Evolutionary biology: essence of mitochondria

Assessing the joint effects of mitochondrial genes and physical activity on the psychiatric phenotype of subjective well-being based on the UK Biobank data

Subjective well-being (SWB) is an important measure for mental health status. Previous research has shown that physical activity can affect an individual's well-being, yet the underlying molecular mechanism remains to be clarified. In this study, we aim to evaluate the potential interactions between mitochondrial genes and physical activity (PA) as well as their combined effects on individual well-being. SWB phenotype data in UK Biobank were enrolled for this study including nine aspects such as work/job satisfaction, health satisfaction, family relationship satisfaction, friendships satisfaction, financial situation satisfaction, ever depressed for a whole week, general happiness, general happiness with own health and belief that own life is meaningful. We made analysis for each aspects separately. Firstly, mitochondria-wide association studies (MiWAS) was conducted to assess the association of mitochondrial Single Nucleotide Polymorphisms SNP with each aspect of SWB. Then an interaction analysis of mitochondrial DNA (mtDNA) mutation and PA was performed to evaluate their joint effect on SWB status. Meanwhile, these two analysis were made for female and male group separately as well as the total samples, all under the control of possible confounding factors including gender, age, Townsend Deprivation Index (TDI), education, alcohol consumption, smoking habits, and 10 principal components. MiWAS analysis identified 45 mtSNPs associated with 9 phenotypes of SWB. For example, m.15218A > G on MT-CYB in the health satisfaction phenotype of the total subjects. Gender-specific analyses found 30 mtSNPs in females and 58 in males, involving 13 mtGenes. In mtDNA-PA interaction analysis, we also identified 10 significant mtDNA-PA interaction sets for SWB. For instance, m.13020 T > C (MT-ND5) was associated with the SWB financial situation satisfaction phenotype in all subjects (P = 0.00577). In addition, MiWAS analysis identified 12 mtGene variants associated with SWB, as MT-ND1 and MT-ND2. However, in mtDNA-PA interactions we detected 7 mtDNA affecting psychiatric disorders occurring, as in the friendships satisfaction phenotype (m.3394 T > C on MT-ND1). Our study results suggest an implication of the interaction between mitochondrial function and physical activity in the risk of psychiatric disorder development.

Mitochondria-targeted BODIPY dyes for small molecule recognition, bio-imaging and photodynamic therapy

Mitochondria are essential for a diverse array of biological functions. There is increasing research focus on developing efficient tools for mitochondria-targeted detection and treatment. BODIPY dyes, known for their structural versatility and excellent spectroscopic properties, are being actively explored in this context. Numerous studies have focused on developing innovative BODIPYs that utilize optical signals for imaging mitochondria. This review presents a comprehensive overview of the progress made in this field, aiming to investigate mitochondria-related biological events. It covers key factors such as design strategies, spectroscopic properties, and cytotoxicity, as well as mechanism to facilitate their future application in organelle imaging and targeted therapy. This work is anticipated to provide valuable insights for guiding future development and facilitating further investigation into mitochondria-related biological sensing and phototherapy.

Recent advances in FRET probes for mitochondrial imaging and sensing

Mitochondria, as essential organelles in cells, play a crucial role in cellular growth and apoptosis. Monitoring mitochondria is of great importance, as mitochondrial dysfunction is often considered a hallmark event of cell apoptosis. Traditional fluorescence probes used for mitochondrial imaging and sensing are mostly intensity-based and are susceptible to factors such as concentration, the probe environment, and fluorescence intensity. Probes based on fluorescence resonance energy transfer (FRET) can effectively overcome external interference and achieve high-contrast imaging of mitochondria as well as quantitative monitoring of mitochondrial microenvironments. This review focuses on recent advances in the application of FRET-based probes for mitochondrial structure imaging and microenvironment sensing.

Mitochondrial dysfunction and therapeutic perspectives in osteoporosis

Osteoporosis (OP) is a systemic skeletal disorder characterized by reduced bone mass and structural deterioration of bone tissue, resulting in heightened vulnerability to fractures due to increased bone fragility. This condition primarily arises from an imbalance between the processes of bone resorption and formation. Mitochondrial dysfunction has been reported to potentially constitute one of the most crucial mechanisms influencing the pathogenesis of osteoporosis. In essence, mitochondria play a crucial role in maintaining the delicate equilibrium between bone formation and resorption, thereby ensuring optimal skeletal health. Nevertheless, disruption of this delicate balance can arise as a consequence of mitochondrial dysfunction. In dysfunctional mitochondria, the mitochondrial electron transport chain (ETC) becomes uncoupled, resulting in reduced ATP synthesis and increased generation of reactive oxygen species (ROS). Reinforcement of mitochondrial dysfunction is further exacerbated by the accumulation of aberrant mitochondria. In this review, we investigated and analyzed the correlation between mitochondrial dysfunction, encompassing mitochondrial DNA (mtDNA) alterations, oxidative phosphorylation (OXPHOS) impairment, mitophagy dysregulation, defects in mitochondrial biogenesis and dynamics, as well as excessive ROS accumulation, with regards to OP (Figure 1). Furthermore, we explore prospective strategies currently available for modulating mitochondria to ameliorate osteoporosis. Undoubtedly, certain therapeutic strategies still require further investigation to ensure their safety and efficacy as clinical treatments. However, from a mitochondrial perspective, the potential for establishing effective and safe therapeutic approaches for osteoporosis appears promising.

Mitochondria-targeted neutral and cationic iridium(III) anticancer complexes chelating simple hybrid sp2-N/sp3-N donor ligands

Most platinum group-based cyclometalated neutral and cationic anticancer complexes with the general formula [(C^N)2Ir(XY)]0/+ (neutral complex: XY = bidentate anionic ligand; cationic complex: XY = bidentate neutral ligand) are notable owing to their intrinsic luminescence properties, good cell permeability, interaction with some biomolecular targets and unique mechanisms of action (MoAs). We herein synthesized a series of neutral and cationic amine-imine cyclometalated iridium(III) complexes using Schiff base ligands with sp2-N/sp3-N N^NH2 chelating donors. The cyclometalated iridium(III) complexes were identified by various techniques. They were stable in aqueous media, displayed moderate fluorescence and exhibited affinity toward bovine serum albumin (BSA). The complexes demonstrated promising cytotoxicity against lung cancer A549 cells, cisplatin-resistant lung cancer A549/DDP cells, cervical carcinoma HeLa cells and human liver carcinoma HepG2 cells, with IC50 values ranging from 9.98 to 19.63 μM. Unfortunately, these complexes had a low selectivity (selectivity index: 1.62-1.98) towards A549 cells and BEAS-2B normal cells. The charge pattern of the metal center (neutral or cationic) and ligand substituents showed little influence on the cytotoxicity and selectivity of these complexes. The study revealed that these complexes could target mitochondria, cause depolarization of the mitochondrial membrane, and trigger the production of intracellular ROS. Additionally, the complexes were observed to induce late apoptosis and perturb the cell cycle in the G2/M or S phase in A549 cells. Based on these results, it appears that the anticancer efficacy of these complexes was predominantly attributed to the redox mechanism.

Discovery of a far-red carbazole-benzoindolium fluorescent ligand that selectively targets mitochondrial DNA and suppresses breast cancer growth

G-quadruplex (G4) formation was considered to be more prevalent in the mitochondrial DNA (mtDNA) of cancer cells compared with normal cells. Stabilization of these G4s may induce mtDNA instability and cause mitochondrial dysfunction and subsequent cell death, which may be treated as a new strategy for cancer treatment. However, few ligands were developed to target mtG4s, leaving a huge room to improve. In this study, we designed and synthesized a series of carbazole-based ligands, among which, BKN-1 was identified as the most promising mitochondrial targeting fluorescent ligand with far-red emission. Then, we demonstrated that BKN-1 may robustly interact with mtG4s via a variety of biophysical, biological experiments. Subsequently, we proved that BKN-1 may cause mtDNA loss, disrupt mitochondrial integrity, decrease ATP level and trigger unbalanced ROS, thereby leading to apoptosis and autophagy. Finally, we verified that BKN-1 had good anti-tumor activity in both cellular and in vivo models. Altogether, this study provided a dual-function ligand that may not only track the formation of mtG4s but also induce mitochondrial dysfunction, which may be developed into an applicable chemical tool for investigating the structure and function of mtG4s, and moreover, an effective therapeutic agent for cancer interference.

Probing the dynamic crosstalk of lysosomes and mitochondria with structured illumination microscopy

Structured illumination microscopy (SIM) is a super-resolution technology for imaging living cells and has been used for studying the dynamics of lysosomes and mitochondria. Recently, new probes and analyzing methods have been developed for SIM imaging, enabling the quantitative analysis of these subcellular structures and their interactions. This review provides an overview of the working principle and advances of SIM, as well as the organelle-targeting principles and types of fluorescence probes, including small molecules, metal complexes, nanoparticles, and fluorescent proteins. Additionally, quantitative methods based on organelle morphology and distribution are outlined. Finally, the review provides an outlook on the current challenges and future directions for improving the combination of SIM imaging and image analysis to further advance the study of organelles. We hope that this review will be useful for researchers working in the field of organelle research and help to facilitate the development of SIM imaging and analysis techniques.

Unraveling the Intricacies of Autophagy and Mitophagy: Implications in Cancer Biology

Autophagy is an essential lysosome-mediated degradation pathway that maintains cellular homeostasis and viability in response to various intra- and extracellular stresses. Mitophagy is a type of autophagy that is involved in the intricate removal of dysfunctional mitochondria during conditions of metabolic stress. In this review, we describe the multifaceted roles of autophagy and mitophagy in normal physiology and the field of cancer biology. Autophagy and mitophagy exhibit dual context-dependent roles in cancer development, acting as tumor suppressors and promoters. We also discuss the important role of autophagy and mitophagy within the cancer microenvironment and how autophagy and mitophagy influence tumor host-cell interactions to overcome metabolic deficiencies and sustain the activity of cancer-associated fibroblasts (CAFs) in a stromal environment. Finally, we explore the dynamic interplay between autophagy and the immune response in tumors, indicating their potential as immunomodulatory targets in cancer therapy. As the field of autophagy and mitophagy continues to evolve, this comprehensive review provides insights into their important roles in cancer and cancer microenvironment.

Evolution of the Critically Endangered Green Sawfish Pristis zijsron (Rhinopristiformes, Pristidae), Inferred from the Whole Mitochondrial Genome

The green sawfish Pristis zijsron (Bleeker, 1851), a species of sawfish in the family Pristidae (Rhinopristiformes), mainly inhabits the Indo-West Pacific region. In this study, the complete mitochondrial genome of the critically endangered green sawfish is first described. The length of the genome is 16,804 bp, with a nucleotide composition of 32.0% A, 24.8% C, 13.1% G, and 30.0% T. It contains 37 genes in the typical gene order of fish. Two start (GTG and ATG) and two stop (TAG and TAA/T-) codons are found in the thirteen protein-coding genes. The 22 tRNA genes range from 67 bp (tRNA-Ser) to 75 bp (tRNA-Leu). The ratio of nonsynonymous substitution (Ka) and synonymous substitution (Ks) indicates that the family Pristidae are suffering a purifying selection. The reconstruction of Bayesian inference and the maximum likelihood phylogenetic tree show the same topological structure, and the family Pristidae is a monophyletic group with strong posterior probability. Pristis zijsron and P. pectinata form a sister group in the terminal clade. And the divergence time of Rhinopristiformes show that P. zijsron and P. pectinata diverged as two separate species in about Paleogene 31.53 Mya. Complete mitochondrial genomes of all five sawfishes have been published and phylogenetic relationships have been analyzed. The results of our study will provide base molecular information for subsequent research (e.g., distribution, conservation, phylogenetics, etc.) on this endangered group.

Mitochondrial Membrane-Associated Protein Mba1 Confers Antifungal Resistance by Affecting the Production of Reactive Oxygen Species in Aspergillus fumigatus

Azole resistance in the human fungal pathogen Aspergillus fumigatus is becoming a major threat to global health. To date, mutations in the azole target-encoding cyp51A gene have been implicated in conferring azole resistance, but a steady increase in the number of A. fumigatus isolates with azole resistance resulting from non-cyp51A mutations has been recognized. Previous studies have revealed that some isolates with non-cyp51A mutation-induced azole resistance are related to mitochondrial dysfunction. However, knowledge of the molecular mechanism underlying the involvement of non-cyp51A mutations is limited. In this study, using next-generation sequencing, we found that nine independent azole-resistant isolates without cyp51A mutations had normal mitochondrial membrane potential. Among these isolates, a mutation in a mitochondrial ribosome-binding protein, Mba1, conferred multidrug resistance to azoles, terbinafine, and amphotericin B but not caspofungin. Molecular characterization verified that the TIM44 domain of Mba1 was crucial for drug resistance and that the N terminus of Mba1 played a major role in growth. Deletion of mba1 had no effect on Cyp51A expression but decreased the fungal cellular reactive oxygen species (ROS) content, which contributed to mba1-mediated drug resistance. The findings in this study suggest that some non-cyp51A proteins drive drug resistance mechanisms that result from reduced ROS production induced by antifungals.

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health.

Stimulus-Responsive Drug Delivery Nanoplatforms for Osteoarthritis Therapy

Osteoarthritis (OA) is one of the most prevalent age-related degenerative diseases. With an increasingly aging global population, greater numbers of OA patients are providing clear economic and societal burdens. Surgical and pharmacological treatments are the most common and conventional therapeutic strategies for OA, but often fall considerably short of desired or optimal outcomes. With the development of stimulus-responsive nanoplatforms has come the potential for improved therapeutic strategies for OA. Enhanced control, longer retention time, higher loading rates, and increased sensitivity are among the potential benefits. This review summarizes the advanced application of stimulus-responsive drug delivery nanoplatforms for OA, categorized by either those that depend on endogenous stimulus (reactive oxygen species, pH, enzyme, and temperature), or those that depend on exogenous stimulus (near-infrared ray, ultrasound, magnetic fields). The opportunities, restrictions, and limitations related to these various drug delivery systems, or their combinations, are discussed in areas such as multi-functionality, image guidance, and multi-stimulus response. The remaining constraints and potential solutions that are represented by the clinical application of stimulus-responsive drug delivery nanoplatforms are finally summarized.

Targeting Mitochondrial Oxidative Stress as a Strategy to Treat Aging and Age-Related Diseases

Mitochondria are one of the organelles undergoing rapid alteration during the senescence process. Senescent cells show an increase in mitochondrial size, which is attributed to the accumulation of defective mitochondria, which causes mitochondrial oxidative stress. Defective mitochondria are also targets of mitochondrial oxidative stress, and the vicious cycle between defective mitochondria and mitochondrial oxidative stress contributes to the onset and development of aging and age-related diseases. Based on the findings, strategies to reduce mitochondrial oxidative stress have been suggested for the effective treatment of aging and age-related diseases. In this article, we discuss mitochondrial alterations and the consequent increase in mitochondrial oxidative stress. Then, the causal role of mitochondrial oxidative stress on aging is investigated by examining how aging and age-related diseases are exacerbated by induced stress. Furthermore, we assess the importance of targeting mitochondrial oxidative stress for the regulation of aging and suggest different therapeutic strategies to reduce mitochondrial oxidative stress. Therefore, this review will not only shed light on a new perspective on the role of mitochondrial oxidative stress in aging but also provide effective therapeutic strategies for the treatment of aging and age-related diseases through the regulation of mitochondrial oxidative stress.

Phytotherapeutic targeting of the mitochondria in neurodegenerative disorders

Neurodegenerative diseases are characterized by degeneration or cellular atrophy within specific structures of the brain. Neurons are the major target of neurodegeneration. Neurons utilize 75-80% of the energy produced in the brain. This energy is either formed by utilizing the glucose provided by the cerebrovascular blood flow or by the in-house energy producers, mitochondria. Mitochondrial dysfunction has been associated with neurodegenerative diseases. But recently it has been noticed that neurodegenerative diseases are often associated with cerebrovascular diseases. Cerebral blood flow requires vasodilation which to an extent regulated by mitochondria. We hypothesize that when mitochondrial functioning is disrupted, it is not able to supply energy to the neurons. This disruption also affects cerebral blood flow, further reducing the possibilities of energy supply. Loss of sufficient energy leads to neuronal dysfunction, atrophy, and degeneration. In this chapter, we will discuss the metabolic modifications of mitochondria in aging-related neurological disorders and the potential of phytocompounds targeting them.

Recent Development of Advanced Fluorescent Molecular Probes for Organelle-Targeted Cell Imaging

Fluorescent molecular probes are very powerful tools that have been generally applied in cell imaging in the research fields of biology, pathology, pharmacology, biochemistry, and medical science. In the last couple of decades, numerous molecular probes endowed with high specificity to particular organelles have been designed to illustrate intracellular images in more detail at the subcellular level. Nowadays, the development of cell biology has enabled the investigation process to go deeply into cells, even at the molecular level. Therefore, probes that can sketch a particular organelle's location while responding to certain parameters to evaluate intracellular bioprocesses are under urgent demand. It is significant to understand the basic ideas of organelle properties, as well as the vital substances related to each unique organelle, for the design of probes with high specificity and efficiency. In this review, we summarize representative multifunctional fluorescent molecular probes developed in the last decade. We focus on probes that can specially target nuclei, mitochondria, endoplasmic reticulums, and lysosomes. In each section, we first briefly introduce the significance and properties of different organelles. We then discuss how probes are designed to make them highly organelle-specific. Finally, we also consider how probes are constructed to endow them with additional functions to recognize particular physical/chemical signals of targeted organelles. Moreover, a perspective on the challenges in future applications of highly specific molecular probes in cell imaging is also proposed. We hope that this review can provide researchers with additional conceptual information about developing probes for cell imaging, assisting scientists interested in molecular biology, cell biology, and biochemistry to accelerate their scientific studies.

Mitochondria-targeting sonosensitizer-loaded extracellular vesicles for chemo-sonodynamic therapy

Sonodynamic therapy (SDT) has emerged as an effective therapeutic modality as it employs ultrasound (US) to eradicate deep-seated tumors noninvasively. However, the therapeutic efficacy of SDT in clinical settings remains limited owing to the low aqueous stability and poor pharmacokinetic properties of sonosensitizers. In this study, extracellular vesicles (EVs), which have low systemic toxicity, were used as clinically available nanocarriers to effectively transfer a sonosensitizer to cancer cells. Chlorin e6 (Ce6), a sonosensitizer, was conjugated to a mitochondria-targeting triphenylphosphonium (TPP) moiety and loaded into EVs to enhance the efficacy of SDT, because mitochondria are critical subcellular organelles that regulate cell survival and death. Additionally, piperlongumine (PL), a pro-oxidant and cancer-specific chemotherapeutic agent, was co-encapsulated into EVs to achieve efficient and selective anticancer activity. The EVs substantially amplified the cellular internalization of TPP-conjugated Ce6 (TPP-Ce6), resulting in the enhanced generation of intracellular reactive oxygen species (ROS) in MCF-7 human breast cancer cells upon US exposure. Importantly, EVs encapsulating TPP-Ce6 effectively destroyed the mitochondria under irradiation with US, leading to efficient anticancer activity. The co-encapsulation of pro-oxidant PL into EVs significantly enhanced the SDT efficacy in MCF-7 cells through the excessive generation of ROS. Moreover, the EV co-encapsulating TPP-Ce6 and PL [EV(TPP-Ce6/PL)] exhibited cancer-specific cell death owing to the cancer-selective apoptosis triggered by PL. In vivo study using MCF-7 tumor-xenograft mice revealed that EV(TPP-Ce6/PL) effectively accumulated in tumors after intravenous injection. Notably, treatment with EV(TPP-Ce6/PL) and US inhibited tumor growth significantly without causing systemic toxicity. This study demonstrated the feasibility of using EV(TPP-Ce6/PL) for biocompatible and cancer-specific chemo-SDT.

Neurobiological Mechanisms Of Depression Following Traumatic Brain Injury

OBJECTIVE

Depression is among the most pervasive and debilitating neuropsychiatric sequelae experienced by patients following a traumatic brain injury (TBI). While the individual mechanisms underlying depression and TBI have been widely studied, the neurobiological bases of depression after TBI remain largely unknown. This article highlights the potential mechanisms of action implicated in depression after TBI.

RESULTS

We review putative mechanisms of action including neuroinflammation, neuroendocrine dysregulation, metabolic abnormalities, and neurotransmitter and circuitry dysfunction. We also identify the current limitations in the field and propose directions for future research.

CONCLUSION

An improved understanding of the underlying mechanisms will aid the development of precision-guided and personalized treatments for patients suffering from depression after TBI.

New insights into the persistent effect of transient cinnamaldehyde vapor treatment on the growth and aflatoxin synthesis of Aspergillus flavus

The antimicrobial effects of continuous treatment with essential oils (EOs) in both liquid and gaseous phases have been intensively studied. Due to their rapid volatility, the effects of EOs on microorganisms after transient treatment are also worth exploring. In this work, the persistent effects of cinnamaldehyde (CA) vapor on Aspergillus flavus were detected by a series of biochemical analyses. Transcriptome analysis was also conducted to study the gene expression changes between recovered and normal A. flavus. When CA vapor was removed, biochemical analyses showed that the oxidative stress induced by the antimicrobial atmosphere was alleviated, and almost all the damaged functions were restored apart from mitochondrial function. Remarkably, the suppressed aflatoxin production intensified, which was confirmed by the up-regulation of most genes in the aflatoxin synthetic gene cluster, the velvet-related gene FluG and the aflatoxin precursor acetyl-CoA. Transcriptomic analysis also demonstrated significant changes in secondary metabolism, energy metabolism, oxidative stress, and amino acid metabolism in the recovery group. Taken together, these findings provide new insights into the mechanisms underlying the response of A. flavus to CA vapor treatment and will guide the rational application of EOs.

Mitochondria in innate immunity signaling and its therapeutic implications in autoimmune diseases

Autoimmune diseases are characterized by vast alterations in immune responses, but the pathogenesis remains sophisticated and yet to be fully elucidated. Multiple mechanisms regulating cell differentiation, maturation, and death are critical, among which mitochondria-related cellular organelle functions have recently gained accumulating attention. Mitochondria, as a highly preserved organelle in eukaryotes, have crucial roles in the cellular response to both exogenous and endogenous stress beyond their fundamental functions in chemical energy conversion. In this review, we aim to summarize recent findings on the function of mitochondria in the innate immune response and its aberrancy in autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, etc., mainly focusing on its direct impact on cellular metabolism and its machinery on regulating immune response signaling pathways. More importantly, we summarize the status quo of potential therapeutic targets found in the mitochondrial regulation in the setting of autoimmune diseases and wish to shed light on future studies.

Mitochondrial Targeting and Imaging with Small Organic Conjugated Fluorophores: A Review

The last decade has seen an increasingly large number of studies reporting on the development of novel small organic conjugated systems for mitochondrial imaging exploiting optical signal transduction pathways. Mitochondria are known to play a critical role in a number of key biological processes, including cellular metabolism. Importantly, irregularities on their working function are nowadays understood to be intimately linked to a range of clinical conditions, highlighting the importance of targeting mitochondria for therapeutic benefits. In this work we carry out an in-depth evaluation on the progress to date in the field to pave the way for the realization of superior alternatives to those currently existing. The manuscript is structured by commonly used chemical scaffolds and comprehensively covers key aspects factored in design strategies such as synthetic approaches as well as photophysical and biological characterization, to foster collaborative work among organic and physical chemists as well as cell biologists.

Mitochondrial Dysfunction as an Underlying Cause of Skeletal Muscle Disorders

Mitochondria are an important energy source in skeletal muscle. A main function of mitochondria is the generation of ATP for energy through oxidative phosphorylation (OXPHOS). Mitochondrial defects or abnormalities can lead to muscle disease or multisystem disease. Mitochondrial dysfunction can be caused by defective mitochondrial OXPHOS, mtDNA mutations, Ca2+ imbalances, mitochondrial-related proteins, mitochondrial chaperone proteins, and ultrastructural defects. In addition, an imbalance between mitochondrial fusion and fission, lysosomal dysfunction due to insufficient biosynthesis, and/or defects in mitophagy can result in mitochondrial damage. In this review, we explore the association between impaired mitochondrial function and skeletal muscle disorders. Furthermore, we emphasize the need for more research to determine the specific clinical benefits of mitochondrial therapy in the treatment of skeletal muscle disorders.

Mitochondria-Targeted Luminescent Organotin(IV) Complexes: Synthesis, Photophysical Characterization, and Live Cell Imaging

Five fluorescent ONO donor-based organotin(IV) complexes, [Sn^IV(L^1-5)Ph₂] (1-5), were synthesized by the one-pot reaction method and fully characterized spectroscopically including the single-crystal X-ray diffraction studies of 2-4. Detailed photophysical characterization of all compounds was performed. All the compounds exhibited high luminescent properties with a quantum yield of 17-53%. Additionally, the results of cellular permeability analysis suggest that they are lipophilic and easily absorbed by cells. Confocal microscopy was used to examine the live cell imaging capability of 1-5, and the results show that the compounds are mostly internalized in mitochondria and exhibit negligible cytotoxicity at imaging concentration. Also, 1-5 exhibited high photostability as compared to the commercial dye and can be used in long-term real-time tracking of cell organelles. Also, it is found that the probes (1-5) are highly tolerable during the changes in mitochondrial morphology. Thus, this kind of low-toxic organotin-based fluorescent probe can assist in imaging of mitochondria within living cells and tracking changes in their morphology.

Intracellular Physical Properties with Small Organic Fluorescent Probes: Recent Advances and Future Perspectives

The intracellular physical parameters i. e., polarity, viscosity, fluidity, tension, potential, and temperature of a live cell are the hallmark of cellular health and have garnered immense interest over the past decade. In this context, small molecule organic fluorophores exhibit prominent useful properties including easy functionalizability, environmental sensitivity, biocompatibility, and fast yet efficient cellular uptakability which has made them a popular tool to understand intra-cellular micro-environmental properties. Throughout this discussion, we have outlined the basic design strategies of small molecules for specific organelle targeting and quantification of physical properties. The values of these parameters are indicative of cellular homeostasis and subtle alteration may be considered as the onset of disease. We believe this comprehensive review will facilitate the development of potential future probes for superior insight into the physical parameters that are yet to be quantified.

Photostable polymorphic organic cages for targeted live cell imaging

Fluorescent microscopy is a powerful tool for studying the cellular dynamics of biological systems. Small-molecule organic fluorophores are the most commonly used for live cell imaging; however, they often suffer from low solubility, limited photostability and variable targetability. Herein, we demonstrate that a tautomeric organic cage, OC1, has high cell permeability, photostability and selectivity towards the mitochondria. We further performed a structure–activity study to investigate the role of the keto–enol tautomerization, which affords strong and consistent fluorescence in dilute solutions through supramolecular self-assembly. Significantly, OC1 can passively diffuse through the cell membrane directly targeting the mitochondria without going through the endosomes or the lysosomes. We envisage that designing highly stable and biocompatible self-assembled fluorophores that can passively diffuse through the cell membrane while selectively targeting specific organelles will push the boundaries of fluorescent microscopy to visualize intricate cellular processes at the single molecule level in live samples.

In this article, we demonstrate the relatively unexplored potential of organic cages for use in targeted live cell imaging and highlight the importance of inter- and intramolecular interactions to stabilize and improve the performance of fluorophores.

Prehabilitative resistance exercise reduces neuroinflammation and improves mitochondrial health in aged mice with perioperative neurocognitive disorders

Background

Postoperative neurocognitive dysfunction remains a significant problem in vulnerable groups such as the elderly. While experimental data regarding its possible pathogenic mechanisms accumulate, therapeutic options for this disorder are limited. In this study, we evaluated the neuroprotective effect of a period of preconditioning resistant training on aged mice undergoing abdominal surgery. Further, we examined the underlying mechanisms from the perspective of neuroinflammatory state and synaptic plasticity in the hippocampus.

Methods

18-month-old C57BL/6N mice were trained for 5 weeks using a ladder-climbing protocol with progressively increasing weight loading. Preoperative baseline body parameters, cognitive performance and neuroinflammatory states were assessed and compared between sedentary and trained groups of 9-month-old and 18-month-old mice. To access the neuroprotective effect of resistance training on postoperative aged mice, both sedentary and trained mice were subjected to a laparotomy under 3% sevoflurane anesthesia. Cognitive performance on postoperative day 14, hippocampal neuroinflammation, mitochondrial dysfunction and synaptic plasticity were examined and compared during groups.

Results

18-month-old mice have increased body weight, higher peripheral and central inflammatory status, reduction in muscle strength and cognitive performance compared with middle-aged 9-month-old mice, which were improved by resistance exercise. In the laparotomy group, prehabilitative resistant exercise improved cognitive performance and synaptic plasticity, reduced inflammatory factors and glial cells activation after surgery. Furthermore, resistance exercise activated hippocampal PGC-1α/BDNF/Akt/GSK-3β signaling and improved mitochondrial biogenesis, as well as ameliorated mitochondrial dynamics in postoperative-aged mice.

Conclusions

Resistance exercise reduced risk factors for perioperative neurocognitive disorders such as increased body weight, elevated inflammatory markers, and pre-existing cognitive impairment. Accordantly, preoperative resistance exercise improved surgery-induced adverse effects including cognitive impairment, synaptic deficit and neuroinflammation, possibly by facilitate mitochondrial health through the PGC1-a/BDNF pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02483-1.

A new HClO-activated "turn-off" mitochondria-targetable NIR fluorescent probe for imaging of osteoarthritis in vivo

Hypochlorous acid (HClO) as a biomarker of inflammation has been implicated in redox signaling and combating microbial infection. Therefore, it is of great significance to develop an efficient method for detection and analysis of HClO in osteoarthritis. Herein, a new"turn-off" mitochondria-targetable NIR fluorescent probe, NIR-ClO, was reported for specific analysis and imaging of osteoarthritis response-related HOCl levels in vitro and in vivo. In the presence of HClO, due to the specific HOCl-triggered C = C bond cleavage reaction, NIR-ClO obtained a high sensitive and selective fluorescence "On-Off" response toward HClO with a good limit of detection(LOD) as low as 28.3 nM, and showed a fast response time (<60 s) , which allow it to be used for detection of HClO under a simulated physiological condition. In addition, NIR-ClO was successfully used to imaging of HClO in living RAW264.7 cells and osteoarthritis model rat. The results suggest that NIR-ClO is a robust tool for future studies on diagnosis osteoarthritis.

Mitochondrial structural variations in the process of mitophagy

Mitochondrion is one of significant organelles inside cells because it serves as a hub for energy management and intracellular signaling. Internal/external damages on mitochondria would lead to mitochondrial stresses with the malfunctions, accompanying with the changes of morphological structure and abnormal local environments (pH values). Mitophagy is capable of degradation of damaged mitochondrial segments to restore its normal metabolism, dynamics, and biogenesis. The dynamic structural visualization and pH quantification can be helpful for the understanding of mitochondrial functions as well as the diagnosis of disorders linking with this process. In this work, we use confocal laser scanning microscopy, STED super-resolution nanoscopy and fluorescence lifetime imaging microscopy, in conjunction with a mitochondrial probe to image the dynamic changes in the mitochondrial morphology and microenvironmental pH values during mitophagy in live cells, in particular, the structural changes of mitochondrial cristae beyond optical diffraction can be distinguished by STED nanoscopy with/without treatment by CCCP, which will provide a new view for the diagnosis and personalized treatment of mitochondrial dysfunction-related diseases.

Novel duplication remnant in the first complete mitogenome of Hemitriakis japanica and the unique phylogenetic position of family Triakidae

In this study, we firstly determined the complete mitogenome of the Japanese topeshark (Hemitriakis japonica), which belong to the family Triakidae and was assessed as Endangered A2d on the IUCN Red List in 2021. The mitogenome is 17,301 bp long, has a high AT content (60.0%), and contains 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, a control region and specially a 594 bp-long non-coding region between Cytb gene and tRNA-Thr gene. The novel non-coding region share high sequence similarity with segments of the former and latter genes, so it was recognized as a duplication remnant. In addition, the Cytb gene and tRNA-Thr gene tandemly duplicated twice while accompanied by being deleted once at least. This is the first report of mitogenomic gene-arrangement in Triakidae. The phylogenetic trees were constructed using Bayesian inference (BI) and maximum likelihood (ML) methods based on the mitogenomic data of 51 shark species and two outgroups. In summary, basing on a novel type of gene rearrangements in houndshark mitogenome, the possibly rearranged process was analyzed and contributed further insight of shark mitogenomes evolution and phylogeny.

Recent advances in biological applications of nanomaterials through defect engineering

In recent years, defect engineering sprung up in the artificial nanomaterials (NMs) has attracted significant attention, since the physical and chemical properties of NMs could be largely optimized based on the rational control of different defect types and densities. Defective NMs equipped with the improved electric and catalytic ability, would be widely utilized as the photoelectric device and catalysts to alleviate the growing demands of industrial production and environmental treatments. In particular, considering that the features of targeting, adsorptive, loading and optical could be adjusted by the introduction of defects, numerous defective NMs are encouraged to be applied in the biological fields including bacterial inactivation, cancer therapy and so on. And this review is devoted to summarize the recent biological applications of NMs with abundant defects. Moreover, the opportunity of these defective NMs released into the surrounding environment continue to increase, the direct and indirect contact with biological molecules and organisms would be inevitable. Due to its high reactivity and adsorption triggered by defects, NMs tend to exhibit overestimate biological behaviors and effects on organisms. Thus, the sections regarding toxicological effects of NMs with abundant defects are also carried out to supplement the safety assessments of NMs and guide further applications in the industrial production and living.

Phosphinate-benzoindocyanin fluorescent probe for endogenous mitochondrial peroxynitrite detection in living cells and gallbladder access in inflammatory zebrafish animal models

Potent oxidants such as peroxynitrite (ONOO^-) play important roles in the regulation of different physiopathological processes; their overproduction is thought to potentially cause several diseases in living organisms. Hence, the precise and selective monitoring of ONOO^- is imperative for elucidating its interplay and roles in pathological and physiological processes. Herein, we present a novel diphenyl phosphinate-masked benzoindocyanin "turn-on" fluorogenic probe to help detect mitochondrial ONOO^- in living cells and zebrafish models. A pale yellow color solution of BICBzDP turns rose-red upon the addition of ONOO^-_, selectively, contrary to that of other competitive bioactive molecules. BICBzDP displays an ultra-sensitivity detection limit (47.8 nM) with outstanding selectivity and sensitivity towards mitochondrial ONOO^- and possesses a notable 68-fold fluorescence enhancement involving a large redshift of 91 nm. Importantly, further biological experimental investigations with BICBzDP indicate specific sensitivity and reliability of the probe to track the ONOO^- level, not only in live cells, but also demonstrates dynamic fluctuations in the inflammatory zebrafish animal models. Thus, BICBzDP could be employed as a future potential biological tool for exploiting the role of ONOO^- in a variety of different physiological systems.

Construction of fluorescent probes for ratiometric visualization of mitochondrial depolarization based on the FRET mechanism

Two fluorescent probes based on the FRET mechanism were reasonably fabricated for the visualization of mitochondrial depolarization in a ratiometric manner.

Mitonuclear Genetic Interactions in the Basidiomycete Heterobasidion parviporum Involve a Non-conserved Mitochondrial Open Reading Frame

The mitochondrial and nuclear genomes of Eukaryotes are inherited separately and consequently follow distinct evolutionary paths. Nevertheless, the encoding of many mitochondrial proteins by the nuclear genome shows the high level of integration they have reached, which makes mitonuclear genetic interactions all the more conceivable. For each species, natural selection has fostered the evolution of coadapted alleles in both genomes, but a population-wise divergence of such alleles could lead to important phenotypic variation, and, ultimately, to speciation. In this study in the Basidiomycete Heterobasidion parviporum, we have investigated the genetic basis of phenotypic variation among laboratory-designed heterokaryons carrying the same pair of haploid nuclei, but a different mitochondrial genome. Radial growth rate data of thirteen unrelated homokaryotic parents and of their heterokaryotic offspring were combined with SNP data extracted from parental genome sequences to identify nuclear and mitochondrial loci involved in mitonuclear interactions. Two nuclear loci encoding mitochondrial proteins appeared as best candidates to engage in a genetic interaction affecting radial growth rate with a non-conserved mitochondrial open reading frame of unknown function and not reported apart from the Russulales order of Basidiomycete fungi. We believe our approach could be useful to investigate several important traits of fungal biology where mitonuclear interactions play a role, including virulence of fungal pathogens.

Role of Mitochondria in Physiology of Chondrocytes and Diseases of Osteoarthritis and Rheumatoid Arthritis

PURPOSE OF REVIEW

Mitochondria are recognized to be one of the most important organelles in chondrocytes for their role in triphosphate (ATP) generation through aerobic phosphorylation. Mitochondria also participate in many intracellular processes involving modulating reactive oxygen species (ROS), responding to instantaneous hypoxia stress, regulating cytoplasmic transport of calcium ion, and directing mitophagy to maintain the homeostasis of individual chondrocytes.

DESIGNS

To summarize the specific role of mitochondria in chondrocytes, we screened related papers in PubMed database and the search strategy is ((mitochondria) AND (chondrocyte)) AND (English [Language]). The articles published in the past 5 years were included and 130 papers were studied.

RESULTS

In recent years, the integrity of mitochondrial structure has been regarded as a prerequisite for normal chondrocyte survival and defect in mitochondrial function has been found in cartilage-related diseases, such as osteoarthritis (OA) and rheumatoid arthritis (RA). However, the understanding of mitochondria in cartilage is still largely limited. The mechanism on how the changes in mitochondrial structure and function directly lead to the occurrence and development of cartilage-related diseases remains to be elusive.

CONCLUSION

This review aims to summarize the role of mitochondria in chondrocytes under the physiological and pathological changes from ATP generation, calcium homeostasis, redox regulation, mitophagy modulation, mitochondria biogenesis to immune response activation. The enhanced understanding of molecular mechanisms in mitochondria might offer some new cues for cartilage remodeling and pathological intervention.

Photostable Red-Emitting Fluorescent Rhein-Magnesium(Ⅱ) Coordination Polymer Nanodot-Based Nanostructures With a Large Stokes Shift for Imaging Mitochondria in Cancer Cell

The mitochondria play a significant role in many cellular processes and are recognized as one of the most important therapeutic targets in cancer. Direct long-term imaging of the mitochondria is very crucial for treating cancer. However, the development of a red-emitting mitochondrial probe with a large Stokes shift and photostability remains highly challenging. Fluorescent metal complexes with superior physicochemical property have emerged as new fluorescent nanomaterials due to their increasing advantages in bioimaging. Herein, a luminescent pitaya-type nanostructure based on rhein-magnesium(II) (Rh-Mg) coordination polymer nanodots was used as a fluorescent nanoprobe to selectively image the mitochondria benefiting from the introduction of triphenylphosphine. The as-prepared Rh-Mg nanodot-based nanoprobe showed red emission peaking at 620 nm, a large Stokes shift (100 nm), and excellent photostability as compared with commercial mitochondrial probes. Due to these extraordinary features, this fluorescent nanoprobe was successfully used for mitochondrial targeting imaging of live cancer cell line Neuro-2a (mouse neuroblastoma) and BV2 microglial cells. Therefore, our results pave a new way for the design of fluorescent nanoprobes for imaging mitochondria in cancer cell.

The Gene Rearrangement, Loss, Transfer, and Deep Intronic Variation in Mitochondrial Genomes of Conidiobolus

The genus Conidiobolus s.s. was newly delimited from Conidiobolus s.l. In order to gain insight into its mitochondrial genetic background, this study sequenced six mitochondrial genomes of the genus Conidiobolus s.s. These mitogenomes were all composed of circular DNA molecules, ranging from 29,253 to 48,417 bp in size and from 26.61 to 27.90% in GC content. The order and direction for 14 core protein-coding genes (PCGs) were identical, except for the atp8 gene lost in Conidiobolus chlamydosporus, Conidiobolus polyspermus, and Conidiobolus polytocus, and rearranged in the other Conidiobolus s.s. species. Besides, the atp8 gene split the cox1 gene in Conidiobolus taihushanensis. Phylogenomic analysis based on the 14 core PCGs confirmed that all Conidiobolus s.s. species formed a monophyly in the Entomophthoromycotina lineage. The number and length of introns were the main factors contributing to mitogenomic size, and deep variations and potential transfer were detected in introns. In addition, gene transfer occurred between the mitochondrial and nuclear genomes. This study promoted the understanding of the evolution and phylogeny of the Conidiobolus s.s. genus.

Acetylation in Mitochondria Dynamics and Neurodegeneration

Mitochondria are a unique intracellular organelle due to their evolutionary origin and multifunctional role in overall cellular physiology and pathophysiology. To meet the specific spatial metabolic demands within the cell, mitochondria are actively moving, dividing, or fusing. This process of mitochondrial dynamics is fine-tuned by a specific group of proteins and their complex post-translational modifications. In this review, we discuss the mitochondrial dynamics regulatory enzymes, their adaptor proteins, and the effect of acetylation on the activity of fusion and fission machinery as a ubiquitous response to metabolic stresses. Further, we discuss the role of intracellular cytoskeleton structures and their post-translational modifications in the modulation of mitochondrial fusion and fission. Finally, we review the role of mitochondrial dynamics dysregulation in the pathophysiology of acute brain injury and the treatment strategies based on modulation of NAD⁺-dependent deacetylation.

Targeting Mitochondrial Metabolism as a Strategy to Treat Senescence

Mitochondria are one of organelles that undergo significant changes associated with senescence. An increase in mitochondrial size is observed in senescent cells, and this increase is ascribed to the accumulation of dysfunctional mitochondria that generate excessive reactive oxygen species (ROS). Such dysfunctional mitochondria are prime targets for ROS-induced damage, which leads to the deterioration of oxidative phosphorylation and increased dependence on glycolysis as an energy source. Based on findings indicating that senescent cells exhibit mitochondrial metabolic alterations, a strategy to induce mitochondrial metabolic reprogramming has been proposed to treat aging and age-related diseases. In this review, we discuss senescence-related mitochondrial changes and consequent mitochondrial metabolic alterations. We assess the significance of mitochondrial metabolic reprogramming for senescence regulation and propose the appropriate control of mitochondrial metabolism to ameliorate senescence. Learning how to regulate mitochondrial metabolism will provide knowledge for the control of aging and age-related pathologies. Further research focusing on mitochondrial metabolic reprogramming will be an important guide for the development of anti-aging therapies, and will provide novel strategies for anti-aging interventions.

Progress on the Physiological Function of Mitochondrial DNA and Its Specific Detection and Therapy

Mitochondrial DNA (mtDNA) is the genetic information of mitochondrion, and its structure is circular double-stranded. Despite the diminutive size of the mitochondrial genome, mtDNA mutations are an important cause of mitochondrial diseases which are characterized by defects in oxidative phosphorylation (OXPHOS). Mitochondrial diseases are involved in multiple systems, particularly in the organs that are highly dependent on aerobic metabolism. The diagnosis of mitochondrial disease is more complicated since mtDNA mutations can cause various clinical symptoms. To realize more accurate diagnosis and treatment of mitochondrial diseases, the detection of mtDNA and the design of drugs acting on it are extremely important. Over the past few years, many probes and therapeutic drugs targeting mtDNA have been developed, making significant contributions to fundamental research including elucidation of the mechanisms of mitochondrial diseases at the genetic level. In this review, we summarize the structure, function, and detection approaches for mtDNA. The most current topics in this field, such as mechanistic exploration and treatment of mtDNA mutation-related disorders, are also reviewed. Specific attention is given to discussing the design and development of these probes and drugs for mtDNA. We hope that this review will provide readers with a comprehensive understanding of the importance of mtDNA, and promote the development of effective molecules for theragnosis of mtDNA mutation-related diseases.

Characterization of mitogenomes from four Mucorales species and insights into pathogenicity

BACKGROUND

Mucorales, as one major order of Zygomycetes fungi, can infect human beings and cause serious consequence. We have noticed the pathogenicity of Mucorales is closely related to energy metabolism, while mitochondria play the role of energy factories in almost all biological activities.

METHODS

Virulence of M irregularis, M hiemalis, L corymbifera and R arrhizus were verified in Galleria mellonella larvae, as well as mitochondrial gene copies analysed with RT-qPCR. Mitogenomes of the four Mucorales species were sequenced based on illumina NovaSeq technology to study their characteristic features and functional regions.

RESULTS

Variant virulence of M irregularis, M hiemalis, L corymbifera and R arrhizu were verified by clinical retrospective data and our G mellonella infection models, also copies of mitochondrial genes indicated the significant associations with pathogenicity. A total of 274.18 clean reads were generated to be assembled; the complete mitogenomes of the four Mucorales species were obtained with totally different length. After the genomes annotated and compared, M irregularis was found more similar with M hiemalis than those of L corymbifera and R arrhizus, especially the small (rrns) and large (rrnl) subunits of mitochondrial ribosomal RNA (rRNA) genes. The GC content, ncRNAs and the distribution of the SNPs and InDels were also compared, and the GC content rate of fungi seems to be related to the fungal thermal adaptability. In addition, linear mitogenomes of these four Mucorales showed diverse arrangements of orf genes and directionality of some conserved gene elements.

CONCLUSION

This study uncovered the pathogenicity variances among the four Mucorales species and the relationship between their mitogenomic features and clinical pathogenicity. Further studies like spatial structure of mitochondrial genomes and the comprehensive analysis of transcription regulation are needed.

Cyclometalated Ru(II) β-carboline complexes induce cell cycle arrest and apoptosis in human HeLa cervical cancer cells via suppressing ERK and Akt signaling

Two new cyclometalated Ru(II)-β-carboline complexes, [Ru(dmb)₂(Cl-Ph-βC)](PF₆) (dmb = 4,4'-dimethyl-2,2'-bipyridine; Cl-Ph-βC = Cl-phenyl-9H-pyrido[3,4-b]indole; RuβC-3) and [Ru(bpy)₂(Cl-Ph-βC)](PF₆) (bpy = 2,2'-bipyridine; RuβC-4) were synthesized and characterized. The Ru(II) complexes display high cytotoxicity against HeLa cells, the stabilized human cervical cancer cell, with IC₅₀ values of 3.2 ± 0.4 μM (RuβC-3) and 4.1 ± 0.6 μM (RuβC-4), which were considerably lower than that of non-cyclometalated Ru(II)-β-carboline complex [Ru(bpy)₂(1-Py-βC)] (PF₆)₂ (61.2 ± 3.9 μM) by 19- and 15-folds, respectively. The mechanism studies indicated that both Ru(II) complexes could significantly inhibit HeLa cell migration and invasion, and effectively induce G0/G1 cell cycle arrest. The new Ru(II) complexes could also trigger apoptosis through activating caspase-3 and poly (ADP-ribose) polymerase (PARP), increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS) generation, decreasing mitochondrial membrane potential (MMP), and inducing cytochrome c release from mitochondria. Further research revealed that RuβC-3 could deactivate the ERK/Akt signaling pathway thus inhibiting HeLa cell invasion and migration, and inducing apoptosis. In addition, RuβC-3-induced apoptosis in HeLa cells was closely associated with the increase of intracellular ROS levels, which may act as upstream factors to regulate ERK and Akt pathways. More importantly, RuβC-3 exhibited low toxicity on both normal BEAS-2B cells in vitro and zebrafish embryos in vivo. Consequently, the developed Ru(II) complexes have great potential on developing novel low-toxic anticancer drugs.

Cancer cell membrane camouflaged iridium complexes functionalized black-titanium nanoparticles for hierarchical-targeted synergistic NIR-II photothermal and sonodynamic therapy

The diagnosis and treatment of cancer is one of the biggest medical challenges of the century. Despite significant improvements, there remains an urgent need for novel anticancer procedures. Among the most promising approaches, increasing attention has been devoted towards photothermal and sonodynamic therapy in which sensitizers are activated upon light/ultrasound radiation to generate a cytotoxic effect. While these methods have undoubtedly shown a high therapeutic success, these techniques are intrinsically limited. Herein, the functionalization of black-titanium nanoparticle with iridium complexes and cancer cell membranes in a nanoplatform for hierarchical targeted synergistic photothermal and sonodynamic cancer imaging and therapy is proposed. The particles showed to generate efficiently heat upon irradiation and catalytically form reactive oxygen species upon ultrasound radiation. The nanoparticle formulation demonstrated to selectively localize in the mitochondria as well as to preferentially accumulate in cancerous over non-cancerous cells as well as in the tumor inside a mouse model, presenting a hierarchical targeting strategy. Upon synergistic irradiation at 1064 nm and ultrasound radiation, the nanoparticles were able to act as an imaging agent and identify the tumor site with high spatial resolution as well as act as a therapeutic agent and completely eradicate a tumor inside a mouse model.

Rh(iii)-Catalysed synthesis of cinnolinium and fluoranthenium salts using C-H activation/annulation reactions: organelle specific mitochondrial staining applications

The construction of a novel class of indazolo[2,1-a]cinnolin-7-ium and diazabenzofluoranthenium salts was developed by using Rh(iii)-catalyzed C-H activation/annulation reactions with 2-phenyl-2H-indazole, and internal alkynes, which resulted in structurally important polycyclic heteroaromatic compounds (PHAs). This reaction uses mild reaction conditions and has a high efficiency, low catalyst loading, and wide substrate scope. The overall catalytic process involves C-H activation followed by C-C/C-N bond formation. Furthermore, the synthesised cinnolinium/fluoranthenium salts exhibit potential fluorescence properties and 5i was targeted in particular for specific mitochondrial staining in order to investigate cancer cell lines.

Recent progress in developing fluorescent probes for imaging cell metabolites

Cellular metabolites play a crucial role in promoting and regulating cellular activities, but it has been difficult to monitor these cellular metabolites in living cells and in real time. Over the past decades, iterative development and improvements of fluorescent probes have been made, resulting in the effective monitoring of metabolites. In this review, we highlight recent progress in the use of fluorescent probes for tracking some key metabolites, such as adenosine triphosphate, cyclic adenosine monophosphate, cyclic guanosine 5'-monophosphate, Nicotinamide adenine dinucleotide (NADH), reactive oxygen species, sugar, carbon monoxide, and nitric oxide for both whole cell and subcellular imaging.

Organelle-Targeted Photosensitizers for Precision Photodynamic Therapy

Subcellular organelles are the cornerstones of cells, and destroying them will cause cell dysfunction and even death. Therefore, realizing precise organelle targeting of photosensitizers (PSs) can help reduce PS dosage, minimize side effects, avoid drug resistance, and enhance therapeutic efficacy in photodynamic therapy (PDT). Organelle-targeted PSs provide a new paradigm for the construction of the next generation of PSs and may provide implementable strategies for future precision medicine. In this Review, the recent targeting strategies of different organelles and the corresponding design principles of molecular and nanostructured PSs are summarized and discussed. The current challenges and opportunities in organelle-targeted PDT are also presented.

Symbiotic behaviour in the public goods game with altruistic punishment

Finding ways to overcome the temptation to exploit one another is still a challenge in behavioural sciences. In the framework of evolutionary game theory, punishing strategies are frequently used to promote cooperation in competitive environments. Here, we introduce altruistic punishers in the spatial public goods game. This strategy acts as a cooperator in the absence of defectors, otherwise it will punish all defectors in their vicinity while bearing a cost to do so. We observe three distinct behaviours in our model: i) in the absence of punishers, cooperators (who don't punish defectors) are driven to extinction by defectors for most parameter values; ii) clusters of punishers thrive by sharing the punishment costs when these are low; iii) for higher punishment costs, punishers, when alone, are subject to exploitation but in the presence of cooperators can form a symbiotic spatial structure that benefits both. This last observation is our main finding since neither cooperation nor punishment alone can survive the defector strategy in this parameter region and the specificity of the symbiotic spatial configuration shows that lattice topology plays a central role in sustaining cooperation. Results were obtained by means of Monte Carlo simulations on a square lattice and subsequently confirmed by a pairwise comparison of different strategies' payoffs in diverse group compositions, leading to a phase diagram of the possible states.

Autophagic Organelles in DNA Damage Response

Autophagy is an important subcellular event engaged in the maintenance of cellular homeostasis via the degradation of cargo proteins and malfunctioning organelles. In response to cellular stresses, like nutrient deprivation, infection, and DNA damaging agents, autophagy is activated to reduce the damage and restore cellular homeostasis. One of the responses to cellular stresses is the DNA damage response (DDR), the intracellular pathway that senses and repairs damaged DNA. Proper regulation of these pathways is crucial for preventing diseases. The involvement of autophagy in the repair and elimination of DNA aberrations is essential for cell survival and recovery to normal conditions, highlighting the importance of autophagy in the resolution of cell fate. In this review, we summarized the latest information about autophagic recycling of mitochondria, endoplasmic reticulum (ER), and ribosomes (called mitophagy, ER-phagy, and ribophagy, respectively) in response to DNA damage. In addition, we have described the key events necessary for a comprehensive understanding of autophagy signaling networks. Finally, we have highlighted the importance of the autophagy activated by DDR and appropriate regulation of autophagic organelles, suggesting insights for future studies. Especially, DDR from DNA damaging agents including ionizing radiation (IR) or anti-cancer drugs, induces damage to subcellular organelles and autophagy is the key mechanism for removing impaired organelles.

Sirtuins-Mediated System-Level Regulation of Mammalian Tissues at the Interface between Metabolism and Cell Cycle: A Systematic Review

Sirtuins are a family of highly conserved NAD+-dependent proteins and this dependency links Sirtuins directly to metabolism. Sirtuins' activity has been shown to extend the lifespan of several organisms and mainly through the post-translational modification of their many target proteins, with deacetylation being the most common modification. The seven mammalian Sirtuins, SIRT1 through SIRT7, have been implicated in regulating physiological responses to metabolism and stress by acting as nutrient sensors, linking environmental and nutrient signals to mammalian metabolic homeostasis. Furthermore, mammalian Sirtuins have been implicated in playing major roles in mammalian pathophysiological conditions such as inflammation, obesity and cancer. Mammalian Sirtuins are expressed heterogeneously among different organs and tissues, and the same holds true for their substrates. Thus, the function of mammalian Sirtuins together with their substrates is expected to vary among tissues. Any therapy depending on Sirtuins could therefore have different local as well as systemic effects. Here, an introduction to processes relevant for the actions of Sirtuins, such as metabolism and cell cycle, will be followed by reasoning on the system-level function of Sirtuins and their substrates in different mammalian tissues. Their involvement in the healthy metabolism and metabolic disorders will be reviewed and critically discussed.