Cellular Molecular Mechanisms Research Articles

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury.

In addition to the loss of motor function, ~60% of patients develop pain after spinal cord injury. The cellular-molecular mechanisms are not well understood, but the data suggests that plasticity within the rostral, epicenter, and caudal penumbra of the injury site initiates a cellular-molecular interplay that acts as a rewiring mechanism leading to central neuropathic pain. Sprouting can lead to the formation of new connections triggering abnormal sensory transmission. The excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and excitotoxicity. Our previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator tamoxifen. In this study, we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord injury. We hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters, leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant sprouting. Male and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control (placebo). We used von Frey monofilaments and the "up-down method" to evaluate mechanical allodynia. Tamoxifen treatment decreased allodynia only in female rats with spinal cord injury revealing a sex-dependent effect. The expression profile of glutamatergic transporters (excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1) revealed a sexual dimorphism in the rostral, epicenter, and caudal areas of the spinal cord with a pattern of expression primarily on astrocytes. Female rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased excitatory amino acid transporter-2 expression compared with female rodents. Analyses of peptidergic (calcitonin gene-related peptide-α) and non-peptidergic (isolectin B4) fibers outgrowth in the dorsal horn after spinal cord injury showed an increased calcitonin gene-related peptide-α/ isolectin B4 ratio in comparison with sham, suggesting increased receptive fields in the dorsal horn. Although the behavioral assay shows decreased allodynia in tamoxifen-treated female rats, this was not associated with overexpression of glutamate transporters or alterations in the dorsal horn laminae fibers at 28 days post-injury. Our findings provide new evidence of the sexually dimorphic expression of glutamate transporters in the spinal cord. The dimorphic expression revealed in this study provides a therapeutic opportunity for treating chronic pain, an area with a critical need for treatment.

An in vitro assessment of ionizing radiation impact on the efficacy of radiotherapy for breast cancer

Abstract Objectives Ionizing radiation is still one of the most effective treatment options for various cancers. It is possible to reduce the side effects of this effective treatment method and increase the chance of success by elucidating the responses it creates at the molecular level in the cell. This study aims to investigate of the molecular effects of therapeutic ionizing radiation on breast cancer, which is the most prevalent cancer type. Methods MDA-MB-231 and MCF7 cell lines were irradiated with 4 and 8 Gy ionizing radiation and monitored for up to 7 days. RNA was collected at 48 and 96 h, when cellular molecular mechanisms became most evident, and quantitative expression levels of microRNAs (miR-208a, miR-124, miR-145), for which cancer-radiation associations have been determined from existing literature and databases, were evaluated. Results Exposure to ionizing radiation resulted in a dose-dependent reduction in cell viability in both MCF7 and MDA-MB-231 breast cancer cell lines. Furthermore, microRNA expression analysis revealed notable changes at all levels. The research demonstrates that miR-208a, miR-145, and miR-124 are crucial in the biological response to ionizing radiation. Conclusions Therapeutic ionizing radiation profoundly affects cell viability and microRNA expression in breast cancer cell lines, showing dose and time-dependent effects. The observed microRNA expression patterns suggest potential biomarkers for radiation response and therapeutic targets to improve radiotherapy efficacy. Further in vivo validation and exploration of these microRNAs’ roles in modulating cellular response to ionizing radiation are needed.

Decoding dynamic miRNA:ceRNA interactions unveils therapeutic insights and targets across predominant cancer landscapes.

Competing endogenous RNAs play key roles in cellular molecular mechanisms through cross-talk in post-transcriptional interactions. Studies on ceRNA cross-talk, which is particularly dependent on the abundance of free transcripts, generally involve large- and small-scale studies involving the integration of transcriptomic data from tissues and correlation analyses. This abundance-dependent nature of ceRNA interactions suggests that tissue- and condition-specific ceRNA dynamics may fluctuate. However, there are no comprehensive studies investigating the ceRNA interactions in normal tissue, ceRNAs that are lost and/or appear in cancerous tissues or their interactions. In this study, we comprehensively analyzed the tumor-specific ceRNA fluctuations observed in the three highest-incidence cancers, LUAD, PRAD, and BRCA, compared to healthy lung, prostate, and breast tissues, respectively. Our observations pertaining to tumor-specific competing endogenous RNA (ceRNA) interactions revealed that, in the cases of lung adenocarcinoma (LUAD), prostate adenocarcinoma (PRAD), and breast invasive carcinoma (BRCA), 3,204, 1,233, and 406 ceRNAs, respectively, engage in post-transcriptional intercommunication within tumor tissues, in contrast to their absence in corresponding healthy samples. We also found that 90 ceRNAs are shared by the three cancer types and that these ceRNAs participate in ceRNA interactions in tumor tissues compared to those in normal tissues. Among the 90 ceRNAs that directly interact with miRNAs, we uncovered a core network of 165 miRNAs and 63 ceRNAs that should be considered in RNA-targeted and RNA-mediated approaches in future studies and could be used in these three aggressive cancer types. More specifically, in this core interaction network, ceRNAs such as GALNT7, KLF9, and DAB2 and miRNAs like miR-106a/b-5p, miR-20a-5p, and miR-519d-3p may have potential as common targets in the three critical cancers. In contrast to conventional methods that construct ceRNA networks using differentially expressed genes compared to normal tissues, our proposed approach identifies ceRNA players by considering their context within the ceRNA:miRNA interactions. Our results have the potential to reveal distinct and common ceRNA interactions in cancer types and to pinpoint critical RNAs, thereby paving the way for RNA-based strategies in the battle against cancer.

Active forgetting and neuropsychiatric diseases.

Recent and pioneering animal research has revealed the brain utilizes a variety of molecular, cellular, and network-level mechanisms used to forget memories in a process referred to as "active forgetting". Active forgetting increases behavioral flexibility and removes irrelevant information. Individuals with impaired active forgetting mechanisms can experience intrusive memories, distressing thoughts, and unwanted impulses that occur in neuropsychiatric diseases. The current evidence indicates that active forgetting mechanisms degrade, or mask, molecular and cellular memory traces created in synaptic connections of "engram cells" that are specific for a given memory. Combined molecular genetic/behavioral studies using Drosophila have uncovered a complex system of cellular active-forgetting pathways within engram cells that is regulated by dopamine neurons and involves dopamine-nitric oxide co-transmission and reception, endoplasmic reticulum Ca2+ signaling, and cytoskeletal remodeling machinery regulated by small GTPases. Some of these molecular cellular mechanisms have already been found to be conserved in mammals. Interestingly, some pathways independently regulate forgetting of distinct memory types and temporal phases, suggesting a multi-layering organization of forgetting systems. In mammals, active forgetting also involves modulation of memory trace synaptic strength by altering AMPA receptor trafficking. Furthermore, active-forgetting employs network level mechanisms wherein non-engram neurons, newly born-engram neurons, and glial cells regulate engram synapses in a state and experience dependent manner. Remarkably, there is evidence for potential coordination between the network and cellular level forgetting mechanisms. Finally, subjects with several neuropsychiatric diseases have been tested and shown to be impaired in active forgetting. Insights obtained from research on active forgetting in animal models will continue to enrich our understanding of the brain dysfunctions that occur in neuropsychiatric diseases.

Harnessing tumor-derived exosomes: A promising approach for the expansion of clinical diagnosis, prognosis, and therapeutic outcome of prostate cancer.

Prostate cancer is the second leading cause of men's death worldwide. Although early diagnosis and therapy for localized prostate cancer have improved, the majority of men with metastatic disease die from prostate cancer annually. Therefore, identification of the cellular-molecular mechanisms underlying the progression of prostate cancer is essential for overcoming controlled proliferation, invasion, and metastasis. Exosomes are small extracellular vesicles that mediate most cells' interactions and contain membrane proteins, cytosolic and nuclear proteins, extracellular matrix proteins, lipids, metabolites, and nucleic acids. Exosomes play an essential role in paracrine pathways, potentially influencing Prostate cancer progression through a wide variety of mechanisms. In the present review, we outline and discuss recent progress in our understanding of the role of exosomes in the Prostate cancer microenvironment, like their involvement in prostate cancer occurrence, progression, angiogenesis, epithelial-mesenchymal transition, metastasis, and drug resistance. We also present the latest findings regarding the function of exosomes as biomarkers, direct therapeutic targets in prostate cancer, and the challenges and advantages associated with using exosomes as natural carriers and in exosome-based immunotherapy. These findings are a promising avenue for the expansion of potential clinical approaches.

МОРФОЛОГИЧЕСКИЕ ИЗМЕНЕНИЯ МИОМЕТРИЯ ВО ВРЕМЯ БЕРЕМЕННОСТИ И В ОТДАЛЕННОМ ПОСЛЕРОДОВОМ ПЕРИОДЕ В УСЛОВИЯХ ОСТРОГО ТОКСИЧЕСКОГО ГЕПАТОЗА И КОРРЕКЦИИ ИММОБИЛИЗИРОВАННОЙ ГИАЛУРОНИДАЗОЙ У МЫШЕЙ

Introduction. The prevalence of acute and chronic liver diseases in pregnant women increases every year, which is associated with a high risk of adverse outcome for the mother and fetus. At the same time, the mechanisms that ensure an increase in uterine mass, structural changes in the myometrium before childbirth and the process of postpartum involution of the uterus to the initial mass, the participation of molecular cellular mechanisms in pregnant women with liver pathology, and ways to correct it remain poorly understood. Aim. The aim of the study was to investigate morphological changes in the myometrium, during pregnancy and the late postpartum period in the myometrium of mice with acute CCl4-induced hepatosis and under conditions of its correction with immobilized hyaluronidase. Materials and methods. The experiment was performed on 200 female pregnant mice of the C57B1/6 line at two months of age. Acute toxic hepatosis was modeled by a single injection of tetrachlormethane. Correction of acute hepatosis was performed on the next day after administration of tetrachloromethane and subsequent days of pregnancy with a single injection of immobilized hyaluronidase. The animals were divided into 4 groups: a group with physiological pregnancy, animals with the immobilized hyaluronidase drug injection; animals with acute hepatosis; animals with acute hepatosis treated with immobilized hyaluronidase. Uterine samples were collected on the 18th, 21st days of pregnancy and on the 1st, 5th, 10th, 15th days after delivery. Results. The volume density (Vv) of myocytes in the state of apoptosis, interstitial cytoplasmic conglomerates, which are products of clasmacytosis, and necrotized myocytes were calculated, as well as the numerical density (Nai) of myocytes with positive expression of the p53 protein. Under conditions of acute hepatosis, structural transformations of the myometrium in the form of an increase in clasmacytosis, necrotized myocytes occur already during pregnancy. The main structural mechanism of the process of postpartum involution of the myometrium of mice in conditions of acute hepatosis in the long-term period of postpartum involution was clasmacyto sis and, to a lesser extent, necrosis of myocytes. The processes of myometrial involution in mice under conditions of acute hepatosis slow down and do not complete by the 15th day of the postpartum period. When correcting acute hepatosis with immobilized hyaluronidase, the volume density of cytoplasmic conglomerates, apoptotically altered myocytes and necrotized myocytes decreases from the 1st to the 15th day of the postpartum period, which indicates the completeness of postpartum uterine involution. Conclusion. Liver damage is accompanied by a change in the metabolism of sex hormones, which leads to an abnormality of the mechanisms of postpartum involution of the uterus, as well as its structural changes before childbirth.

Association between Nfr2, HO-1, NF-kB Expression, Plasma ADMA, and Oxidative Stress in Metabolic Syndrome.

Endothelial dysfunction is one of the major factors in the pathogenesis of metabolic syndrome (MetS), and its molecular mechanisms are not completely understood. The present study aimed to examine the connection between nuclear factor2-related factor2 (Nrf2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), heme oxygenase 1 (HO-1), and plasma asymmetric dimethylarginine (ADMA) and malondialdehyde (MDA) in people with MetS. Participants in the study were as follows: with MetS (n = 30) and without MetS (Control) (n = 14). Expression of Nrf2, NF-kB, and HO-1 was measured in peripheral blood mononuclear cells (PBMCs). Plasma ADMA was determined using the ELISA technique and MDA via the thiobarbituric acid method. Our study showed that mRNA of NF-kB, Nrf2, and HO-1 levels in PBMCs in the MetS group were significantly higher than in the controls by 53%, 130%, and 185% (p < 0.05), respectively. Similarly, elevated levels of MDA (by 78%, p < 0.001) and ADMA (by 18.7%, p < 0.001) were established in the MetS group. Our findings show the importance of transcription factor Nrf2, playing an integral role in the protection of the endothelium, and of NF-κB, a transcription factor mediating the inflammatory response in MetS. Knowledge of complex cellular-molecular mechanisms would allow the use of biomarkers such as Nrf2, NF-kB, HO-1, and ADMA for the assessment of endothelial dysfunction in clinical practice.

Effects of regular exercise on vascular function with aging: Does sex matter?

Vascular aging, featuring endothelial dysfunction and large elastic artery stiffening, is a major risk factor for the development of age-associated cardiovascular diseases (CVDs). Vascular aging is largely mediated by an excessive production of reactive oxygen species (ROS) and increased inflammation leading to reduced bioavailability of the vasodilatory molecule nitric oxide and remodeling of the arterial wall. Other cellular mechanisms (i.e., mitochondrial dysfunction, impaired stress response, deregulated nutrient sensing, cellular senescence), termed "hallmarks" or "pillars" of aging, may also contribute to vascular aging. Gonadal aging, which largely impacts women but also impacts some men, modulates the vascular aging process. Regular physical activity, including both aerobic and resistance exercise, is a first-line strategy for reducing CVD risk with aging. Although exercise is an effective intervention to counter vascular aging, there is considerable variation in the vascular response to exercise training with aging. Aerobic exercise improves large elastic artery stiffening in both middle-aged/older men and women and enhances endothelial function in middle-aged/older men by reducing oxidative stress and inflammation and preserving nitric oxide bioavailability; however, similar aerobic exercise training improvements are not consistently observed in estrogen-deficient postmenopausal women. Sex differences in adaptations to exercise may be related to gonadal aging and declines in estrogen in women that influence cellular-molecular mechanisms, disconnecting favorable signaling in the vasculature induced by exercise training. The present review will summarize the current state of knowledge on vascular adaptations to regular aerobic and resistance exercise with aging, the underlying mechanisms involved, and the moderating role of biological sex.

Chlorogenic Acid from Burdock Roots Ameliorates Oleic Acid-Induced Steatosis in HepG2 Cells through AMPK/ACC/CPT-1 Pathway.

Hepatic steatosis can cause liver dysfunction and cell injury, on which natural functional factors are expected to be an effective approach for long-term intervention. However, the cellular molecular mechanisms are unclear. Chlorogenic acid is a phenolic compound, which can regulate lipid metabolism and is abundant in burdock root. The aim of this study was to investigate the potential molecular mechanism of the effect of chlorogenic acid from burdock root (ACQA) on steatosis in HepG2 cells. In this study, we found that ACQA reduced the number of lipid droplets and lipid levels in oleic acid-treated HepG2 cells. Molecular mechanistic results showed that ACQA enhanced CPT-1 expression by activating AMPK-related signaling pathways, and the concentrations of Ca2+ and cAMP were increased with the intervention of ACQA. In addition, ACQA enhanced the β-oxidation of fatty acids, reduced alanine transaminase and aspartate transaminase, and inhibited apoptosis in oleic acid-treated HepG2 cells. Our studies elucidate a novel mechanism that ACQA enhances the β-oxidation of fatty acids through the AMPK/ACC/CPT-1 pathway to protect against steatosis in HepG2 cells, which provides insight into its molecular mechanism as well as intervention strategies for chlorogenic acid against fatty liver diseases.

Orexin A alleviates LPS-induced acute lung injury by inhibiting macrophage activation through JNK-mediated autophagy

Crosstalk between the central nervous system and immune system by the neuroendocrine and autonomic nervous systems is critical during the inflammatory response. Exposure to endotoxin alters the activity of hypothalamic homeostatic systems, resulting in changed transmitter release within the brain. This study investigated the effects and cellular molecular mechanisms of neurogenic and exogenous orexin-A (OXA) in LPS-induced acute lung injury (ALI). We found the production of OXA in the hypothalamus and lungs was both decreased following LPS infection. LPS-induced lung injury including the destruction of the structure, inflammatory cell infiltration, and pro-inflammatory cytokines generation was aggravated in mice in which orexin neurons were lesioned with the neurotoxin orexin-saporin (orexin-SAP). Administration of exogenous OXA greatly improved lung pathology and reduced inflammatory response. Orexin receptors were found in cultured mouse bone marrow-derived macrophages (BMDMs) and lung macrophages (LMs), adoptive transfer of OXA-treated macrophages showed alleviative lung injury compared to adoptive transfer of macrophages without OXA treatment. Mechanistically, it is the induction of autophagy via JNK activation that is responsible for OXA to suppress macrophage-derived pro-inflammatory cytokine production. These findings highlight the importance of neuro-immune crosstalk and indicate that OXA may be a potential therapeutic agent in the treatment of ALI.

Potential targets of heparin during progression and metastasis of malignant neoplasms

In the modern world, oncological diseases occupy the leading positions in the structure of mortality. An integrated approach to oncotherapy is not only aimed at immediate affection of malignant tumors, but also directed at reducing the risk of tumor recurrence and metastasis, as well as alleviating side effects of chemotherapy and radiotherapy of the disease. In oncologic disorders, blood viscosity increases, thus being associated with hypercoagulation syndrome. To prevent its consequences, the direct and indirect anticoagulants, especially heparin and its derivatives, are actively used. Biological functions and structural features of heparin make it a potential universal platform of a drug development for broad application, including oncology. With the advent of heparin fractionation technology and preparation of low-molecular weight forms and their derivatives, it has become possible to focus not only on anticoagulant activity but also to obtain fractions with targeted pharmacological activity. Usage of the anticoagulants has shown their antitumor activity in some cases, thus providing a basis for a more detailed study of pharmacotherapeutic effects of this group of drugs. Currently, some data suggest various pathways of interaction between heparin and tumor cells. There are multiple common features in development of a primary tumor and formation of secondary distant metastases, which may be attributed to similar molecular cellular mechanisms. The molecules mediating intercellular interactions, both between the tumor cells and between malignant cells and tumor-associated immune cells (e.g., lymphocytes and macrophages) may serve as targets for heparin thus helping the tumor to evade immune surveillance. The cytokines that stimulate tumor angiogenesis represent another important therapeutic target. Heparin derivatives are able to suppress tumor activity and prevent metastatic processes at various stages by inhibiting heparanase, P-/L-selectin, and angiogenesis activity, modulating the CXCL12-CXCR4 chemokine axis, and regulating OAM activity.This brief review addresses the current understanding and application of the potentially antimetastatic properties of heparin and its derivatives in malignant bone tumors since the heparin-based drugs are used as anticoagulants in arthroplasty of large joints and bone defects in patients with osteosarcoma.

Imbalance of immunoregulatory molecular cellular mechanisms as a cause of recurrent miscarriage

Introduction. Recurrent pregnancy loss (RPL) is an early spontaneous termination of pregnancy before 20 weeks, which is defined as two or more miscarriages. Most of the known causes associated with the pathophysiology of RPL include endocrine disorders, antiphospholipid syndrome, intrauterine infection, anatomical defects of the uterus, etc. However, in approximately 50% of cases, the cause of the pathogenesis of RPL remains unclear and may be associated with a violation of immune mechanisms, such as maternal tolerance to fetal alloantigens and controlled inflammation, which play a decisive role in successful pregnancy. Purpose of the review. To summarize current knowledge about the molecular cellular immune mechanisms that ensure the induction and maintenance of maternal-fetal tolerance and highlight the association between impaired immunoregulation and the development of RPL. Methods. The materials were the results of research on the topic over the past 23 years. Publications included in the Pubmed and eLibrary.ru databases were analyzed. Results. This review provides information about the immune regulation of pregnancy, which is carried out through the interaction of molecular mediators and effector cells of the innate and adaptive immunity. Current evidence points to a key role of the immune system in the pathophysiology of RPL. Successful pregnancy requires a finely regulated and tightly controlled balance between immune activation and tolerance to fetal antigens. Conclusion. The main events occur in the uteroplacental zone, where trophoblast cells and maternal lymphocytes come into close contact. The search for biomarkers for pregnancy complications is the focus of scientists.

Insect-pathogen crosstalk and the cellular-molecular mechanisms of insect immunity: uncovering the underlying signaling pathways and immune regulatory function of non-coding RNAs.

Multicellular organisms are constantly subjected to pathogens that might be harmful. Although insects lack an adaptive immune system, they possess highly effective anti-infective mechanisms. Bacterial phagocytosis and parasite encapsulation are some forms of cellular responses. Insects often defend themselves against infections through a humoral response. This phenomenon includes the secretion of antimicrobial peptides into the hemolymph. Specific receptors for detecting infection are required for the recognition of foreign pathogens such as the proteins that recognize glucans and peptidoglycans, together referred to as PGRPs and βGRPs. Activation of these receptors leads to the stimulation of signaling pathways which further activates the genes encoding for antimicrobial peptides. Some instances of such pathways are the JAK-STAT, Imd, and Toll. The host immune response that frequently accompanies infections has, however, been circumvented by diseases, which may have assisted insects evolve their own complicated immune systems. The role of ncRNAs in insect immunology has been discussed in several notable studies and reviews. This paper examines the most recent research on the immune regulatory function of ncRNAs during insect-pathogen crosstalk, including insect- and pathogen-encoded miRNAs and lncRNAs, and provides an overview of the important insect signaling pathways and effector mechanisms activated by diverse pathogen invaders.

Gender effects on autism spectrum disorder: a multi-site resting-state functional magnetic resonance imaging study of transcriptome-neuroimaging.

The gender disparity in autism spectrum disorder (ASD) has been one of the salient features of condition. However, its relationship between the pathogenesis and genetic transcription in patients of different genders has yet to reach a reliable conclusion. To address this gap, this study aimed to establish a reliable potential neuro-marker in gender-specific patients, by employing multi-site functional magnetic resonance imaging (fMRI) data, and to further investigate the role of genetic transcription molecules in neurogenetic abnormalities and gender differences in autism at the neuro-transcriptional level. To this end, age was firstly used as a regression covariate, followed by the use of ComBat to remove the site effect from the fMRI data, and abnormal functional activity was subsequently identified. The resulting abnormal functional activity was then correlated by genetic transcription to explore underlying molecular functions and cellular molecular mechanisms. Abnormal brain functional activities were identified in autism patients of different genders, mainly located in the default model network (DMN) and precuneus-cingulate gyrus-frontal lobe. The correlation analysis of neuroimaging and genetic transcription further found that heterogeneous brain regions were highly correlated with genes involved in signal transmission between neurons' plasma membranes. Additionally, we further identified different weighted gene expression patterns and specific expression tissues of risk genes in ASD of different genders. Thus, this work not only identified the mechanism of abnormal brain functional activities caused by gender differences in ASD, but also explored the genetic and molecular characteristics caused by these related changes. Moreover, we further analyzed the genetic basis of sex differences in ASD from a neuro-transcriptional perspective.

The long-term neurodevelopmental outcomes of febrile seizures and underlying mechanisms.

Febrile seizures (FSs) are convulsions caused by a sudden increase in body temperature during a fever. FSs are one of the commonest presentations in young children, occurring in up to 4% of children between the ages of about 6months and 5years old. FSs not only endanger children's health, cause panic and anxiety to families, but also have many adverse consequences. Both clinical and animal studies show that FSs have detrimental effects on neurodevelopment, that cause attention deficit hyperactivity disorder (ADHD), increased susceptibility to epilepsy, hippocampal sclerosis and cognitive decline during adulthood. However, the mechanisms of FSs in developmental abnormalities and disease occurrence during adulthood have not been determined. This article provides an overview of the association of FSs with neurodevelopmental outcomes, outlining both the underlying mechanisms and the possible appropriate clinical biomarkers, from histological changes to cellular molecular mechanisms. The hippocampus is the brain region most significantly altered after FSs, but the motor cortex and subcortical white matter may also be involved in the development disorders induced by FSs. The occurrence of multiple diseases after FSs may share common mechanisms, and the long-term role of inflammation and γ-aminobutyric acid (GABA) system are currently well studied.

Актуальные проблемы планктонологии

Actual problems of planktonology, their detailed consideration and in-depth analysis at the modern scientific level are of great importance both for fundamental research and for generalizations in the field of aquatic ecology, and for solving the most important tasks of applied hydrobiology, fisheries and environmental protection. In this regard, in September 2022, scientists from Kaliningrad gathered domestic and foreign planktonologists for the fourth time on the Baltic coast to participate in the scientific forum "Actual problems of planktonology". The most striking results and the latest achievements were presented at the forum in the field of studying species richness, functional diversity, systematics, distribution features and specifics of trophic relationships of planktonic invertebrates and algoflora. Special attention was paid to harmful phytoplankton blooms and the disclosure of ecological, physico-chemical and molecular-cellular mechanisms of these dangerous phenomena, as well as the importance of planktonic organisms in bioindication, the role of invasive species in aquatic ecosystems and anthropogenic impact on populations and communities of planktonic organisms.

PFKFB2-mediated glycolysis promotes lactate-driven continual efferocytosis by macrophages.

Resolving-type macrophages prevent chronic inflammation by clearing apoptotic cells through efferocytosis. These macrophages are thought to rely mainly on oxidative phosphorylation, but emerging evidence suggests a possible link between efferocytosis and glycolysis. To gain further insight into this issue, we investigated molecular-cellular mechanisms involved in efferocytosis-induced macrophage glycolysis and its consequences. We found that efferocytosis promotes a transient increase in macrophage glycolysis that is dependent on rapid activation of the enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 2 (PFKFB2), which distinguishes this process from glycolysis in pro-inflammatory macrophages. Mice transplanted with activation-defective PFKFB2 bone marrow and then subjected to dexamethasone-induced thymocyte apoptosis exhibit impaired thymic efferocytosis, increased thymic necrosis, and lower expression of the efferocytosis receptors MerTK and LRP1 on thymic macrophages compared with wild-type control mice. In vitro mechanistic studies revealed that glycolysis stimulated by the uptake of a first apoptotic cell promotes continual efferocytosis through lactate-mediated upregulation of MerTK and LRP1. Thus, efferocytosis-induced macrophage glycolysis represents a unique metabolic process that sustains continual efferocytosis in a lactate-dependent manner. The differentiation of this process from inflammatory macrophage glycolysis raises the possibility that it could be therapeutically enhanced to promote efferocytosis and resolution in chronic inflammatory diseases.

Lysosomal exocytosis releases pathogenic α-synuclein species from neurons.

Considerable evidence supports the release of pathogenic aggregates of the neuronal protein α-Synuclein (αSyn) into the extracellular space. While this release is proposed to instigate the neuron-to-neuron transmission and spread of αSyn pathology in synucleinopathies including Parkinson's disease, the molecular-cellular mechanism(s) remain unclear. To study this, we generated a new mouse model to specifically immunoisolate neuronal lysosomes, and a long-term culture model where αSyn aggregates are produced within neurons without the addition of exogenous fibrils. We show that neuronally generated pathogenic species of αSyn accumulate within neuronal lysosomes in mouse brains and primary neurons. We then find that neurons release these pathogenic αSyn species via SNARE-dependent lysosomal exocytosis. The released aggregates are non-membrane enveloped and seeding-competent. Additionally, we found that this release is dependent on neuronal activity and cytosolic Ca2+. These results propose lysosomal exocytosis as a central mechanism for the release of aggregated and degradation-resistant proteins from neurons.

Augmentation of bone morphogenetic protein signaling in cranial neural crest cells in mice deforms skull base due to premature fusion of intersphenoidal synchondrosis.

Craniofacial anomalies (CFAs) are a diverse group of disorders affecting the shapes of the face and the head. Malformation of the cranial base in humans leads CFAs, such as midfacial hypoplasia and craniosynostosis. These patients have significant burdens associated with breathing, speaking, and chewing. Invasive surgical intervention is the current primary option to correct these structural deficiencies. Understanding molecular cellular mechanism for craniofacial development would provide novel therapeutic options for CFAs. In this study, we found that enhanced bone morphogenetic protein (BMP) signaling in cranial neural crest cells (NCCs) (P0-Cre;caBmpr1a mice) causes premature fusion of intersphenoid synchondrosis (ISS) resulting in leading to short snouts and hypertelorism. Histological analyses revealed reduction of proliferation and higher cell death in ISS at postnatal day 3. We demonstrated to prevent the premature fusion of ISS in P0-Cre;caBmpr1a mice by injecting a p53 inhibitor Pifithrin-α to the pregnant mother from E15.5 to E18.5, resulting in rescue from short snouts and hypertelorism. We further demonstrated to prevent premature fusion of cranial sutures in P0-Cre;caBmpr1a mice by injecting Pifithrin-α through E8.5 to E18.5. These results suggested that enhanced BMP-p53-induced cell death in cranial NCCs causes premature fusion of ISS and sutures in time-dependent manner.

Neuronal lack of PDE7a disrupted working memory, spatial learning, and memory but facilitated cued fear memory in mice

BackgroundPDEs regulate cAMP levels which is critical for PKA activity-dependent activation of CREB-mediated transcription in learning and memory. Inhibitors of PDEs like PDE4 and Pde7 improve learning and memory in rodents. However, the role of PDE7 in cognition or learning and memory has not been reported yet. MethodsTherefore, we aimed to explore the cognitive effects of a PDE7 subtype, PDE7a, using combined pharmacological and genetic approaches. ResultsPDE7a-nko mice showed deficient working memory, impaired novel object recognition, deficient spatial learning & memory, and contextual fear memory, contrary to enhanced cued fear memory, highlighting the potential opposite role of PDE7a in the hippocampal neurons. Further, pharmacological inhibition of PDE7 by AGF2.20 selectively strengthens cued fear memory in C57BL/6 J mice, decreasing its extinction but did not affect cognitive processes assessed in other behavioral tests. The further biochemical analysis detected deficient cAMP in neural cell culture with genetic excision of the PDE7a gene, as well as in the hippocampus of PDE7a-nko mice in vivo. Importantly, we found overexpression of PKA-R and the reduced level of pPKA-C in the hippocampus of PDE7a-nko mice, suggesting a novel mechanism of the cAMP regulation by PDE7a. Consequently, the decreased phosphorylation of CREB, CAMKII, eif2a, ERK, and AMPK, and reduced total level of NR2A have been found in the brain of PDE7a-nko animals. Notably, genetic excision of PDE7a in neurons was not able to change the expression of NR2B, BDNF, synapsin1, synaptophysin, or snap25. ConclusionAltogether, our current findings demonstrated, for the first time, the role of PDE7a in cognitive processes. Future studies will untangle PDE7a-dependent neurobiological and molecular-cellular mechanisms related to cAMP-associated disorders.