Cellular Basis Research Articles

Developing Multiple Media Approach to Investigate Reproducible Characteristic VOCs of Lung Cancer Cells.

Cellular volatile organic compound (VOC) detection is crucial for studying lung cancer biomarkers. However, the reported VOC biomarkers from the same cell line seem to be inconsistent across different research groups. It is possibly related to the variation in culture media, and the result obtained by a conventional single medium approach (SMA) depends on what medium is used in the cell experiment. This study proposes a multiple media approach (MMA) to investigate reproducible characteristic VOCs of lung cancer cells. Using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) in combination with untargeted analysis, we conducted two independently repetitive experiments to compare lung cancer cells (A549) and normal lung cells (BEAS-2B) under three culture media conditions (RPMI 1640, DMEM, and Ham's F12). Both experiments indicated that, compared with 62-96 VOCs obtained by the SMA, only two VOCs (3-methyl-1-butanol and 2-methyl-1-butanol) were reproducibly achieved by the MMA. Moreover, their concentrations were significantly lower in lung cancer cells than in normal cells. Further targeted analysis confirmed the downregulation trend of both VOCs in subcutaneous and primary tumor tissues from the lung cancer model mouse. The present work demonstrated that the MMA cell experiment, just like the multicenter trials for cell lines, can facilitate the discovery of reproducible characteristic VOCs. This provides a cellular experimental basis and scientific evidence for lung cancer biomarker investigation and even breath biopsy technique development.

Infection-induced trained immunity: a twist in paradigm of innate host defense and generation of immunological memory.

In contrast to adaptive immunity, which relies on memory T and B cells for long-term pathogen-specific responses, trained immunity involves the enhancement of innate immune responses through cellular reprogramming. Experimental evidence from animal models and human studies supports the concept of trained immunity and its potential therapeutic applications in the development of personalized medicine. However, there remains a huge gap in understanding the mechanisms, identifying specific microbial triggers responsible for the induction of trained immunity. This underscores the importance of investigating the potential role of trained immunity in redefining host defense and highlights future research directions. This minireview will provide a comprehensive summary of the new paradigm of trained immunity or innate memory pathways. It will shed light on infection-induced pathways through non-specific stimulation within macrophages and natural killer cells, which will be further elaborated in multiple disease perspectives caused by infectious agents such as bacteria, fungi, and viruses. The article further elaborates on the biochemical and cellular basis of trained immunity and its impact on disease status during recurrent exposures. The review concludes with a perspective segment discussing potential therapeutic benefits, limitations, and future challenges in this area of study. The review also sheds light upon potential risks involved in the induction of trained immunity.

Reproductive mechanisms, pathologies, and health inclusivity: insights from the 2023 Annual Meeting of the Society for Reproductive Biology.

In 2023, the Society for Reproductive Biology met in Brisbane to deliver its largest scientific program to date. Herein, we detail key areas of notable discovery across the reproductive biology and fertility landscapes, as well as pressing areas that require further research. Specifically, we focus on five key themes: the cellular basis of reproduction; environmental impacts on reproduction; inclusivity in reproductive health; reproductive cancers; and evolution of reproduction mechanisms. Highlights included the utility of organism models, such as using fruit flies to model human genetic disease, and the development of new blastocyst models; the impact of elevated temperature and endocrine-disrupting chemicals on the germline, sex organ development, and fertility in mammals; how we can improve the inclusivity of transgender and Pacific Rainbow+ people in reproductive health; novel insights in reproductive cancer pathogenesis and inhibitor treatments; and the evolution of the sex chromosomes and sex determination across animals. The breadth of topics covered underscores the far-reaching impacts of reproduction and its related processes across life, health, and wellbeing, as well as for food production and the economy.

Molecular and genetic insights into human ovarian aging from single-nuclei multi-omics analyses.

The ovary is the first organ to age in the human body, affecting both fertility and overall health. However, the biological mechanisms underlying human ovarian aging remain poorly understood. Here we present a comprehensive single-nuclei multi-omics atlas of four young (ages 23-29 years) and four reproductively aged (ages 49-54 years) human ovaries. Our analyses reveal coordinated changes in transcriptomes and chromatin accessibilities across cell types in the ovary during aging, notably mTOR signaling being a prominent ovary-specific aging pathway. Cell-type-specific regulatory networks reveal enhanced activity of the transcription factor CEBPD across cell types in the aged ovary. Integration of our multi-omics data with genetic variants associated with age at natural menopause demonstrates a global impact of functional variants on gene regulatory networks across ovarian cell types. We nominate functional non-coding regulatory variants, their target genes and ovarian cell types and regulatory mechanisms. This atlas provides a valuable resource for understanding the cellular, molecular and genetic basis of human ovarian aging.

Cellular mechanism of polarized auxin transport on fruit shape determination revealed by time-lapse live imaging.

Polarized auxin transport regulates fruit shape determination by promoting anisotropic cell growth. Angiosperms produce organs with distinct shape resultant from adaptive evolution. Understanding the cellular basis underlying the development of plant organ has been a central topic in plant biology as it is key to unlock the mechanisms leading to the diversification of plants. Variations in the location of synthesis, polarized auxin transport (PAT) have been proposed to account for the development of diverse organ shapes, but the exact cellular mechanism has yet to be elucidated. The Capsella rubella develops a perfect heart-shaped fruit from an ovate shape gynoecium that is tightly linked to the localized auxin synthesis in the valve tips and provides a unique opportunity to address this question. In this study, we studied auxin movement in the fruits and the cellular effect of N-1-Naphthylphthalamic Acid (NPA) on the fruitshape determination by constructing the pCrPIN3:PIN3:GFP reporter and live-imaging. We found PAT in the valve epidermis is in congruent with fruit shape development and NPA treatment disrupts the heat-shaped fruit development mainly by repressing cell anisotropic growth with minor effect on division. As the Capsella fruit is unusually big in size, we also included a detailed step-by-step protocol on how to conduct live-imaging experiment. We further test the utility of this protocol by conducting a live-imaging analysis of the gynophore in Arachis hypogaea. Collectively, the results of this study elucidated the mechanism on how auxin signal was translated into instructions guiding cell growth during organ shape determination. In addition, the description of the detailed live-imaging protocol will encourage further studies of the cellular mechanisms underlying shape diversification in angiosperms.

Uncovering protein regulation during adventitious root formation in Platycladus orientalis cuttings.

Cell totipotency and pluripotency are the cellular basis for root regeneration in Platycladus orientalis cuttings, and the regeneration of adventitious roots is a key determinant for improving stem-cutting. However, the cellular basis and physiological regulation of adventitious root formation are still ambiguous. In this research, root primordia initiation and organogenesis were histologically observed, dynamic alterations in soluble proteins were monitored, and Tandem Mass Tag protein profiling during adventitious root development was carried out. It was explicitly shown that the root primordium primarily originated from undifferentiated xylem cells for indirect (callus) rooting and from dividing cells in the cortex for direct (cortex) rooting. During the entire process of adventitious root development, the activities of peroxidase (POD) and polyphenol oxidase (PPO) peaked, and the activity of indole acetic acid oxidase (IAAO) decreased during the prophase of adventitious root formation in both the direct and indirect rooting, suggesting the positive regulation of POD and PPO and the negative regulation of IAAO during adventitious root initiation. Compared with those of indirect rooting, the relatively greater activities of POD and PPO and lower activity of IAAO were related to direct rooting and the number of adventitious roots. A total of 4265 proteins were identified from the base of the cuttings, of which 343, 236 and 37 proteins were highly expressed before treatment, in root primordia induction to adventitious root formation, and adventitious root elongation stages, respectively. Through hierarchical cluster analysis, 23 peroxidase and endogenous hormone regulatory proteins were screened and obtained; these included 10 peroxidases, 1 auxin regulatory protein, 3 ABA regulatory proteins, 2 jasmonic acid regulatory proteins, and 3 gibberellin regulatory proteins, which were highly expressed during the late cutting period. Finally, a hypothetical model of the regulatory network of the differential proteins involved in adventitious root formation in P. orientalis was constructed.

Synaptic and cognitive impairment associated with L444P heterozygous glucocerebrosidase mutation.

Cognitive impairment is a common but poorly understood non-motor aspect of Parkinson's disease, negatively affecting patient's functional capacity and quality of life. The mechanisms underlying cognitive impairment in Parkinson's disease are still elusive, limiting treatment and prevention strategies. This study investigates the molecular and cellular basis of cognitive impairment associated with heterozygous mutations in GBA1, the strongest risk gene for Parkinson's disease that encodes glucocerebrosidase (GCase), a lysosome enzyme that degrades the glycosphingolipid glucosylceramide into glucose and ceramide. Using a Gba1L444P/+ mouse model, we provide evidence that L444P heterozygous Gba1 mutation (L444P/+) causes hippocampus-dependent spatial and reference memory deficits independently of α-synuclein (αSyn) accumulation, GCase lipid substrate accumulation, dopaminergic dysfunction and motor deficits. The mutation disrupts hippocampal synaptic plasticity and basal synaptic transmission by reducing the density of hippocampal CA3-CA1 synapses, a mechanism that is dissociated from αSyn-mediated presynaptic neurotransmitter release. Using a well-characterized Thy1-αSyn pre-manifest Parkinson's disease mouse model overexpressing wild type human αSyn, we find that the L444P/+ mutation exacerbates hippocampal synaptic αSyn accumulation, synaptic and cognitive impairment in young Gba1L444P/+:Thy1-αSyn double mutant animals. With age, Thy1-αSyn mice manifest motor symptoms, and the double mutant mice exhibit more exacerbated synaptic and motor impairment than the Thy1-αSyn mice. Taken together, our results suggest that heterozygous L444P GBA1 mutation alone perturbs hippocampal synaptic structure and function, imposing a subclinical pathological burden for cognitive impairment. When co-existing αSyn overexpression is present, heterozygous L444P GBA1 mutation interacts with αSyn pathology to accelerate Parkinson's disease-related cognitive impairment and motor symptoms.

SMN Deficiency Induces an Early Non-Atrophic Myopathy with Alterations in the Contractile and Excitatory Coupling Machinery of Skeletal Myofibers in the SMN∆7 Mouse Model of Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is caused by a deficiency of the ubiquitously expressed survival motor neuron (SMN) protein. The main pathological hallmark of SMA is the degeneration of lower motor neurons (MNs) with subsequent denervation and atrophy of skeletal muscle. However, increasing evidence indicates that low SMN levels not only are detrimental to the central nervous system (CNS) but also directly affect other peripheral tissues and organs, including skeletal muscle. To better understand the potential primary impact of SMN deficiency in muscle, we explored the cellular, ultrastructural, and molecular basis of SMA myopathy in the SMNΔ7 mouse model of severe SMA at an early postnatal period (P0-7) prior to muscle denervation and MN loss (preneurodegenerative [PND] stage). This period contrasts with the neurodegenerative (ND) stage (P8-14), in which MN loss and muscle atrophy occur. At the PND stage, we found that SMN∆7 mice displayed early signs of motor dysfunction with overt myofiber alterations in the absence of atrophy. We provide essential new ultrastructural data on focal and segmental lesions in the myofibrillar contractile apparatus. These lesions were observed in association with specific myonuclear domains and included abnormal accumulations of actin-thin myofilaments, sarcomere disruption, and the formation of minisarcomeres. The sarcoplasmic reticulum and triads also exhibited ultrastructural alterations, suggesting decoupling during the excitation-contraction process. Finally, changes in intermyofibrillar mitochondrial organization and dynamics, indicative of mitochondrial biogenesis overactivation, were also found. Overall, our results demonstrated that SMN deficiency induces early and MN loss-independent alterations in myofibers that essentially contribute to SMA myopathy. This strongly supports the growing body of evidence indicating the existence of intrinsic alterations in the skeletal muscle in SMA and further reinforces the relevance of this peripheral tissue as a key therapeutic target for the disease.

The Role of Synaptopathy in Alzheimer's Disease: A Review of Key Transgenic Mouse Models

Introduction: Long-term potentiation (LTP) and its counterpart, long-term depression (LTD), are considered the cellular basis underpinning learning and memory. Impairments in these processes are associated with neurodegenerative diseases such as Alzheimer’s disease (AD). These impairments are emergent during the onset of AD, suggesting a critical role in the pathophysiology of AD. Popular transgenic AD models, such as 5xFAD, 3xTg, Tau MAPT P301L, and APPswe/PSEN1dE9 demonstrate changes in synaptic plasticity early during their lifespan. This systematic review aims to investigate localization and onset of synaptopathy associated with AD. Methods: A comprehensive literature search was conducted using PubMed (Medline) to identify common features across models associated with synaptic plasticity. Papers were screened through two stages. The first stage involved establishing a set of criteria, including search terms. The second stage centered on ensuring chosen studies focused on synaptopathy and utilized the models selected. Results: Eight studies were selected across the four transgenic mouse models that established onset and localization of synaptopathy in AD pathophysiology. In the majority of studies, impairments in synaptic plasticity were first found in the CA1 region of the hippocampus. Moreover, onset of these impairments developed prior to onset of neuropathology and behavioral or cognitive deficits. Impairments in synaptic plasticity included inhibition of glutamate release, decreased cell excitability, dendritic atrophy and impaired receptor signaling. Discussion: The results of this review suggest localization of synaptic plasticity impairments to the CA1 region preceding development of neuropathologies such as amyloid or tau aggregation and cognitive deficits. This indicates an early and critical role of synaptopathy at the CA1 region, implicating it as a potential causal factor in the pathophysiology of AD. Conclusion: While the FAD models evaluated in this review implicate changes in synaptic plasticity within AD, they are not representative of late onset AD (LOAD), the prevalent form of the disease in the population. Currently research using LOAD models is limited, causing reliance on FAD models for the study of AD. As prevalence of AD increases in the population, it is essential that new models of LOAD are developed and studied to further current understandings of AD pathophysiology.

EL HÁBITO DE FUMAR Y SU INFLUENCIA EN LA CONSOLIDACIÓN ÓSEA: UNA REVISIÓN INTEGRADORA

Smoking is considered one of the risk factors for various diseases, not only related to the respiratory system but also influencing the physiological processes of various organs and body systems. This article aims to deepen the understanding of the effects of smoking on bone healing by analyzing its molecular, cellular, and clinical bases. This process is subject to possible direct or indirect interferences from chemical substances such as nicotine. It is important to note that, besides conventional cigarettes, there is also indiscriminate use of electronic cigarettes, which, according to an analysis conducted by Pérez and Duarte (2022), have considerably higher nicotine levels than traditional cigarettes. Another study conducted by González et al. (2021) highlights the increasing popularity of these devices among young people, underscoring the importance of preventive measures. According to the National Institute of Traumatology and Orthopedics (INTO), inhaling tobacco smoke increases bone tissue healing time by 60%, thus delaying the body's ability to heal injuries and compromising bone absorption. The clinical repercussions of smoking on the quality and speed of bone recovery after fractures and orthopedic procedures are identified to improve understanding and develop specific clinical strategies and interventions for smoking patients. The specific objectives of this research were to: investigate the molecular and cellular mechanisms of the bone healing process, analyze the effects of smoking on the quality of the formed tissue, evaluate the influence of smoking on the bone healing time in patients after fracture or orthopedic surgery, and finally propose therapeutic strategies and preventive measures to improve bone healing. To this end, a bibliographic search was conducted on articles relevant to the topic using various means. The selection of articles was based on three stages, choosing those that met the inclusion criteria. During the development of this article, it is observed that smoking is an extended and ancestral practice, being a constant and emerging health problem. Additionally, it is considered a modifiable risk factor for decreasing bone density. In conclusion, the need for specific strategies to address complications in bone healing in smoking patients is highlighted.

Etienne Sibille: Investigating the cellular and molecular bases of depression and aging for innovative therapeutics

Etienne Sibille, a pioneering figure in neuropsychiatric research, has yet to follow conventional paths. From his early days as a photojournalist editor in New York to becoming one of neuroscience's most innovative voices, his journey reflects the same creative thinking that drives his groundbreaking research at the University of Toronto. As a Professor of Psychiatry, Pharmacology & Toxicology, he brings a fresh perspective to understanding how our brains age and why we get depressed. At the Center for Addiction and Mental Health (CAMH), where he directs the Neurobiology of Depression and Aging research program, his team is turning fascinating discoveries about brain chemistry into potential new treatments. Building on his influential work at Columbia University and the University of Pittsburgh, Sibille has challenged traditional views of brain disorders, particularly through his insights into the GABAergic system and aging. While serving as CAMH's Campbell Chair (2014–2024) and Deputy Director of the Campbell Institute (2017–2020), he has pushed the boundaries between basic research and real-world treatments, recently diving into biopharma development to help bridge this gap. In this Genomic Press Interview, he shares the winding road that led him from behind a camera lens to the forefront of psychiatric research, offering a candid look at what drives his passion for unraveling the brain's mysteries.

Genetic and Cellular Basis of Impaired Phagocytosis and Photoreceptor Degeneration in CLN3 Disease.

CLN3 Batten disease (also known as juvenile neuronal ceroid lipofuscinosis) is a lysosomal storage disorder that typically initiates with retinal degeneration but is followed by seizure onset, motor decline and premature death. Patient-derived CLN3 disease induced pluripotent stem cell-RPE cells show defective phagocytosis of photoreceptor outer segment (POS). Because modifier genes are implicated in CLN3 disease, our goal here was to investigate a direct link between CLN3 mutation and POS phagocytosis defect. Isogenic control and CLN3 mutant stem cell lines were generated by CRISPR-Cas9-mediated biallelic deletion of exons 7 and 8. A transgenic CLN3Δ7-8/Δ7-8 (CLN3) Yucatan miniswine was also used to study the impact of CLN3Δ7-8/Δ7-8 mutation on POS phagocytosis. POS phagocytosis by cultured RPE cells was analyzed by Western blotting and immunohistochemistry. Electroretinogram, optical coherence tomography and histological analysis of CLN3Δ7-8/Δ7-8 and wild-type miniswine eyes were carried out at 6, 36, or 48 months of age. CLN3Δ7-8/Δ7-8 RPE (CLN3 RPE) displayed decreased POS binding and consequently decreased uptake of POS compared with isogenic control RPE cells. Furthermore, wild-type miniswine RPE cells phagocytosed CLN3Δ7-8/Δ7-8 POS less efficiently than wild-type POS. Consistent with decreased POS phagocytosis, lipofuscin/autofluorescence was decreased in CLN3 miniswine RPE at 36months of age and was followed by almost complete loss of photoreceptors at 48months of age. CLN3Δ7-8/Δ7-8 mutation (which affects ≤85% of patients) affects both RPE and POS and leads to photoreceptor cell loss in CLN3 disease. Furthermore, both primary RPE dysfunction and mutant POS independently contribute to impaired POS phagocytosis in CLN3 disease.

Promising strategies for the prevention of alcohol-related brain damage through optimised management of acute alcohol withdrawal: A focussed literature review.

There is an increasing awareness of the link between chronic alcohol consumption and the development of cognitive, behavioural and functional deficits. Currently, preventative strategies are limited and require engagement in dedicated long-term rehabilitation and sobriety services, the availability of which is low. The acute alcohol withdrawal syndrome is an episode of neurochemical imbalance leading to autonomic dysregulation, increased seizure risk and cognitive disorientation. In addition to harm from symptoms of alcohol withdrawal (e.g. seizures), the underpinning neurochemical changes may also lead to cytotoxicity through various cellular mechanisms, which long-term, may translate to some of the cognitive impairments observed in Alcohol-Related Brain Damage (ARBD). Here we review some of the pharmacological and neurochemical mechanisms underpinning alcohol withdrawal. We discuss the cellular and pharmacological basis of various potential neuroprotective strategies that warrant further exploration in clinical populations with a view to preventing the development of ARBD. Such strategies, when integrated into the clinical management of acute alcohol withdrawal, may impact large populations of individuals, who currently face limited dedicated service delivery and healthcare resource.

Leaf growth in third dimension: a perspective of leaf thickness from genetic regulation to ecophysiology.

Leaf thickness, the leaf growth in the third dimension as quantified by the distance between the adaxial and abaxial surface, is an indispensable aspect of leaf development. The fitness of a plant is strongly influenced by leaf thickness via modulation of major physiological processes, including photosynthesis and water use efficiency. The cellular basis of leaf thickness by alterations in either cell size or the number of cell layers is envisaged using Arabidopsis leaf thickness mutants, such as angustifolia (an) and rotundifolia (rot). Environmental factors coordinate with endogenous signaling mechanisms to exhibit leaf thickness plasticity. Plants growing in different ecological and environmental regimes show different leaf thickness attributes. However, genetic and molecular understandings of leaf thickness regulation remain largely limited. In this review, we highlight how cellular growth is transposed to fine-tune the leaf thickness via the integration of potential cues and molecular players. We further discuss the physiological significance of leaf thickness plasticity to the environmental cues that might serve as ecological adaptation enabling the plants to withstand future climatic conditions. Taken together, we seek to bridge the genetics and molecular biology of leaf thickness to its physiological significance so that leaf thickness can be systemically targeted in crop improvement programs.

A cellular basis for mapping behavioural structure

To flexibly adapt to new situations, our brains must understand the regularities in the world, as well as those in our own patterns of behaviour. A wealth of findings is beginning to reveal the algorithms that we use to map the outside world1, 2, 3, 4, 5–6. However, the biological algorithms that map the complex structured behaviours that we compose to reach our goals remain unknown. Here we reveal a neuronal implementation of an algorithm for mapping abstract behavioural structure and transferring it to new scenarios. We trained mice on many tasks that shared a common structure (organizing a sequence of goals) but differed in the specific goal locations. The mice discovered the underlying task structure, enabling zero-shot inferences on the first trial of new tasks. The activity of most neurons in the medial frontal cortex tiled progress to goal, akin to how place cells map physical space. These ‘goal-progress cells’ generalized, stretching and compressing their tiling to accommodate different goal distances. By contrast, progress along the overall sequence of goals was not encoded explicitly. Instead, a subset of goal-progress cells was further tuned such that individual neurons fired with a fixed task lag from a particular behavioural step. Together, these cells acted as task-structured memory buffers, implementing an algorithm that instantaneously encoded the entire sequence of future behavioural steps, and whose dynamics automatically computed the appropriate action at each step. These dynamics mirrored the abstract task structure both on-task and during offline sleep. Our findings suggest that schemata of complex behavioural structures can be generated by sculpting progress-to-goal tuning into task-structured buffers of individual behavioural steps.

Altered immune response is associated with sex difference in vulnerability to Alzheimer's disease in human prefrontal cortex.

Alzheimer's disease (AD) is a neurodegenerative disorder with a higher risk incidence in females than in males, and there are also differences in AD pathophysiology between sexes. The role of sex in the pathogenesis of AD may be crucial, yet the cellular and molecular basis remains unclear. Here, we performed a comprehensive analysis using four public transcriptome datasets of AD patients and age-matched control individuals in prefrontal cortex, including bulk transcriptome (295 females and 402 males) and single-nucleus RNA sequencing (snRNA-seq) data (224 females and 219 males). We found that the transcriptomic profile in female control was similar to those in AD. To characterize the key features associated with both the pathogenesis of AD and sex difference, we identified a co-expressed gene module that positively correlated with AD, sex, and aging, and was also enriched with immune-associated pathways. Using snRNA-seq datasets, we found that microglia (MG), a resident immune cell in the brain, demonstrated substantial differences in several aspects between sexes, such as an elevated proportion of activated MG, altered transcriptomic profile and cell-cell interaction between MG and other brain cell types in female control. Additionally, genes upregulated in female MG, such as TLR2, MERTK, SPP1, SLA, ACSL1, and FKBP5, had high confidence to be identified as biomarkers to distinguish AD status, and these genes also interacted with some approved drugs for treatment of AD. These findings underscore the altered immune response in female is associated with sex difference in susceptibility to AD, and the necessity of considering sex factors when developing AD biomarkers and therapeutic strategies, providing a scientific basis for further in-depth studies on sex differences in AD.

Molecular Insights and Pharmacotherapy of Diabetic Neuropathy

Background: Diabetes mellitus is a chronic disorder of energy metabolism caused by lack or decrease in the effectiveness of insulin, and is characterised by an abnormally elevated blood glucose concentrations and the development of macrovascular, microvascular and/or neuropathic complications. Diabetic neuropathy (DN) is one of the most debilitating outcomes of diabetes mellitus, and may cause pain, decreased mobility as well as amputation. Diabetes can damage the peripheral nervous system (PNS), through the induction of de-myelination in neurones, precipitated by chronic hyperglycaemia-induced oxidative stress, and causing a condition that involves the upper and lower limbs. Objective: The study discussed the risk factors for insulin resistance and pre-diabetes, type II diabetes mellitus and vascular complications, cellular and molecular basis of DN, physiopathological mechanisms, and the pharmacological treatment of DN. Method: The study examined journal articles and standard textbooks, as it relates to diabetes mellitus and its complications. Search for articles on DN was carried out in the literature. These were identified and reviewed for selection using chemical abstracts service, pubmed, google scholar, crossreference, web of science, pubmed central free article, and scopus. The key words used for search were: diabetic neuropathy; diabetic peripheral neuropathy; peripheral neuropathy; microvascular complications of diabetes mellitus; and neuromuscular complications of diabetes mellitus. Result & Discussion: Two hundred and fifty (250) articles and other works were identified, while ninety-seven (97) articles and non-journal materials were extracted and reviewed, taking into account the criteria for selection. Studies done in the last 4.5 decades were included, while works written on other languages, outside English were excluded. Findings indicate that DN is a complex disorder that affects the peripheral and/or cranial nerves, which is caused by unattended or poorly attended, long-term increase in blood glucose concentrations. It relatively manifests early, affecting a significant proportion of the micro-blood vessels in the middle-aged and elderly diabetic patients. DN causes numbness, loss of sensation, and sometimes pain in the feet, legs, arms or hands. Hyperglycaemia causes the activation and inhibition of several molecular pathways that are crucial for homeostasis in neuronal and neuroglial cells. Conclusion: DN is the commonest complication of diabetes mellitus. It has no known definitive therapy. Treatment is essentially symptomatic with huge economic and psychological burden, hence the rationale for a cost effective and targeted therapies. Achieving euglycaemia using anti-diabetic regimens (i.e., insulin and oral hypoglycaemic agents), foot care, changes in feeding habits and lifestyle modification are critical to holistically address the problem.

Effects of combined action of proline-rich peptides of human saliva with antimicrobial proteins

BACKGROUND: The substances that make up mixed saliva exhibit activity against bacteria, viruses and fungi. Among them are various cationic antimicrobial peptides: alpha- and beta-defensins, cathelicidins, histatins, but their concentration is relatively low. On the other hand, saliva widely contains a fraction of proline-rich proteins and products of their proteolysis — peptides, the functions of which currently remain poorly studied and unclear. The study of the antimicrobial activity of proline-rich proteins, in particular, when they act together with antimicrobial peptides, and the deciphering of the molecular and cellular basis for the implementation of the protective functions of proline-rich peptides is an urgent task in medicine and biology. The data obtained will help to understand the mechanisms of anti-infective protection of the oral cavity with the participation of the innate immune system, and in the future will allow the creation of drugs based on proline-rich proteins in humans and animals. AIM: Study of the individual antibacterial action of proline-rich salivary proteins, their combined action with the antimicrobial proteins lactoferrin and lysozyme, as well as with one of the most significant endogenous protective peptides — cathelicidin LL-37 on the formation of bacterial biofilms. MATERIALS AND METHODS: Human lactoferrin and egg lysozyme were used in the work. The minimum inhibitory concentrations of peptides against gram-negative and gram-positive bacteria were estimated using serial dilutions in a liquid nutrient medium. Using serial dilutions using the “chessboard” method, it was shown that proline-rich proteins can increase the antibacterial activity of innate immunity peptides present in the oral cavity. The ability of combinations of cationic proline-rich peptides with cathelicidin LL-37 to prevent the formation of bacterial biofilms was studied. RESULTS: In the presence of proline-rich peptides, the antimicrobial activity of some antimicrobial peptides and proteins present in saliva against planktonic bacteria increases. The combined action of proline-rich proteins with LL-37 increases the inhibition of bacterial biofilm formation. CONCLUSIONS: As a result of the study, it was shown that the analyzed cationic proline-rich peptides of human saliva exhibit anti-inflammatory effects, which suggests their significant role in the regulation of inflammatory processes in the oral cavity, as well as their participation in recovery processes.

Ageing leads to selective type II myofibre deterioration and denervation independent of reinnervative capacity in human skeletal muscle.

Age-related loss of muscle mass and function is underpinned by changes at the myocellular level. However, our understanding of the aged muscle phenotype might be confounded by factors secondary to ageing per se, such as inactivity and adiposity. Here, using healthy, lean, recreationally active, older men, we investigated the impact of ageing on myocellular properties in skeletal muscle. Muscle biopsies were obtained from young men (22±3years, n=10) and older men (69±3years, n=11) matched for health status, activity level and body mass index. Immunofluorescence was used to assess myofibre composition, morphology (size and shape), capillarization, the content of satellite cells and myonuclei, the spatial relationship between satellite cells and capillaries, denervation and myofibre grouping. Compared with young muscle, aged muscle contained 53% more type I myofibres, in addition to smaller (-32%) and misshapen (3%) type II myofibres (P<0.05). Aged muscle manifested fewer capillaries (-29%) and satellite cells (-38%) surrounding type II myofibres (P<0.05); however, the spatial relationship between these two remained intact. The proportion of denervated myofibres was ∼2.6-fold higher in old than young muscle (P<0.05). Aged muscle had more grouped type I myofibres (∼18-fold), primarily driven by increased size of existing groups rather than increased group frequency (P<0.05). Aged muscle displayed selective deterioration of type II myofibres alongside increased denervation and myofibre grouping. These data are key to understanding the cellular basis of age-related muscle decline and reveal a pressing need to fine-tune strategies to preserve type II myofibres and innervation status in ageing populations.

Brief disruption of activity in a subset of dopaminergic neurons during consolidation impairs long-term memory by fragmenting sleep.

Sleep disturbances are associated with poor long-term memory (LTM) formation, yet the underlying cell types and neural circuits involved have not been fully decoded. Dopamine neurons (DANs) are involved in memory processing at multiple stages. Here, using both male and female flies, Drosophila melanogaster , we show that, during the first few hours of memory consolidation, disruption of basal activity of a small subset of protocerebral anterior medial DANs (PAM-DANs), by either brief activation or inhibition of the two dorsal posterior medial (DPM) neurons, impairs 24 h LTM. Interestingly, these brief changes in activity using female flies result in sleep loss and fragmentation, especially at night. Pharmacological rescue of sleep after manipulation restores LTM. A specific subset of PAM-DANs (PAM-α1) that synapse onto DPM neurons specify the microcircuit that links sleep and memory. PAM-DANs, including PAM-α1, form functional synapses onto DPM mainly via multiple dopamine receptor subtypes. This PAM-α1 to DPM microcircuit exhibits a synchronized, transient, post-training increase in activity during the critical memory consolidation window, suggesting an effect of this microcircuit on maintaining the sleep necessary for LTM consolidation. Our results provide a new cellular and circuit basis for the complex relationship between sleep and memory.