Neurogenesis dynamics in the olfactory bulb: deciphering circuitry organization, function, and adaptive plasticity

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover, the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.

Decoding the nexus: branched-chain amino acids and their connection with sleep, circadian rhythms, and cardiometabolic health

The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and, either directly or indirectly, overall body health, encompassing metabolic and cardiovascular well-being. Given the heightened metabolic activity of the brain, there exists a considerable demand for nutrients in comparison to other organs. Among these, the branched-chain amino acids, comprising leucine, isoleucine, and valine, display distinctive significance, from their contribution to protein structure to their involvement in overall metabolism, especially in cerebral processes. Among the first amino acids that are released into circulation post-food intake, branched-chain amino acids assume a pivotal role in the regulation of protein synthesis, modulating insulin secretion and the amino acid sensing pathway of target of rapamycin. Branched-chain amino acids are key players in influencing the brain's uptake of monoamine precursors, competing for a shared transporter. Beyond their involvement in protein synthesis, these amino acids contribute to the metabolic cycles of γ-aminobutyric acid and glutamate, as well as energy metabolism. Notably, they impact GABAergic neurons and the excitation/inhibition balance. The rhythmicity of branched-chain amino acids in plasma concentrations, observed over a 24-hour cycle and conserved in rodent models, is under circadian clock control. The mechanisms underlying those rhythms and the physiological consequences of their disruption are not fully understood. Disturbed sleep, obesity, diabetes, and cardiovascular diseases can elevate branched-chain amino acid concentrations or modify their oscillatory dynamics. The mechanisms driving these effects are currently the focal point of ongoing research efforts, since normalizing branched-chain amino acid levels has the ability to alleviate the severity of these pathologies. In this context, the Drosophila model, though underutilized, holds promise in shedding new light on these mechanisms. Initial findings indicate its potential to introduce novel concepts, particularly in elucidating the intricate connections between the circadian clock, sleep/wake, and metabolism. Consequently, the use and transport of branched-chain amino acids emerge as critical components and orchestrators in the web of interactions across multiple organs throughout the sleep/wake cycle. They could represent one of the so far elusive mechanisms connecting sleep patterns to metabolic and cardiovascular health, paving the way for potential therapeutic interventions.

Induced neural stem cells regulate microglial activation through Akt-mediated upregulation of CXCR4 and Crry in a mouse model of closed head injury

JOURNAL/nrgr/04.03/01300535-202505000-00025/figure1/v/2024-07-28T173839Z/r/image-tiff Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and repair. We previously reported that induced neural stem cells can modulate the behavior of activated microglia via CXCL12/CXCR4 signaling, influencing their activation such that they can promote neurological recovery. However, the mechanism of CXCR4 upregulation in induced neural stem cells remains unclear. In this study, we found that nuclear factor-κB activation induced by closed head injury mouse serum in microglia promoted CXCL12 and tumor necrosis factor-α expression but suppressed insulin-like growth factor-1 expression. However, recombinant complement receptor 2-conjugated Crry (CR2-Crry) reduced the effects of closed head injury mouse serum-induced nuclear factor-κB activation in microglia and the levels of activated microglia, CXCL12, and tumor necrosis factor-α. Additionally, we observed that, in response to stimulation (including stimulation by CXCL12 secreted by activated microglia), CXCR4 and Crry levels can be upregulated in induced neural stem cells via the interplay among CXCL12/CXCR4, Crry, and Akt signaling to modulate microglial activation. In agreement with these in vitro experimental results, we found that Akt activation enhanced the immunoregulatory effects of induced neural stem cell grafts on microglial activation, leading to the promotion of neurological recovery via insulin-like growth factor-1 secretion and the neuroprotective effects of induced neural stem cell grafts through CXCR4 and Crry upregulation in the injured cortices of closed head injury mice. Notably, these beneficial effects of Akt activation in induced neural stem cells were positively correlated with the therapeutic effects of induced neural stem cells on neuronal injury, cerebral edema, and neurological disorders post-closed head injury. In conclusion, our findings reveal that Akt activation may enhance the immunoregulatory effects of induced neural stem cells on microglial activation via upregulation of CXCR4 and Crry, thereby promoting induced neural stem cell-mediated improvement of neuronal injury, cerebral edema, and neurological disorders following closed head injury.

Metabolic reprogramming: a new option for the treatment of spinal cord injury

Spinal cord injuries impose a notably economic burden on society, mainly because of the severe after-effects they cause. Despite the ongoing development of various therapies for spinal cord injuries, their effectiveness remains unsatisfactory. However, a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming. In this review, we explore the metabolic changes that occur during spinal cord injuries, their consequences, and the therapeutic tools available for metabolic reprogramming. Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling. However, spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism, lipid metabolism, and mitochondrial dysfunction. These metabolic disturbances lead to corresponding pathological changes, including the failure of axonal regeneration, the accumulation of scarring, and the activation of microglia. To rescue spinal cord injury at the metabolic level, potential metabolic reprogramming approaches have emerged, including replenishing metabolic substrates, reconstituting metabolic couplings, and targeting mitochondrial therapies to alter cell fate. The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury. To further advance the metabolic treatment of the spinal cord injury, future efforts should focus on a deeper understanding of neurometabolism, the development of more advanced metabolomics technologies, and the design of highly effective metabolic interventions.

Investigating Müller glia reprogramming in mice: a retrospective of the last decade, and a look to the future

Müller glia, as prominent glial cells within the retina, plays a significant role in maintaining retinal homeostasis in both healthy and diseased states. In lower vertebrates like zebrafish, these cells assume responsibility for spontaneous retinal regeneration, wherein endogenous Müller glia undergo proliferation, transform into Müller glia-derived progenitor cells, and subsequently regenerate the entire retina with restored functionality. Conversely, Müller glia in the mouse and human retina exhibit limited neural reprogramming. Müller glia reprogramming is thus a promising strategy for treating neurodegenerative ocular disorders. Müller glia reprogramming in mice has been accomplished with remarkable success, through various technologies. Advancements in molecular, genetic, epigenetic, morphological, and physiological evaluations have made it easier to document and investigate the Müller glia programming process in mice. Nevertheless, there remain issues that hinder improving reprogramming efficiency and maturity. Thus, understanding the reprogramming mechanism is crucial toward exploring factors that will improve Müller glia reprogramming efficiency, and for developing novel Müller glia reprogramming strategies. This review describes recent progress in relatively successful Müller glia reprogramming strategies. It also provides a basis for developing new Müller glia reprogramming strategies in mice, including epigenetic remodeling, metabolic modulation, immune regulation, chemical small-molecules regulation, extracellular matrix remodeling, and cell-cell fusion, to achieve Müller glia reprogramming in mice.

Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients' clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.

Cholesterol metabolism: physiological versus pathological aspects in intracerebral hemorrhage

Cholesterol is an important component of plasma membranes and participates in many basic life functions, such as the maintenance of cell membrane stability, the synthesis of steroid hormones, and myelination. Cholesterol plays a key role in the establishment and maintenance of the central nervous system. The brain contains 20% of the whole body's cholesterol, 80% of which is located within myelin. A huge number of processes (e.g., the sterol regulatory element-binding protein pathway and liver X receptor pathway) participate in the regulation of cholesterol metabolism in the brain via mechanisms that include cholesterol biosynthesis, intracellular transport, and efflux. Certain brain injuries or diseases involving crosstalk among the processes above can affect normal cholesterol metabolism to induce detrimental consequences. Therefore, we hypothesized that cholesterol-related molecules and pathways can serve as therapeutic targets for central nervous system diseases. Intracerebral hemorrhage is the most severe hemorrhagic stroke subtype, with high mortality and morbidity. Historical cholesterol levels are associated with the risk of intracerebral hemorrhage. Moreover, secondary pathological changes after intracerebral hemorrhage are associated with cholesterol metabolism dysregulation, such as neuroinflammation, demyelination, and multiple types of programmed cell death. Intracellular cholesterol accumulation in the brain has been found after intracerebral hemorrhage. In this paper, we review normal cholesterol metabolism in the central nervous system, the mechanisms known to participate in the disturbance of cholesterol metabolism after intracerebral hemorrhage, and the links between cholesterol metabolism and cell death. We also review several possible and constructive therapeutic targets identified based on cholesterol metabolism to provide cholesterol-based perspectives and a reference for those interested in the treatment of intracerebral hemorrhage.

Targeting TrkB-PSD-95 coupling to mitigate neurological disorders

Tropomyosin receptor kinase B (TrkB) signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and memory. The activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre- or postsynaptic TrkB resulting in the strengthening of synapses, reflected by long-term potentiation. Postsynaptically, the association of postsynaptic density protein-95 with TrkB enhances phospholipase Cγ-Ca2+/calmodulin-dependent protein kinase II and phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term potentiation. In this review, we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders. A reduction of TrkB signaling has been observed in neurodegenerative disorders, such as Alzheimer's disease and Huntington's disease, and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and depression. Treatment with brain-derived neurotrophic factor is problematic, due to poor pharmacokinetics, low brain penetration, and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 isoform. Although TrkB agonists and antibodies that activate TrkB are being intensively investigated, they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific functions. Targeting TrkB-postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.

Lipid droplets in the nervous system: involvement in cell metabolic homeostasis

Lipid droplets serve as primary storage organelles for neutral lipids in neurons, glial cells, and other cells in the nervous system. Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic reticulum. Previously, lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis; however, recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous system. In addition to their role in regulating cell metabolism, lipid droplets play a protective role in various cellular stress responses. Furthermore, lipid droplets exhibit specific functions in neurons and glial cells. Dysregulation of lipid droplet formation leads to cellular dysfunction, metabolic abnormalities, and nervous system diseases. This review aims to provide an overview of the role of lipid droplets in the nervous system, covering topics such as biogenesis, cellular specificity, and functions. Additionally, it will explore the association between lipid droplets and neurodegenerative disorders. Understanding the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.

Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

Spastin and alsin protein interactome analyses begin to reveal key canonical pathways and suggest novel druggable targets

Developing effective and long-term treatment strategies for rare and complex neurodegenerative diseases is challenging. One of the major roadblocks is the extensive heterogeneity among patients. This hinders understanding the underlying disease-causing mechanisms and building solutions that have implications for a broad spectrum of patients. One potential solution is to develop personalized medicine approaches based on strategies that target the most prevalent cellular events that are perturbed in patients. Especially in patients with a known genetic mutation, it may be possible to understand how these mutations contribute to problems that lead to neurodegeneration. Protein-protein interaction analyses offer great advantages for revealing how proteins interact, which cellular events are primarily involved in these interactions, and how they become affected when key genes are mutated in patients. This line of investigation also suggests novel druggable targets for patients with different mutations. Here, we focus on alsin and spastin, two proteins that are identified as "causative" for amyotrophic lateral sclerosis and hereditary spastic paraplegia, respectively, when mutated. Our review analyzes the protein interactome for alsin and spastin, the canonical pathways that are primarily important for each protein domain, as well as compounds that are either Food and Drug Administration-approved or are in active clinical trials concerning the affected cellular pathways. This line of research begins to pave the way for personalized medicine approaches that are desperately needed for rare neurodegenerative diseases that are complex and heterogeneous.

Microglia: a promising therapeutic target in spinal cord injury

Microglia are present throughout the central nervous system and are vital in neural repair, nutrition, phagocytosis, immunological regulation, and maintaining neuronal function. In a healthy spinal cord, microglia are accountable for immune surveillance, however, when a spinal cord injury occurs, the microenvironment drastically changes, leading to glial scars and failed axonal regeneration. In this context, microglia vary their gene and protein expression during activation, and proliferation in reaction to the injury, influencing injury responses both favorably and unfavorably. A dynamic and multifaceted injury response is mediated by microglia, which interact directly with neurons, astrocytes, oligodendrocytes, and neural stem/progenitor cells. Despite a clear understanding of their essential nature and origin, the mechanisms of action and new functions of microglia in spinal cord injury require extensive research. This review summarizes current studies on microglial genesis, physiological function, and pathological state, highlights their crucial roles in spinal cord injury, and proposes microglia as a therapeutic target.

From the cauldron of conflict: Endogenous gene regulation by piRNA and other modes of adaptation enabled by selfish transposable elements

Transposable elements (TEs) provide a prime example of genetic conflict because they can proliferate in genomes and populations even if they harm the host. However, numerous studies have shown that TEs, though typically harmful, can also provide fuel for adaptation. This is because they code functional sequences that can be useful for the host in which they reside. In this review, I summarize the "how" and "why" of adaptation enabled by the genetic conflict between TEs and hosts. In addition, focusing on mechanisms of TE control by small piwi-interacting RNAs (piRNAs), I highlight an indirect form of adaptation enabled by conflict. In this case, mechanisms of host defense that regulate TEs have been redeployed for endogenous gene regulation. I propose that the genetic conflict released by meiosis in early eukaryotes may have been important because, among other reasons, it spurred evolutionary innovation on multiple interwoven trajectories - on the part of hosts and also embedded genetic parasites. This form of evolution may function as a complexity generating engine that was a critical player in eukaryotic evolution.

Regulation and function of endoplasmic reticulum autophagy in neurodegenerative diseases

The endoplasmic reticulum, a key cellular organelle, regulates a wide variety of cellular activities. Endoplasmic reticulum autophagy, one of the quality control systems of the endoplasmic reticulum, plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover, remodeling, and proteostasis. In this review, we briefly describe the endoplasmic reticulum quality control system, and subsequently focus on the role of endoplasmic reticulum autophagy, emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular requirements. We also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative diseases. In summary, this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve disorders. This review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.

Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

JOURNAL/nrgr/04.03/01300535-202501000-00032/figure1/v/2024-05-14T021156Z/r/image-tiff Human brain development is a complex process, and animal models often have significant limitations. To address this, researchers have developed pluripotent stem cell-derived three-dimensional structures, known as brain-like organoids, to more accurately model early human brain development and disease. To enable more consistent and intuitive reproduction of early brain development, in this study, we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture. This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation, resulting in a new type of human brain organoid system. This cerebral organoid system replicated the temporospatial characteristics of early human brain development, including neuroepithelium derivation, neural progenitor cell production and maintenance, neuron differentiation and migration, and cortical layer patterning and formation, providing more consistent and reproducible organoids for developmental modeling and toxicology testing. As a proof of concept, we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins. Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns, including bursts of cortical cell death and premature differentiation. Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity, accompanied by compensatory cell proliferation at ectopic locations. The convenience, flexibility, and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental, neurological, and neurotoxicological studies.

Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures

JOURNAL/nrgr/04.03/01300535-202501000-00034/figure1/v/2024-05-14T021156Z/r/image-tiff Certain amino acids changes in the human Na+/K+-ATPase pump, ATPase Na+/K+ transporting subunit alpha 1 (ATP1A1), cause Charcot-Marie-Tooth disease type 2 (CMT2) disease and refractory seizures. To develop in vivo models to study the role of Na+/K+-ATPase in these diseases, we modified the Drosophila gene homolog, Atpα, to mimic the human ATP1A1 gene mutations that cause CMT2. Mutations located within the helical linker region of human ATP1A1 (I592T, A597T, P600T, and D601F) were simultaneously introduced into endogenous DrosophilaAtpα by CRISPR/Cas9-mediated genome editing, generating the AtpαTTTF model. In addition, the same strategy was used to generate the corresponding single point mutations in flies (AtpαI571T, AtpαA576T, AtpαP579T, and AtpαD580F). Moreover, a deletion mutation (Atpαmut) that causes premature termination of translation was generated as a positive control. Of these alleles, we found two that could be maintained as homozygotes (AtpαI571T and AtpαP579T). Three alleles (AtpαA576T, AtpαP579 and AtpαD580F) can form heterozygotes with the Atpαmut allele. We found that the Atpα allele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila. Flies heterozygous for AtpαTTTF mutations have motor performance defects, a reduced lifespan, seizures, and an abnormal neuronal morphology. These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.

The interaction between KIF21A and KANK1 regulates dendritic morphology and synapse plasticity in neurons

JOURNAL/nrgr/04.03/01300535-202501000-00029/figure1/v/2024-05-14T021156Z/r/image-tiff Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory. Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1; however, whether KIF21A modulates dendritic structure and function in neurons remains unknown. In this study, we found that KIF21A was distributed in a subset of dendritic spines, and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines. Furthermore, the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity. Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching, and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1, but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1. Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals' cognitive abilities. Taken together, our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.

The autophagy-lysosome pathway: a potential target in the chemical and gene therapeutic strategies for Parkinson's disease

Parkinson's disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such as α-synuclein in neurons. As one of the major intracellular degradation pathways, the autophagy-lysosome pathway plays an important role in eliminating these proteins. Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance of α-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson's disease. Moreover, multiple genes associated with the pathogenesis of Parkinson's disease are intimately linked to alterations in the autophagy-lysosome pathway. Thus, this pathway appears to be a promising therapeutic target for treatment of Parkinson's disease. In this review, we briefly introduce the machinery of autophagy. Then, we provide a description of the effects of Parkinson's disease-related genes on the autophagy-lysosome pathway. Finally, we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy-lysosome pathway and their applications in Parkinson's disease.

The link between changing in host carbon allocation and resistance to Magnaporthe oryzae: a possible tactic for mitigating the rice blast fungus

One of the most destructive diseases affecting rice is rice blast, which is brought on by the rice blast fungus Magnaporthe oryzae. The preventive measures, however, are not well established. To effectively reduce the negative effects of rice blasts on crop yields, it is imperative to comprehend the dynamic interactions between pathogen resistance and patterns of host carbon allocation. This review explores the relationship between variations in carbon allocation and rice plants' ability to withstand the damaging effects of M. oryzae. The review highlights potential strategies for altering host carbon allocation including transgenic, selective breeding, crop rotation, and nutrient management practices as a promising avenue for enhancing rice blast resistance. This study advances our knowledge of the interaction between plants' carbon allocation and M. oryzae resistance and provides stakeholders and farmers with practical guidance on mitigating the adverse effects of the rice blast globally. This information may be used in the future to create varieties that are resistant to M. oryzae.

SATB1 mediated tumor colonization and β-catenin nuclear localization are associated with colorectal cancer progression

Colorectal cancer (CRC) is a malignancy with high incidence and poor prognosis. It is urgent to identify valuable biomarkers for early diagnosis and potent therapeutic targets. It has been reported that SATB1 is associated with the malignant progression in CRC. To explore the role of SATB1 in CRC progression and the underlying mechanism, we evaluated the expression of SATB1 in the paired CRC tissues with immunohistochemistry. The results showed that the expression of SATB1 in lymph node metastasis was higher than that in primary lesion, and that in distant organ metastasis was higher than that in primary lesion. The retrospective analysis showed that patients with high expression of SATB1 had a significantly worse prognosis than those with negative and moderate expression. In vitro experiments that employing SATB1 over-expressing and depleted CRC cell lines confirmed that SATB1 contributes to cell proliferation and colonization, while inhibiting cell motility. Furthermore, the tissue immunofluorescence assay, Co-IP and Western blot were conducted to reveal that SATB1 induced translocation of β-catenin and formed a protein complex with it in the nuclei. In conclusion, SATB1 mediated tumor colonization and β-catenin nuclear localization are associated with the malignant progression and poor prognosis of CRC.

Understanding the molecular mechanism responsible for developing therapeutic radiation-induced radioresistance of rectal cancer and improving the clinical outcomes of radiotherapy - A review

Rectal cancer accounts for the second highest cancer-related mortality, which is predominant in Western civilizations. The treatment for rectal cancers includes surgery, radiotherapy, chemotherapy, and immunotherapy. Radiotherapy, specifically external beam radiation therapy, is the most common way to treat rectal cancer because radiation not only limits cancer progression but also significantly reduces the risk of local recurrence. However, therapeutic radiation-induced radioresistance to rectal cancer cells and toxicity to normal tissues are major drawbacks. Therefore, understanding the mechanistic basis of developing radioresistance during and after radiation therapy would provide crucial insight to improve clinical outcomes of radiation therapy for rectal cancer patients. Studies by various groups have shown that radiotherapy-mediated changes in the tumor microenvironment play a crucial role in developing radioresistance. Therapeutic radiation-induced hypoxia and functional alterations in the stromal cells, specifically tumor-associated macrophage (TAM) and cancer-associated fibroblasts (CAF), play a crucial role in developing radioresistance. In addition, signaling pathways, such as - the PI3K/AKT pathway, Wnt/β-catenin signaling, and the hippo pathway, modulate the radiation responsiveness of cancer cells. Different radiosensitizers, such as small molecules, microRNA, nanomaterials, and natural and chemical sensitizers, are being used to increase the effectiveness of radiotherapy. This review highlights the mechanism responsible for developing radioresistance of rectal cancer following radiotherapy and potential strategies to enhance the effectiveness of radiotherapy for better management of rectal cancer.

Endogenous cAMP elevation in Brassica napus causes changes in phytohormone levels

In higher plants, the regulatory roles of cAMP (cyclic adenosine 3',5'-monophosphate) signaling remain elusive until now. Cellular cAMP levels are generally much lower in higher plants than in animals and transiently elevated for triggering downstream signaling events. Moreover, plant adenylate cyclase (AC) activities are found in different moonlighting multifunctional proteins, which may pose additional complications in distinguishing a specific signaling role for cAMP. Here, we have developed rapeseed (Brassica napus L.) transgenic plants that overexpress an inducible plant-origin AC activity for generating high AC levels much like that in animal cells, which served the genetic model disturbing native cAMP signaling as a whole in plants. We found that overexpression of the soluble AC activity had significant impacts on the contents of indole-3-acetic acid (IAA) and stress phytohormones, i.e. jasmonic acid (JA), abscisic acid (ABA), and salicylic acid (SA) in the transgenic plants. Acute induction of the AC activity caused IAA overaccumulation, and upregulation of TAA1 and CYP83B1 in the IAA biosynthesis pathways, but also simultaneously the hyper-induction of PR4 and KIN2 expression indicating activation of JA and ABA signaling pathways. We observed typical overgrowth phenotypes related to IAA excess in the transgenic plants, including significant increases in plant height, internode length, width of leaf blade, petiole length, root length, and fresh shoot biomass, as well as the precocious seed development, as compared to wild-type plants. In addition, we identified a set of 1465 cAMP-responsive genes (CRGs), which are most significantly enriched in plant hormone signal transduction pathway, and function mainly in relevance to hormonal, abiotic and biotic stress responses, as well as growth and development. Collectively, our results support that cAMP elevation impacts phytohormone homeostasis and signaling, and modulates plant growth and development. We proposed that cAMP signaling may be critical in configuring the coordinated regulation of growth and development in higher plants.

Chaperonin containing TCP1 subunit 6A may activate Notch and Wnt pathways to facilitate the malignant behaviors and cancer stemness in oral squamous cell carcinoma

Chaperonin containing TCP1 subunit 6A (CCT6A) was recently discovered to be involved in cancer pathogenesis and stemness; however, its role in oral squamous cell carcinoma (OSCC) has not been reported. The current study aimed to investigate the impact of CCT6A on OSCC cell malignant behaviors and stemness and to explore its potentially interreacted pathways. SCC-15 and HSC-3 cells were transfected with the plasmid loading control overexpression, CCT6A overexpression, control knockout, or CCT6A knockout. Wnt4 overexpression or Notch1 overexpression plasmids were transfected into CCT6A-knockout SCC-15 cells. Cell proliferation, apoptosis, invasion, stemness, Notch, and Wnt pathways were detected in both cell lines, whereas RNA sequencing was only performed in SCC-15 cells. CCT6A was upregulated in five OSCC cell lines, including SCC-15, HSC-3, SAT, SCC-9, and KON, compared to that in the control cell line. In SCC-15 and HSC-3 cells, CCT6A overexpression increased cell proliferation, invasion, sphere formation, CD133, and Sox2 expression, but decreased cell apoptosis; on the contrary, CCT6A knockout exhibited an opposite effect on the above indexes. RNA-sequencing data revealed that the Wnt and Notch pathways were involved in the CCT6A'effect on SCC-15 cell functions. CCT6A positively regulates the Wnt and Notch pathways in SCC-15 and HSC-3 cells. Importantly, it was shown that activation of the Wnt or Notch pathways attenuated the effect of CCT6A knockout on SCC-15 cell survival, invasion, and stemness. CCT6A may promote OSCC malignant behavior and stemness by activating the Wnt and Notch pathways.

Autophagy as a Therapeutic Target in Breast Tumors: The Cancer stem cell perspective

Breast cancer is a heterogeneous disease, with a subpopulation of tumor cells known as breast cancer stem cells (BCSCs) with self-renewal and differentiation abilities that play a critical role in tumor initiation, progression, and therapy resistance. The tumor microenvironment (TME) is a complex area where diverse cancer cells reside creating a highly interactive environment with secreted factors, and the extracellular matrix. Autophagy, a cellular self-digestion process, influences dynamic cellular processes in the tumor TME integrating diverse signals that regulate tumor development and heterogeneity. Autophagy acts as a double-edged sword in the breast TME, with both tumor-promoting and tumor-suppressing roles. Autophagy promotes breast tumorigenesis by regulating tumor cell survival, migration and invasion, metabolic reprogramming, and epithelial-mesenchymal transition (EMT). BCSCs harness autophagy to maintain stemness properties, evade immune surveillance, and resist therapeutic interventions. Conversely, excessive, or dysregulated autophagy may lead to BCSC differentiation or cell death, offering a potential avenue for therapeutic exploration. The molecular mechanisms that regulate autophagy in BCSCs including the mammalian target of rapamycin (mTOR), AMPK, and Beclin-1 signaling pathways may be potential targets for pharmacological intervention in breast cancer. This review provides a comprehensive overview of the relationship between autophagy and BCSCs, highlighting recent advancements in our understanding of their interplay. We also discuss the current state of autophagy-targeting agents and their preclinical and clinical development in BCSCs.

The role of liver cancer stem cells in hepatocellular carcinoma metastasis

Metastasis accounts for the vast majority of cancer deaths; however, this complex process has yet to be fully explained. To form metastases, cancer cells must undergo a series of steps, known as the "Metastatic cascade", each of which requires a specific functional transformation. Cancer stem cells (CSCs) play a vital role in tumor metastasis, but their dynamic behavior and regulatory mechanisms have not been fully elucidated. Based on the "Metastatic cascade" theory, this review summarizes the effect of liver CSCs on the metastatic biological programs that underlie the dissemination and metastatic growth of cancer cells. Liver CSCs have the capacity to initiate distant organ metastasis via EMT, and the microenvironment transformation that supports the ability of these cells to disseminate, evade immune surveillance, dormancy, and regenerate metastasis. Understanding the heterogeneity and traits of liver CSCs in these processes is critical for developing strategies to prevent and treat metastasis of advanced hepatocellular carcinoma (HCC).

Bidirectional crosstalk between the epithelial-mesenchymal transition and immunotherapy: A bibliometric study

Immunotherapy has recently attracted considerable attention. However, currently, a thorough analysis of the trends associated with the epithelial-mesenchymal transition (EMT) and immunotherapy is lacking. In this study, we used bibliometric tools to provide a comprehensive overview of the progress in EMT-immunotherapy research. A total of 1,302 articles related to EMT and immunotherapy were retrieved from the Web of Science Core Collection (WOSCC). The analysis indicated that in terms of the volume of research, China was the most productive country (49.07%, 639), followed by the United States (16.89%, 220) and Italy (3.6%, 47). The United States was the most influential country according to the frequency of citations and citation burstiness. The results also suggested that Frontiers in Immunotherapy can be considered as the most influential journal with respect to the number of articles and impact factors. "Immune infiltration," "bioinformatics analysis," "traditional Chinese medicine," "gene signature," and "ferroptosis" were found to be emerging keywords in EMT-immunotherapy research. These findings point to potential new directions that can deepen our understanding of the mechanisms underlying the combined effects of immunotherapy and EMT and help develop strategies for improving immunotherapy.

Mechanosensitive channels TMEM63A and TMEM63B mediate lung inflation-induced surfactant secretion

Pulmonary surfactant is a lipoprotein complex lining the alveolar surface to decrease the surface tension and facilitate inspiration. Surfactant deficiency is often seen in premature infants and in children and adults with respiratory distress syndrome. Mechanical stretch of alveolar type 2 epithelial (AT2) cells during lung expansion is the primary physiological factor that stimulates surfactant secretion; however, it is unclear whether there is a mechanosensor dedicated to this process. Here, we show that loss of the mechanosensitive channels TMEM63A and TMEM63B (TMEM63A/B) resulted in atelectasis and respiratory failure in mice due to a deficit of surfactant secretion. TMEM63A/B were predominantly localized at the limiting membrane of the lamellar body (LB), a lysosome-related organelle that stores pulmonary surfactant and ATP in AT2 cells. Activation of TMEM63A/B channels during cell stretch facilitated the release of surfactant and ATP from LBs fused with the plasma membrane. The released ATP evoked Ca2+ signaling in AT2 cells and potentiated exocytic fusion of more LBs. Our study uncovered a vital physiological function of TMEM63 mechanosensitive channels in preparing the lungs for the first breath at birth and maintaining respiration throughout life.

A Golgi-targeted fluorescent probe for monitoring polarity dynamic during programmed cell death

Programmed cell death (PCD) is a controlled form of cell death and it plays an essential role in maintaining homeostasis. Golgi apparatus works as the hotspot during the early event of PCD and Golgi polarity, a vital microenvironment factor, can be regarded as an indicator of physiological status. Combined Golgi-targeted group phenylsulfonamide as electron acceptor group and triphenylamine as electron donor group, a novel Golgi-targeted fluorescent probe GTO had been developed. GTO showed good sensitivity and selectivity to polarity and its remarkable photostability makes it potentially useful for long-term cellular monitoring. In practice, GTO demonstrated good cell permeability and Golgi targeting capabilities. According to our results, GTO was applied to reveal the polarity increase during the early event of PCD and the encouraging results illustrated that GTO was an imaging tool for monitoring polarity in Golgi apparatus and the exploration in early diagnosis and drug discovery.

Regulation of a novel DsGATA1 from Dunaliella salina on the synthesis of carotenoids under red light

Dunaliella salina is a high-quality industrial effector for carotenoid production. The mechanism by which red light regulates carotenoid synthesis is still unclear. In this study, a transcription factor of DsGATA1 with a distinct structure was discovered in D. salina. The recognition motif of DsGATA1 was comparable to that of plant and fungal GATA, despite its evolutionary proximity to animal-derived GATA. The expression of DsGATA1 in D. salina was still noticeably decreased when exposed to red light. Analysis of physiological and biochemical transcriptomic data from overexpressed, interfering, and wild-type strains of DsGATA1 revealed that DsGATA1 acts as a global regulator of D. salina carotenoid synthesis. The upregulated genes in the CBP pathway by DsGATA1 were involved in its regulation of the synthesis of carotenoids. DsGATA1 also enhanced carotenoid accumulation under red light by affecting N metabolism. DsGATA1 was found to directly bind to the promoter of nitrate reductase to activate its expression, promoting D. salina nitrate uptake and accelerating biomass accumulation. DsGATA1 affected the expression of the genes encoding GOGAT, GDH, and ammonia transporter proteins. Moreover, our study revealed that the regulation of N metabolism by DsGATA1 led to the production of NO molecules that inhibited carotenoid synthesis. However, DsGATA1 significantly enhanced carotenoid synthesis by NO scavenger removal of NO. The D. salina carotenoid accumulation under red light was elevated by 46% in the presence of overexpression of DsGATA1 and NO scavenger. Nevertheless, our results indicated that DsGATA1 could be an important target for engineering carotenoid production. KEY POINTS: • DsGATA1 with a distinct structure and recognition motif was found in D. salina • DsGATA1 enhanced carotenoid production and biomass in D. salina under red light • DsGATA1 is involved in the regulation of N metabolism and carotenoid synthesis.

Transcriptomic profiling of Dip2a in the neural differentiation of mouse embryonic stem cells

Introduction

The disconnected-interacting protein 2 homolog A (DIP2A), a member of disconnected-interacting 2 protein family, has been shown to be involved in human nervous system-related mental illness. This protein is highly expressed in the nervous system of mouse. Mutation of mouse DIP2A causes defects in spine morphology and synaptic transmission, autism-like behaviors, and defective social novelty [5], [27], indicating that DIP2A is critical to the maintenance of neural development. However, the role of DIP2A in neural differentiation has yet to be investigated.

Objective

To determine the role of DIP2A in neural differentiation, a neural differentiation model was established using mouse embryonic stem cells (mESCs) and studied by using gene-knockout technology and RNA-sequencing-based transcriptome analysis.

Results

We found that DIP2A is not required for mESCs pluripotency maintenance, but loss of DIP2A causes the neural differentiation abnormalities in both N2B27 and KSR medium. Functional knockout of Dip2a gene also decreased proliferation of mESCs by perturbation of the cell cycle and profoundly inhibited the expression of a large number of neural development-associated genes which mainly enriched in spinal cord development and postsynapse assembly.

Conclusions

The results of this report demonstrate that DIP2A plays an essential role in regulating differentiation of mESCs towards the neural fate.

Heterochromatin in plant meiosis

Heterochromatin is an organizational property of eukaryotic chromosomes, characterized by extensive DNA and histone modifications, that is associated with the silencing of transposable elements and repetitive sequences. Maintaining heterochromatin is crucial for ensuring genomic integrity and stability during the cell cycle. During meiosis, heterochromatin is important for homologous chromosome synapsis, recombination, and segregation, but our understanding of meiotic heterochromatin formation and condensation is limited. In this review, we focus on the dynamics and features of heterochromatin and how it condenses during meiosis in plants. We also discuss how meiotic heterochromatin influences the interaction and recombination of homologous chromosomes during prophase I.

Nuclear actin filaments - a historical perspective

The view on nuclear filaments formed by non-skeletal β-actin has significantly changed over the decades. Initially, filamentous actin was observed in amphibian oocyte nuclei and only under specific cell stress conditions in mammalian cell nuclei. Improved labeling and imaging technologies have permitted insights into a transient but microscopically apparent filament network that is relevant for chromatin organization, biomechanics of the mammalian cell nucleus, gene expression, and DNA damage repair. Here, we will provide a historical perspective on the developing insight into nuclear actin filaments.

In vivo dynamics of hard tissue-forming cell origins: Insights from Cre/loxP-based cell lineage tracing studies

Bone tissue provides structural support for our bodies, with the inner bone marrow (BM) acting as a hematopoietic organ. Within the BM tissue, two types of stem cells play crucial roles: mesenchymal stem cells (MSCs) (or skeletal stem cells) and hematopoietic stem cells (HSCs). These stem cells are intricately connected, where BM-MSCs give rise to bone-forming osteoblasts and serve as essential components in the BM microenvironment for sustaining HSCs. Despite the mid-20th century proposal of BM-MSCs, their in vivo identification remained elusive owing to a lack of tools for analyzing stemness, specifically self-renewal and multipotency. To address this challenge, Cre/loxP-based cell lineage tracing analyses are being employed. This technology facilitated the in vivo labeling of specific cells, enabling the tracking of their lineage, determining their stemness, and providing a deeper understanding of the in vivo dynamics governing stem cell populations responsible for maintaining hard tissues. This review delves into cell lineage tracing studies conducted using commonly employed genetically modified mice expressing Cre under the influence of LepR, Gli1, and Axin2 genes. These studies focus on research fields spanning long bones and oral/maxillofacial hard tissues, offering insights into the in vivo dynamics of stem cell populations crucial for hard tissue homeostasis.

Glutamine sustains energy metabolism and alleviates liver injury in burn sepsis by promoting the assembly of mitochondrial HSP60-HSP10 complex via SIRT4 dependent protein deacetylation

Burns and burn sepsis, characterized by persistent and profound hypercatabolism, cause energy metabolism dysfunction that worsens organ injury and systemic disorders. Glutamine (Gln) is a key nutrient that remarkably replenishes energy metabolism in burn and sepsis patients, but its exact roles beyond substrate supply is unclear. In this study, we demonstrated that Gln alleviated liver injury by sustaining energy supply and restoring redox balance. Meanwhile, Gln also rescued the dysfunctional mitochondrial electron transport chain (ETC) complexes, improved ATP production, reduced oxidative stress, and protected hepatocytes from burn sepsis injury. Mechanistically, we revealed that Gln could activate SIRT4 by upregulating its protein synthesis and increasing the level of Nicotinamide adenine dinucleotide (NAD+), a co-enzyme that sustains the activity of SIRT4. This, in turn, reduced the acetylation of shock protein (HSP) 60 to facilitate the assembly of the HSP60-HSP10 complex, which maintains the activity of ETC complex II and III and thus sustain ATP generation and reduce reactive oxygen species release. Overall, our study uncovers a previously unknown pharmacological mechanism involving the regulation of HSP60-HSP10 assembly by which Gln recovers mitochondrial complex activity, sustains cellular energy metabolism and exerts a hepato-protective role in burn sepsis.

Autophagy-related protein PlATG2 regulates the vegetative growth, sporangial cleavage, autophagosome formation, and pathogenicity of peronophythora litchii

Autophagy is an intracellular degradation process that is important for the development and pathogenicity of phytopathogenic fungi and for the defence response of plants. However, the molecular mechanisms underlying autophagy in the pathogenicity of the plant pathogenic oomycete Peronophythora litchii, the causal agent of litchi downy blight, have not been well characterized. In this study, the autophagy-related protein ATG2 homolog, PlATG2, was identified and characterized using a CRISPR/Cas9-mediated gene replacement strategy in P. litchii. A monodansylcadaverine (MDC) staining assay indicated that deletion of PlATG2 abolished autophagosome formation. Infection assays demonstrated that ΔPlatg2 mutants showed significantly impaired pathogenicity in litchi leaves and fruits. Further studies have revealed that PlATG2 participates in radial growth and asexual/sexual development of P. litchii. Moreover, zoospore release and cytoplasmic cleavage of sporangia were considerably lower in the ΔPlatg2 mutants than in the wild-type strain by FM4-64 staining. Taken together, our results revealed that PlATG2 plays a pivotal role in vegetative growth, sporangia and oospore production, zoospore release, sporangial cleavage, and plant infection of P. litchii. This study advances our understanding of the pathogenicity mechanisms of the phytopathogenic oomycete P. litchii and is conducive to the development of effective control strategies.

PANoptosis signaling enables broad immune response in psoriasis: From pathogenesis to new therapeutic strategies

Background

Accumulating evidence suggests that regulated cell death, such as pyroptosis, apoptosis, and necroptosis, is deeply involved in the pathogenesis of psoriasis. As a newly recognized form of systematic cell death, PANoptosis is involved in a variety of inflammatory disorders through amplifying inflammatory and immune cascades, but its role in psoriasis remains elusive.

Objectives

To reveal the role of PANoptosis in psoriasis for a potential therapeutic strategy.

Methods

Multitranscriptomic analysis and experimental validation were used to identify PANoptosis signaling in psoriasis. RNA-seq and scRNA-seq analyses were performed to establish a PANoptosis-mediated immune response in psoriasis, which revealed hub genes through WGCNA and predicted disulfiram as a potential drug. The effect and mechanism of disulfiram were verified in imiquimod (IMQ)-induced psoriasis.

Results

Here, we found a highlighted PANoptosis signature in psoriasis patients through multitranscriptomic analysis and experimental validation. Based on this, two distinct PANoptosis patterns (non/high) were identified, which were the options for clinical classification. The high-PANoptosis-related group had a higher response rate to immune cell infiltration (such as M1 macrophages and keratinocytes). Subsequently, WGCNA showed the hub genes (e.g., S100A12, CYCS, NOD2, STAT1, HSPA4, AIM2, MAPK7), which were significantly associated with clinical phenotype, PANoptosis signature, and identified immune response in psoriasis. Finally, we explored disulfiram (DSF) as a candidate drug for psoriasis through network pharmacology, which ameliorated IMQ-mediated psoriatic symptoms through antipyroptosis-mediated inflammation and enhanced apoptotic progression. By analyzing the specific ligand-receptor interaction pairs within and between cell lineages, we speculated that DSF might exert its effects by targeting keratinocytes directly or targeting M1 macrophages to downregulate the proliferation of keratinocytes.

Conclusions

PANoptosis with its mediated immune cell infiltration provides a roadmap for research on the pathogenesis and therapeutic strategies of psoriasis.

CRISPR/Cas9-mediated knock-in of a fluorescent reporter into the target locus of interest in human pluripotent stem cells

The method presented herein is associated with the Lab Resource article titled "Generation of αMHC-EGFP knock-in in human pluripotent stem cell line, SNUe003-A-3, using CRISPR/CAS9-based gene targeting" [1]. The cardiac muscle-specific protein, α-myosin heavy chain (αMHC), is encoded by the human MYH6 gene, which is expressed in both the atria and ventricles during embryonic development and is predominantly expressed in the atria after birth [2]. Herein, the methods used to achieve CRISPR/SpCas9-mediated introduction of an EGFP reporter into αMHC, the target locus in human pluripotent stem cells (hPSCs) for cardiac lineage tracing and clinical cell sorting are described. The CRISPR-Cas9 system enables efficient replacement of the stop codon in the last exon of αMHC with a 2A non-joining peptide (T2A)-EGFP cassette. First, hPSCs are transfected with the donor construct and Cas9/sgRNA plasmids via electroporation and selected with neomycin for approximately 3 weeks. Thereafter, the established cell line exhibits typical characteristics of human embryonic stem cells (hESCs). When these cells differentiate into cardiomyocytes, the expression of EGFP is confirmed using confocal microscopy, flow cytometry analysis, and immunostaining.•The line enables monitoring of cell maturation events during human cardiac development.•The line is a valuable platform for cardiotoxicity tests and drug screening.•This method has already been employed in two original studies, as previously reported for reporter cell line generation using CRISPR/Cas9.

Nuclear and degradative functions of the ESCRT-III pathway: implications for neurodegenerative disease

The ESCRT machinery plays a pivotal role in membrane-remodeling events across multiple cellular processes including nuclear envelope repair and reformation, nuclear pore complex surveillance, endolysosomal trafficking, and neuronal pruning. Alterations in ESCRT-III functionality have been associated with neurodegenerative diseases including Frontotemporal Dementia (FTD), Amyotrophic Lateral Sclerosis (ALS), and Alzheimer's Disease (AD). In addition, mutations in specific ESCRT-III proteins have been identified in FTD/ALS. Thus, understanding how disruptions in the fundamental functions of this pathway and its individual protein components in the human central nervous system (CNS) may offer valuable insights into mechanisms underlying neurodegenerative disease pathogenesis and identification of potential therapeutic targets. In this review, we discuss ESCRT components, dynamics, and functions, with a focus on the ESCRT-III pathway. In addition, we explore the implications of altered ESCRT-III function for neurodegeneration with a primary emphasis on nuclear surveillance and endolysosomal trafficking within the CNS.

Emergent microenvironments of nucleoli

In higher eukaryotes, the nucleolus harbors at least three sub-phases that facilitate multiple functionalities including ribosome biogenesis. The three prominent coexisting sub-phases are the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). Here, we review recent efforts in profiling sub-phase compositions that shed light on the types of physicochemical properties that emerge from compositional biases and territorial organization of specific types of macromolecules. We highlight roles played by molecular grammars which refers to protein sequence features including the substrate binding domains, the sequence features of intrinsically disordered regions, and the multivalence of these distinct types of domains / regions. We introduce the concept of a barcode of emergent physicochemical properties of nucleoli. Although our knowledge of the full barcode remains incomplete, we hope that the concept prompts investigations into undiscovered emergent properties and engenders an appreciation for how and why unique microenvironments control biochemical reactions.

Unraveling the hidden complexity: Exploring dental tissues through single-cell transcriptional profiling

Understanding the composition and function of cells constituting tissues and organs is vital for unraveling biological processes. Single-cell analysis has allowed us to move beyond traditional methods of categorizing cell types. This innovative technology allows the transcriptional and epigenetic profiling of numerous individual cells, leading to significant insights into the development, homeostasis, and pathology of various organs and tissues in both animal models and human samples. In this review, we delve into the outcomes of major investigations using single-cell transcriptomics to decipher the cellular composition of mammalian teeth and periodontal tissues. The recent single-cell transcriptome-based studies have traced in detail the dental epithelium-ameloblast lineage and dental mesenchyme lineages in the mouse incisors and the tooth germ of both mice and humans; unraveled the microenvironment, the identity of niche cells, and cellular intricacies in the dental pulp; shed light on the molecular mechanisms orchestrating root formation; and characterized cellular dynamics of the periodontal ligament. Additionally, cellular components in dental pulps were compared between healthy and carious teeth at a single-cell level. Each section of this review contributes to a comprehensive understanding of tooth biology, offering valuable insights into developmental processes, niche cell identification, and the molecular secrets of the dental environment.

Interaction of noncoding RNAs with hippo signaling pathway in cancer cells and cancer stem cells

The Hippo signaling pathway has a regulatory function in the organogenesis process and cellular homeostasis, switching the cascade reactions of crucial kinases acts to turn off/on the Hippo pathway, altering the downstream gene expression and thereby regulating proliferation, apoptosis, or stemness. Disruption of this pathway can lead to the occurrence of various disorders and different types of cancer. Recent findings highlight the importance of ncRNAs, such as microRNA, circular RNA, and lncRNAs, in modulating the Hippo pathway. Defects in ncRNAs can disrupt Hippo pathway balance, increasing tumor cells, tumorigenesis, and chemotherapeutic resistance. This review summarizes ncRNAs' inhibitory or stimulatory role in - Hippo pathway regulation in cancer and stem cells. Identifying the relation between ncRNAs and the components of this pathway could pave the way for developing new biomarkers in the treatment and diagnosis of cancers.

A 3D micro-printed single cell micro-niche with asymmetric niche signals - An in vitro model for asymmetric cell division study

Intricate microenvironment signals orchestrate to affect cell behavior and fate during tissue morphogenesis. However, the underlying mechanisms on how specific local niche signals influence cell behavior and fate are not fully understood, owing to the lack of in vitro platform able to precisely, quantitatively, spatially, and independently manipulate individual niche signals. Here, microarrays of protein-based 3D single cell micro-niche (3D-SCμN), with precisely engineered biophysical and biochemical niche signals, are micro-printed by a multiphoton microfabrication and micropatterning technology. Mouse embryonic stem cell (mESC) is used as the model cell to study how local niche signals affect stem cell behavior and fate. By precisely engineering the internal microstructures of the 3D SCμNs, we demonstrate that the cell division direction can be controlled by the biophysical niche signals, in a cell shape-independent manner. After confining the cell division direction to a dominating axis, single mESCs are exposed to asymmetric biochemical niche signals, specifically, cell-cell adhesion molecule on one side and extracellular matrix on the other side. We demonstrate that, symmetry-breaking (asymmetric) niche signals successfully trigger cell polarity formation and bias the orientation of asymmetric cell division, the mitosis process resulting in two daughter cells with differential fates, in mESCs.

TET1 displays catalytic and non-catalytic functions in the adult mouse cortex

TET1/2/3 dioxygenases iteratively demethylate 5-methylcytosine, beginning with the formation of 5-hydroxymethylcytosine (5hmC). The post-mitotic brain maintains higher levels of 5hmC than most peripheral tissues, and TET1 ablation studies have underscored the critical role of TET1 in brain physiology. However, deletion of Tet1 precludes the disentangling of the catalytic and non-catalytic functions of TET1. Here, we dissect these functions of TET1 by comparing adult cortex of Tet1 wildtype (Tet1 WT), a novel Tet1 catalytically dead mutant (Tet1 HxD), and Tet1 knockout (Tet1 KO) mice. Using DNA methylation array, we uncover that Tet1 HxD and KO mutations perturb the methylation status of distinct subsets of CpG sites. Gene ontology (GO) analysis on specific differential 5hmC regions indicates that TET1's catalytic activity is linked to neuronal-specific functions. RNA-Seq further shows that Tet1 mutations predominantly impact the genes that are associated with alternative splicing. Lastly, we performed High-performance Liquid Chromatography Mass-Spectrometry lipidomics on WT and mutant cortices and uncover accumulation of lysophospholipids lysophosphatidylethanolamine and lysophosphatidylcholine in Tet1 HxD cortex. In summary, we show that Tet1 HxD does not completely phenocopy Tet1 KO, providing evidence that TET1 modulates distinct cortical functions through its catalytic and non-catalytic roles.

A novel adipose loss-of-function mutant in Drosophila

To identify genes required for brain growth, we took an RNAi knockdown reverse genetic approach in Drosophila. One potential candidate isolated from this effort is the anti-lipogenic gene adipose (adp). Adp has an established role in the negative regulation of lipogenesis in the fat body of the fly and adipose tissue in mammals. While fat is key to proper development in general, adp has not been investigated during brain development. Here, we found that RNAi knockdown of adp in neuronal stem cells and neurons results in reduced brain lobe volume and sought to replicate this with a mutant fly. We generated a novel adp mutant that acts as a loss-of-function mutant based on buoyancy assay results. We found that despite a change in fat content in the body overall and a decrease in the number of larger (>5 µm) brain lipid droplets, there was no change in the brain lobe volume of mutant larvae. Overall, our work describes a novel adp mutant that can functionally replace the long-standing adp60 mutant and shows that the adp gene has no obvious involvement in brain growth.

Ion channel-mediated mitochondrial volume regulation and its relationship with mitochondrial dynamics

The mitochondrion, one of the important cellular organelles, has the major function of generating adenosine triphosphate and plays an important role in maintaining cellular homeostasis, governing signal transduction, regulating membrane potential, controlling programmed cell death and modulating cell proliferation. The dynamic balance of mitochondrial volume is an important factor required for maintaining the structural integrity of the organelle and exerting corresponding functions. Changes in the mitochondrial volume are closely reflected in a series of biological functions and pathological changes. The mitochondrial volume is controlled by the osmotic balance between the cytoplasm and the mitochondrial matrix. Thus, any disruption in the influx of the main ion, potassium, into the cells can disturb the osmotic balance between the cytoplasm and the matrix, leading to water movement between these compartments and subsequent alterations in mitochondrial volume. Recent studies have shown that mitochondrial volume homeostasis is closely implicated in a variety of diseases. In this review, we provide an overview of the main influencing factors and research progress in the field of mitochondrial volume homeostasis.

The crucial roles and research advances of cGAS‑STING pathway in liver diseases

Inflammation responses have identified as a key mediator of in various liver diseases with high morbidity and mortality. cGAS-STING signalling is essential in innate immunity since it triggers release of type I interferons and various of proinflammatory cytokines. The potential connection between cGAS-STING pathway and liver inflammatory diseases has recently been reported widely. In our review, the impact of cGAS-STING on liver inflammation and regulatory mechanism are summarized. Furthermore, many inhibitors of cGAS-STING signalling as promising agents to cure liver inflammation are also explored in detail. A comprehensive knowledge of molecular mechanisms of cGAS-STING signalling in liver inflammation is vital for exploring novel treatments and providing recommendations and perspectives for future utilization.

Developmental changes in nuclear lamina components during germ cell differentiation

The nuclear lamina (NL) changes composition for regulation of nuclear events. We investigated changes that occur in Drosophila oogenesis, revealing switches in NL composition during germ cell differentiation. Germline stem cells (GSCs) express only LamB and predominantly emerin, whereas differentiating nurse cells predominantly express LamC and emerin2. A change in LamC-specific localization also occurs, wherein phosphorylated LamC redistributes to the nuclear interior only in the oocyte, prior to transcriptional reactivation of the meiotic genome. These changes support existing concepts that LamC promotes differentiation, a premise that was tested. Remarkably ectopic LamC production in GSCs did not promote premature differentiation. Increased LamC levels in differentiating germ cells altered internal nuclear structure, increased RNA production, and reduced female fertility due to defects in eggshell formation. These studies suggest differences between Drosophila lamins are regulatory, not functional, and reveal an unexpected robustness to level changes of a major scaffolding component of the NL.

Jaceosidin induces apoptosis and inhibits migration in AGS gastric cancer cells by regulating ROS-mediated signaling pathways

Jaceosidin (JAC) is a natural flavonoid with anti-oxidant and other pharmacological activities; however, its anti-cancer mechanism remains unclear. We investigated the mechanism of action of JAC in gastric cancer cells. Cytotoxicity and apoptosis assays showed that JAC effectively killed multiple gastric cancer cells and induced apoptosis in human gastric adenocarcinoma AGS cells via the mitochondrial pathway. Network pharmacological analysis suggested that its activity was linked to reactive oxygen species (ROS), AKT, and MAPK signaling pathways. Furthermore, JAC accumulated ROS to up-regulate p-JNK, p-p38, and IκB-α protein expressions and down-regulate the p-ERK, p-STAT3, and NF-κB protein expressions. Cell cycle assay results showed that JAC accumulated ROS to up-regulate p21 and p27 protein expressions and down-regulate p-AKT, CDK2, CDK4, CDK6, Cyclin D1, and Cyclin E protein expressions to induce G0/G1 phase arrest. Cell migration assay results showed JAC accumulated ROS to down-regulate Wnt-3a, p-GSK-3β, N-cadherin, and β-catenin protein expressions and up-regulate E-cadherin protein expression to inhibit migration. Furthermore, N-acetyl cysteine pre-treatment prevented the change of these protein expressions. In summary, JAC induced apoptosis and G0/G1 phase arrest and inhibited migration through ROS-mediated signaling pathways in AGS cells.

Tension directs cancer cell migration over fiber alignment through energy minimization

Cell migration during many fundamental biological processes including metastasis requires cells to traverse tissue with heterogeneous mechanical cues that direct migration as well as determine force and energy requirements for motility. However, the influence of discrete structural and mechanical cues on migration remains challenging to determine as they are often coupled. Here, we decouple the pro-invasive cues of collagen fiber alignment and tension to study their individual impact on migration. When presented with both cues, cells preferentially travel in the axis of tension against fiber alignment. Computational and experimental data show applying tension perpendicular to alignment increases potential energy stored within collagen fibers, lowering requirements for cell-induced matrix deformation and energy usage during migration compared to motility in the direction of fiber alignment. Energy minimization directs migration trajectory, and tension can facilitate migration against fiber alignment. These findings provide a conceptual understanding of bioenergetics during migration through a fibrous matrix.