Alleviating binary toxicity of polystyrene nanoplastics and atrazine to Chlorella vulgaris through humic acid interaction: Long-term toxicity using environmentally relevant concentrations.

In this study, microalgae Chlorella vulgaris (C. vulgaris) were simultaneously exposed to environmental concentrations of amino-functionalized polystyrene nanoplastics (PS-NH2; 0.05, 0.1, 0.2, 0.3 and 0.4 mg/L) and the world's second most used pesticide, the herbicide atrazine (ATZ; 10 µg/L), in the absence and presence of humic acid (HA; 1 mg/L) for 21 days. Due to the low concentrations of PS-NH2, the majority of them could not cause a significant difference in the end-points of biomass, chlorophylls a and b, total antioxidant, total protein, and superoxide dismutase and malondialdehyde compared to the control group (p > 0.05). On the other hand, by adding ATZ to the PS-NH2, all the mentioned end-point values showed a considerable difference from the control (p < 0.05). The exposure of PS-NH2+ATZ treatments to the HA could remarkably reduce their toxicity, additionally, HA was able to decrease the changes in the expression of genes related to oxidative stress (e.g., superoxide dismutase, glutathione reductase, and catalase) in the C. vulgaris in the most toxic treatment group (e.g., PS-NH2+ATZ). The synergistic toxicity of the PS-NH2+ATZ group could be due to their enhanced bioavailability for algal cells. Nevertheless, the toxicity alleviation in the PS-NH2+ATZ treatment group after the addition of HA could be due to the eco-corona formation, and changes in their zeta potential from positive to negative value, which would increase their electrostatic repulsion with the C. vulgaris cells, in such a way that HA also caused a decrease in the formation of C. vulgaris-NPs hetero-aggregates. This research underscores the complex interplay between PS-NH2, ATZ, and HA in aquatic environments and their collective impact on microalgal communities.

Presence of humic acid in the environment holds promise as a potential mitigating factor for the joint toxicity of polystyrene nanoplastics and herbicide atrazine to Chlorella vulgaris: 96-H acute toxicity.

Increasing amounts of amino-functionalized polystyrene nanoplastics (PS-NH2) are entering aquatic ecosystems, raising concerns. Hence, this study investigated 96-h acute toxicity of PS-NH2 and its combination with the pesticide atrazine (ATZ) in the absence/presence of humic acid (HA) on the microalgae Chlorella vulgaris (C. vulgaris). Results showed that both PS-NH2 and PS-NH2+ATZ reduced algal growth, photosynthetic pigments, protein content, and antioxidant capacity, while increasing enzymatic activities. Gene expression related to oxidative stress was altered in C. vulgaris exposed to these treatments. Morphological and intracellular changes were also observed. The combined toxicity of PS-NH2+ATZ demonstrated a synergistic effect, but the addition of environmentally relevant concentration of HA significantly alleviated its toxicity to C. vulgaris, indicating an antagonistic effect due to the emergence of an eco-corona, and entrapment and sedimentation of PS-NH2+ATZ particles by HA. This study firstly highlights the role of HA in mitigating the toxicity of PS-NH2 when combined with other harmful compounds, enhancing our understanding of HA's presence in the environment.

Improvement Effect of Mitotherapy on the Cognitive Ability of Alzheimer's Disease through NAD+/SIRT1-Mediated Autophagy.

To date, Alzheimer's disease (AD) has grown to be a predominant health challenge that disturbs the elderly population. Studies have shown that mitochondrial dysfunction is one of the most significant features of AD. Transplantation therapy of healthy mitochondria (mitotherapy), as a novel therapeutic strategy to restore mitochondrial function, is proposed to treat the mitochondria-associated disease. Also, the molecular mechanism of mitotherapy remains unclear. Here, we applied the mitotherapy in AD model mice induced by amyloid-ß (Aß) plaque deposition and suggested that autophagy would be an important mechanism of the mitotherapy. After the healthy mitochondria entered the defective neuronal cells damaged by the misfolded Aß protein, autophagy was activated through the NAD+-dependent deacetylase sirtuin 1 (SIRT1) signal. The damaged mitochondria and Aß protein were eliminated by autophagy, which could also decrease the content of radical oxygen species (ROS). Moreover, the levels of brain-derived neurotrophic factor (BDNF) and extracellular-regulated protein kinases (ERK) phosphorylation increased after mitotherapy, which would be beneficial to repair neuronal function. As a result, the cognitive ability of AD animals was ameliorated in a water maze test after the healthy mitochondria were administrated to the mice. The study indicated that mitotherapy would be an effective approach to AD treatment through the mechanism of autophagy activation.

Treatment of colorectal cancer by anticancer and antibacterial effects of hemiprotonic phenanthroline-phenanthroline+ with nanomicelle delivery.

Colorectal cancer (CRC) is a common digestive tract tumor worldwide. Specific microorganisms, including Fusobacterium nucleatum (F. nucleatum) and Escherichia coli (E. coli), are abundant in colonic mucosa and can promote the cancer progression and malignancy. Therefore, a therapeutic strategy is proposed to deliver effective drugs to colorectum for both anticancer and antibacteria. Here we used thin-film dispersion method to encapsulate hemiprotonic phenanthroline-phenanthroline+ (ph-ph+) into nanomicelle. The results showed that the drug-loading nanomicelle had good dispersion, and the particle size was about 28 nm. In vitro assay indicated that the nanomicelle was active against CRC-related obligate and facultative anaerobes. In human CRC cells, the nanomicelle could effectively inhibit cell proliferation and induce apoptosis. In vivo distribution showed that the nanomicelle could release ph-ph+ mainly in the colorectum. In CRC model mice, the nanomicelle significantly reduced tumor number and volume, and decreased the bacteria load and colorectal inflammation. Together, the study identifies that the ph-ph+nanomicelle has the potential to apply in treating CRC, and also suggests that anticancer combined with antimicrobial therapy would be a feasible way for CRC therapy.

Discovery of the Effects of the Hemiprotonic Phenanthroline-Phenanthroline+ against Trichophyton rubrum by Inducing Fungal Apoptosis.

Trichophyton rubrum (T. rubrum) is the most common causative agent of dermatophytosis worldwide. The development of antifungal drugs will contribute to treating the disease. In this study, we suggest that a hemiprotonic compound phenanthroline-phenanthroline+ (ph-ph+) is active in inhibiting the growth and reproduction of T. rubrum, and the minimum inhibitory concentration and minimum fungicidal concentration values were 2 µg/ml and 8 µg/ml, respectively. In an in vitro onychomycosis model, ph-ph+ killed T. rubrum by inducing apoptosis, which was evaluated by transmission electron microscopy and Annexin V-FITC/propidium iodide staining. Transcriptomic analysis and biochemical assay showed that ph-ph+ elevated iron ion content in T. rubrum cells and reduced glutathione antioxidant system level, leading to an increase in the contents of ROS and malondialdehyde. Therefore, the antifungal mechanism of ph-ph+ would be associated with iron ion-induced cell apoptosis, which is different from other known antifungal drugs. Furthermore, ph-ph+ was prepared into gel for application in guinea pigs with dermatophytosis caused by T. rubrum. The results showed that the ph-ph+ gel eliminated the fungus in the animals without causing skin irritation or other adverse reactions. The study would not only provide a potential compound to treat dermatophytosis, but also suggest that iron ion-induced cell apoptosis might be a new approach to killing fungi.

Association of psychological symptoms with job burnout and occupational stress among coal miners in Xinjiang, China: A cross-sectional study.

Objective: The study aimed to investigate the influencing factors of psychological symptoms in relation to job burnout and occupational stress among coal miners in Xinjiang, so as to provide data support for enterprises in an effort to help them identify internal psychological risk factors and improve the mental health of coal miners. Methods: A cross-sectional study was carried out. A total of 12 coal mines were selected using the stratified cluster random sampling method and 4,109 coal miners were investigated by means of online electronic questionnaires. The Symptoms Check List-90 (SCL-90), Chinese Maslach Burnout Inventory (CMBI), and Job Demand-Control (JDC) model were respectively used to measure the status of psychological symptoms, job burnout, and occupational stress among coal miners. The mediation analysis was performed through structural equation modeling (SEM) by using Analysis of Moment Structure (AMOS). Results: The prevalence of psychological symptoms was higher in the occupational stress group than in the non-occupational stress group, and increased with job burnout (P < 0.05). The multivariate logistic regression analysis results showed that mild (OR = 1.401, 95% CL: 1.165, 1.685), moderate (OR = 2.190, 95% CL: 1.795, 2.672), or severe levels of burnout (OR = 6.102, 95% CL: 3.481, 10.694) and occupational stress (OR = 1.462, 95% CL: 1.272, 1.679) were risk factors for psychological symptoms in coal miners. The results of structural equation modeling indicated that occupational stress (ß = 0.11, P = 0.002) and job burnout (ß = 0.46, P = 0.002) had significant positive direct effects on psychological symptoms, and job burnout was an intermediate variable between occupational stress and psychological symptoms. Conclusion: High levels of job burnout and occupational stress were risk factors for psychological symptoms. Both occupational stress and job burnout had direct effects on psychological symptoms, and occupational stress could also have an indirect effect on coal miners' psychological symptoms through the intermediate variable of job burnout.

Mitochondrial transplantation therapy inhibits the proliferation of malignant hepatocellular carcinoma and its mechanism.

Mitochondrial dysfunction plays a vital role in growth and malignancy of tumors. In recent scenarios, mitochondrial transplantation therapy is considered as an effective method to remodel mitochondrial function in mitochondria-related diseases. However, the mechanism by which mitochondrial transplantation blocks tumor cell proliferation is still not determined. In addition, mitochondria are maternal inheritance in evolution, and mitochondria obtained from genders exhibit differences in mitochondrial activity. Therefore, the study indicates the inhibitory effect of mitochondria from different genders on hepatocellular carcinoma and explores the molecular mechanism. The results reveal that the healthy mitochondria can retard the proliferation of the hepatocellular carcinoma cells in vitro and in vivo through arresting cell cycle and inducing apoptosis. The molecular mechanism suggests that mitochondrial transplantation therapy can decrease aerobic glycolysis, and down-regulate the expression of cycle-related proteins while up-regulate apoptosis-related proteins in tumor cells. In addition, the antitumor activity of mitochondria from female mice (F-Mito) is relatively higher than that of mitochondria from male mice (M-Mito), which would be related to the evidence that the F-Mito process higher activity than the M-Mito. This study clarifies the mechanism of exogenous mitochondria inhibiting the proliferation of hepatocellular carcinoma and contributes a new biotechnology for therapy of mitochondria-related diseases from different genders.

Synthesis of Hemiprotonic Phenanthroline-Phenanthroline+ Compounds with both Antitumor and Antimicrobial Activity.

Currently, cancer patients with microbial infection are a severe challenge in clinical treatment. To address the problem, we synthesized hemiprotonic compounds based on the unique structure of hemiprotonic nucleotide base pairs in a DNA i-motif. These compounds were produced from phenanthroline (ph) dimerization with phenanthroline as a proton receptor and ammonium as a donor. The biological activity shows that the compounds have a selective antitumor effect through inducing cell apoptosis. The molecular mechanism could be related to specific inhibition of transcription factor PLAGL2 of tumor cells, assessed by transcriptomic analysis. Moreover, results show that the hemiprotonic ph-ph+ has broad-spectrum antibacterial and antifungal activities, and drug-resistant bacteria, including methicillin-resistant Staphylococcus aureus, are sensitive to the compound. In animal models of liver cancer with fungal infection, the ph-ph+ retards proliferation of hepatoma cells in tumor-bearing mice and remedies pneumonia and encephalitis caused by Cryptococcus neoformans. The study provides a novel therapeutic candidate for cancer patients accompanied by infection.

Dimeric Histidine as a Novel Free Radical Scavenger Alleviates Non-Alcoholic Liver Injury.

Non-alcoholic liver injury (NLI) is a common disease worldwide. Since free radical damage in the liver is a crucial initiator leading to diseases, scavenging excess free radicals has become an essential therapeutic strategy. To enhance the antioxidant capacity of histidine, we synthesized a protonated dimeric histidine, H-bihistidine, and investigated its anti-free radical potential in several free-radical-induced NLI. Results showed that H-bihistidine could strongly scavenge free radicals caused by H2O2, fatty acid, and CCl4, respectively, and recover cell viability in cultured hepatocytes. In the animal model of nonalcoholic fatty liver injury caused by high-fat diet, H-bihistidine reduced the contents of transaminases and lipids in serum, eliminated the liver's fat accumulation, and decreased the oxidative damage. Moreover, H-bihistidine could rescue CCl4-induced liver injury and recover energy supply through scavenging free radicals. Moreover, liver fibrosis prepared by high-fat diet and CCl4 administration was significantly alleviated after H-bihistidine treatment. This study suggests a novel nonenzymatic free radical scavenger against NLI and, potentially, other free-radical-induced diseases.

Mitochondrial dysfunction, UPRmt signaling, and targeted therapy in metastasis tumor.

In modern research, mitochondria are considered a more crucial energy plant in cells. Mitochondrial dysfunction, including mitochondrial DNA (mtDNA) mutation and denatured protein accumulation, is a common feature of tumors. The dysfunctional mitochondria reprogram molecular metabolism and allow tumor cells to proliferate in the hostile microenvironment. One of the crucial signaling pathways of the mitochondrial dysfunction activation in the tumor cells is the retrograde signaling of mitochondria-nucleus interaction, mitochondrial unfolded protein response (UPRmt), which is initiated by accumulation of denatured protein and excess ROS production. In the process of UPRmt, various components are activitated to enhance the mitochondria-nucleus retrograde signaling to promote carcinoma progression, including hypoxia-inducible factor (HIF), activating transcription factor ATF-4, ATF-5, CHOP, AKT, AMPK. The retrograde signaling molecules of overexpression ATF-5, SIRT3, CREB, SOD1, SOD2, early growth response protein 1 (EGR1), ATF2, CCAAT/enhancer-binding protein-d, and CHOP also involved in the process. Targeted blockage of the UPRmt pathway could obviously inhibit tumor proliferation and metastasis. This review indicates the UPRmt pathways and its crucial role in targeted therapy of metastasis tumors.

Study on an artificial phenomenon observed in terahertz biological imaging.

Terahertz (THz) wave-based imaging of biological samples is an emerging but promising field. In the present work, we report an artificial phenomenon observed in imaging melanoma slices, which can lead to mistakenly interpretation of the experimental results. It was observed that a structure similar to but smaller than the sample contour appeared inside the melanoma slice image. The underlying mechanism of this phenomenon was then investigated both experimentally and theoretically. By imaging a regular standard sample (vinyl coverslip) with a THz time domain spectroscopy (THz-TDS) system and reconstructing its images at 0.8 and 1.2 THz, we can clearly observe the afore-mentioned artifacts. The experimental results are highly consistent with the simulations based on the Fresnel-Kirchhoff diffraction theory in which possible optical aberrations were incorporated. It can be concluded that this artifact was caused by the frequency-dependent diffraction of the sample edge. The work demonstrated here is essential for correct interpretation of the images obtained by the THz-TDS technique.

The effect of mitochondrial transplantation therapy from different gender on inhibiting cell proliferation of malignant melanoma.

Today mitochondria are considered much more than a energy plant in cells. Mitochondrial transplantation therapy has been an active research area for treating mitochondria-associated diseases from animal studies to clinical trials. However, the specific mechanism involved in the anti-tumor activity of healthy mitochondria remain to be characterized. Here we investigate the signal mechanism and gender difference of mitochondrial transplantation therapy against malignant melanoma. In the study, we administrated intact mitochondria extracted from mouse livers respectively to the mice bearing malignantly subcutaneous and metastatic melanoma, and identified the signal mechanism responsible for the mitochondrial treatment through transcriptomic analysis. Meanwhile, the efficiency of female mitochondria and male mitochondria was compared in the cultured melanoma cells and transplanted melanoma in mice. The results suggested that the mitochondria significantly inhibited the tumor cell proliferation in vitro through cell cycle arrest and induction of cell apoptosis. In the melanoma-bearing mice, the mitochondria retard the tumor growth and lung migration, and the transcriptomic analysis indicated that general chromosome silencing was strongly associated with the mitochondria against melanoma after the mitochondrial transplantation on the metastasis melanoma. Moreover, the anti-tumor activity of mitochondria from female animals was more efficient in comparison to the males, and the female mitochondria could probably induce more persuasive mitochondria-nuclear communication than the mitochondria from male mice. The study identifies the anti-tumor mechanism of the mitochondrial transplantation therapy, and provides a novel insight into the effect of mitochondria from different gender.

Mitochondrial transplantation therapy inhibit carbon tetrachloride-induced liver injury through scavenging free radicals and protecting hepatocytes.

Carbon tetrachloride (CCl4)-induced liver injury is predominantly caused by free radicals, in which mitochondrial function of hepatocytes is impaired, accompanying with the production of ROS and decreased ATP energy supply in animals intoxicated with CCl4. Here we explored a novel therapeutic approach, mitochondrial transplantation therapy, for treating the liver injury. The results showed that mitochondria entered hepatocytes through macropinocytosis pathway, and thereby cell viability was recovered in a concentration-dependent manner. Mitochondrial therapy could increase ATP supply and reduce free radical damage. In liver injury model of mice, mitochondrial therapy significantly improved liver function and prevented tissue fibrogenesis. Transcriptomic data revealed that mitochondrial unfold protein response (UPRmt), a protective transcriptional response of mitochondria-to-nuclear retrograde signaling, would be triggered after mitochondrial administration. Then the anti-oxidant genes were up-regulated to scavenge free radicals. The mitochondrial function was rehabilitated through the transcriptional activation of respiratory chain enzyme and mitophage-associated genes. The protective response re-balanced the cellular homeostasis, and eventually enhanced stress resistance that is linked to cell survival. The efficacy of mitochondrial transplantation therapy in the animals would suggest a novel approach for treating liver injury caused by toxins.

[Mitochondrial therapy: a new strategy for treating mitochondrion-associated diseases].

Mitochondrion is a multifunctional organelle in cells and responsible for energy production, cell apoptosis and various life processes. Dysfunctional mitochondria are associated with hundreds of diseases. Increasing evidences have shown that extracellular mitochondria can be endocytosed by cells, directly into cells, and then play roles in cells. Mitochondria are the organelles that are extremely sensitive to oxygen content and pH of microenvironment that induces the adverse effect based on the cellular environment: mitochondria will increase cell survival and viability when they arrive in cells of physiological environment, but mitochondria will cause cell death when they enter the hypoxic and acidic tumor tissues, because they can produce a large amounts of oxygen free radicals. The pharmacological feature of environmental responsiveness of mitochondria could make them as a potential biological drug to kill cancer cells and restore the function of damaged tissues. Currently, mitochondria are used in the treatment of central nervous system diseases (Parkinson's disease, depression, schizophrenia, etc.), peripheral system diseases (ischemic myocardial injury, fatty liver, emphysema, etc.) and tumor. In this review, we summarize the research progress, medical application and challenges of mitochondrial therapy.

Application progress of RVG peptides to facilitate the delivery of therapeutic agents into the central nervous system.

The incidence of central nervous system (CNS) diseases is increasing with the aging population. However, it remains challenging to deliver drugs into the CNS because of the existence of a blood-brain barrier (BBB). Notably, rabies virus glycoprotein (RVG) peptides have been developed as delivery ligands for CNS diseases. So far, massive RVG peptide modified carriers have been reported, such as liposomes, micelles, polymers, exosomes, dendrimers, and proteins. Moreover, these drug delivery systems can encapsulate almost all small molecules and macromolecule drugs, including siRNA, microRNAs, DNA, proteins, and other nanoparticles, to treat various CNS diseases with efficient and safe drugs. In this review, targeted delivery systems with RVG peptide modified carriers possessing favorable biocompatibility and delivery efficiency are summarized.

Photodynamic Nanophotosensitizers: Promising Materials for Tumor Theranostics.

Photodynamic theranostics/therapy (PDT) is a potential strategy for selectively imaging malignant sites and treating cancer via a non-invasive therapeutic method. Photosensitizers, the crucial components of PDT, enable colocalization of photons and light, and photon/light therapy in the therapeutic window of 400-900 nm exhibits photocytotoxicity to tumor cells. Due to their high biostability and photocytotoxicity, nanophotosensitizers (NPSs) are of much interest for malignant tumor theranostics at present. NPS-activated photons transfer energy through the absorption of a photon and convert molecular oxygen to the singlet reactive oxygen species, which leads to apoptosis and necrosis. Moreover, NPSs modified by polymers, including PLGA, PEG-PLA, PDLLA, PVCL-g-PLA, and P(VCL-co-VIM)-g-PLA, exhibit excellent biocompatibility, and a tumor-targeting molecule linked on the nanoparticle surface can precisely deliver NPSs into the tumor region. The development of NPSs will accelerate the progress in tumor theranostics through the photon/light pathway.

Detecting melanoma with a terahertz spectroscopy imaging technique.

Transmission mode terahertz time-domain spectroscopy system was employed to image BALB/c mouse skin tissue slices containing melanoma. The melanoma was unambiguously identified in the frequency region of 0.6-1.8 THz because melanoma has a higher refractive index as well as a higher absorption coefficient than the normal region of the skin tissue. Based on the results of hematoxylin-eosin staining and mass weighing, it was further suggested that the higher density of nucleic acids, higher water content, and lower fat content in the melanoma compared to the normal region are major factors responsible for melanoma's higher refractive index and absorption coefficient than normal tissue. The present work validates that terahertz time-domain spectroscopy imaging technique is possible to be used for the diagnosis of melanoma.

Improvement of cognitive and motor performance with mitotherapy in aged mice.

Changes in mitochondrial structure and function are mostly responsible for aging and age-related features. Whether healthy mitochondria could prevent aging is, however, unclear. Here we intravenously injected the mitochondria isolated from young mice into aged mice and investigated the mitotherapy on biochemistry metabolism and animal behaviors. The results showed that heterozygous mitochondrial DNA (mtDNA) of both aged and young mouse coexisted in tissues of aged mice after mitochondrial administration, and meanwhile, ATP content in tissues increased while reactive oxygen species (ROS) level reduced. Besides, the mitotherapy significantly improved cognitive and motor performance of aged mice. Our study, at the first report in aged animals, not only provides a useful approach to study mitochondrial function associated with aging, but also a new insight into anti-aging through mitotherapy.

Inhibition of thioredoxin reductase 1 correlates with platinum-based chemotherapeutic induced tissue injury.

Platinum-containing drugs (PtDs; e.g. cisplatin, carboplatin, and oxaliplatin) have been widely used as anticancer reagents against various cancers. However, treatment with these drugs results in undesirable adverse effects with unknown mechanisms. Herein, we found a strong correlation between the inhibitory effects of PtDs on cytosolic thioredoxin reductase (TXNRD1) and tissue injury. Of the PtDs tested, cisplatin was found to be the most effective inhibitory PtD against TXRND1, causing the severest kidney injury. The initial inhibition of TXNRD1 in the kidney resulted from cisplatin-induced transcriptional activation of Nrf2-regulated genes including Txnrd1. However, the antioxidant responses in the kidney did not reverse the cisplatin-induced oxidation process. Nephrotoxicity was accompanied with an increase of protein glutathionylation and a cellular thiol redox environment oxidation. These results suggest that the changes of the cellular thiol-dependent redox environment regulated by TXNRD1 is a major event in the adverse effects of cisplatin in kidney.

Mitotherapy as a Novel Therapeutic Strategy for Mitochondrial Diseases.

BACKGROUND: The mitochondrion is a multi-functional organelle that is mainly responsible for energy supply in the mammalian cells. Over 100 human diseases are attributed to mitochondrial dysfunction. Mitochondrial therapy (mitotherapy) aims to transfer functional exogenous mitochondria into mitochondria-defective cells for recovery of the cell viability and consequently, prevention of the disease progress. OBJECTIVE: The review summarizes the evidence on exogenous mitochondria that can directly enter mammalian cells for disease therapy following local and intravenous administration, and suggests that when healthy cells donate their mitochondria to damaged cells, the mitochondrial transfer between cells serve as a new mode of cell rescue. Then the transferred mitochondria play their roles in recipient cells, including energy production and maintenance of cell function. CONCLUSION: Mitotherapy makes the of modulation of cell survival possible, and it would be a potential therapeutic strategy for mitochondrial diseases.