Role of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor regulation in stress-induced pain chronification

Persistent postsurgical pain is a serious issue in public health, which has received increased interest in recent years. Previous studies have reported that psychological factors promote the development of chronic postsurgical pain. However, it is unclear how chronification of postsurgical pain occurs. The α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPA) phosphorylation in the central nervous system plays a critical role in synaptic plasticity and contributes to central sensitization and chronic pain development. Here, we discuss the role of AMPA receptor regulation in stress-induced pain chronification after surgery.

Regeneration and DNA demethylation do not trigger PDX-1 expression in rat hepatocytes

AIM: To explore the possibility that PDX-1 gene is reactivated as a consequence of molecular events that occur during liver regeneration.

METHODS: Rat hepatocytes were maintained in DMEM-F12, 10% fetal bovine serum (FBS), penicillin/streptomycin and geneticin when applicable. Rat insulinoma RIN 1046-38 cells were maintained in M-199-10% FBS and penicillin/streptomycin. The final concentration of glucose was 11.1 mmol/L. During regeneration, lateral and medial liver lobes of adult male Wistar rats were surgically removed, with up 70% loss of liver mass. In methylation experiments, 5-aza-deoxycytidine (5-aza-dC) was used. Primer3 software was used for polymerase chain reaction (PCR). Quantitative real time PCR (qRT-PCR) was performed using SYBR Green technology; primers were designed by Beacon Designer 6 software. Western blotting and SDS-PAGE were performed according to standard procedures. Antibodies were purchased from commercial suppliers.

RESULTS: We explored the possibility that liver regeneration could trigger PDX-1 expression, and hence insulin production. Twenty-four hours after surgical liver removal, regeneration was active as demonstrated by the increased proliferating cell nuclear antigen; however, all the other checked genes (involved in insulin gene expression): PC-1, Ngn3, NeuroD1, Btc, PDX-1 and Ins-1, were not related to the molecular events caused by this process. The only marker detected in regenerating liver was E47: a transcription factor of the the basic helix-loop-helix family known to be expressed ubiquitously in mammalian cells. In the rat pancreas, almost all of the tested genes were expressed as shown by RT-PCR, except for Ngn3, which was silenced 2 d after birth. Therefore, the molecular events in liver regeneration are not sufficient to promote PDX-1 expression. DNA methylation is a known mechanism to achieve stable repression of gene expression in mammals: Hxk 2 gene is silenced through this mechanism in normal hepatocytes. The administration of 5-aza-dC to cultured cells is in fact able to upregulate Hxk 2 mRNA. We investigated whether PDX-1 silencing in liver cells could be exerted through methylation of CpG islands in both the promoter and the gene coding regions. The results show that the drug increased the expression level of the Hxk 2 control gene but failed to rescue the expression of PDX-1, thus DNA demethylation is not sufficient to override repression of the PDX-1 gene.

CONCLUSION: During liver regeneration, PDX-1 gene is not reactivated. Demethylation does not de-repress PDX-1 gene expression. Therefore gene silencing is not achieved through this epigenetic mechanism.

Refractoriness of interferon-beta signaling through NOD1 pathway in mouse respiratory epithelial cells using the anticancer xanthone compound

AIM: To explore the possibility that nucleotide oligomerization domain 1 (NOD1) pathway involved in refractoriness of interferon-β signaling in mouse respiratory epithelial cells induced by the anticancer xanthone compound, 5,6-dimethylxanthenone-4-acetic acid (DMXAA).

METHODS: C10 mouse bronchial epithelial cells were grown in Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum, 2 mmol/L glutamine, 100 units/mL penicillin, 100 g/mL streptomycin. Pathogen-free female BALB/c mice were used to explore the mechanisms of refractoriness of interferon-signaling. Mouse thioglycollate-elicited peritoneal macrophages, bone marrow derived macrophages and bone marrow derived dendritic cells were collected and cultured. The amount of interferon (IFN)-inducible protein-10 (IP10/CXCL10), macrophage chemotactic protein (MCP1/CCL2) and interleukin (IL)-6 secreted by cells activated by DMXAA was quantified using enzyme-linked immunosorbent assay kits according to the instructions of the manufacturers. Total RNA was isolated from cells or nasal epithelium with RNeasy Plus Mini Kit, and cDNA was synthesized. Gene expression was checked using Applied Biosystems StepOne Real-Time Polymerase Chain Reaction System. Transfection of small interfering RNA (siRNA) control, NOD1 duplexed RNA oligonucleotides, and high-mobility group box 1/2/3 (HMGB1/2/3) siRNA was performed using siRNA transfection reagent.

RESULTS: DMXAA activates IFN-β pathway with high level of IFN-β dependent antiviral genes including 2’, 5’-oligoadenylate synthetase 1 and myxovirus resistance 1 in mouse thioglycollate-elicited peritoneal macrophages, bone marrow derived macrophages and bone marrow derived dendritic cells. Activation of IFN-β by DMXAA involved in NOD1, but not HMGB1/2/3 signal pathway demonstrated by siRNA. NOD1 pathway plays an important role in refractoriness of IFN-β signaling induced by DMXAA in mouse C10 respiratory epithelial cells and BALB/c mice nasal epithelia. These data indicate that DMXAA is not well adapted to the intrinsic properties of IFN-β signaling. Approaches to restore sensitivity of IFN-β signaling by find other xanthone compounds may function similarly, could enhance the efficacy of protection from influenza pneumonia and potentially in other respiratory viral infections.

CONCLUSION: NOD1 pathway may play an important role in refractoriness of IFN-β signaling in mouse respiratory epithelial cells induced by DMXAA.

Techniques to elucidate the conformation of prions

Proteinaceous infectious particles (prions) are unique pathogens as they are devoid of any coding nucleic acid. Whilst it is assumed that prion disease is transmitted by a misfolded isoform of the cellular prion protein, the structural insight of prions is still vague and research for high resolution structural information of prions is still ongoing. In this review, techniques that may contribute to the clarification of the conformation of prions are presented and discussed.

In silico evidence of Remdesivir action in blood coagulation cascade modulation in COVID-19 treatment

BACKGROUND

Coronavirus disease 2019 (COVID-19) has demonstrated several clinical manifestations which include not only respiratory system issues but also liver, kidney, and other organ injuries. One of these abnormalities is coagulopathies, including thrombosis and disseminated intravascular coagulation. Because of this, the administration of low molecular weight heparin is required for patients that need to be hospitalized. In addition, Remdesivir is an antiviral that was used against Middle East Acute Respiratory Syndrome, Ebola, Acute Respiratory Syndrome, and other diseases, showing satisfactory results on recovery. Besides, there is evidence suggesting that this medication can provide a better prognosis for patients with COVID-19.

AIM

To investigate in silico the interaction between Remdesivir and clotting factors, pursuing a possibility of using it as medicine.

METHODS

In this in silico study, the 3D structures of angiotensin-converting enzyme 2 (ACE2), Factor I (fibrinogen), Factor II (prothrombin), Factor III (thromboplastin), Factor V (proaccelerin), Factor VII (proconvertin), Factor VIII (antihemophilic factor A), Factor IX (antihemophilic factor B), Factor X (Stuart-Prower factor), and Factor XI (precursor of thromboplastin (these structures are technically called receptors) were selected from the Protein Data Bank. The structures of the antivirals Remdesivir and Osetalmivir (these structures are called ligands) were selected from the PubChem database, while the structure of Atazanavir was selected from the ZINC database. The software AutoDock Tools (ADT) was used to prepare the receptors for molecular docking. Ions, peptides, water molecules, and other ones were removed from each ligand, and then, hydrogen atoms were added to the structures. The grid box was delimited and calculated using the same software ADT. A physiological environment with pH 7.4 is needed to make the ligands interact with the receptors, and still the software Marvin sketch® (ChemAxon®) was used to forecast the protonation state. To perform molecular docking, ADT and Vina software was connected. Using PyMol® software and Discovery studio® software from BIOVIA, it was possible to analyze the amino acid residues from receptors that were involved in the interactions with the ligands. Ligand tortions, atoms that participated in the interactions, and the type, strength, and duration of the interactions were also analyzed using those software.

RESULTS

Molecular docking analysis showed that Remdesivir and ACE2 had an affinity energy of -8.8 kcal/moL, forming a complex with eight hydrogen bonds involving seven atoms of Remdesivir and five amino acid residues of ACE2. Remdesivir and prothrombin had an interaction with six hydrogen bonds involving atoms of the drug and five amino acid residues of the clotting factor. Similar to that, Remdesivir and thromboplastin presented interactions via seven hydrogen bonds involving five atoms of the drug and four residues of the clotting factor. While Remdesivir and Factor V established a complex with seven hydrogen bonds between six antiviral atoms and six amino acid residues from the factor, and Factor VII connected with the drug by four hydrogen bonds, which involved three atoms of the drug and three residues of amino acids of the factor. The complex between Remdesivir and Factor IX formed an interaction via 11 hydrophilic bonds with seven atoms of the drug and seven residues of the clotting factor, plus one electrostatic bond and three hydrophobic interactions. Factor X and Remdesivir had an affinity energy of -9.6 kcal/moL, and the complex presented 10 hydrogen bonds and 14 different hydrophobic interactions which involved nine atoms of the drug and 16 amino acid residues of the clotting factor. The interaction between Remdesivir and Factor XI formed five hydrogen bonds involving five amino acid residues of the clotting factor and five of the antiviral atoms.

CONCLUSION

Because of the in silico significant affinity, Remdesivir possibly could act in the severe acute respiratory syndrome coronavirus 2 infection blockade by interacting with ACE2 and concomitantly act in the modulation of the coagulation cascade preventing the hypercoagulable state.

Innate immunity and wound repair: The platelet-rich fibrin advantage

In this editorial, we comment on the article by Sá-Oliveira et al. We focus specifically on the role of platelet-rich fibrin (PRF) in modulating innate immunity to enhance wound repair. The process of wound healing is complex and involves a coordinated series of biological events, including inflammation, cell proliferation, and tissue remodeling. The innate immune system is important in the early stages of wound repair, with inflammation being a crucial initial phase in tissue regeneration. However, the inflammatory response should be regulated, as excessive or dysregulated inflammation can impair healing. Platelet concentrates, specifically PRF, have originated as promising tools to optimize the tissue repair process. PRF is a second-generation platelet concentrate, and the release of growth factors (GFs) plays a determining role in several aspects of wound healing, including promoting cell proliferation, stimulating angiogenesis, and modulating inflammation. PRF forms a fibrin matrix that entraps platelets and GFs. This structure allows for their sustained release over time, which is believed to provide a more favorable microenvironment for tissue repair. Recent research by Sá-Oliveira et al has provided valuable evidence supporting the efficacy of PRF in promoting wound healing. Their study, conducted on an animal model, demonstrated that PRF-based dressings were more effective in accelerating wound closure in the early stages of the healing process, enhancing tissue repair, and modulating the inflammatory response. We explore how PRF's unique properties contribute to a more controlled and effective healing process. By examining these findings, we aim to highlight PRF's potential as a promising therapeutic strategy for improved wound management.

Chloroquine and hydroxychloroquine: Immunomodulatory effects in autoimmune diseases

Chloroquine (CQ) and hydroxychloroquine (HCQ), originally developed as antimalarial drugs, have found a new purpose in treating various autoimmune diseases due to their immunomodulatory properties. These drugs work through multiple mechanisms, including inhibiting Toll-like receptor signaling, suppressing antigen presentation, and modulating autophagy. This review article provides a comprehensive analysis of the immunomodulatory effects of CQ and HCQ in several autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and others. We delve into the intricate mechanisms of action, highlighting the key immune cells involved and discussing the clinical implications of these drugs in managing autoimmune conditions. Our review covers the latest research and clinical trials, offering a comprehensive understanding of the therapeutic potential of CQ and HCQ in autoimmune diseases. We also discuss the challenges and controversies surrounding the use of these drugs, such as their long-term side effects and the need for personalized treatment approaches. By synthesizing current knowledge and identifying areas for future research, this review aims to provide a valuable resource for healthcare professionals and researchers involved in the management of autoimmune diseases.

Heart and Brain: A neutro-genomic link

The philosophy of heart and brain are very ancient in our literature where the things good for the heart are not suggested good for the brain and vice-versa. Modern medicine is characterized by a high degree of specialization and the heart-brain connection that could be targeted to treat these complex cardiovascular/brain disorders. The idea that adverse diet/genome interactions can cause disease is not new. In the recent era the science of nutritional genomics have increased our understanding of diet-health-gene interactions and have provided a number of benefits for individuals, groups and societies. Since dietary chemicals are regularly ingested and participate indirectly and directly in regulating gene expression, it follows that a subset of genes regulated by diet must be involved in disease initiation, progression, and severity. In this regards Liver X Receptor (LXR)-α, a key transcription factors, associated with the several chronic pathological situation including coronary heart disease and neurodegenerative diseases have recently been found to be regulated by the dietary components. The crucial findings at molecular biology unit, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, INDIA have not only forced us to explore nutritional genomics as a holistic systems approach to understand the relationship between diet and health, but also to look into the disease preventing and health promoting foods that match our lifestyles, cultures and genetics. After all, we are what we eat.

Bioactivity of dressings based on platelet-rich plasma and Platelet-rich fibrin for tissue regeneration in animal model

BACKGROUND

Skin wounds are common injuries that affect quality of life and incur high costs. A considerable portion of healthcare resources in Western countries is allocated to wound treatment, mainly using mechanical, biological, or artificial dressings. Biological and artificial dressings, such as hydrogels, are preferred for their biocompatibility. Platelet concentrates, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), stand out for accelerating tissue repair and minimizing risks of allergies and rejection. This study developed PRF and PRP-based dressings to treat skin wounds in an animal model, evaluating their functionality and efficiency in accelerating the tissue repair process.

AIM

To develop wound dressings based on platelet concentrates and evaluating their efficiency in treating skin wounds in Wistar rats.

METHODS

Wistar rats, both male and female, were subjected to the creation of a skin wound, distributed into groups (n = 64/group), and treated with Carbopol (negative control); PRP + Carbopol; PRF + Carbopol; or PRF + CaCl2 + Carbopol, on days zero (D0), D3, D7, D14, and D21. PRP and PRF were obtained only from male rats. On D3, D7, D14, and D21, the wounds were analyzed for area, contraction rate, and histopathology of the tissue repair process.

RESULTS

The PRF-based dressing was more effective in accelerating wound closure early in the tissue repair process (up to D7), while PRF + CaCl2 seemed to delay the process, as wound closure was not complete by D21. Regarding macroscopic parameters, animals treated with PRF + CaCl2 showed significantly more crusting (necrosis) early in the repair process (D3). In terms of histopathological parameters, the PRF group exhibited significant collagenization at the later stages of the repair process (D14 and D21). By D21, fibroblast proliferation and inflammatory infiltration were higher in the PRP group. Animals treated with PRF + CaCl2 experienced a more pronounced inflammatory response up to D7, which diminished from D14 onwards.

CONCLUSION

The PRF-based dressing was effective in accelerating the closure of cutaneous wounds in Wistar rats early in the process and in aiding tissue repair at the later stages.

Temporal pattern of humoral immune response in mild cases of COVID-19

BACKGROUND

Understanding the humoral response pattern of coronavirus disease 2019 (COVID-19) is one of the essential factors to better characterize the immune memory of patients, which allows understanding the temporality of reinfection, provides answers about the efficacy and durability of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and consequently helps in global public health and vaccination strategy. Among the patients who became infected with SARS-CoV-2, the majority who did not progress to death were those who developed the mild COVID-19, so understanding the pattern and temporality of the antibody response of these patients is certainly relevant.

AIM

To investigate the temporal pattern of humoral response of specific immunoglobulin G (IgG) in mild cases of COVID-19.

METHODS

Blood samples from 191 COVID-19 real-time reverse transcriptase-polymerase chain reaction (RT-qPCR)-positive volunteers from the municipality of Toledo/ Paraná/Brazil, underwent two distinct serological tests, enzyme-linked immunosorbent assay, and detection of anti-nucleocapsid IgG. Blood samples and clinicoepidemiological data of the volunteers were collected between November 2020 and February 2021. All assays were performed in duplicate and the manufacturers' recommendations were strictly followed. The data were statistically analyzed using multiple logistic regression; the variables were selected by applying the P < 0.05 criterion.

RESULTS

Serological tests to detect specific IgG were performed on serum samples from volunteers who were diagnosed as being positive by RT-qPCR for COVID-19 or had disease onset in the time interval from less than 1 mo to 7 mo. The time periods when the highest number of participants with detectable IgG was observed were 1, 2 and 3 mo. It was observed that 9.42% of participants no longer had detectable IgG antibodies 1 mo only after being infected with SARS-CoV-2 and 1.57% were also IgG negative at less than 1 mo. At 5 mo, 3.14% of volunteers were IgG negative, and at 6 or 7 mo, 1 volunteer (0.52%) had no detectable IgG. During the period between diagnosis by RT-qPCR/symptoms onset and the date of collection for the study, no statistical significance was observed for any association analyzed. Moreover, considering the age category between 31 and 59 years as the exposed group, the P value was 0.11 for the category 31 to 59 years and 0.32 for the category 60 years or older, showing that in both age categories there was no association between the pair of variables analyzed. Regarding chronic disease, the exposure group consisted of the participants without any comorbidity, so the P value of 0.07 for the category of those with at least one chronic disease showed no association between the two variables.

CONCLUSION

A temporal pattern of IgG response was not observed, but it is suggested that immunological memory is weak and there is no association between IgG production and age or chronic disease in mild COVID-19.

Stem cell therapy for Parkinson’s disease: A new hope for neural regeneration

Parkinson’s disease (PD) is a progressive neurodegenerative disorder marked by the loss of dopaminergic neurons in the substantia nigra that leads to reduced dopamine levels and impaired motor function. Current treatments only provide temporary symptom relief without addressing the underlying neuronal loss. A promising new approach for treating PD is stem cell therapy, particularly induced pluripotent stem cells and human pluripotent stem cells. They have the ability to differentiate into various neural cells, offering potential for neuronal replacement and restoration of brain function. Induced pluripotent stem cells are derived from reprogramming adult cells and present advantages such as genetic compatibility and reduced immune rejection, overcoming ethical concerns associated with embryonic stem cells. Preclinical studies show promising results, demonstrating that stem cells can differentiate into dopaminergic neurons and improve motor function in animal models. These advancements pave the way for clinical trials and potential long-term solutions for patients with PD. This review highlighted the significance of stem cell therapy in neuroregeneration and addressed preclinical successes, challenges in long-term safety, and ethical considerations, with the hope of revolutionizing PD treatment and improving patient outcomes.

Correlation of serum SARS-CoV-2 IgM and IgG serology and clinical outcomes in COVID-19 patients: Experience from a tertiary care centre

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a pandemic for the last 2 years. Inflammatory response to the virus leads to organ dysfunction and death. Predicting the severity of inflammatory response helps in managing critical patients using serology tests IgG and IgM.

AIM

To investigate the correlation of the serology (IgM and IgG) with reverse transcriptase polymerase chain reaction (RT-PCR) status, disease severity [mild to critical], intensive care unit (ICU) admission, septic shock, acute kidney injury, and in-hospital mortality.

METHODS

We conducted a longitudinal study to correlate serum SARS-CoV-2 immunoglobulin M (IgM) and immunoglobulin G (IgG) serology with clinical outcomes in coronavirus disease 2019 (COVID-19) patients. We analyzed patient data from March to December 2020 for those who were admitted at All India Institute of Medical Sciences Rishikesh. Clinical and laboratory data of these patients were collected from the e-hospital portal and analyzed. A correlation was seen with clinical outcomes and was assessed using MS Excel 2010 and SPSS software.

RESULTS

Out of 494 patients, the mean age of patients was 48.95 ± 16.40 years and there were more male patients in the study (66.0%). The patients were classified as mild-moderate 328 (67.1%), severe 131 (26.8%), and critical 30 (6.1%). The mean duration from symptom onset to serology testing was 19.87 ± 30.53 d. In-hospital mortality was observed in 25.1% of patients. The seropositivity rate (i.e., either IgG or IgM > 10 AU) was 50%. IgM levels (AU/mL) (W = 33428.000, P ≤ 0.001) and IgG levels (AU/mL) (W = 39256.500, P ≤ 0.001), with the median IgM/ IgG levels (AU/mL), were highest in the RT-PCR-Positive group compared to RT-PCR-Negative clinical COVID-19. There was no significant difference between the two groups in terms of all other clinical outcomes (disease severity, septic shock, ICU admission, mechanical ventilation, and mortality).

CONCLUSION

The study showed that serology levels are high in RT-PCR positive group compared to clinical COVID-19. However, serology cannot be useful for the prediction of disease outcomes. The study also highlights the importance of doing serology at a particular time as antibody titers vary with the duration of the disease. In week intervals there was a significant correlation between clinical outcomes and serology on week 3.

Control of nuclear-cytoplasmic shuttling of Ankrd54 by PKCδ

AIM

To identify and characterize the effect of phosphorylation on the subcellular localization of Ankrd54.

METHODS

HEK293T cells were treated with calyculin A, staurosporin or phorbol 12-myristate 13-acetate (PMA). Cells were transfected with eGFP-tagged Ankrd54 with or without Lyn tyrosine kinase (wild-type, Y397F mutant, or Y508F mutant). The subcellular localization was assessed by immunofluorescence imaging of cells, immunoblotting of subcellular fractionations. The phosphorylation of Ankrd54 was monitored using Phos-tagTM gel retardation. Phosphorylated peptides were analysed by multiple-reaction-monitoring (MRM) proteomic analysis.

RESULTS

Activation of PKC kinases using PMA promoted nuclear export of Ankrd54 and correlated with increased Ankrd54 phosphorylation, assayed using Phos-tagTM gel retardation. Co-expression of an active form of the PKCδ isoform specifically promoted both phosphorylation and cytoplasmic localization of Ankrd54, while PKCδ, Akt and PKA did not. Alanine mutation of several serine residues in the amino-terminal region of Ankrd54 (Ser14, Ser17, Ser18, Ser19) reduced both PMA induced cytoplasmic localization and phosphorylation of Ankrd54. Using MRM proteomic analysis, phosphorylation of the Ser18 residue of Ankrd54 was readily detectable in response to PMA stimulation. PMA stimulation of cells co-expressing Ankrd54 and Lyn tyrosine kinase displayed increased co-immunoprecipitation and enhanced co-localization in the cytoplasm.

CONCLUSION

We identify phosphorylation by PKCδ as a major regulator of nuclear-cytoplasmic shuttling of Ankrd54, and its interaction with the tyrosine kinase Lyn.

Development of regional specificity of spinal and medullary dorsal horn neurons

Extensive studies have focused on the development and regionalization of neurons in the central nervous system (CNS). Many genes, which play crucial roles in the development of CNS neurons, have been identified. By using the technique “direct reprogramming”, neurons can be produced from multiple cell sources such as fibroblasts. However, understanding the region-specific regulation of neurons in the CNS is still one of the biggest challenges in the research field of neuroscience. Neurons located in the trigeminal subnucleus caudalis (Vc) and in the spinal dorsal horn (SDH) play crucial roles in pain and sensorimotor functions in the orofacial and other somatic body regions, respectively. Anatomically, Vc represents the most caudal component of the trigeminal system, and is contiguous with SDH. This review is focused on recent data dealing with the regional specificity involved in the development of neurons in Vc and SDH.

Marine biological injuries and their medical management: A narrative review

The marine environment can be extremely dangerous, and the harm caused by marine organisms when they contact the human body can be especially harmful, even deadly. Contact includes stings, bites, wounds, and consumption as food. In this article, the characteristics of the common marine biological injuries are summarized, the major marine organisms causing damage in China's marine waters are described, and injury prevention and treatment methods are discussed.

Modulation of protein tyrosine phosphorylation in gastric mucosa during re-epithelization processes

AIM: To investigate the role of protein tyrosine phosphorylation in gastric wound formation and repair following ulceration.

METHODS: Gastric lesions were induced in rats using restraint cold stress. To investigate the effect of oxidative and nitrosative cell stress on tyrosine phosphorylation during wound repair, total activity of protein tyrosine kinase (PTK), protein tyrosine phosphatase (PTP), antioxidant enzymes, nitric oxide synthase (NOS), 2’,5’-oligoadenylate synthetase, hydroxyl radical and zinc levels were assayed in parallel.

RESULTS: Ulcer provocation induced an immediate decrease in tyrosine kinase (40% in plasma membranes and 56% in cytosol, P < 0.05) and phosphatase activity (threefold in plasma membranes and 3.3-fold in cytosol), followed by 2.3-2.4-fold decrease (P < 0.05) in protein phosphotyrosine content in the gastric mucosa. Ulceration induced no immediate change in superoxide dismutase (SOD) activity, 30% increase (P < 0.05) in catalase activity, 2.3-fold inhibition (P < 0.05) of glutathione peroxidase, 3.3-fold increase (P < 0.05) in hydroxyl radical content, and 2.3-fold decrease (P < 0.05) in zinc level in gastric mucosa. NOS activity was three times higher in gastric mucosa cells after cold stress. Following ulceration, PTK activity increased in plasma membranes and reached a maximum on day 4 after stress (twofold increase, P < 0.05), but remained inhibited (1.6-3-fold decrease on days 3, 4 and 5, P < 0.05) in the cytosol. Tyrosine phosphatases remained inhibited both in membranes and cytosol (1.5-2.4-fold, P < 0.05). NOS activity remained increased on days 1, 2 and 3 (3.8-, 2.6-, 2.2-fold, respectively, P < 0.05). Activity of SOD increased 1.6 times (P < 0.05) days 4 and 5 after stress. Catalase activity normalized after day 2. Glutathione peroxidase activity and zinc level decreased (3.3- and 2-fold, respectively, P < 0.05) on the last day. Activity of 2’,5’-oligoadenylate synthethase increased 2.8-fold (P < 0.05) at the beginning, and 1.6-2.3-fold (P < 0.05) during ulcer recuperation, and normalized on day 5, consistent with slowing of inflammation processes.

CONCLUSION: These studies show diverse changes in total tyrosine kinase activity in gastric mucosa during the recovery process. Oxidative and nitrosative stress during lesion formation might lead to the observed reduction in tyrosine phosphorylation during ulceration.

Localization and function of a eukaryotic-initiation-factor-2-associated 67-kDa glycoprotein

AIM: To study the localization and function of a eukaryotic initiation factor 2 (eIF2α)-associated 67-kDa glycoprotein (p67).

METHODS: Immunofluorescence staining, ³⁵S-Met/Cys metabolic labeling, Western blotting analysis, sucrose gradient centrifugation and high speed centrifugation were used to determine the localization of proteins in transiently transfected COS-1 cells. Transient co-transfection followed by co-immunoprecipitation was used to study the interaction between p67 and double-stranded RNA (dsRNA)-dependent protein kinase (PKR). Wheat germ agglutinin agarose beads were used to absorb glycosylated proteins. In vivo³²P-labeling followed by immunoprecipitation and Western blotting were used to measure PKR autophosphorylation, eIF2α phosphorylation, and p67 expression in normal and breast cancer cells.

RESULTS: The image from immunofluorescence staining showed that p67 was overexpressed in the cytosol but not in the nucleus. In a sucrose gradient, approximately 30% of the overexpressed p67 was bound with ribosomes. p67 interacted with the kinase domain, but not the dsRNA-binding domains of PKR. Only the glycosylated p67 was associated with the ribosome, and p67 did not compete with PKR for ribosome binding. In breast cancer cells, there was increased autophosphorylation of PKR but no phosphorylation of eIF2α, compared with normal breast cells.α The ratio of glycosylated/deglycosylated p67 was altered in breast cancer cells.

CONCLUSION: Glycosylation of p67 is required for its ribosomal association and can potentially inhibit PKR via interaction with the kinase domain of PKR.

Hmo1: A versatile member of the high mobility group box family of chromosomal architecture proteins

Eukaryotic chromatin consisting of nucleosomes connected by linker DNA is organized into higher order structures, which is facilitated by linker histone H1. Formation of chromatin compacts and protects the genome, but also hinders DNA transactions. Cells have evolved mechanisms to modify/remodel chromatin resulting in chromatin states suitable for genome functions. The high mobility group box (HMGB) proteins are non-histone chromatin architectural factors characterized by one or more HMGB motifs that bind DNA in a sequence nonspecific fashion. They play a major role in chromatin dynamics. The Saccharomyces cerevisiae (yeast hereafter) HMGB protein Hmo1 contains two HMGB motifs. However, unlike a canonical HMGB protein that has an acidic C-terminus, Hmo1 ends with a lysine rich, basic, C-terminus, resembling linker histone H1. Hmo1 exhibits characteristics of both HMGB proteins and linker histones in its multiple functions. For instance, Hmo1 promotes transcription by RNA polymerases I and II like canonical HMGB proteins but makes chromatin more compact/stable like linker histones. Recent studies have demonstrated that Hmo1 destabilizes/disrupts nucleosome similarly as other HMGB proteins in vitro and acts to maintain a common topological architecture of genes in yeast genome. This minireview reviews the functions of Hmo1 and the underlying mechanisms, highlighting recent discoveries.

Therapeutic potential of elafibranor in alcohol-associated liver disease: Insights into macrophage modulation and fibrosis reduction

Alcohol-associated liver disease (ALD) is a major global health concern, contributing to liver injury, morbidity, and mortality. Elafibranor (EFN), a dual peroxisome proliferator-activated receptor α/δ agonist, has shown promise as a therapeutic candidate in preclinical studies. EFN reduces liver fibrosis by inhibiting lipid accumulation, apoptosis, and inflammatory pathways (LPS/TLR4/NF-κB), while enhancing autophagy and antioxidant responses. It also improves intestinal barrier function and modulates gut microbiota, reducing endotoxin-producing bacteria and increasing beneficial species. By strengthening the intestinal barrier and suppressing pro-inflammatory mediators like tumor necrosis factor-alpha and interleukin-6, EFN mitigates hepatic stellate cell activation and fibrogenic signaling. Macrophages play a central role in ALD progression, and EFN's ability to modulate macrophage activity further highlights its anti-inflammatory properties. This review emphasizes EFN's dual-targeted approach, addressing both hepatic and intestinal dysfunctions, distinguishing it from conventional ALD treatments. While preclinical results are promising, EFN remains under clinical investigation, with ongoing trials evaluating its safety and efficacy. Future research should focus on elucidating EFN's molecular mechanisms and advancing its clinical application to establish its therapeutic potential in human populations. EFN represents a novel, comprehensive strategy for ALD management, targeting both liver and gut pathologies.