Dopa5T-Ctl is able to induce the self-killing of S. aureus after release of Ctl by the endoprotease Glu-C produced by this pathogen. It permits localized on-demand delivery of the antimicrobial drug directly at the infectious site.

Chromogranin A regulates gut permeability via the antagonistic actions of its proteolytic peptides

AIM

A "leaky" gut barrier has been implicated in the initiation and progression of a multitude of diseases, for example, inflammatory bowel disease (IBD), irritable bowel syndrome and celiac disease. Here we show how pro-hormone Chromogranin A (CgA), produced by the enteroendocrine cells, and Catestatin (CST: hCgA_352-372 ), the most abundant CgA-derived proteolytic peptide, affect the gut barrier.

METHODS

Colon tissues from region-specific CST-knockout (CST-KO) mice, CgA-knockout (CgA-KO) and WT mice were analysed by immunohistochemistry, western blot, ultrastructural and flowcytometry studies. FITC-dextran assays were used to measure intestinal barrier function. Mice were supplemented with CST or CgA fragment pancreastatin (PST: CgA_250-301 ). The microbial composition of cecum was determined. CgA and CST levels were measured in blood of IBD patients.

RESULTS

Plasma levels of CST were elevated in IBD patients. CST-KO mice displayed (a) elongated tight, adherens junctions and desmosomes similar to IBD patients, (b) elevated expression of Claudin 2, and (c) gut inflammation. Plasma FITC-dextran measurements showed increased intestinal paracellular permeability in the CST-KO mice. This correlated with a higher ratio of Firmicutes to Bacteroidetes, a dysbiotic pattern commonly encountered in various diseases. Supplementation of CST-KO mice with recombinant CST restored paracellular permeability and reversed inflammation, whereas CgA-KO mice supplementation with CST and/or PST in CgA-KO mice showed that intestinal paracellular permeability is regulated by the antagonistic roles of these two peptides: CST reduces and PST increases permeability.

CONCLUSION

The pro-hormone CgA regulates the intestinal paracellular permeability. CST is both necessary and sufficient to reduce permeability and primarily acts by antagonizing PST.

Immunosuppression of Macrophages Underlies the Cardioprotective Effects of CST (Catestatin)

[Figure: see text].

Plasma Catestatin Levels and Advanced Glycation End Products in Patients on Hemodialysis

Catestatin (CST) is a pleiotropic peptide involved in cardiovascular protection with its antihypertensive and angiogenic effects. Considering that patients with end-stage renal disease (ESRD) who are undergoing hemodialysis (HD) are associated with higher cardiovascular risk, the aim of this study was to investigate plasma CST levels in HD patients, compare them to healthy controls and evaluate possible CST associations with advanced glycation end products (AGEs) and laboratory, anthropometric and clinical parameters. The study included 91 patients on HD and 70 healthy controls. Plasma CST levels were determined by an enzyme-linked immunosorbent assay in a commercially available diagnostic kit, while AGEs were determined using skin autofluorescence. Plasma CST levels were significantly higher in the HD group compared to the controls (32.85 ± 20.18 vs. 5.39 ± 1.24 ng/mL, p < 0.001) and there was a significant positive correlation between CST and AGEs (r = 0.492, p < 0.001). Furthermore, there was a significant positive correlation between plasma CST levels with both the Dialysis Malnutrition Score (r = 0.295, p = 0.004) and Malnutrition-Inflammation Score (r = 0.290, p = 0.005). These results suggest that CST could be playing a role in the complex pathophysiology of ESRD/HD and that it could affect the higher cardiovascular risk of patients on HD.

Cateslytin abrogates lipopolysaccharide-induced cardiomyocyte injury by reducing inflammation and oxidative stress through toll like receptor 4 interaction

Global public health is threatened by new pathogens, antimicrobial resistant microorganisms and a rapid decline of conventional antimicrobials efficacy. Thus, numerous medical procedures become life-threating. Sepsis can lead to tissue damage such as myocardium inflammation, associated with reduction of contractility and diastolic dysfunction, which may cause death. In this perspective, growing interest and attention are paid on host defence peptides considered as new potential antimicrobials. In the present study, we investigated the physiological and biochemical properties of Cateslytin (Ctl), an endogenous antimicrobial chromogranin A-derived peptide, in H9c2 cardiomyocytes exposed to lipopolysaccharide (LPS) infection. We showed that both Ctl (L and D) enantiomers, but not their scrambled counterparts, significantly increased cardiomyocytes viability following LPS, even if L-Ctl was effective at lower concentration (1 nM) compared to D-Ctl (10 nM). L-Ctl mitigated LPS-induced LDH release and oxidative stress, as visible by a reduction of MDA and protein carbonyl groups content, and by an increase of SOD activity. Molecular docking simulations strongly suggested that L-Ctl modulates TLR4 through a direct binding to the partner protein MD-2. Molecular analyses indicated that the protection mediated by L-Ctl against LPS-evoked sepsis targeted the TLR4/ERK/JNK/p38-MAPK pathway, regulating NFkB p65, NFkB p52 and COX2 expression and repressing the mRNA expression levels of the LPS-induced proinflammatory factors IL-1β, IL-6, TNF-α and NOS2. These findings indicate that Ctl could be considered as a possible candidate for the development of new antimicrobials strategies in the treatment of myocarditis. Interestingly, L-enantiomeric Ctl showed remarkable properties in strengthening the anti-inflammatory and anti-oxidant effects on cardiomyocytes.

Catestatin peptide of chromogranin A as a potential new target for several risk factors management in the course of metabolic syndrome

Obesity, lipodystrophy, diabetes, and hypertension collectively constitute the main features of Metabolic Syndrome (MetS), together with insulin resistance (IR), which is considered as a defining element. MetS generally leads to the development of cardiovascular disease (CVD), which is a determinant cause of mortality and morbidity in humans and animals. Therefore, it is essential to implement and put in place adequate management strategies for the treatment of this disease. Catestatin is a bioactive peptide with 21 amino acids, which is derived through cleaving of the prohormone chromogranin A (CHGA/CgA) that is co-released with catecholamines from secretory vesicles and, which is responsible for hepatic/plasma lipids and insulin levels regulation, improves insulin sensitivity, reduces hypertension and attenuates obesity in murine models. In humans, there were few published studies, which showed that low levels of catestatin are significant risk factors for hypertension in adult patients. These accumulating evidence documents clearly that catestatin peptide (CST) is linked to inflammatory and metabolic syndrome diseases and can be a novel regulator of insulin and lipid levels, blood pressure, and cardiac function. The goal of this review is to provide an overview of the CST effects in metabolic syndrome given its role in metabolic regulation and thus, provide new insights into the use of CST as a diagnostic marker and therapeutic target.

Serum Catestatin Levels and Arterial Stiffness Parameters Are Increased in Patients with Inflammatory Bowel Disease

Catestatin (CST) is an important peptide in the pathophysiology of chronic inflammatory disorders. However, clinical studies on inflammatory bowel disease (IBD) patients are lacking. Our goal was to investigate CST concentrations in IBD patients compared to healthy subjects. Additionally, we aimed to determine arterial stiffness parameters in relation to CST. This cross-sectional study compared 80 IBD patients (45 Crohn's disease (CD) and 35 ulcerative colitis (UC) patients) with 75 control subjects. Serum CST levels were significantly higher in the IBD group compared to control subjects (11.29 ± 9.14 vs. 7.13 ± 6.08 ng/mL, p = 0.001) and in the UC group compared to CD patients (13.50 ± 9.58 vs. 9.03 ± 6.92 ng/mL, p = 0.021), irrespective of age and BMI. IBD patients exhibited significantly higher values of heart rate adjusted central augmentation index (cAIx-75) (14.88 ± 10.59 vs. 6.87 ± 9.50 %, p < 0.001) and pulse wave velocity (PWV) (8.06 ± 3.23 vs. 6.42 ± 1.47 m/s, p < 0.001) compared to control group. Furthermore, PWV was the only significant independent correlate of CST (B = 1.20, t = 4.15, p < 0.001), while CST, PWV, cAIx-75, high-sensitivity C-reactive protein and BMI were significant predictors of positive IBD status (1.089 (1.022-1.161), 1.515 (1.166-1.968), 1.060 (1.024-1.097), 1.458 (1.116-1.906), 0.793 (0.683-0.920), respectively). Serum CST levels were significantly higher in IBD patients compared to controls and an independent positive correlation of CST with PWV existed. Therefore, it is possible that CST could have a role in the complex pathophysiology of IBD and its cardiovascular complications.

Catestatin in defense of oxidative-stress-induced apoptosis: A novel mechanism by activating the beta2 adrenergic receptor and PKB/Akt pathway in ischemic-reperfused myocardium

Apoptosis induced by oxidative stress is one of the most important cardiomyocytes losses during ischemia-reperfusion (I/R). Catestatin (CST) has been demonstrated to have the anti-oxidative capacity in vitro. We hypothesized that CST intervention could reduce apoptosis of cardiomyocytes induced by oxidative stress in I/R. In Langendorff-perfused rat heart global I/R model, CST was introduced at the reperfusion stage. In comparison to the control group, CST led to preservation on activities of superoxide dismutase and glutathione peroxidase, improvement of hemodynamics, and reduced infarction area in reperfused myocardium. The protection of CST was also shown by less apoptotic cardiomyocytes in TUNEL staining, less caspase-3 activation, and increased phosphorylation of protein kinase B (PKB/Akt) in Western blot. To further demonstrate the benefits of CST and explore the possible underlying mechanism, H₂O₂-challenged primary-cultured neonatal rat cardiomyocytes were used to simulate the oxidative-stressed scenario. CST incubation with the H₂O₂-challenged cardiomyocytes led to reduction of apoptosis, which was demonstrated by less Hoechst 33342 positive staining of nuclei, less caspase-3 activation, and DNA fragmentation. The effect of CST was abrogated by pretreatment of the cardiomyocytes with the PI3K inhibitor LY294002. Furthermore, Akt activation and the anti-apoptosis effect of CST were abolished by pretreatment of the cardiomyocytes with β2 receptor inhibitor ICI118551. Thus, the salvage of oxidative-stress-induced apoptotic cardiomyocytes in I/R by CST might involve activation β2 receptor and regulation of PI3K/Akt signaling in reperfusion injury salvage kinase (RISK) pathway.

Chromogranin A and its fragments in cardiovascular, immunometabolic, and cancer regulation

Chromogranin A (CgA)-the index member of the chromogranin/secretogranin secretory protein family-is ubiquitously distributed in endocrine, neuroendocrine, and immune cells. Elevated levels of CgA-related polypeptides, consisting of full-length molecules and fragments, are detected in the blood of patients suffering from neuroendocrine tumors, heart failure, renal failure, hypertension, rheumatoid arthritis, and inflammatory bowel disease. Full-length CgA and various CgA-derived peptides, including vasostatin-1, pancreastatin, catestatin, and serpinin, are expressed at different relative levels in normal and pathological conditions and exert diverse, and sometime opposite, biological functions. For example, CgA is overexpressed in genetic hypertension, whereas catestatin is diminished. In rodents, the administration of catestatin decreases hypertension, cardiac contractility, obesity, atherosclerosis, and inflammation, and it improves insulin sensitivity. By contrast, pancreastatin is elevated in diabetic patients, and the administration of this peptide to obese mice decreases insulin sensitivity and increases inflammation. CgA and the N-terminal fragment of vasostatin-1 can enhance the endothelial barrier function, exert antiangiogenic effects, and inhibit tumor growth in animal models, whereas CgA fragments lacking the CgA C-terminal region promote angiogenesis and tumor growth. Overall, the CgA system, consisting of full-length CgA and its fragments, is emerging as an important and complex player in cardiovascular, immunometabolic, and cancer regulation.

Serum catestatin concentrations are decreased in obese children and adolescents

BACKGROUND

Catestatin is a chromogranin A-derived peptide with a wide spectrum of biological activities, such as inhibiting catecholamine release, decreasing blood pressure, stimulating histamine release, reducing beta-adrenergic stimulation, and regulating oxidative stress.

OBJECTIVES

The aims of our study were to determine serum catestatin concentrations in obese children and adolescents in regard to presence or absence of metabolic syndrome (MS) and to evaluate the possible relations between catestatin levels and other cardiovascular risk factors.

SUBJECTS

Ninety-two obese subjects with a body mass index z score > 2, aged 10 to 18 years, and 39 healthy, normal weight controls were enrolled in the study.

METHODS

Serum catestatin concentrations were measured using an enzyme-linked immunosorbent assay.

RESULTS

Significantly lower serum catestatin concentrations were recorded in the group of obese subjects compared with a control group (10.03 ± 5.05 vs 13.13 ± 6.25 ng/mL, P = 0.004). Further analyses revealed significantly lower catestatin concentrations in the subgroup of obese patients with MS (9.02 ± 4.3 vs 10.54 ± 5.36 vs 13.13 ± 6.25, P = 0.008). Serum catestatin concentrations were significantly negatively correlated with diastolic blood pressure (r = -0.253, P = 0.014), homeostatic model assessment of insulin resistance (r = -0.215, P = 0.037) and high sensitivity C-reactive protein (r = -0.208, P = 0.044).

CONCLUSIONS

To the best of our knowledge, this study is the first to report catestatin concentrations in obese children and adolescents and their possible relations with MS and cardiovascular risk factors in a pediatric population. Obese subjects with MS have lower serum catestatin concentrations than obese subjects without MS and controls.