Curcumin alleviates myocardial inflammation, apoptosis, and oxidative stress induced by acute pulmonary embolism by regulating microRNA-145-5P/insulin receptor substrate 1 axis.

The treatment of patients with acute pulmonary embolism (APE) is extremely challenging due to the complex clinical presentation and prognosis of APE related to the patient's hemodynamic status and insufficient arterial blood flow and right ventricular overload. Protective efficacy against cardiovascular diseases of curcumin, a common natural polyphenolic compound, which has antithrombotic properties and reduces platelet accumulation in the circulation by inhibiting thromboxane synthesis has been demonstrated. However, the direct effect of curcumin on APE has rarely been studied. Therefore, the present study aimed to investigate the therapeutic potential of curcumin in APE and associated myocardial injury to provide new insights into curcumin as a promising competitive new target for the treatment of APE. A suspension of 12 mg/kg microspheres was injected intravenously into rats. An APE rat model was built. Before modeling, intragastric 100 mg/kg curcumin was given, and/or lentiviral plasmid vector targeting microRNA-145-5p or insulin receptor substrate 1 (IRS1) was injected. Pulmonary artery pressure was measured to assess right ventricular systolic pressure (RVSP). Hematoxylin and eosin (H&E) staining was performed on liver tissues and myocardial tissues of APE rats. TUNEL (terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling) staining and immunohistochemical (IHC) staining were conducted to measure apoptosis and CyPA-CD147 expression in the myocardium, respectively. Inflammatory indices interleukin-1beta (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were measured by ELISA in cardiac tissues. RT-qPCR and Western blot were performed to determine the expression levels of related genes. In addition, by dual luciferase reporter assay and RIP assay, the relationship between microRNA-145-5p and insulin receptor substrate 1 (IRS1) was confirmed. In results: curcumin improved APE-induced myocardial injury, reduced myocardial tissue edema, and thrombus volume. It attenuated APE-induced myocardial inflammation and apoptosis, as well as reduced lung injury and pulmonary artery pressure. Curcumin promoted microRNA-145-5p expression in APE rat myocardium. MicroRNA-145-5p overexpression protected against APE-induced myocardial injury, and microRNA-145-5p silencing abolished the beneficial effects of curcumin in APE-induced myocardial injury. IRS1 was targeted by microRNA-145-5p. IRS1 silencing attenuated APE-induced myocardial injury, and enhanced therapeutic effect of curcumin on myocardial injury in APE rats. In conclusion, curcumin alleviates myocardial inflammation, apoptosis, and oxidative stress induced by APE by regulating microRNA-145-5p/IRS1 axis.

Digging deeper into ancient skeletal proteomes through consecutive digestion with multiple proteases.

An increasing number of studies utilise the recovery of ancient skeletal proteomes for phylogenetic and evolutionary analysis. Although these studies manage to extract and analyse ancient peptides, the recovered proteomes are generally small in size and with low protein sequence coverage. We expand on previous observations which have shown that the parallel digestion and analysis of Pleistocene skeletal proteomes increases overall proteome size and protein sequence coverage. Furthermore, we demonstrate that the consecutive digestion of a skeletal proteome using two proteases, particularly the combination of Glu-C or chymotrypsin followed by trypsin digestion, enables the recovery of alternative proteome components not reachable through trypsin digestion alone. The proteomes preserved in Pleistocene skeletal specimens are larger than previously anticipated, but unlocking this protein sequence information requires adaptation of extraction and protein digestion protocols. The sequential utilisation of several proteases is, in this regard, a promising avenue for the study of highly degraded but unique hominin proteomes for phylogenetic purposes. SIGNIFICANCE: Palaeoproteomic analysis of archaeological materials, such as hominin skeletal elements, show great promise in studying past organisms and evolutionary relationships. However, as most proteomic methods are inherently destructive, it is essential to aim to recover as much information as possible from every sample. Currently, digestion with trypsin is the standard approach in most palaeoproteomic studies. We find that parallel or consecutive digestion with multiple proteases can improve proteome size and coverage for both Holocene and Pleistocene bone specimens. This allows for recovery of more proteomic data from a sample and maximises the chance of recovering phylogenetically relevant information.

Neurotoxicant effects of bisphenol A, nonylphenol, and tert­butyl phenol in the Nile tilapia (Oreochromis niloticus).

Worldwide production of alkyl phenols and ethoxylated alkyl phenols is high due to their broad industrial uses. It has been widely documented that they are endocrine disruptors, and it has been suggested that they could exert neurotoxic effects. However, a lack of information about the neurotoxic effects of APs and APEs prevails. In this study, the bisphenol A (BPA), 4-nonylphenol (NP), and 3­tert-butylphenol (tertBP) effects on brain and spinal cord of Nile tilapia exposed to environmental concentrations were evaluated by assessing acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and carboxylesterases (CES) activities, and γ-aminobutyric acid (GABA) levels and their effects were evaluated by molecular docking. BPA and NP, tertBP behave as agonists and antagonists of AChE, BuChE, CES, and GABA, with notable differences among organs. However, none of these compounds or their metabolites interact with the enzymes' catalytic triad, suggesting an indirect alteration of enzymatic activities. While inhibiting these enzymes stand out hydrophobic interactions with the peripheral anion site, contacts with the inner face of the active site and blocking the mouth of the gorge of the active site, and steric hindrance in the enzyme pocket of glutamate decarboxylase (GAD). In contrast, inductions probably are by homotropic pseudo-cooperative phenomenon, where APEs behave as anchors favoring the active site to remain open and interactions that confer a conservative stabilization of the regulatory domain. Although the results of this study are complex, with notable differences between organs and toxicants, they are some of the first evidence of the neurotoxicity of alkylphenols and their ethoxylated derivatives.

Diverse cytomegalovirus US11 antagonism and MHC-A evasion strategies reveal a tit-for-tat coevolutionary arms race in hominids.

Recurrent, ancient arms races between viruses and hosts have shaped both host immunological defense strategies as well as viral countermeasures. One such battle is waged by the glycoprotein US11 encoded by the persisting human cytomegalovirus. US11 mediates degradation of major histocompatibility class I (MHC-I) molecules to prevent CD8+ T-cell activation. Here, we studied the consequences of the arms race between US11 and primate MHC-A proteins, leading us to uncover a tit-for-tat coevolution and its impact on MHC-A diversification. We found that US11 spurred MHC-A adaptation to evade viral antagonism: In an ancestor of great apes, the MHC-A A2 lineage acquired a Pro184Ala mutation, which confers resistance against the ancestral US11 targeting strategy. In response, US11 deployed a unique low-complexity region (LCR), which exploits the MHC-I peptide loading complex to target the MHC-A2 peptide-binding groove. In addition, the global spread of the human HLA-A*02 allelic family prompted US11 to employ a superior LCR strategy with an optimally fitting peptide mimetic that specifically antagonizes HLA-A*02. Thus, despite cytomegaloviruses low pathogenic potential, the increasing commitment of US11 to MHC-A has significantly promoted diversification of MHC-A in hominids.

APE-Gen2.0: Expanding Rapid Class I Peptide-Major Histocompatibility Complex Modeling to Post-Translational Modifications and Noncanonical Peptide Geometries.

The recognition of peptides bound to class I major histocompatibility complex (MHC-I) receptors by T-cell receptors (TCRs) is a determinant of triggering the adaptive immune response. While the exact molecular features that drive the TCR recognition are still unknown, studies have suggested that the geometry of the joint peptide-MHC (pMHC) structure plays an important role. As such, there is a definite need for methods and tools that accurately predict the structure of the peptide bound to the MHC-I receptor. In the past few years, many pMHC structural modeling tools have emerged that provide high-quality modeled structures in the general case. However, there are numerous instances of non-canonical cases in the immunopeptidome that the majority of pMHC modeling tools do not attend to, most notably, peptides that exhibit non-standard amino acids and post-translational modifications (PTMs) or peptides that assume non-canonical geometries in the MHC binding cleft. Such chemical and structural properties have been shown to be present in neoantigens; therefore, accurate structural modeling of these instances can be vital for cancer immunotherapy. To this end, we have developed APE-Gen2.0, a tool that improves upon its predecessor and other pMHC modeling tools, both in terms of modeling accuracy and the available modeling range of non-canonical peptide cases. Some of the improvements include (i) the ability to model peptides that have different types of PTMs such as phosphorylation, nitration, and citrullination; (ii) a new and improved anchor identification routine in order to identify and model peptides that exhibit a non-canonical anchor conformation; and (iii) a web server that provides a platform for easy and accessible pMHC modeling. We further show that structures predicted by APE-Gen2.0 can be used to assess the effects that PTMs have in binding affinity in a more accurate manner than just using solely the sequence of the peptide. APE-Gen2.0 is freely available at https://apegen.kavrakilab.org.

Signatures of Co-evolution and Co-regulation in the CYP3A and CYP4F Genes in Humans.

Cytochromes P450 (CYP450) are hemoproteins generally involved in the detoxification of the body of xenobiotic molecules. They participate in the metabolism of many drugs and genetic polymorphisms in humans have been found to impact drug responses and metabolic functions. In this study, we investigate the genetic diversity of CYP450 genes. We found that two clusters, CYP3A and CYP4F, are notably differentiated across human populations with evidence for selective pressures acting on both clusters: we found signals of recent positive selection in CYP3A and CYP4F genes and signals of balancing selection in CYP4F genes. Furthermore, an extensive amount of unusual linkage disequilibrium is detected in this latter cluster, indicating co-evolution signatures among CYP4F genes. Several of the selective signals uncovered co-localize with expression quantitative trait loci (eQTL), which could suggest epistasis acting on co-regulation in these gene families. In particular, we detected a potential co-regulation event between CYP3A5 and CYP3A43, a gene whose function remains poorly characterized. We further identified a causal relationship between CYP3A5 expression and reticulocyte count through Mendelian randomization analyses, potentially involving a regulatory region displaying a selective signal specific to African populations. Our findings linking natural selection and gene expression in CYP3A and CYP4F subfamilies are of importance in understanding population differences in metabolism of nutrients and drugs.

Phytochemical profiles, antioxidant activities, and synergistic antiproliferative effects of blueberry and apple peel extracts.

BACKGROUND: Blueberries and apples exhibit favorable bioactivity and health benefits as a result of their rich phytochemicals. Natural phytochemicals exist in complex forms, but there are few reports on whether have additive, synergistic or antagonistic effects between different phytochemicals. The present study aimed to elucidate the synergistic effects of blueberry extract (BE) and apple peel extract (APE) together with respect to inhibiting the proliferation of HepG2 liver cancer cells. Meanwhile, phytochemical characterization of BE and APE was conducted by HPLC, and total antioxidant activity was determined via a cellular antioxidant activity assay, oxygen radical absorption capacity assay and peroxy radical scavenging capacity assay. RESULTS: The results showed that BE and APE were rich in phytochemicals and had potent antioxidant activities, which synergistically inhibited cell proliferation. In the bilateral combination, the dose reduction index value increased by two-fold, and the combination index value at 95% inhibition was less than 1. Additionally, BE + APE supplementation could promote the expression levels of p53 and c-myc genes. In conclusion, the BE and APE had strong antioxidant activity and exhibited synergistic inhibition against proliferation of HepG2 cells. CONCLUSION: The present study can provide a theoretical basis for the synergistic effect of different phytochemicals in health care. © 2023 Society of Chemical Industry.

Preventive Effects of Apple Polyphenol Extract on High-Fat-Diet-Induced Hepatic Steatosis Are Related to the Regulation of Hepatic Lipid Metabolism, Autophagy, and Gut Microbiota in Aged Mice.

Our previous study confirmed that the ameliorated effects of an intervention with an apple polyphenol extract (APE) on hepatic steatosis induced by a high-fat diet (HFD) are dependent on SIRT1. Since SIRT1 expression decreases with age, it remains unclear whether APE intervention is effective against hepatic steatosis in aged mice. Thus, 12-month-old C57BL/6 male mice were fed with an HFD to establish an aging model of hepatic steatosis and treated with 500 mg/(kg·bw·d) APE for 12 weeks. Young mice (two months old) and baseline mice were used as controls to examine the effects of natural aging on hepatic steatosis. Compared with baseline mice, no obvious difference in hepatic histopathological assessment was observed for both young and aged mice on normal diets. Meanwhile, HFD induced much higher nonalcoholic fatty liver disease (NAFLD) activity scores in aged mice than in young mice. APE intervention ameliorated lipid and glucose metabolic disorders and liver injury in HFD-fed aged mice, improved hepatic steatosis, and reduced NAFLD activity scores. The upregulated expressions of SIRT1, HSL, ATG5, Ulk1, and Becn1 and downregulated expressions of HMGCR and FOXO1 suggested improved lipid metabolism and activated autophagy. APE intervention decreased the ratio of Firmicutes/Bacteroidetes and elevated the Akkermansia probiotics abundance. In summary, HFD showed a more significant effect on hepatic steatosis compared to the natural aging process in aged mice, and APE might be a promising dietary ingredient for alleviating hepatic steatosis.

Wheat Germ-Derived Peptide Alleviates Dextran Sulfate Sodium-Induced Colitis in Mice.

This study explores the protective properties and potential mechanisms of wheat-germ-derived peptide APEPEPAF (APE) against ulcerative colitis. Colitis mice induced by dextran sulfate sodium (DSS) were used as the animal model. The results showed that the APE peptide could alleviate colitis symptoms including weight loss, colon shortening, and histopathological changes. This peptide attenuated the generation of inflammatory cytokines by inhibiting the phosphorylation of protein kinase PKCζ (Thr410) and NF-κB transcriptional activity in DSS-induced mice, suggesting that APE ameliorates colitis inflammation by regulating the PKCζ/NF-κB signaling pathway. APE also preserved the barrier function of the colon by dose-dependently promoting the expression of tight junction proteins (claudin-1, zonula occluded-1, and occludin). In addition, APE significantly decreased the abundance of Bacteroides and increased the abundance of Dubosiella and Lachnospiraceae_UCG-006 to improve the intestinal flora imbalance in DSS-induced colitis mice. Therefore, wheat germ peptide APE can be used as a novel agent and dietary supplement to treat ulcerative colitis..

Apple Polyphenol Extract Ameliorates Atherosclerosis and Associated Cognitive Impairment through Alleviating Neuroinflammation by Weakening TLR4 Signaling and NLRP3 Inflammasome in High-Fat/Cholesterol Diet-Fed LDLR-/- Male Mice.

Although studies have supported the beneficial effects of the ingredients of apple polyphenol extract (APE), a polyphenol mixture being extracted from whole fresh apples, on neurodegenerative diseases, the role of APE in atherosclerosis-related cognitive impairment remains unclear. To clarify the role of APE in regulating cognitive dysfunction in mice with atherosclerosis and the underlying mechanisms, high-fat/cholesterol diet-fed male LDLR-/- mice were gavaged with 125 or 500 mg/(kg·bw·d) APE solution or sterile double-distilled water for consecutive 8 weeks, and age-matched C57BL/6 male mice were employed as normal control. APE intervention increased the serum concentration of high-density apolipoprotein cholesterol, improved atherosclerosis, and ameliorated cognitive function of mice by inhibiting the phosphorylation of tau protein, supporting with significantly reduced platform latency and obviously increased swimming distance in the target quadrant according to the Morris water maze test. APE intervention alleviated neuroinflammation by attenuating the activation of microglia and astrocytes and inhibiting TLR4 signaling with reduced protein expression of NF-κB, MyD88, TRIF, and IKKß. Meanwhile, APE intervention inactivated NLRP3 inflammasome with downregulated protein expression of caspase-1, IL-18, and IL-1ß. Additionally, APE intervention improved the damaged brain barrier structure by upregulating the protein expression of ZO-1 and occludin. Therefore, our research supplemented new data, supporting the potential of APE as an effective dietary bioactive ingredient to improve atherosclerosis and associated cognitive impairment.

Machine learning-based protein signatures for differentiating hypertensive disorders of pregnancy.

Hypertensive disorders of pregnancy (HDP) result in major maternal and fetal complications. Our study aimed to find a panel of protein markers to identify HDP by applying machine-learning models. The study was conducted on a total of 133 samples, divided into four groups, healthy pregnancy (HP, n = 42), gestational hypertension (GH, n = 67), preeclampsia (PE, n = 9), and ante-partum eclampsia (APE, n = 15). Thirty circulatory protein markers were measured using Luminex multiplex immunoassay and ELISA. Significant markers were screened for potential predictive markers by both statistical and machine-learning approaches. Statistical analysis found seven markers such as sFlt-1, PlGF, endothelin-1(ET-1), basic-FGF, IL-4, eotaxin and RANTES to be altered significantly in disease groups compared to healthy pregnant. Support vector machine (SVM) learning model classified GH and HP with 11 markers (eotaxin, GM-CSF, IL-4, IL-6, IL-13, MCP-1, MIP-1α, MIP-1ß, RANTES, ET-1, sFlt-1) and HDP with 13 markers (eotaxin, G-CSF, GM-CSF, IFN-gamma, IL-4, IL-5, IL-6, IL-13, MCP-1, MIP-1ß, RANTES, ET-1, sFlt-1). While logistic regression (LR) model classified PE with 13 markers (basic FGF, IL-1ß, IL-1ra, IL-7, IL-9, MIP-1ß, RANTES, TNF-alpha, nitric oxide, superoxide dismutase, ET-1, PlGF, sFlt-1) and APE by 12 markers (eotaxin, basic-FGF, G-CSF, GM-CSF, IL-1ß, IL-5, IL-8, IL-13, IL-17, PDGF-BB, RANTES, PlGF). These markers may be used to diagnose the progression of healthy pregnant to a hypertensive state. Future longitudinal studies with large number of samples are needed to validate these findings.

Aldehyde-Based Inhibitors of the Peptidoglycan O-Acetylesterase Ape.

The O-acetylation of the muramic acid residues in peptidoglycan (PG) is a modification that protects the bacteria from lysis due to the action of lysozyme. In Gram-negative bacteria, deacetylation is required to allow lytic transglycosylases to promote PG cleavage during cell growth and division. This deacetylation is catalyzed by O-acetylpeptidoglycan esterase (Ape) which is a serine esterase and employs covalent catalysis via a serine-linked acyl enzyme intermediate. Loss of Ape activity affects the size and shape of bacteria and dramatically reduces virulence. In this work, we report the first rationally designed aldehyde-based inhibitors of Ape from Campylobacter jejuni. The most potent of these acts as a competitive inhibitor with a Ki value of 13 µM. We suspect that the inhibitors are forming adducts with the active site serine that closely mimic the tetrahedral intermediate of the normal catalytic cycle. Support for this notion is found in the observation that reduction of the aldehyde to an alcohol effectively abolishes the inhibition.

Functional importance and divergence of plant apurinic/apyrimidinic endonucleases in somatic and meiotic DNA repair.

Apurinic/apyrimidinic (AP) sites are one of the most abundant DNA lesions and are mainly repaired by AP endonucleases (APEs). While most eukaryotic genomes encode two APEs, plants usually possess three APEs, namely APE1L, APE2, and ARP. To date, the biological relevance and functional divergence of plant APEs are unclear. Here, we show that the three plant APEs have ancient origins, with the APE1L clade being plant-specific. In Arabidopsis thaliana, simultaneously mutating APE1L and APE2, but not ARP alone or in combination with either APE1L or APE2, results in clear developmental defects linked to genotoxic stress. Genetic analyses indicated that the three plant APEs have different substrate preferences in vivo. ARP is mainly responsible for AP site repair, while APE1L and APE2 prefer to repair 3'-blocked single-stranded DNA breaks. We further determined that APEs play an important role in DNA repair and the maintenance of genomic integrity in meiotic cells. The ape1l ape2 double mutant exhibited a greatly enhanced frequency of sporulation 1 (SPO11-1)-dependent and SPO11-1-independent double-stranded DNA breaks. The DNA damage response (DDR) was activated in ape1l ape2 to trigger pollen abortion. Our findings suggest functional divergence of plant APEs and reveal important roles of plant APEs during vegetative and reproductive development.

HDAC6 inhibition alleviates acute pulmonary embolism: a possible future therapeutic option.

INTRODUCTION: Acute pulmonary embolism (APE) is a clinical syndrome of pulmonary circulation disorder caused by obstruction of the pulmonary artery or its branches. Histone deacetylase 6 (HDAC6) has been reported to play an important role in lung-related diseases. However, the functional role of HDAC6 in APE remains unclear. MATERIAL AND METHODS: Male Sprague Dawley rats were used. The APE model was constructed by inserting an intravenous cannula into the right femoral vein and injecting Sephadex G-50 microspheres (12 mg/kg; 300 µm in diameter). After 1 h, the control and APE rats were intraperitoneally injected with tubastatin A (TubA) (40 mg/kg, an inhibitor of HDAC6) and sampled at 24 h after modeling. H&E staining, arterial blood gas analysis, and wet/dry (W/D) weight ratio were used to evaluate the histopathological changes and pulmonary function in APE rats. ELISA, Western blot, and immunohistochemistry were used to explore the potential mechanism of HDAC6-mediated inflammation in APE. RESULTS: The results indicated that HDAC6 expression was significantly increased in lungs of APE rats. TubA treatment in vivo decreased HDAC6 expression in lung tissues. HDAC6 inhibition alleviated histopathological damage and pulmonary dysfunction, as evidenced by decreased PaO2/FiO2 ratio and W/D weight ratio in APE rats. Furthermore, HDAC6 inhibition alleviated APE-induced inflammatory response. Specifically, APE rats exhibited increased production of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, IL-6, and IL-18, however, this increase was reversed by HDAC6 inhibition. Meanwhile, the activation of the NLRP3 inflammasome was also observed in lungs of APE rats, while HDAC6 inhibition blocked this activation. Mechanically, we demonstrated that HDAC6 inhibition blocked the activation of the protein kinase B (AKT)/extracellular signal-regulated protein kinase (ERK) signaling pathway, a classic pathway promoting inflammation. CONCLUSIONS: These findings demonstrate that the inhibition of HDAC6 may alleviate lung dysfunction and pathological injury resulting from APE by blocking the AKT/ERK signaling pathway, providing new theoretical fundamentals for APE therapy.

Sirtuin3 confers protection against acute pulmonary embolism through anti-inflammation, and anti-oxidative stress, and anti-apoptosis properties: participation of the AMP-activated protein kinase/mammalian target of rapamycin pathway.

An increasing number of studies have suggested that oxidative stress and inflammation play momentous roles in acute pulmonary embolism (APE). Honokiol, a bioactive biphenolic phytochemical substance, is known for its strong anti-oxidative and anti-inflammatory effects, and it served as an activator of sirtuin3 (SIRT3) in the present study. The purposes of the study were to explore the effects of honokiol on APE rats and investigate whether the function of honokiol is mediated by SIRT3 activation. In the study, the rats received a right femoral vein injection of dextran gel G-50 particles (12 mg/kg) to establish the APE model and were subsequently administered honokiol and/or a selective SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine (3-TYP; 5 mg/kg) intraperitoneally. The results showed that SIRT3 activation by honokiol attenuated the loss in lung function, ameliorated the inflammatory response and oxidative damage, and inhibited apoptosis in lung tissues of the rats with APE but that this was reversed by 3-TYP. In addition, we found that the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway might be activated by honokiol but restrained by 3-TYP. These results indicated that honokiol was capable of suppressing the adverse effects of APE and that this was diminished by SIRT3 suppression, implying that activation of SIRT3 might serve as a therapeutic method for APE.

Potentially reduced fusogenicity of syncytin-2 in New World monkeys.

Syncytin-2 is a membrane fusion protein involved in placenta development that is derived from the endogenous retrovirus envelope gene acquired in the common ancestral lineage of New World and Old World monkeys (OWMs). It is known that syncytin-2 is conserved between apes and OWMs, suggesting its functional importance; however, syncytin-2 of common marmosets (Callithrix jacchus) exhibits lower fusogenic activity than those of humans and OWMs in human cell lines. To obtain insight into the functional diversity of syncytin-2 genes in primates, we examined the syncytin-2 gene in New World monkeys (NWMs). We experimentally evaluated the cell fusion ability of syncytin-2 in humans, C. jacchus, and tufted capuchins (Sapajus apella). We found that the cell fusion ability of S. apella was lower than that of human syncytin-2. Chimeric syncytin-2 constructs revealed that the amino acid differences in the surface unit of S. apella syncytin-2 were responsible for the weak cell fusion activity. In addition, genomic sequence analyses of syncytin-2 revealed that the open reading frames (ORFs) of syncytin-2 were highly conserved in seven apes and 22 OWMs; however, the syncytin-2 ORFs of three of 12 NWM species were truncated. Our results suggest that syncytin-2 in several NWMs may be of less importance than in OWMs and apes, and other syncytin-like genes may be required for placental development in various NWM species.

Discovery, classification, evolution and diversity of Siglecs.

Immunoglobulin (Ig) superfamily proteins play diverse roles in vertebrates, including regulation of cellular responses by sensing endogenous or exogenous ligands. Siglecs are a family of glycan-recognizing proteins belonging to the Ig superfamily (i.e., I-type lectins). Siglecs are expressed on various leukocyte types and are involved in diverse aspects of immunity, including the regulation of inflammatory responses, leukocyte proliferation, host-microbe interaction, and cancer immunity. Sialoadhesin/Siglec-1, CD22/Siglec-2, and myelin-associated glycoprotein/Siglec-4 were among the first to be characterized as members of the Siglec family, and along with Siglec-15, they are relatively well-conserved among tetrapods. Conversely, CD33/Siglec-3-related Siglecs (CD33rSiglecs, so named as they show high sequence similarity with CD33/Siglec-3) are encoded in a gene cluster with many interspecies variations and even intraspecies variations within some lineages such as humans. The rapid evolution of CD33rSiglecs expressed on leukocytes involved in innate immunity likely reflects the selective pressure by pathogens that interact and possibly exploit these Siglecs. Human Siglecs have several additional unique and/or polymorphic properties as compared with closely related great apes, changes possibly related to the loss of the sialic acid Neu5Gc, another distinctly human event in sialobiology. Multiple changes in human CD33rSiglecs compared to great apes include many examples of human-specific expression in non-immune cells, coinciding with human-specific diseases involving such cell types. Some Siglec gene polymorphisms have dual consequences-beneficial in a situation but detrimental in another. The association of human Siglec gene polymorphisms with several infectious and non-infectious diseases likely reflects the ongoing competition between the host and microbial pathogens.

Transcutaneous vagus nerve stimulation attenuates autoantibody-mediated cardiovagal dysfunction and inflammation in a rabbit model of postural tachycardia syndrome.

PURPOSE: Previous studies demonstrated M2 muscarinic acetylcholine receptor-activating autoantibodies (M2R-AAb) were present in some patients with postural tachycardia syndrome (POTS). This study examines how these autoantibodies might contribute to the pathophysiology of POTS, and whether low-level tragus stimulation (LLTS) can ameliorate autoantibody-mediated autonomic dysregulation in the rabbit. METHODS: Five New Zealand white rabbits were immunized with a M2R second extracellular loop peptide to produce cholinomimetic M2R-AAb. Tilt test and infusion studies were performed on conscious rabbits before immunization, 6 weeks after immunization, and 8 weeks after immunization with 2-week daily LLTS treatment. Each rabbit served as its own control. RESULTS: Compared to preimmune state, an enhanced heart rate increase and decreased parasympathetic activity upon tilting were observed in immunized rabbits. Furthermore, these rabbits demonstrated an attenuated heart rate-slowing response to infusion of the M2R orthosteric agonist arecaidine propargyl ester (APE), suggesting an inhibitory allosteric effect of M2R-AAb. There was also a significant increase in serum inflammatory cytokines in immunized rabbits. LLTS treatment suppressed the postural tachycardia, improved the sympathovagal balance with increased acetylcholine secretion, reduced the levels of inflammatory cytokines, and reversed the attenuated heart rate response to APE in immunized rabbits. No suppression of M2R-AAb expression by LLTS was found during this short-term study period. Receptor-modulating activity of M2R-AAb produced in immunized rabbits was confirmed with in vitro bioassay. CONCLUSIONS: Autoantibody inhibition of cholinergic ligand activity may be involved in the development of cardiovagal dysfunction and inflammation associated with POTS, both of which can be improved by vagal stimulation.

The effects of pomegranate peel extract on the gene expressions of antioxidant enzymes in a rat model of alloxan-induced diabetes.

This study was conducted to evaluate the anti-diabetic and antioxidant effects of hydroalcoholic pomegranate peel extract (APE) in alloxan-induced diabetes rat models. We divided 60 rats into the following six equal groups (n = 10): Healthy control; diabetic control (100 mg/kg alloxan); sham + glibenclamide (10 mg/kg); diabetic + glibenclamide (10 mg/kg); sham + APE (200 mg/kg) and diabetic + APE (200 mg/kg). After 8 weeks, kidneys were taken out for biochemical and molecular studies. Following APE treatment, biochemical parameters including malondialdehyde (MDA), and glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) significantly induced in the treated group as compared with the control group (p < 0.05). Also, gene expression of GPx (3-fold), CAT (2.6-fold), and SOD (1.5-fold) were increased as compared to controls (p < 0.05). Overall, our results indicated that pomegranate can be used as an antioxidant agent to reduce complications from diseases associated with oxidative stress.