Endogenous Molecules Research Articles

Oleanolic acid improved intestinal immune function by activating and potentiating bile acids receptor signaling in E. coli-challenged piglets

BackgroundInfection with pathogenic bacteria during nonantibiotic breeding is one of the main causes of animal intestinal diseases. Oleanolic acid (OA) is a pentacyclic triterpene that is ubiquitous in plants. Our previous work demonstrated the protective effect of OA on intestinal health, but the underlying molecular mechanisms remain unclear. This study investigated whether dietary supplementation with OA can prevent diarrhea and intestinal immune dysregulation caused by enterotoxigenic Escherichia coli (ETEC) in piglets. The key molecular role of bile acid receptor signaling in this process has also been explored.ResultsOur results demonstrated that OA supplementation alleviated the disturbance of bile acid metabolism in ETEC-infected piglets (P < 0.05). OA supplementation stabilized the composition of the bile acid pool in piglets by regulating the enterohepatic circulation of bile acids and significantly increased the contents of UDCA and CDCA in the ileum and cecum (P < 0.05). This may also explain why OA can maintain the stability of the intestinal microbiota structure in ETEC-challenged piglets. In addition, as a natural ligand of bile acid receptors, OA can reduce the severity of intestinal inflammation and enhance the strength of intestinal epithelial cell antimicrobial programs through the bile acid receptors TGR5 and FXR (P < 0.05). Specifically, OA inhibited NF-κB-mediated intestinal inflammation by directly activating TGR5 and its downstream cAMP-PKA-CREB signaling pathway (P < 0.05). Furthermore, OA enhanced CDCA-mediated MEK-ERK signaling in intestinal epithelial cells by upregulating the expression of FXR (P < 0.05), thereby upregulating the expression of endogenous defense molecules in intestinal epithelial cells.ConclusionsIn conclusion, our findings suggest that OA-mediated regulation of bile acid metabolism plays an important role in the innate immune response, which provides a new diet-based intervention for intestinal diseases caused by pathogenic bacterial infections in piglets.Graphical

Impact of Gut–Brain Axis on Hepatobiliary Diseases in Fetal Programming

The hepatobiliary system is vital for the biotransformation and disposition of endogenous molecules. Any impairment in the normal functioning of the hepatobiliary system leads to a spectrum of hepatobiliary diseases (HBDs), such as liver cirrhosis, fatty liver, biliary dyskinesia, gallbladder cancer, etc. Especially in pregnancy, HBD may result in increased maternal and fetal morbidity and mortality. Maternal HBD is a burden to the fetus’s growth, complicates fetal development, and risks the mother’s life. In fetal programming, the maternal mechanism is significantly disturbed by multiple factors (especially diet) that influence the development of the fetus and increase the frequency of metabolic diseases later in life. Additionally, maternal under-nutrition or over-nutrition (especially in high-fat, high-carbohydrate, or protein-rich diets) lead to dysregulation in gut hormones (CCK, GLP-1, etc.), microbiota metabolite production (SCFA, LPS, TMA, etc.), neurotransmitters (POMC, NPY, etc.), and hepatobiliary signaling (insulin resistance, TNF-a, SREBPs, etc.), which significantly impact fetal programming. Recently, biotherapeutics have provided a new horizon for treating HBD during fetal programming to save the lives of the mother and fetus. This review focuses on how maternal impaired hepatobiliary metabolic signaling leads to disease transmission to the fetus mediated through the gut–brain axis.

Crosstalk between brassinosteroids and other phytohormones during plant development and stress adaption.

Brassinosteroids (BRs) are a group of polyhydroxylated phytosterols that play essential roles in regulating plant growth and development as well as stress adaptation. It is worth noting that BRs do not function alone, but rather they crosstalk with other endogenous signaling molecules, including the phytohormones auxin, cytokinins (CKs), gibberellins (GAs), abscisic acid (ABA), ethylene (ET), jasmonates (JAs), salicylic acid (SA), and strigolactones (SLs), forming elaborate signaling networks to modulate plant growth and development. BRs interact with other phytohormones mainly by regulating each others' homeostasis, transport, or signaling pathway at the transcriptional and posttranslational levels. In this review, we focus our attention on current research progress in BR signal transduction and the crosstalk between BRs and other phytohormones.

IL-2RG as a possible immunotherapeutic target in CRC predicting poor prognosis and regulated by miR-7-5p and miR-26b-5p

Despite advances in treatment strategies, colorectal cancer (CRC) continues to cause significant morbidity and mortality, with mounting evidence a close link between immune system dysfunctions issued. Interleukin-2 receptor gamma (IL-2RG) plays a pivotal role as a common subunit receptor in the IL-2 family cytokines and activates the JAK-STAT pathway. This study delves into the role of Interleukin-2 receptor gamma (IL-2RG) within the tumor microenvironment and investigates potential microRNAs (miRNAs) that directly inhibit IL-2RG, aiming to discern their impact on CRC clinical outcomes. Bioinformatics analysis revealed a significant upregulation of IL-2RG mRNA in TCGA-COAD samples and showed strong correlations with the infiltration of various lymphocytes. Single-cell analysis corroborated these findings, highlighting IL-2RG expression in critical immune cell subsets. To explore miRNA involvement in IL-2RG dysregulation, mRNA was isolated from the tumor tissues and lymphocytes of 258 CRC patients and 30 healthy controls, and IL-2RG was cloned into the pcDNA3.1/CT-GFP-TOPO vector. Human embryonic kidney cell lines (HEK-293T) were transfected with this construct. Our research involved a comprehensive analysis of miRPathDB, miRWalk, and Targetscan databases to identify the miRNAs associated with the 3′ UTR of human IL-2RG. The human microRNA (miRNA) molecules, hsa-miR-7-5p and hsa-miR-26b-5p, have been identified as potent suppressors of IL-2RG expression in CRC patients. Specifically, the downregulation of hsa-miR-7-5p and hsa-miR-26b-5p has been shown to result in the upregulation of IL-2RG mRNA expression in these patients. Prognostic evaluation of IL-2RG, hsa-miR-7-5p, and hsa-miR-26b-5p, using TCGA-COAD data and patient samples, established that higher IL-2RG expression and lower expression of both miRNAs were associated with poorer outcomes. Additionally, this study identified several long non-coding RNAs (LncRNAs), such as ZFAS1, SOX21-AS1, SNHG11, SNHG16, SNHG1, DLX6-AS1, GAS5, SNHG6, and MALAT1, which may act as competing endogenous RNA molecules for IL2RG by sequestering shared hsa-miR-7-5p and hsa-miR-26b-5p. In summary, this investigation underscores the potential utility of IL-2RG, hsa-miR-7-5p, and hsa-miR-26b-5p as serum and tissue biomarkers for predicting CRC patient prognosis while also offering promise as targets for immunotherapy in CRC management.Graphical

PNA-Functionalized, Silica Nanowires-Filled Glass Microtube for Ultrasensitive and Label-Free Detection of miRNA-21.

MicroRNAs (miRNAs) are endogenous and noncoding single-stranded RNA molecules with a length of approximately 18-25 nucleotides, which play an undeniable role in early cancer screening. Therefore, it is very important to develop an ultrasensitive and highly specific method for detecting miRNAs. Here, we present a bottom-up assembly approach for modifying glass microtubes with silica nanowires (SiNWs) and develop a label-free sensing platform for miRNA-21 detection. The three-dimensional (3D) networks formed by SiNWs make them abundant and highly accessible sites for binding with peptide nucleic acid (PNA). As a receptor, PNA has no phosphate groups and exhibits an overall electrically neutral state, resulting in a relatively small repulsion between PNA and RNA, which can improve the hybridization efficiency. The SiNWs-filled glass microtube (SiNWs@GMT) sensor enables ultrasensitive, label-free detection of miRNA-21 with a detection limit as low as 1 aM at a detection range of 1 aM-100 nM. Noteworthy, the sensor can still detect miRNA-21 in the range of 102-108 fM in complex solutions containing 1000-fold homologous interference of miRNAs. The high anti-interference performance of the sensor enables it to specifically recognize target miRNA-21 in the presence of other miRNAs and distinguish 1-, 3-mismatch nucleotide sequences. Significantly, the sensor platform is able to detect miRNA-21 in the lysate of breast cancer cell lines (e.g., MCF-7 cells and MDA-MB-231 cells), indicating that it has good potential in the screening of early breast cancers.

Regulation of immune responses to infection through interaction between stem cell-derived exosomes and toll-like receptors mediated by microRNA cargoes.

Infectious diseases are among the factors that account for a significant proportion of disease-related deaths worldwide. The primary treatment approach to combat microbial infections is the use of antibiotics. However, the widespread use of these drugs over the past two decades has led to the emergence of resistant microbial species, making the control of microbial infections a serious challenge. One of the most important solutions in the field of combating infectious diseases is the regulation of the host's defense system. Toll-like receptors (TLRs) play a crucial role in the first primary defense against pathogens by identifying harmful endogenous molecules released from dying cells and damaged tissues as well as invading microbial agents. Therefore, they play an important role in communicating and regulating innate and adaptive immunity. Of course, excessive activation of TLRs can lead to disruption of immune homeostasis and increase the risk of inflammatory reactions. Targeting TLR signaling pathways has emerged as a new therapeutic approach for infectious diseases based on host-directed therapy (HDT). In recent years, stem cell-derived exosomes have received significant attention as factors regulating the immune system. The regulation effects of exosomes on the immune system are based on the HDT strategy, which is due to their cargoes. In general, the mechanism of action of stem cell-derived exosomes in HDT is by regulating and modulating immunity, promoting tissue regeneration, and reducing host toxicity. One of their most important cargoes is microRNAs, which have been shown to play a significant role in regulating immunity through TLRs. This review investigates the therapeutic properties of stem cell-derived exosomes in combating infections through the interaction between exosomal microRNAs and Toll-like receptors.

A New Paradigm in Spinal Cord Injury Therapy: from Cell-free Treatment to Engineering Modifications.

Spinal cord injury (SCI) is an intractable and poorly prognostic neurological disease, and current treatments are still unable to cure it completely and avoid sequelae. Extracellular vesicles (EVs), as important carriers of intercellular communication and pharmacological effects, are considered to be the most promising candidates for SCI therapy because of their low toxicity and immunogenicity, their ability to encapsulate endogenous bioactive molecules (e.g., proteins, lipids, and nucleic acids), and their ability to cross the blood-brain/cerebrospinal barriers. However, poor targeting, low retention rate, and limited therapeutic efficacy of natural EVs have bottlenecked EVs-based SCI therapy. A new paradigm for SCI treatment will be provided by engineering modified EVs. Furthermore, our limited understanding of the role of EVs in SCI pathology hinders the rational design of novel EVbased therapeutic approaches. In this study, we review the pathophysiology after SCI, especially the multicellular EVs-mediated crosstalk; briefly describe the shift from cellular to cell-free therapies for SCI treatment; discuss and analyze the issues related to the route and dose of EVs administration; summarize and present the common strategies for EVs drug loading in the treatment of SCI and point out the shortcomings of these drug loading methods; finally, we analyze and highlight the feasibility and advantages of bio-scaffold-encapsulated EVs for SCI treatment, providing scalable insights into cell-free therapy for SCI.

Pleiotropic effects of nitric oxide sustained-release system for peripheral nerve repair

The regenerative microenvironment after peripheral nerve injury is imbalanced and difficult to rebalance, which is mainly affected by inflammation, oxidative stress, and inadequate blood supply. The difficulty in remodeling the nerve regeneration microenvironment is the main reason for slow nerve regeneration. Traditional drug treatments have certain limitations, such as difficulty in penetrating the blood-nerve barrier and lack of pleiotropic effects. Therefore, there is an urgent need to build multifunctional nerve grafts that can effectively regulate the regenerative microenvironment and promote nerve regeneration. Nitric oxide (NO), a highly effective gas transmitter with diatomic radicals, is an important regulator of axonal growth and migration, synaptic plasticity, proliferation of neural precursor cells, and neuronal survival. Moreover, NO provides potential anti-inflammation, anti-oxidation, and blood vessel promotion applications. However, excess NO may cause cell death and neuroinflammatory cell damage. The prerequisite for NO treatment of peripheral nerve injury is that it is gradually released over time. In this study, we constructed an injectable NO slow-release system with two main components, including macromolecular NO donor nanoparticles (mPEG-P(MSNO-EG) nanoparticles, NO-NPs) and a carrier for the nanoparticles, mPEG-PA-PP injectable temperature-sensitive hydrogel. Due to the multiple physiological regulation of NO and better physiological barrier penetration, the conduit effectively regulates the inflammatory response and oxidative stress of damaged peripheral nerves, promotes nerve vascularization, and nerve regeneration and docking, accelerating the nerve regeneration process. Statement of SignificanceThe slow regeneration speed of peripheral nerves is mainly due to the destruction of the regeneration microenvironment. Neural conduits with drug delivery capabilities have the potential to improve the microenvironment of nerve regeneration. However, traditional drugs are hindered by the blood nerve barrier and cannot effectively target the injured area. NO, an endogenous gas signaling molecule, can freely cross the blood nerve barrier and act on target cells. However, excessive NO can lead to cell apoptosis. In this study, a NO sustained-release system was constructed to regulate the microenvironment of nerve regeneration through various pathways and promote nerve regeneration.

DAMP sensing and sterile inflammation: intracellular, intercellular and inter-organ pathways.

Damage-associated molecular patterns (DAMPs) are endogenous molecules that are released from host cells as a result of cell death or damage. The release of DAMPs in tissues is associated with loss of tissue homeostasis. Sensing of DAMPs by innate immune receptors triggers inflammation, which can be beneficial in initiating the processes that restore tissue homeostasis but can also drive inflammatory diseases. In recent years, the sensing of intracellular DAMPs has received extensive attention in the field of sterile inflammation. However, emerging studies have shown that DAMPs that originate from neighbouring cells, and even from distal tissues or organs, also mediate sterile inflammatory responses. This multi-level sensing of DAMPs is crucial for intercellular, trans-tissue and trans-organ communication. Here, we summarize how DAMP-sensing receptors detect DAMPs from intracellular, intercellular or distal tissue and organ sources to mediate sterile inflammation. We also discuss the possibility of targeting DAMPs or their corresponding receptors to treat inflammatory diseases.

Construction of a NIR hydrogen sulfide fluorescent probe for revealing the role of astrocytes in hypothalamic inflammation

Hydrogen sulfide (H2S) is a crucial endogenous gas signaling molecule in the central nervous system, playing a significant role in anti-inflammation, anti-oxidation, and neuroprotection. Our studies have shown that the level of H2S is closely related to hypothalamic inflammation-induced obesity. Compared to neurons, astrocytes, exhibit a preferential activation in response to high-fat diet-induced hypothalamic inflammation. Whether the reduction of hydrogen sulfide in astrocytes is the cause of neuronal damage leading to hypothalamic inflammation is worth exploring. The key to discussing the role of astrocytes is to accurately and quickly detect the levels of H2S in the complex microenvironment of the brain. In this work, we designed and synthesized a H2S near-infrared fluorescence probe (NIR-HS) based on dicyanideisophorone. NIR-HS selectively responds to H2S at 668 nm, with an effective linear range (0–20 μM), high sensitivity (35 nM). This probe has been successfully applied to detect hydrogen sulfide levels in astrocytes and to perform H2S fluorescence imaging on the slices of the ventromedial nucleus of the hypothalamus. Additionally, the effect of the H2S donor drug allicin on the levels of H2S in the hypothalamus and its therapeutic effect on hypothalamic inflammation were confirmed using NIR-HS and a series of signal pathway studies. Ultimately, we revealed the mechanism of that H2S inhibits hypothalamic neuronal inflammation by suppressing the expression of the pro-inflammatory factor IL-1β in astrocytes.

Phospholipid Complex Formulation Technology for Improved Drug Delivery in Oncological Settings: a Comprehensive Review.

Addressing poor solubility and permeability issues associated with synthetic drugs and naturally occurring active compounds is crucial for improving bioavailability. This review explores the potential of phospholipid complex formulation technology to overcome these challenges. Phospholipids, as endogenous molecules, offer a viable solution, with drugs complexed with phospholipids demonstrating a similar absorption mechanism. The non-toxic and biodegradable nature of the phospholipid complex positions it as an ideal candidate for drug delivery. This article provides a comprehensive exploration of the mechanisms underlying phospholipid complexes. Special emphasis is placed on the solvent evaporation method, with meticulous scrutiny of formulation aspects such as the phospholipid ratio to the drug and solvent. Characterization techniques are employed to understand structural and functional attributes. Highlighting the adaptability of the phospholipid complex, the review discusses the loading of various nanoformulations and emulsion systems. These strategies aim to enhance drug delivery and efficacy in various malignancies, including breast, liver, lung, cervical, and pancreatic cancers. The broader application of the drug phospholipid complex is showcased, emphasizing its adaptability in diverse oncological settings. The review not only explores the mechanisms and formulation aspects of phospholipid complexes but also provides an overview of key clinical studies and patents. These insights contribute to the intellectual and translational advancements in drug phospholipid complexes.

Endogenous Antimicrobial-Immunomodulatory Molecules: Networking Biomolecules of Innate Immunity.

Endogenous antimicrobial-immunomodulatory molecules (EAIMs) are essential to immune-mediated human health and evolution. Conventionally, antimicrobial peptides (AMPs) have been regarded as the dominant endogenous antimicrobial molecule; however, AMPs are not sufficient to account for the full spectrum of antimicrobial-immunomodulatory duality occurring within the human body. The threat posed by pathogenic microbes is pervasive with the capacity for widespread impact across many organ systems and multiple biochemical pathways; accordingly, the host needs the capacity to react with an equally diverse response. This can be attained by having EAIMs that traverse the full range of molecular size (small to large molecules) and structural diversity (including molecules other than peptides). This review identifies multiple molecules (peptide/protein, lipid, carbohydrate, nucleic acid, small organic molecule, and metallic cation) as EAIMs and discusses the possibility of cooperative, additive effects amongst the various EAIM classes during the host response to a microbial assault. This comprehensive consideration of the full molecular diversity of EAIMs enables the conclusion that EAIMs constitute a previously uncatalogued structurally diverse and collectively underappreciated immuno-active group of integrated molecular responders within the innate immune system's first line of defence.

Lysophosphatidic acid receptor 1 (LPA1) antagonists as potential migrastatics for triple negative breast cancer.

Metastasis is responsible for about 90% of cancer deaths. Anti-metastatic drugs, termed as migrastatics, offer a distinctive therapeutic approach to address cancer migration and invasion. However, therapeutic exploitation of metastasis-specific targets remains limited, and the effective prevention and suppression of metastatic cancer continue to be elusive. Lysophosphatidic acid receptor 1 (LPA1) is activated by an endogenous lipid molecule LPA, leading to a diverse array of cellular activities. Previous studies have shown that the LPA/LPA1 axis supports the progression of metastasis for many types of cancer. In this study, we report the synthesis and biological evaluation of fluorine-containing triazole derivatives as potent LPA1 antagonists, offering potential as migrastatic drugs for triple negative breast cancer (TNBC). In particular, compound 12f, the most potent and highly selective in this series with an IC50 value of 16.0 nM in the cAMP assay and 18.4 nM in the calcium mobilization assay, inhibited cell survival, migration, and invasion in the TNBC cell line. Interestingly, the compound did not induce apoptosis in TNBC cells and demonstrated no cytotoxic effects. These results highlight the potential of LPA1 as a migrastatic target. Consequently, the LPA1 antagonists developed in this study hold promise as potential migrastatic candidates for TNBC.

On Connective Tissue Mast Cells as Protectors of Life, Reproduction, and Progeny.

The connective tissue mast cell (MC), a sentinel tissue-residing secretory immune cell, has been preserved in all vertebrate classes since approximately 500 million years. No physiological role of the MC has yet been established. Considering the power of natural selection of cells during evolution, it is likely that the MCs exert essential yet unidentified life-promoting actions. All vertebrates feature a circulatory system, and the MCs interact readily with the vasculature. It is notable that embryonic MC progenitors are generated from endothelial cells. The MC hosts many surface receptors, enabling its activation via a vast variety of potentially harmful exogenous and endogenous molecules and via reproductive hormones in the female sex organs. Activated MCs release a unique composition of preformed and newly synthesized bioactive molecules, like heparin, histamine, serotonin, proteolytic enzymes, cytokines, chemokines, and growth factors. MCs play important roles in immune responses, tissue remodeling, cell proliferation, angiogenesis, inflammation, wound healing, tissue homeostasis, health, and reproduction. As recently suggested, MCs enable perpetuation of the vertebrates because of key effects-spanning generations-in ovulation and pregnancy, as in life-preserving activities in inflammation and wound healing from birth till reproductive age, thus creating a permanent life-sustaining loop. Here, we present recent advances that further indicate that the MC is a specific life-supporting and progeny-safeguarding cell.

The Construction of CRISPR-Cas9 System Targeting Vector for CYP3A4 Gene in Hepatic Cell Lines

Drug metabolism in the human liver initiated by Cytochrome P450 (CYP450) has been widely acknowledged. They oxidise drugs, harmful compounds, and endogenous molecules like steroids. In our research study, we mainly focused on CYP3A4 of the CYP450 subfamily that is widely available in the liver around 15% - 20% of hepatic content and plays a significant function in metabolising up to 50% of drugs in the market today. However, the CYP3A4 gene encodes CYP3A4 enzymes that are highly polymorphic, which could affect enzymatic activity and cause variable responses in drug metabolism. Clustered Regularly Interspaced Short Palindromic Repeats Associated Protein 9 also known as the CRISPR-Cas9 system is a gene editing method that allows scientists to edit parts of the genome by insertions and deletions. Hence, this method would be useful for genetic variants such as the CYP3A4 gene. The objectives of this study are to design a guide RNA (gRNA), to insert the designed gRNA into pGuide-it-Zs-Green1 vector, to quantify the purified CYP3A4-KO plasmid vector by using NanoDrop® and to transfect the constructed vector in a hepatic cell line. The methodology involved the selection of the gRNA by using the online gene editing tool, Synthego (https://design.synthego.com), annealing oligos of the gRNA for CYP3A4, cloning gRNA into a plasmid vector, isolation, and purification of the CYP3A4-KO plasmid vector. The construction of the CRISPR-Cas9 targeting vector in this study was successfully achieved and promising since the selected gRNA for CYP3A4 gene which is 5’-ATAAATCCCACTGGACCAAA-3’ and located in exon 5 was correctly ligated after the confirmed with sequencing reaction and cloned it into a plasmid vector. The yield of pCYP3A4-KO plasmid DNA was a good candidate for transfection.

Amplified Biosensors Powered by Endogenous Molecules for Intracellular Fluorescence Imaging.

Amplified Biosensors Powered by Endogenous Molecules for Intracellular Fluorescence Imaging.

Electrochemical Detection of Gasotransmitters: Status and Roadmap.

Gasotransmitters, including nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), are a class of gaseous, endogenous signaling molecules that interact with one another in the regulation of critical cardiovascular, immune, and neurological processes. The development of analytical sensing mechanisms for gasotransmitters, especially multianalyte mechanisms, holds vast importance and constitutes a growing area of study. This review provides an overview of electrochemical sensing mechanisms with an emphasis on opportunities in multianalyte sensing. Electrochemical methods demonstrate good sensitivity, adequate selectivity, and the most well-developed potential for the multianalyte detection of gasotransmitters. Future research will likely address challenges with sensor stability and biocompatibility (i.e., sensor lifetime and cytotoxicity), sensor miniaturization, and multianalyte detection in biological settings.

Cutting edge of genetically modified pigs targeting complement activation for xenotransplantation.

In the quest to address the critical shortage of donor organs for transplantation, xenotransplantation stands out as a promising solution, offering a more abundant supply of donor organs. Yet, its widespread clinical adoption remains hindered by significant challenges, chief among them being immunological rejection. Central to this issue is the role of the complement system, an essential component of innate immunity that frequently triggers acute and chronic rejection through hyperacute immune responses. Such responses can rapidly lead to transplant embolism, compromising the function of the transplanted organ and ultimately causing graft failure. This review delves into three key areas of xenotransplantation research. It begins by examining the mechanisms through which xenotransplantation activates both the classical and alternative complement pathways. It then assesses the current landscape of xenotransplantation from donor pigs, with a particular emphasis on the innovative strides made in genetically engineering pigs to evade complement system activation. These modifications are critical in mitigating the discordance between pig endogenous retroviruses and human immune molecules. Additionally, the review discusses pharmacological interventions designed to support transplantation. By exploring the intricate relationship between the complement system and xenotransplantation, this retrospective analysis not only underscores the scientific and clinical importance of this field but also sheds light on the potential pathways to overcoming one of the major barriers to the success of xenografts. As such, the insights offered here hold significant promise for advancing xenotransplantation from a research concept to a viable clinical reality.

N-oleoyl alanine attenuates nicotine reward and spontaneous nicotine withdrawal in mice

BackgroundAs nicotine dependence represents a longstanding major public health issue, new nicotine cessation pharmacotherapies are needed. Administration of N-oleoyl glycine (OlGly), an endogenous lipid signaling molecule, prevents nicotine-induced conditioned place preference (CPP) through a peroxisome proliferator-activated receptor-alpha (PPARα) dependent mechanism, and also ameliorated withdrawal signs in nicotine-dependent mice. Pharmacological evidence suggests that the methylated analog of OlGly, N-oleoyl alanine (OlAla), has an increased duration of action and may offer translational benefit. Accordingly, OlAla was assessed in nicotine CPP and dependence assays as well as its pharmacokinetics compared to OlGly. MethodsICR female and male mice were tested in nicotine-induced CPP with and without the PPARα antagonist GW6471. OlAla was also assessed in nicotine-dependent mice following removal of nicotine minipumps: somatic withdrawal signs, thermal hyper-nociception and altered affective behavior (i.e., light/dark box). Finally, plasma and brain were collected after administration of OlGly or OlAla and analyzed by high-performance liquid chromatography tandem mass spectrometry. ResultsOlAla prevented nicotine-induced CPP, but this effect was not blocked by GW6471. OlAla attenuated somatic and affective nicotine withdrawal signs, but not thermal hyper-nociception in nicotine-dependent mice undergoing withdrawal. OlAla and OlGly showed similar time-courses in plasma and brain. ConclusionsThe observation that both molecules showed similar pharmacokinetics argues against the notion that OlAla offers increased metabolic stability. Moreover, while these structurally similar lipids show efficacy in mouse models of reward and dependence, they reduce nicotine reward through distinct mechanisms.

Physiological healing of chronic gastric ulcer is not impaired by the hydrogen sulphide (H2S)-releasing derivative of acetylsalicylic acid (ATB-340): functional and proteomic approaches.

Gastric ulcers affect approx. 10% of population. Non-steroidal anti-inflammatory drugs (NSAIDs), including acetylsalicylic acid (ASA) predispose to or impair the physiologically complex healing ofpre-existing ulcers. Since H2S is an endogenous cytoprotective molecule, we hypothesized that new H2S-releasing ASA-derivative (ATB-340) could overcome pathological impact of NSAIDs on GI regeneration.Clinically translational gastric ulcers were induced in Wistar rats using state-of-the-art microsurgical model employing serosal application of acetic acid. This was followed by 9 days long i.g. daily treatment with vehicle, ATB-340 (6-24mg/kg) or equimolar ASA doses (4-14mg/kg). Ulcer area was assessed macro- and microscopically. Prostaglandin (PG)E2 levels,indicating pharmacological activity of NSAIDsand 8-hydroxyguanozine content,reflecting nucleic acids oxidation in serum/gastric mucosa, were determined by ELISA. Qualitative and/or quantitative pathway-specific alterations at the ulcer margin were evaluated using real-time PCR and mass spectrometry-based proteomics.ASA, unlike ATB-340, dose-dependently delayed/impaired gastric tissue recovery, deregulating 310 proteins at the ulcer margin, including Ras signalling, wound healing or apoptosis regulators. ATB-340 maintained NSAIDs-specific cyclooxygenase-inhibiting capacity on systemic and GI level but in time-dependent manner. High dose of ATB-340 (24mg/kg daily), but not ASA, decreased nucleic acids oxidation and upregulated anti-oxidative/anti-inflammatory heme oxygenase-1, 24-dehydrocholesterol reductase or suppressor of cytokine signalling (SOCS3) at the ulcer margin.Thus, ASA impairs the physiological healing of pre-existing gastric ulcers, inducing the extensive molecularly functional and proteomic alterations at the wound margin. H2S-releasing ATB-340 maintains the target activity of NSAIDs with limited impact on gastric PGE2 signalling and physiological GI regeneration, enhancing anti-inflammatory and anti-oxidative response, andproviding the pharmacological advantage.