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Theranostics 2024: Recent evidence highlights the pivotal role of mitochondrial dysfunction in mood disorders, but the mechanism involved remains unclear. We studied whether the...
: Recent evidence highlights the pivotal role of mitochondrial dysfunction in mood disorders, but the mechanism involved remains unclear. We studied whether the Hippo/YAP/14-3-3η signaling pathway mediates mitochondrial abnormalities that result in the onset of major depressive disorder (MDD) in a mouse model. : The ROC algorithm was used to identify a subpopulation of mice that were exposed to chronic unpredictable mild stress (CUMS) and exhibited the most prominent depressive phenotype (Dep). Electron microscopy, biochemical assays, quantitative PCR, and immunoblotting were used to evaluate synaptic and mitochondrial changes in the basolateral amygdala (BLA). RNA sequencing was used to explore changes in the Hippo pathway and downstream target genes. pharmacological inhibition and immunoprecipitation was used to confirm YAP/14-3-3η interaction and its role in neuronal mitochondrial dysfunction. We used virus-mediated gene overexpression and knockout in YAP transgenic mice to verify the regulatory effect of the Hippo/YAP/14-3-3η pathway on depressive-like behavior. : Transcriptomic data identified a large number of genes and signaling pathways that were specifically altered from the BLA of Dep mice. Dep mice showed notable synaptic impairment in BLA neurons, as well as mitochondrial damage characterized by abnormal mitochondrial morphology, compromised function, impaired biogenesis, and alterations in mitochondrial marker proteins. The Hippo signaling pathway was activated in Dep mice during CUMS, and the transcriptional regulatory activity of YAP was suppressed by phosphorylation of its Ser127 site. 14-3-3η was identified as an important co-regulatory factor of the Hippo/YAP pathway, as it can respond to chronic stress and regulate cytoplasmic retention of YAP. Importantly, the integrated Hippo/YAP/14-3-3η pathway mediated neuronal mitochondrial dysfunction and depressive behavior in Dep mice. : The integrated Hippo/YAP/14-3-3η pathway in the BLA neuron is critical in mediating depressive-like behaviors in mice, suggesting a causal role for this pathway in susceptibility to chronic stress-induced depression. This pathway therefore may present a therapeutic target against mitochondrial dysfunction and synaptic impairment in MDD.
Topics: Animals; Disease Models, Animal; Mice; Mitochondria; YAP-Signaling Proteins; Signal Transduction; Hippo Signaling Pathway; Basolateral Nuclear Complex; Protein Serine-Threonine Kinases; Male; Stress, Psychological; 14-3-3 Proteins; Adaptor Proteins, Signal Transducing; Depressive Disorder, Major; Depression; Mice, Inbred C57BL; Neurons; Mice, Transgenic
PubMed: 38948066
DOI: 10.7150/thno.92676 -
World Journal of Gastroenterology Jun 2024Hepatocellular carcinoma (HCC) is the most common and deadliest subtype of liver cancer worldwide and, therefore, poses an enormous threat to global health....
Hepatocellular carcinoma (HCC) is the most common and deadliest subtype of liver cancer worldwide and, therefore, poses an enormous threat to global health. Understanding the molecular mechanisms underlying the development and progression of HCC is central to improving our clinical approaches. PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs that bind to PIWI family proteins to regulate gene expression at transcriptional and post-transcriptional levels. A growing body of work shows that the dysregulation of piRNAs plays a crucial role in the progression of various human cancers. In this editorial, we report on the current knowledge of HCC-associated piRNAs and their potential clinical utility. Based on the editorial by Papadopoulos and Trifylli, on the role and clinical evaluation of exosomal circular RNAs in HCC, we highlight this other emerging class of non-coding RNAs.
Topics: Humans; Liver Neoplasms; Carcinoma, Hepatocellular; RNA, Small Interfering; Gene Expression Regulation, Neoplastic; Exosomes; RNA, Circular; Disease Progression; Biomarkers, Tumor
PubMed: 38947286
DOI: 10.3748/wjg.v30.i22.2843 -
MicroPublication Biology 2024Mutations in retinal primary cilia are responsible for human blindness but the mechanisms are not fully understood (Wheway et al., 2014). Characterizing the proteome of...
Mutations in retinal primary cilia are responsible for human blindness but the mechanisms are not fully understood (Wheway et al., 2014). Characterizing the proteome of an organelle such as cilia, is a fruitful way to understand its function but methods often require considerable sample quantities. Here we develop a method to isolate the primary cilia of photoreceptor cells from bovine retinas. Through LC/MS/MS proteomics analysis we identify proteins enriched for cilia function including ciliopathy disease. This study shows our method can be used to isolate retinal primary cilia to obtain sufficient quantities of native protein samples.
PubMed: 38947246
DOI: 10.17912/micropub.biology.001218 -
ACS Central Science Jun 2024Coacervates formed by liquid-liquid phase separation emerge as important biomimetic models for studying the dynamic behaviors of membraneless organelles and...
Coacervates formed by liquid-liquid phase separation emerge as important biomimetic models for studying the dynamic behaviors of membraneless organelles and synchronously motivating the creation of smart architectures with the regulation of cell fate. Despite continuous progress, it remains challenging to balance the trade-offs among structural stability, versatility, and molecular communication for regulation of cell fate and systemic investigation in a complex physiological system. Herein, we present a self-stabilizing and fastener-bound gain-of-function methodology to create a new type of synthetic DNA membraneless organelle (MO) with high stability and controlled bioactivity on the basis of DNA coacervates. Specifically, long single-strand DNA generated by rolling circle amplification (RCA) is selected as the scaffold that assembles into membraneless coacervates via phase separation. Intriguingly, the as-formed DNA MO can recruit RCA byproducts and other components to achieve self-stabilization, nanoscale condensation, and function encoding. As a proof of concept, photoactivatable DNA MO is constructed and successfully employed for time-dependent accumulation and spatiotemporal management of cancer in a mouse model. This study offers new, important insights into synthetic membraneless organelles for the basic understanding and manipulation of important life processes.
PubMed: 38947212
DOI: 10.1021/acscentsci.4c00380 -
ACS Central Science Jun 2024Mitochondria are essential organelles involved in various metabolic processes in eukaryotes. The imaging, targeting, and investigation of cell death mechanisms related...
Mitochondria are essential organelles involved in various metabolic processes in eukaryotes. The imaging, targeting, and investigation of cell death mechanisms related to mitochondria have garnered significant interest. Small-molecule fluorescent probes have proven to be robust tools for utilizing light to advance the study of mitochondrial biology. In this study, we present the rational design of cationic Nile blue probes carrying a permanent positive charge for these purposes. The cationic Nile blue probes exhibit excellent mitochondrial permeability, unique solvatochromism, and resistance to oxidation. We observed weaker fluorescence in aqueous solutions compared to lipophilic solvents, thereby minimizing background fluorescence in the cytoplasm. Additionally, we achieved photoredox switching of the cationic Nile blue probes under mild conditions. This enabled us to demonstrate their application for the first time in single-molecule localization microscopy of mitochondria, allowing us to observe mitochondrial fission and fusion behaviors. Compared to conventional cyanine fluorophores, this class of dyes demonstrated prolonged resistance to photobleaching, likely due to their antioxidation properties. Furthermore, we extended the application of cationic Nile blue probes to the mitochondria-specific delivery of taxanes, facilitating the study of direct interactions between the drug and organelles. Our approach to triggering cell death without reliance on microtubule binding provides valuable insights into anticancer drug research and drug-resistance mechanisms.
PubMed: 38947205
DOI: 10.1021/acscentsci.4c00073 -
ACS Central Science Jun 2024Mitochondrial thermogenesis is a process in which heat is generated by mitochondrial respiration. In living organisms, the thermogenic mechanisms that maintain body...
Mitochondrial thermogenesis is a process in which heat is generated by mitochondrial respiration. In living organisms, the thermogenic mechanisms that maintain body temperature have been studied extensively in fat cells with little knowledge on how mitochondrial heat may act beyond energy expenditure. Here, we highlight that the exothermic oxygen reduction reaction (Δ ° = -286 kJ/mol) is the main source of the protonophore-induced mitochondrial thermogenesis, and this heat is conducted to other cellular organelles, including the nucleus. As a result, mitochondrial heat that reached the nucleus initiated the classical heat shock response, including the formation of nuclear stress granules and the localization of heat shock factor 1 (HSF1) to chromatin. Consequently, activated HSF1 increases the level of gene expression associated with the response to thermal stress in mammalian cells. Our results illustrate heat generated within the cells as a potential source of mitochondria-nucleus communication and expand our understanding of the biological functions of mitochondria in cell physiology.
PubMed: 38947196
DOI: 10.1021/acscentsci.3c01589 -
Journal of Extracellular Biology Jun 2024Chemoresistance is a common problem in ovarian cancer (OvCa) treatment, where resistant cells, in response to chemotherapy, secrete small extracellular vesicles (sEVs),...
Chemoresistance is a common problem in ovarian cancer (OvCa) treatment, where resistant cells, in response to chemotherapy, secrete small extracellular vesicles (sEVs), known as chemo-sEVs, that transfer resistance to recipient cells. sEVs are formed as intraluminal vesicles (ILVs) within multivesicular endosomes (MVEs), whose trafficking is regulated by Ras-associated binding (RAB) GTPases that mediate sEVs secretion or lysosomal degradation. A decrease in lysosomal function can promote sEVs secretion, but the relationship between MVEs trafficking pathways and sEVs secretion in OvCa chemoresistance is unclear. Here, we show that A2780cis cisplatin (CCDP) resistant OvCa cells had an increased number of MVEs and ILVs structures, higher levels of Endosomal Sorting Complex Required for Transport (ESCRTs) machinery components, and RAB27A compared to A2780 CDDP-sensitive OvCa cells. CDDP promoted the secretion of chemo-sEVs in A2780cis cells, enriched in DNA damage response proteins. A2780cis cells exhibited poor lysosomal function with reduced levels of RAB7, essential in MVEs-Lysosomal trafficking. The silencing of RAB27A in A2780cis cells prevents the Chemo-EVs secretion, reduces its chemoresistance and restores lysosomal function and levels of RAB7, switching them into an A2780-like cellular phenotype. Enhancing lysosomal function with rapamycin reduced chemo-sEVs secretion. Our results suggest that adjusting the balance between secretory MVEs and lysosomal MVEs trafficking could be a promising strategy for overcoming CDDP chemoresistance in OvCa.
PubMed: 38947172
DOI: 10.1002/jex2.157 -
International Journal of Nanomedicine 2024To address the problem of suboptimal reactive oxygen species (ROS) production in Radiation therapy (RT) which was resulted from exacerbated tumor hypoxia and the...
PURPOSE
To address the problem of suboptimal reactive oxygen species (ROS) production in Radiation therapy (RT) which was resulted from exacerbated tumor hypoxia and the heterogeneous distribution of radiation sensitizers.
MATERIALS AND METHODS
In this work, a novel nanomedicine, designated as PLGA@IR780-Bi-DTPA (PIBD), was engineered by loading the radiation sensitizer Bi-DTPA and the photothermal agent IR780 onto poly(lactic-co-glycolic acid) (PLGA). This design leverages the tumor-targeting ability of IR780 to ensure selective accumulation of the nanoparticles in tumor cells, particularly within the mitochondria. The effect of the photothermal therapy-enhanced radiation therapy was also examined to assess the alleviation of hypoxia and the enhancement of radiation sensitivity.
RESULTS
The PIBD nanoparticles exhibited strong capacity in mitochondrial targeting and selective tumor accumulation. Upon activation by 808 nm laser irradiation, the nanoparticles effectively alleviated local hypoxia by photothermal effect enhanced blood supplying to improve oxygen content, thereby enhancing the ROS production for effective RT. Comparative studies revealed that PIBD-induced RT significantly outperformed conventional RT in treating hypoxic tumors.
CONCLUSION
This design of tumor-targeting photothermal therapy-enhanced radiation therapy nanomedicine would advance the development of targeted drug delivery system for effective RT regardless of hypoxic microenvironment.
Topics: Animals; Photothermal Therapy; Reactive Oxygen Species; Nanoparticles; Cell Line, Tumor; Humans; Polylactic Acid-Polyglycolic Acid Copolymer; Mice; Indoles; Tumor Hypoxia; Radiation-Sensitizing Agents; Mice, Inbred BALB C; Mitochondria; Neoplasms; Nanomedicine
PubMed: 38946887
DOI: 10.2147/IJN.S450124 -
International Journal of Nanomedicine 2024Mitochondrial oxidative stress is an important factor in cell apoptosis. Cerium oxide nanomaterials show great potential for scavenging free radicals and simulating...
PURPOSE
Mitochondrial oxidative stress is an important factor in cell apoptosis. Cerium oxide nanomaterials show great potential for scavenging free radicals and simulating superoxide dismutase (SOD) and catalase (CAT) activities. To solve the problem of poor targeting of cerium oxide nanomaterials, we designed albumin-cerium oxide nanoclusters (TPP-PCNLs) that target the modification of mitochondria with triphenyl phosphate (TPP). TPP-PCNLs are expected to simulate the activity of superoxide dismutase, continuously remove reactive oxygen species, and play a lasting role in radiation protection.
METHODS
First, cerium dioxide nanoclusters (CNLs), polyethylene glycol cerium dioxide nanoclusters (PCNLs), and TPP-PCNLs were characterized in terms of their morphology and size, ultraviolet spectrum, dispersion stability and cellular uptake, and colocalization Subsequently, the anti-radiation effects of TPP-PCNLs were investigated using in vitro and in vivo experiments including cell viability, apoptosis, comet assays, histopathology, and dose reduction factor (DRF).
RESULTS
TPP-PCNLs exhibited good stability and biocompatibility. In vitro experiments indicated that TPP-PCNLs could not only target mitochondria excellently but also regulate reactive oxygen species (ROS)levels in whole cells. More importantly, TPP-PCNLs improved the integrity and functionality of mitochondria in irradiated L-02 cells, thereby indirectly eliminating the continuous damage to nuclear DNA caused by mitochondrial oxidative stress. TPP-PCNLs are mainly targeted to the liver, spleen, and other extramedullary hematopoietic organs with a radiation dose reduction factor of 1.30. In vivo experiments showed that TPP-PCNLs effectively improved the survival rate, weight change, hematopoietic function of irradiated animals. Western blot experiments have confirmed that TPP-PCNLs play a role in radiation protection by regulating the mitochondrial apoptotic pathway.
CONCLUSION
TPP-PCNLs play a radiologically protective role by targeting extramedullary hematopoietic organ-liver cells and mitochondria to continuously clear ROS.
Topics: Cerium; Animals; Mitochondria; Reactive Oxygen Species; Mice; Apoptosis; Hematopoiesis; Oxidative Stress; Cell Survival; Radiation-Protective Agents; Humans; Radiation Protection; Cell Line
PubMed: 38946882
DOI: 10.2147/IJN.S459607 -
World Journal of Gastroenterology Jun 2024In this editorial, we comment on an article titled "Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases", which was...
In this editorial, we comment on an article titled "Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases", which was published in a recent issue of the . We focused on the statement that "autophagy is closely related to the digestion, secretion, and regeneration of gastrointestinal cells". With advancing research, autophagy, and particularly the pivotal role of the macroautophagy in maintaining cellular equilibrium and stress response in the gastrointestinal system, has garnered extensive study. However, the significance of mitophagy, a unique selective autophagy pathway with ubiquitin-dependent and independent variants, should not be overlooked. In recent decades, mitophagy has been shown to be closely related to the occurrence and development of gastrointestinal diseases, especially inflammatory bowel disease, gastric cancer, and colorectal cancer. The interplay between mitophagy and mitochondrial quality control is crucial for elucidating disease mechanisms, as well as for the development of novel treatment strategies. Exploring the pathogenesis behind gastrointestinal diseases and providing individualized and efficient treatment for patients are subjects we have been exploring. This article reviews the potential mechanism of mitophagy in gastrointestinal diseases with the hope of providing new ideas for diagnosis and treatment.
Topics: Humans; Mitophagy; Autophagy; Gastrointestinal Diseases; Mitochondria; Gastrointestinal Tract; Animals
PubMed: 38946875
DOI: 10.3748/wjg.v30.i23.2934