Endotoxin Effects on Cardiac and Renal Functions and Cardiorenal Syndromes

Recent advances on the Role of Gut Microbiota in the Development of Heart Failure by Mediating Immune Metabolism

The association between gut microbiota and the development of heart failure has become a research hotspot in recent years and the impact of gut microbiota on heart failure has attracted growing interest. From 2006 to 2021, the global research on gut microbiota and heart failure has gradually expanded, indicating a developed and promising research field. There were 40 countries, 196 institutions, and 257 authors involved in the publication on the relationship between gut microbiota and heart failure, respectively. In patients with heart failure, inadequate visceral perfusion leads to ischemia and intestinal edema, which compromise the gut barrier. This subsequently results in the translocation of bacteria and bacterial metabolites into the circulatory system and causes local and systemic inflammatory responses. The gastrointestinal tract contains the largest number of immune cells in the human body and gut microbiota play important roles in the immune system by promoting immune tolerance to symbiotic bacteria. Studies have shown that probiotics can act on gut microorganisms, thereby increasing choline metabolism and reducing plasma TMA and TMAO concentrations, thus inhibiting the development of heart failure. Meanwhile, probiotics induce the production of inflammatory suppressors to maintain gut immune stability and inhibit the progression of heart failure by reducing ventricular remodeling. Here, we review the current understanding of gut microbiota-driven immune dysfunction in experimental and clinical heart failure, as well as the therapeutic interventions that could be used to address these issues.

The oral microbial odyssey influencing chronic metabolic disease

INTRODUCTION

Since the oral cavity is the gateway to the gut, oral microbes likely hold the potential to influence metabolic disease by affecting the gut microbiota.

METHOD

A thorough review of literature has been performed to link the alterations in oral microbiota with chronic metabolic disease by influencing the gut microbiota.

RESULT

A strong correlation exists between abnormalities in oral microbiota and several systemic disorders, such as cardiovascular disease, diabetes, and obesity, which likely initially manifest as oral diseases. Ensuring adequate oral hygiene practices and cultivating diverse oral microflora are crucial for the preservation of general well-being. Oral bacteria have the ability to establish and endure in the gastrointestinal tract, leading to the development of prolonged inflammation and activation of the immune system. Oral microbe-associated prophylactic strategies could be beneficial in mitigating metabolic diseases.

CONCLUSION

Oral microbiota can have a profound impact on the gut microbiota and influence the pathogenesis of metabolic diseases.

UTI-Associated Septic Cardiomyopathy: Saving the Heart in the Nick of Time

A patient with gram-negative sepsis developed acute global biventricular dysfunction with reduced left ventricular ejection fraction. A diagnosis of sepsis-induced cardiomyopathy (SICM) was made following the complete resolution of cardiac dysfunction. This case highlights the importance of the early diagnosis of SICM and treatment of the underlying cause.

The NCOA1-CBP-NF-κB transcriptional complex induces inflammation response and triggers endotoxin-induced myocardial dysfunction

Inflammatory pathways represented by TLR4/NF-κB (Toll-like receptor 4/Nuclear factor-κB) axis signaling are activated in the pathogenesis of endotoxin-induced myocardial dysfunction (EIMD). However, the underlying mechanism by which NF-κB coordinates with other transcriptional coactivators/corepressors to regulate the expression of proinflammatory cytokine genes remains unclear. We established an EIMD-mouse model by intraperitoneal injection of lipopolysaccharides (LPS), and we discovered that NCOA1 (nuclear receptor coactivator 1) assembled with CBP (CREB binding protein) and NF-κB subunits to form a transcriptional complex that specifically bound to promoters of proinflammatory cytokine genes to activate their expression. LPS treatment also inhibited DNMT1 (DNA methyltransferase 1) expression, thereby decreasing DNA methylation of a CpG island located on the promoter of NCOA1 and causing NCOA1 overexpression. Screening small molecules that abolished NCOA1-CBP interaction in a yeast system identified a compound PSSM2126 that effectively blocked the NCOA1-CBP interaction in vitro and in vivo. Administration of PSSM2126 to EIMD mice significantly alleviated the inflammation response and improved cardiac function. Collectively, our results reveal that an NCOA1-dependent transactivation mechanism can regulate proinflammatory cytokine expression, thereby improving our understanding of the activation of NF-κB targets. The promising inhibition of the NCOA1-CBP interaction by PSSM2126 may provide a new therapeutic option for EIMD.

In vivo evaluation of the protective effects of arjunolic acid against lipopolysaccharide-induced septic myocardial injury

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of Gram-negative bacteria, which induces multiple organ dysfunctions, eventually leading to septic shock and death. Arjunolic acid (AA) has been shown to have therapeutic benefits against various organ pathophysiologies, although its role in sepsis remains unclear. Here, we evaluated the effects of AA on LPS-induced free radical production and cardiotoxicity. Male albino mice were allocated to four groups: normal, 1.5 µg/30 g b.w. of LPS (LPS), 20 mg/kg b.w. AA with LPS (AA+LPS) and 20 mg/kg b.w. of AA (AA). Subsequently, blood and heart samples were harvested for biochemical and histopathological examinations. Pretreatment with AA attenuated LPS-induced increased serum levels of cardiac troponin I, lactate dehydrogenase and creatine kinase. In the meantime, AA pretreatment before LPS resulted in a significant increase in endogenous antioxidants (superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione) and a significant decrease in the level of lipid peroxidation product (malondialdehyde) in the heart as compared to the LPS group, while cardiac cytochrome c activity were significantly increased. In addition, in the AA-pretreated mice, C-reactive protein and proinflammatory cytokines (interlukin-1 and tumor necrosis factor-alpha) were significantly reduced, and anti-inflammatory cytokines (interleukin-4 and -10) were significantly increased in cardiac tissues as compared to the LPS-treated animals. Furthermore, prior administration of AA to LPS exposed mice led to a significant a significant decrease in heart caspase-3, -8, and -9 as compared to the LPS group. Interestingly, AA was also able to improve LPS-induced histopathological changes in the cardiomyocytes. In conclusion, these in vivo findings indicate that AA may be a promising cardioprotective agent against LPS-stimulated cardiotoxicity, at least in part, through upregulation of cardiac antioxidants, reduction of lipid peroxidation, and inhibition of inflammation and cardiac cell death.

Covid and Cardiovascular Diseases: Direct and Indirect Damages and Future Perspective

SARS-CoV-2 infection determines a disease that predominantly affects lungs. However the cytokines storms, determined by the huge immune response to the infection, could affect also other organs and apparatus such as heart and vessels. Beyond the acute inflammation itself also hypercoagulative status has been linked to SARSCoV-2 infection and this surely relates to the increase seen in prevalence of pulmonary embolism and myocardial infarction. A number of cardiac abnormalities and pathologies have been observed, with special attention to cardiac arrhythmias and myocardial involvement. Furthermore, indirect damages determined by the reduction in acute and chronic cardiovascular care, results in a strong mortality and morbidity outcomes in cardiological patients. In this review we will summarise current knowledge on both direct and indirect cardiovascular damages determined by the SARS-CoV-2 pandemia.

Ultra-High Packing Density Next Generation Microtube Array Membrane for Absorption Based Applications

Previously, we successfully developed an extracorporeal endotoxin removal device (EERD) that is based on the novel next generation alternating microtube array membrane (MTAM-A) that was superior to the commercial equivalent. In this article, we demonstrated multiple different parameter modifications that led to multiple different types of novel new MTAM structures, which ultimately led to the formation of the MTAM-A. Contrary to the single layered MTAM, the MTAM-A series consisted of a superior packing density fiber connected in a double layered, alternating position which allowed for the greater fiber count to be packed per unit area. The respective MTAM variants were electrospun by utilizing our internally developed tri-axial electrospinning set up to produce the novel microstructures as seen in the respective MTAM variants. A key uniqueness of this study is the ability to produce self-arranged fibers into the respective MTAM variants by utilizing a single spinneret, which has not been demonstrated before. Of the MTAM variants, we observed a change in the microstructure from a single layered MTAM to the MTAM-A series when the ratio of surfactant to shell flow rate approaches 1:1.92. MTAM-A registered the greatest surface area of 2.2 times compared to the traditional single layered MTAM, with the greatest tensile strength at 1.02 ± 0.13 MPa and a maximum elongation of 57.70 ± 9.42%. The MTAM-A was selected for downstream immobilization of polymyxin B (PMB) and assembly into our own internally developed and fabricated dialyzer housing. Subsequently, the entire setup was tested with whole blood spiked with endotoxin; and benchmarked against commercial Toraymyxin fibers of the same size. The results demonstrated that the EERD based on the MTAM-A performed superior to that of the commercial equivalent, registering a rapid reduction of 73.18% of endotoxin (vs. Toraymyxin at 38.78%) at time point 15 min and a final total endotoxin removal of 89.43% (vs. Toraymyxin at 65.03%).

RNA interactions in right ventricular dysfunction induced type II cardiorenal syndrome

Right ventricular (RV) dysfunction induced type II cardiorenal syndrome (CRS) has a high mortality rate, but little attention has been paid to this disease, and its unique molecular characteristics remain unclear. This study aims to investigate the transcriptomic expression profile in this disease and identify key RNA pairs that regulate related molecular signaling networks. We established an RV dysfunction-induced type II CRS mouse model by pulmonary artery constriction (PAC). PAC mice developed severe RV hypertrophy and fibrosis; renal atrophy and dysfunction with elevated creatinine were subsequently observed. Expression profiles in RV and kidney tissues were obtained by whole transcriptome sequencing, revealing a total of 741 and 86 differentially expressed (DE) mRNAs, 159 and 29 DEmiRNAs and 233 and 104 DEcircRNAs between RV and kidney tissue, respectively. Competing endogenous RNA (ceRNA) networks were established. A significant alteration in proliferative, fibrotic and metabolic pathways was found based on GO and KEGG analyses, and the network revealed key ceRNA pairs, such as novel_circ_002631/miR-181a-5p/Creb1 and novel_circ_002631/miR-33-y/Kpan6. These findings indicate that significantly dysregulated pathways in RV dysfunction induced type II CRS include Ras, PI3K/Akt, cGMP-PKG pathways, and thyroid metabolic pathways. These ceRNA pairs can be considered potential targets for the treatment of type II CRS.

Anti-inflammatory, Antioxidant, Lung and Liver Protective Activity of Galaxaura oblongata as Antagonistic Efficacy against LPS using Hematological Parameters and Immunohistochemistry as Biomarkers

BACKGROUND

This study aimed to investigate the potential bioactivity and the ameliorative role of Galaxaura oblongata (G. oblongata) against LPS-induced toxicity by using hematological parameters.

OBJECTIVE

It is aimed also to examine its protective effect using the immunohistochemistry of liver and lungs as biomarkers in male BALB/C albino mice.

MATERIALS AND METHODS

The current study carried out using different in-vitro and in-vivo assays such as phytochemical, antioxidants, anti-inflammatory for in-vitro where the hematological and immunohistochemistry for lung and liver were investigated in vivo.

RESULTS

There are no previous studies were performed to investigate the in vivo and in vitro effects of the G. oblongata extracts as antioxidant and anti-inflammatory due to their rareness compared to other red algae. LPS treated mice revealed a significant decrease in total number of WBCs, RBCs, platelets, and HGB%, MPV, MCV and MCHC compared to the control group. On contrast, the HCT and MCHC were increased in the induction group which was treated with LPS compared to the control group. Furthermore, the immunohistochemistry results of the present study revealed the protective effect of G. oblongata compared to the induction group. G. oblongata can be used as protective marine natural products against the toxicity induced by LPS.

CONCLUSION

It exhibited a significant ameliorative role against the alterations in the hematological parameters and immunohistochemistry of liver and lungs, and helps to reduce as well as coordinate the acute inflammations caused by TNF.

Potential role of lncRNA HULC/miR‑128‑3p/RAC1 axis in the inflammatory response during LPS‑induced sepsis in HMEC‑1 cells

Sepsis is a serious clinical condition characterized by systemic inflammation. The long noncoding RNA (lncRNA) highly upregulated in liver cancer (HULC) was validated to partake in the development of sepsis. The present study aimed to investigate the potential mechanism of HULC in lipopolysaccharide (LPS)-induced sepsis. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis was employed to examine the expression of HULC, microRNA (miR)-128-3p, Rac family small GTPase 1 (RAC1) and pro-inflammatory factors [IL-6, TNF-α, intercellular adhesion molecule (ICAM1) and vascular cell adhesion molecule (VCAM1)] in the serum of patients with sepsis or LPS-induced human dermal microvascular endothelial cells (HMEC-1). Flow cytometry and western blot assays were performed to detect cell apoptosis. The targeted relationship among HULC, miR-128-3p and RAC1 was confirmed by a dual-luciferase reporter assay, RNA binding protein immunoprecipitation (RIP) assay and RNA pull-down assay. HULC and RAC1 were found to be upregulated, and miR-128-3p was downregulated in the serum of patients with sepsis and LPS-stimulated HMEC-1 cells. LPS promoted apoptosis and inflammation, which were decreased by silencing of HULC. HULC targeted miR-128-3p and negatively regulated its expression. HULC knockdown protected HMEC-1 cells from LPS-induced injury by upregulating miR-128-3p. RAC1 was a target of miR-128-3p, and gain of RAC1 also relieved the silencing of HULC-mediated suppressive effects on apoptosis and inflammation in LPS-stimulated HMEC-1 cells. In conclusion, HULC knockdown partially reversed LPS-induced sepsis via the regulation of miR-128-3p/RAC1 axis.

Extraction, Quantification, and Cytokine Inhibitory Response of Bakuchiol in Psoralea coryfolia Linn

(1) Background: The present investigation studies the optimization of extraction, quantification, and cytokine inhibitory effects bakuchiol (BKL) in Psoralea coryfolia Linn. (2) Methods: The seeds of Psoralea coryfolia cleaned, dried, and powdered. Different separation methods maceration, reflux, Soxhlet, and ultrasonic assisted extraction (UAE) were employed for the isolation of BKL by five pure solvents. The quantity of BKL was measured by high-performance liquid chromatography (HPLC) method to determine the highest yield percentage. The effect of optimized BKL was then tested in an animal model of sepsis induced by lipopolysaccharides (LPS). (3) Results: The UAE method was found to be the best among tested separation methods and yielded highest percentage of BKL in petroleum ether extract. Septic rats showed a significant elevation in levels of biochemical markers like AST, ALT, ALP, BIL, SCr, and BUN in plasma. Proinflammatory cytokines (TNF-α and IL-1) levels were also increased in LPS-induced animals. BKL has been found to significantly reverse these elevated levels as compared to the LPS-induced animals. (4) Conclusion: The present results suggest that BKL has positive effects when administered in animals with pathogenic shock by decreasing the circulating levels of biomarkers. Further studies are necessary to explore the clinical implications of such findings.

Challenging the challenge: A randomized controlled trial evaluating the inflammatory response and pain perception of healthy volunteers after single-dose LPS administration, as a potential model for inflammatory pain in early-phase drug development

BACKGROUND AND AIMS

Following an infection, cytokines not only regulate the acute immune response, but also contribute to symptoms such as inflammatory hyperalgesia. We aimed to characterize the acute inflammatory response induced by a human endotoxemia model, and its effect on pain perception using evoked pain tests in two different dose levels. We also attempted to determine whether combining a human endotoxemia challenge with measurement of pain thresholds in healthy subjects could serve as a model to study drug effects on inflammatory pain.

METHODS AND RESULTS

This was a placebo-controlled, randomized, cross-over study in 24 healthy males. Twelve subjects were administered a bolus of 1 ng/kg LPS intravenously, and twelve 2 ng/kg LPS. Before days of placebo/LPS administration, subjects completed a full study day without study drug administration, but with identical pain threshold testing. Blood sampling and evoked pain tests (electrical burst and -stair, heat, pressure, and cold pressor test) were performed pre-dose and at frequent intervals up to 10hr post-dose. Data were analysed with a repeated-measures ANCOVA. For both dose levels, LPS induced an evident acute inflammatory response, but did not significantly affect any of the pain modalities. In a post-hoc analysis, lowering of pain thresholds was observed in the first 3 h after dosing, corresponding with the peak of the acute inflammatory response around 1-3 h post-dose.

CONCLUSION

Mild acute systemic inflammation, as induced by 1 ng/kg and 2 ng/kg LPS intravenous administration, did not significantly change pain thresholds in this study. The endotoxemia model in combination with evoked pain tests is not suitable to study acute inflammatory hyperalgesia in healthy males.

Klotho downregulation contributes to myocardial damage of cardiorenal syndrome in sepsis

Klotho is a type of single-pass transmembrane protein that is important for the proper function of numerous organs. The aim of the present study was to investigate the role of Klotho in sepsis-associated myocardial damage. In the present study, reverse transcription-quantitative PCR, western blotting and ELISA were conducted to examine the expression levels of function genes, and flow cytometry was performed to detect cell apoptosis and reactive oxygen species. The present study demonstrated that Klotho expression was significantly downregulated in septic mice and that the myocardial function of septic mice improved after treatment with exogenous Klotho protein. It further demonstrated that indoxyl sulfate inhibited the expression of Klotho protein. In addition, decreased Klotho protein further led to activation of the reactive oxygen species-p38 mitogen-activated protein kinase signaling pathway, finally resulting in myocardial damage. In conclusion, Klotho protein may be a key regulator in the myocardial damage of cardiorenal syndrome in sepsis. It also has a potential to be a therapeutic target for sepsis-associated myocardial damage in the future.

Plasma Lipopolysaccharide Concentrations in Cardiorenal Syndrome Type 1

BACKGROUND

Cardiorenal syndrome (CRS) type 1 is characterized by a rapid worsening of cardiac function that leads to acute kidney injury (AKI). This study evaluated the role of lipopolysaccharide (LPS) in the development of AKI in patients with acute heart failure (AHF) and its relationship with renal parameters, to enable a better comprehension of the pathophysiology of CRS type 1.

METHODS

We enrolled 32 AHF patients, 15 of whom were classified as having CRS type 1. Eight of these 15 exhibited AKI at the time of admission (caused by AHF) and the other 7 developed AKI during their stay in hospital (in the first 48 h). We evaluated the plasmatic LPS concentrations as well as conventional (serum creatinine [sCr] and urea) and unconventional (neutrophil gelatinase-associated lipocalin [NGAL] and cystatin C) renal markers.

RESULTS

LPS levels were significantly higher in the CRS type 1 patients. No significant difference in LPS level was found in patients who were admitted with AKI and those developed AKI in hospital, but there was a tendency towards a higher level of LPS in CRS type 1 patients admitted with AKI. The LPS concentrations at admission were similar in CRS type 1 survivors (n = 12) and nonsurvivors (n = 3) (p = 0.22). We observed a positive correlation between LPS level and NGAL, Scr at admission and peak Scr during hospitalization and urea at admission.

CONCLUSION

CRS type 1 patients present with an increased level of LPS and there is a direct correlation between LPS and renal parameters. This pilot research is the first study to explore the premise of LPS as novel pathophysiological factor in CRS type 1.

Potentially Important Therapeutic Interactions between Antibiotics, and a Specially Engineered Emulsion Drug Vehicle Containing Krill-Oil-Based Phospholipids and Omega-3 Fatty Acids

The incidence of antimicrobial resistance (AMR) worldwide is increasing as the pipeline for the development of new chemotherapeutic entities is decreasing. Clearly, overexposure to antibiotics, including excessive dosing, is a key factor that fuels AMR. In fact, most of the new antibacterial agents under development are derivatives of existing classes of antibiotics. Novel approaches involving unique antimicrobial combinations, targets, and/or delivery systems are under intense investigation. An innovative combination of active pharmaceutical ingredients (APIs) consisting of antimicrobial drug(s), krill-oil-based phospholipids, and omega-3 fatty acid triglycerides, that may extend the therapeutic viability of currently effective antibiotics, at least until new chemical entities are introduced, is described.