Cellular metabolic stress responses via organelles

Analysis of the stereoselective fate and toxicity of penflufen in the water-sediment system for risk reduction

Chiral succinate dehydrogenase inhibitor (SDHI) fungicides are widely used in agricultural production, but there is insufficient research on their environmental risk in water-sediment ecosystems. Here, the stereoselective fate and toxic effects of the chiral SDHI fungicide, penflufen, in the water-sediment system were investigated. The results showed that S-penflufen is more persistent in water, sediment, and zebrafish. Additionally, the sorption coefficient (Koc) in sediment and uptake rate constant (Ku) in zebrafish of S-penflufen were higher than those of R-penflufen. The acute toxicity of S-penflufen to zebrafish, Daphnia magna and Chironomus kiiensis were 32-, 6.1-, and 8.9-fold higher than those of R-penflufen. The AlphaFold2 and molecular docking results showed that S-penflufen had stronger binding capability with SDH in the three water-sediment organisms than R-penflufen. Therefore, S-penflufen induced stronger sub-chronic toxic effects on zebrafish than R-penflufen, even at 0.05 mg/L. The results of multi-omics analysis showed that S-penflufen affected the tricarboxylic acid cycle in zebrafish and induced antioxidant, detoxification, and immune system responses, ultimately affecting zebrafish metabolic processes and cellular function. The overall results indicate that S-penflufen has a higher risk in water-sediment systems. Moreover, combining multi-omics and AlphaFold2 techniques facilitates the elucidation of the molecular mechanism of the stereoselective toxic effects of chiral pesticides.

The role of mitochondria in iron overload-induced damage

Iron overload is a pathological condition characterized by the abnormal accumulation of iron within the body, which may result from excessive iron intake, disorders of iron metabolism, or specific disease states. This condition can lead to significant health complications and may pose life-threatening risks. The excessive accumulation of iron can induce cellular stress, adversely affecting the structure and function of mitochondria, thereby compromising overall organ function. Given the critical role of mitochondria in cellular metabolism and homeostasis, it is imperative to investigate how mitochondrial dysfunction induced by iron overload contributes to disease progression, as well as to explore mitochondrial-related pathways as potential therapeutic targets for various iron overload disorders. This review examines the mechanisms by which mitochondria are implicated in iron overload-induced damage, including increased oxidative stress, mitochondrial DNA damage, and disruptions in energy metabolism. Additionally, it addresses the relationship between these processes and various forms of programmed cell death, as well as alterations in mitochondrial dynamics. Furthermore, the review discusses strategies aimed at alleviating and mitigating the complications associated with iron overload in patients by targeting mitochondrial pathways.

Stress-Induced Evolution of the Nucleolus: The Role of Ribosomal Intergenic Spacer (rIGS) Transcripts

It became clear more than 20 years ago that the nucleolus not only performs the most important biological function of assembling ribonucleic particles but is also a key controller of many cellular processes, participating in cellular adaptation to stress. The nucleolus's multifunctionality is due to the peculiarities of its biogenesis. The nucleolus is a multilayered biomolecular condensate formed by liquid-liquid phase separation (LLPS). In this review, we focus on changes occurring in the nucleolus during cellular stress, molecular features of the nucleolar response to abnormal and stressful conditions, and the role of long non-coding RNAs transcribed from the intergenic spacer region of ribosomal DNA (IGS rDNA).

Fasudil and viscosity of gelatin promote hepatic differentiation by regulating organelles in human umbilical cord matrix-mesenchymal stem cells

BACKGROUND

Human mesenchymal stem cells originating from umbilical cord matrix are a promising therapeutic resource, and their differentiated cells are spotlighted as a tissue regeneration treatment. However, there are limitations to the medical use of differentiated cells from human umbilical cord matrix-mesenchymal stem cells (hUCM-MSCs), such as efficient differentiation methods.

METHODS

To effectively differentiate hUCM-MSCs into hepatocyte-like cells (HLCs), we used the ROCK inhibitor, fasudil, which is known to induce endoderm formation, and gelatin, which provides extracellular matrix to the differentiated cells. To estimate a differentiation efficiency of early stage according to combination of gelatin and fasudil, transcription analysis was conducted. Moreover, to demonstrate that organelle states affect differentiation, we performed transcription, tomographic, and mitochondrial function analysis at each stage of hepatic differentiation. Finally, we evaluated hepatocyte function based on the expression of mRNA and protein, secretion of albumin, and activity of CYP3A4 in mature HLCs.

RESULTS

Fasudil induced endoderm-related genes (GATA4, SOX17, and FOXA2) in hUCM-MSCs, and it also induced lipid droplets (LDs) inside the differentiated cells. However, the excessive induction of LDs caused by fasudil inhibited mitochondrial function and prevented differentiation into hepatoblasts. To prevent the excessive LDs formation, we used gelatin as a coating material. When hUCM-MSCs were induced into hepatoblasts with fasudil on high-viscosity (1%) gelatin-coated dishes, hepatoblast-related genes (AFP and HNF4A) showed significant upregulation on high-viscosity gelatin-coated dishes compared to those treated with low-viscosity (0.1%) gelatin. Moreover, other germline cell fates, such as ectoderm and mesoderm, were repressed under these conditions. In addition, LDs abundance was also reduced, whereas mitochondrial function was increased. On the other hand, unlike early stage of the differentiation, low viscosity gelatin was more effective in generating mature HLCs. In this condition, the accumulation of LDs was inhibited in the cells, and mitochondria were activated. Consequently, HLCs originated from hUCM-MSCs were genetically and functionally more matured in low-viscosity gelatin.

CONCLUSIONS

This study demonstrated an effective method for differentiating hUCM-MSCs into hepatic cells using fasudil and gelatin of varying viscosities. Moreover, we suggest that efficient hepatic differentiation and the function of hepatic cells differentiated from hUCM-MSCs depend not only on genetic changes but also on the regulation of organelle states.

Protein research in millets: current status and way forward

MAIN CONCLUSION

Millets' protein studies are lagging behind those of major cereals. Current status and future insights into the investigation of millet proteins are discussed. Millets are important small-seeded cereals majorly grown and consumed by people in Asia and Africa and are considered crops of future food security. Although millets possess excellent climate resilience and nutrient supplementation properties, their research advancements have been lagging behind major cereals. Although considerable genomic resources have been developed in recent years, research on millet proteins and proteomes is currently limited, highlighting a need for further investigation in this area. This review provides the current status of protein research in millets and provides insights to understand protein responses for climate resilience and nutrient supplementation in millets. The reference proteome data is available for sorghum, foxtail millet, and proso millet to date; other millets, such as pearl millet, finger millet, barnyard millet, kodo millet, tef, and browntop millet, do not have any reference proteome data. Many studies were reported on stress-responsive protein identification in foxtail millet, with most studies on the identification of proteins under drought-stress conditions. Pearl millet has a few reports on protein identification under drought and saline stress. Finger millet is the only other millet to have a report on stress-responsive (drought) protein identification in the leaf. For protein localization studies, foxtail millet has a few reports. Sorghum has the highest number of 40 experimentally proven crystal structures, and other millets have fewer or no experimentally proven structures. Further proteomics studies will help dissect the specific proteins involved in climate resilience and nutrient supplementation and aid in breeding better crops to conserve food security.

Elevating the significance of legume intake: A novel strategy to counter aging-related mitochondrial dysfunction and physical decline

Mitochondrial dysfunction increasingly becomes a target for promoting healthy aging and longevity. The dysfunction of mitochondria with age ultimately leads to a decline in physical functions. Among them, biogenesis dysfunction and the imbalances in the metabolism of reactive oxygen species and mitochondria as signaling organelles in the aging process have aroused our attention. Dietary intervention in mitochondrial dysfunction and physical decline during aging processes is essential, and greater attention should be directed toward healthful legume intake. Legumes are constantly under investigation for their nutritional and bioactive properties, and their consumption may yield antiaging and mitochondria-protecting benefits. This review summarizes mitochondrial dysfunction with age, discusses the benefits of legumes on mitochondrial function, and introduces the potential role of legumes in managing aging-related physical decline. Additionally, it reveals the benefits of legume intake for the elderly and offers a viable approach to developing legume-based functional food.

Self-Reinforced Bimetallic Mito-Jammer for Ca2+ Overload-Mediated Cascade Mitochondrial Damage for Cancer Cuproptosis Sensitization

Overproduction of reactive oxygen species (ROS), metal ion accumulation, and tricarboxylic acid cycle collapse are crucial factors in mitochondria-mediated cell death. However, the highly adaptive nature and damage-repair capabilities of malignant tumors strongly limit the efficacy of treatments based on a single treatment mode. To address this challenge, a self-reinforced bimetallic Mito-Jammer is developed by incorporating doxorubicin (DOX) and calcium peroxide (CaO2) into hyaluronic acid (HA) -modified metal-organic frameworks (MOF). After cellular, Mito-Jammer dissociates into CaO2 and Cu2+ in the tumor microenvironment. The exposed CaO2 further yields hydrogen peroxide (H2O2) and Ca2+ in a weakly acidic environment to strengthen the Cu2+-based Fenton-like reaction. Furthermore, the combination of chemodynamic therapy and Ca2+ overload exacerbates ROS storms and mitochondrial damage, resulting in the downregulation of intracellular adenosine triphosphate (ATP) levels and blocking of Cu-ATPase to sensitize cuproptosis. This multilevel interaction strategy also activates robust immunogenic cell death and suppresses tumor metastasis simultaneously. This study presents a multivariate model for revolutionizing mitochondria damage, relying on the continuous retention of bimetallic ions to boost cuproptosis/immunotherapy in cancer.

SIRT7: the seventh key to unlocking the mystery of aging

Aging is a chronic yet natural physiological decline of the body. Throughout life, humans are continuously exposed to a variety of exogenous and endogenous stresses, which engender various counteractive responses at the cellular, tissue, organ, as well as organismal levels. The compromised cellular and tissue functions that occur because of genetic factors or prolonged stress (or even the stress response) may accelerate aging. Over the last two decades, the sirtuin (SIRT) family of lysine deacylases has emerged as a key regulator of longevity in a variety of organisms. SIRT7, the most recently identified member of the SIRTs, maintains physiological homeostasis and provides protection against aging by functioning as a watchdog of genomic integrity, a dynamic sensor and modulator of stresses. SIRT7 decline disrupts metabolic homeostasis, accelerates aging, and increases the risk of age-related pathologies including cardiovascular and neurodegenerative diseases, pulmonary and renal disorders, inflammatory diseases, and cancer, etc. Here, we present SIRT7 as the seventh key to unlock the mystery of aging, and its specific manipulation holds great potential to ensure healthiness and longevity.

Research progress in the role and mechanism of Leucine in regulating animal growth and development

Leucine, a branched-chain amino acid, is essential in regulating animal growth and development. Recent research has uncovered the mechanisms underlying Leucine's anabolic effects on muscle and other tissues, including its ability to stimulate protein synthesis by activating the mTORC1 signaling pathway. The co-ingestion of carbohydrates and essential amino acids enhances Leucine's anabolic effects. Moreover, Leucine has been shown to benefit lipid metabolism, and insulin sensitivity, making it a promising strategy for preventing and treating metabolic diseases, including type 2 diabetes and obesity. While emerging evidence indicates that epigenetic mechanisms may mediate Leucine's effects on growth and development, more research is needed to elucidate its mechanisms of action fully. Specific studies have demonstrated that Leucine promotes muscle growth and metabolic health in animals and humans, making it a promising therapeutic agent. However, it is essential to note that Leucine supplementation may cause digestive issues or interact with certain medications, and More study is required to determine definitively optimal dosages. Therefore, it is important to understand how Leucine interacts with other nutrients, dietary factors, and lifestyle habits to maximize its benefits. Overall, Leucine's importance in human nutrition is far-reaching, and its potential to prevent muscle loss and enhance athletic performance warrants further investigation.

Reorganization of Cell Compartmentalization Induced by Stress

The discovery of intrinsically disordered proteins (IDPs) that do not have an ordered structure and nevertheless perform essential functions has opened a new era in the understanding of cellular compartmentalization. It threw the bridge from the mostly mechanistic model of the organization of the living matter to the idea of highly dynamic and functional "soft matter". This paradigm is based on the notion of the major role of liquid-liquid phase separation (LLPS) of biopolymers in the spatial-temporal organization of intracellular space. The LLPS leads to the formation of self-assembled membrane-less organelles (MLOs). MLOs are multicomponent and multifunctional biological condensates, highly dynamic in structure and composition, that allow them to fine-tune the regulation of various intracellular processes. IDPs play a central role in the assembly and functioning of MLOs. The LLPS importance for the regulation of chemical reactions inside the cell is clearly illustrated by the reorganization of the intracellular space during stress response. As a reaction to various types of stresses, stress-induced MLOs appear in the cell, enabling the preservation of the genetic and protein material during unfavourable conditions. In addition, stress causes structural, functional, and compositional changes in the MLOs permanently present inside the cells. In this review, we describe the assembly of stress-induced MLOs and the stress-induced modification of existing MLOs in eukaryotes, yeasts, and prokaryotes in response to various stress factors.

Spatial regulation of endosomes in growing dendrites

Many membrane proteins are highly enriched in either dendrites or axons. This non-uniform distribution is a critical feature of neuronal polarity and underlies neuronal function. The molecular mechanisms responsible for polarized distribution of membrane proteins has been studied for some time and many answers have emerged. A less well studied feature of neurons is that organelles are also frequently non-uniformly distributed. For instance, EEA1-positive early endosomes are somatodendritic whereas synaptic vesicles are axonal. In addition, some organelles are present in both axons and dendrites, but not distributed uniformly along the processes. One well known example are lysosomes which are abundant in the soma and proximal dendrite, but sparse in the distal dendrite and the distal axon. The mechanisms that determine the spatial distribution of organelles along dendrites are only starting to be studied. In this review, we will discuss the cell biological mechanisms of how the distribution of diverse sets of endosomes along the proximal-distal axis of dendrites might be regulated. In particular, we will focus on the regulation of bulk homeostatic mechanisms as opposed to local regulation. We posit that immature dendrites regulate organelle motility differently from mature dendrites in order to spatially organize dendrite growth, branching and sculpting.

Molecular Interactions of Normal and Irradiated Tubulins During Polymerization

Microtubules, one of the cytoskeletons, are highly dynamic structures that play a variety of roles in maintaining cell morphology, cell division and intracellular transport. Microtubules are composed of heterodimers of α- and β-tubulins, which are repeatedly polymerized and depolymerized. To investigate the radiation-induced impacts on the polymerization reaction of tubulins, we evaluated the molecular interactions between normal and irradiated tubulins. First, the polymerization reaction of the tubulins was measured after stepwise irradiation from 0 Gy to 1,000 Gy of X rays. The polymerization was inhibited in a dose-dependent manner. Next, the tubulins' polymerization reaction was then measured after the tubulin that was damaged from the exposure to 1,000 Gy of X rays was mixed with the normal tubulins. Our findings reveal that the radiation dose-dependent change in the degree of overall microtubule polymerization progression depends on the ratio of damaged tubulin. This result is biochemical evidence that non-DNA damage (in this case, cytoskeletal damage) from cytoplasmic radiation exposure may inhibit cell division, suggesting that some cytoskeletal damage may also affect the fate of the entire cell.

Crème de la Créature: Dietary Influences on Behavior in Animal Models

In humans, alterations in cognitive, motivated, and affective behaviors have been described with consumption of processed diets high in refined sugars and saturated fats and with high body mass index, but the causes, mechanisms, and consequences of these changes remain poorly understood. Animal models have provided an opportunity to answer these questions and illuminate the ways in which diet composition, especially high-levels of added sugar and saturated fats, contribute to brain physiology, plasticity, and behavior. Here we review findings from invertebrate (flies) and vertebrate models (rodents, zebrafish) that implicate these diets with changes in multiple behaviors, including eating, learning and memory, and motivation, and discuss limitations, open questions, and future opportunities.