LncRNA NR_030777 promotes mitophagy by targeting CDK1-related mitochondrial fission and ATG12 to attenuate paraquat-induced Parkinson's disease

With the evidence emerging that abnormal expression of long noncoding RNAs (lncRNAs) are involved in onset of Parkinson's disease (PD), the role of NR_030777 contributing to this disease is of great interest. We recently found that a novel lncRNA "NR_030777" demonstrates protective effects on PQ-induced neurodegeneration. However, the underlying molecular mechanisms of NR_030777 in the regulation of mitochondrial fission and mitophagy involved in PQ-induced neuronal damage remain to be explored. NR_030777 brain conditional overexpressing mice as well as in vitro primary neuronal cells from cerebral cortex and Neuro2a cells were adopted. Immunofluorescence, Immunohistochemistry, qRT-PCR and Western blotting were used to evaluate the expression levels of RNA and proteins. RNA immunoprecipitation and RNA pulldown experiment were used to evaluate the interaction of NR_030777 with its target proteins. NR_030777 and mitophagy were increased, and tyrosine hydroxylase (TH) levels recovered after NR_030777 overexpression upon PQ treatment. The overexpression and knockdown of NR_030777 unveiled that NR_030777 positively regulated mitophagy such as the upregulation of LC3B-II:I, ATG12-ATG5, p62 and NBR1. Moreover, the application of mdivi-1, a DRP-1 inhibitor, in combination with NR_030777 genetic modified cells unveiled that NR_030777 promoted DRP1-mediated mitochondrial fission and mitophagy. Furthermore, NR_030777 were directly bound to CDK1 to increase p-DRP1 levels at the Ser616 site, leading to mitochondrial fission and mitophagy. On the other hand, NR_030777 acted directly on ATG12 within the ATG12-ATG5 complex in the 800-1400 nt region to modulate the membrane formation. Accordingly, NR_030777 deficiency in neuron cells compromised cell mitophagy. Finally, the above findings were confirmed using NR_030777-overexpressing mice. NR_030777 exerted a protective effect on PQ-exposed mice by enhancing mitophagy. Our data provide the first scientific evidence for the precise invention of PQ-induced PD. Our findings further propose a breakthrough for understanding the regulatory relationship between NR_030777, CDK1, ATG12 and mitophagy in PQ-induced PD.

ALKBH5 targets ACSL4 mRNA stability to modulate ferroptosis in hyperbilirubinemia-induced brain damage

Bilirubin-induced brain damage is a serious clinical consequence of hyperbilirubinemia, yet the underlying molecular mechanisms remain largely unknown. Ferroptosis, an iron-dependent cell death, is characterized by iron overload and lipid peroxidation. Here, we report a novel regulatory mechanism of demethylase AlkB homolog 5 (ALKBH5) in acyl-coenzyme A synthetase long-chain family member 4 (ACSL4)-mediated ferroptosis in hyperbilirubinemia. Hyperdifferential PC12 cells and newborn Sprague-Dawley rats were used to establish in vitro and in vivo hyperbilirubinemia models, respectively. Proteomics, coupled with bioinformatics analysis, first suggested the important role of ferroptosis in hyperbilirubinemia-induced brain damage. In vitro experiments showed that ferroptosis is activated in hyperbilirubinemia, and ferroptosis inhibitors (desferrioxamine and ferrostatin-1) treatment effectively alleviates hyperbilirubinemia-induced oxidative damage. Notably, we observed that the ferroptosis in hyperbilirubinemia was regulated by m6A modification through the downregulation of ALKBH5 expression. MeRIP-seq and RIP-seq showed that ALKBH5 may trigger hyperbilirubinemia ferroptosis by stabilizing ACSL4 mRNA via m6A modification. Further, hyperbilirubinemia-induced oxidative damage was alleviated through ACSL4 genetic knockdown or rosiglitazone-mediated chemical repression but was exacerbated by ACSL4 overexpression. Mechanistically, ALKBH5 promotes ACSL4 mRNA stability and ferroptosis by combining the 669 and 2015 m6A modified sites within 3' UTR of ACSL4 mRNA. Our findings unveil a novel molecular mechanism of ferroptosis and suggest that m6A-dependent ferroptosis could be an underlying clinical target for the therapy of hyperbilirubinemia.

VGluT2 neuron subtypes in the paraventricular thalamic nucleus regulate depression in paraquat-induced Parkinson's disease

Parkinson's disease (PD) is a prevalent neurodegenerative disease and approximately one third of patients with PD are estimated to experience depression. Paraquat (PQ) is the most widely used herbicide worldwide and PQ exposure is reported to induce PD with depression. However, the specific brain region and neural networks underlying the etiology of depression in PD, especially in the PQ-induced model, have not yet been elucidated. Here, we report that the VGluT2-positive glutamatergic neurons in the paraventricular thalamic nucleus (PVT) promote depression in the PQ-induced PD mouse model. Our results show that PVTVGluT2 neurons are activated by PQ and their activation increases the susceptibility to depression in PD mice. Conversely, inhibition of PVTVGluT2 neurons reversed the depressive-behavioral changes induced by PQ. Similar to the effects of intervention the soma of PVTVGluT2 neurons, stimulation of their projections into the central amygdaloid nucleus (CeA) also strongly influenced depression in PD mice. PQ induced malfunctioning of the glutamate system and changes in the dendritic and synaptic morphology in the CeA through its role on PVTVGluT2 neuronal activation. In summary, our results demonstrate that PVTVGluT2 neurons are key neuronal subtypes for depression in PQ-induced PD and promote depression processes through the PVTVGluT2-CeA pathway.

Microglial exosomes in paraquat-induced Parkinson's disease: Neuroprotection and biomarker clues

The exact mechanisms underlying the initiation and exacerbation of Parkinson's disease (PD) by paraquat remain unclear. We have revealed that exosomes mediate neurotoxicity induced by low dose paraquat exposure by transmitting intercellular signaling. Exposure to 40 μM paraquat promoted exosome release from mouse microglia cells (BV2) in vitro. Paraquat exposure at 100 μM caused degeneration of mouse dopaminergic MN9D cells and inhibited microglia exosome uptake by fluorescently labeling exosomes. We established an incubation model for exosomes and dopaminergic neuron cells under PQ treatment. The results indicated that microglial exosomes alleviated degeneration, increasing proliferation and PD-related protein expression of dopaminergic neurons; however, paraquat reversed this effect. Then, through exosome high-throughput sequencing and qRT-PCR experiments, miR-92a-3p and miR-24-3p were observed to transfer from exosomes to dopaminergic neurons, inhibited by paraquat. The specificity of miR-92a-3p and miR-24-3p was verified in PD patients exosomes, indicating the potential diagnostic value of the exosomal miRNAs in paraquat-induced PD. These results suggest glia-neuron communication in paraquat-induced neurodegeneration and may identify stable paraquat-mediated PD biomarkers, offering clues for early recognition and prevention of pesticide-induced degenerative diseases.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Single-cell RNA-sequencing of cellular heterogeneity and pathogenic mechanisms in paraquat-induced Parkinson's disease with depression

Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, and approximately one third of patients with PD are estimated to have depression. Paraquat (PQ) exposure is an important environmental risk factor for PD. In this study, we established a mouse model of PQ-induced PD with depression to comprehensively investigate cellular heterogeneity and the mechanisms underlying the progression of depression in the context of PD. We utilized single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of individual cells from model mice and characterize the gene expression profiles in each differentially expressed cell type. We identified a specific glutamatergic neuron cluster responsible for the development of heterogeneous depression-associated changes and established a comprehensive gene expression atlas. Furthermore, functional enrichment and cell trajectory analyses revealed that the mechanisms underlying the progression of PD with depression were associated with specific glutamatergic neurons. Together, our findings provide a valuable resource for deciphering the cellular heterogeneity of PD with depression. The suggested connection between intrinsic transcriptional states of neurons and the progression of depression can provide insight into potential biomarkers and specific targets for anti-depression treatment in patients with PD. SYNOPSIS: Our results obtained using model mice confirm the core effects of PQ exposure on glutamatergic neurons and their potential role in the development of PD with depression.

[Epidemiological and spatial-temporal clustering characteristics of pertussis in Hebei Province from 2013 to 2022]

Objective: To analyze the spatial-temporal epidemiological characteristics of pertussis from 2013 to 2022 in Hebei Province and to provide a reference for improving prevention and control measures. Methods: Based on the data of pertussis reported in Hebei Province during 2013-2022 to analyze the popular characteristic, the ArcGIS 10.8 software was used to construct a ring map and to perform spatial autocorrelation analysis; the SaTScan 10.1 software was used for spatial-temporal scan statistics. Results: There were 6 715 cases of the cumulative report in Hebei Province from 2013 to 2022 without death. The annual report incidence was 0.90/100 000. The overall incidence rate showed an upward trend from 2013 to 2019, and during 2020-2021, it showed a sharp decline, but in 2022, it showed a sharp increase. Summer and autumn are the peak seasons of the epidemic. The incidence was highest in age group <1 year (48.67%), and the lowest age group in age group ≥15 years (0.45%) and mainly scattered children (78.03%); the incidence about men is higher than women. Spatial autocorrelation analysis showed that the onset of pertussis has spatial clustering, and high-high clusters were found in Langfang, Baoding, and Cangzhou, the top three countries with reported incidence. The area covered by a low-low cluster was consistent with the distribution of the corresponding low-incidence areas in this study. Space-time scan detects five statistically significant areas, and three zones were concentrated in 2022. Conclusions: The incidence of pertussis in Hebei had obvious season, population, and area-specific differences. There was obvious spatiotemporal and clustering, so the control of key areas should target the characteristics of time and space.

ROS/mtROS promotes TNTs formation via the PI3K/AKT/mTOR pathway to protect against mitochondrial damages in glial cells induced by engineered nanomaterials

BACKGROUND

As the demand and application of engineered nanomaterials have increased, their potential toxicity to the central nervous system has drawn increasing attention. Tunneling nanotubes (TNTs) are novel cell-cell communication that plays a crucial role in pathology and physiology. However, the relationship between TNTs and nanomaterials neurotoxicity remains unclear. Here, three types of commonly used engineered nanomaterials, namely cobalt nanoparticles (CoNPs), titanium dioxide nanoparticles (TiO2NPs), and multi-walled carbon nanotubes (MWCNTs), were selected to address this limitation.

RESULTS

After the complete characterization of the nanomaterials, the induction of TNTs formation with all of the nanomaterials was observed using high-content screening system and confocal microscopy in both primary astrocytes and U251 cells. It was further revealed that TNT formation protected against nanomaterial-induced neurotoxicity due to cell apoptosis and disrupted ATP production. We then determined the mechanism underlying the protective role of TNTs. Since oxidative stress is a common mechanism in nanotoxicity, we first observed a significant increase in total and mitochondrial reactive oxygen species (namely ROS, mtROS), causing mitochondrial damage. Moreover, pretreatment of U251 cells with either the ROS scavenger N-acetylcysteine or the mtROS scavenger mitoquinone attenuated nanomaterial-induced neurotoxicity and TNTs generation, suggesting a central role of ROS in nanomaterials-induced TNTs formation. Furthermore, a vigorous downstream pathway of ROS, the PI3K/AKT/mTOR pathway, was found to be actively involved in nanomaterials-promoted TNTs development, which was abolished by LY294002, Perifosine and Rapamycin, inhibitors of PI3K, AKT, and mTOR, respectively. Finally, western blot analysis demonstrated that ROS and mtROS scavengers suppressed the PI3K/AKT/mTOR pathway, which abrogated TNTs formation.

CONCLUSION

Despite their biophysical properties, various types of nanomaterials promote TNTs formation and mitochondrial transfer, preventing cell apoptosis and disrupting ATP production induced by nanomaterials. ROS/mtROS and the activation of the downstream PI3K/AKT/mTOR pathway are common mechanisms to regulate TNTs formation and mitochondrial transfer. Our study reveals that engineered nanomaterials share the same molecular mechanism of TNTs formation and intercellular mitochondrial transfer, and the proposed adverse outcome pathway contributes to a better understanding of the intercellular protection mechanism against nanomaterials-induced neurotoxicity.

[Application of a new-type of defecator in the treatment of rectal fecal impaction]

Objective: This study aimed to investigate the viability and safety of a novel defecator in managing rectal fecal impaction. Methods: In a descriptive case series, this new defecator was administered to constipated individuals among the ages of 18 and 80 years who met the diagnostic criteria for rectal fecal impaction and were identified with acute rectal fecal impaction through CT scans. The contraindications for this defecator included: (1) Anal stenosis, acute intestinal obstruction, and intestinal perforation; (2) Concomitant rectal malignant tumors; (3) Coagulation dysfunction, low platelet counts, gastrointestinal bleeding, or other bleeding risks; (4) Patients with severe underlying conditions affecting the heart, brain, lungs, or other systems; (5) Individuals with mental health disorders. Based on these criteria, clinical data from 42 patients with rectal fecal impaction who underwent treatment with the new defecator at Deyang People's Hospital between July 2020 and April 2023 were retrospectively analyzed.The defecator comprises three components: a head, a spiral rod, and a handle, constructed from disposable stainless steel wire. The treatment procedure involves the following steps: The patient assumes a flexed, supine position on their left side with their buttocks slightly protruding from the bed's edge. A transparent sealing bag is affixed to the buttocks, centered around the anus. With gloved hands inserted through the bag's entrance, a cotton ball soaked in liquid paraffin lubricates the anal canal and the head of the defecator's spiral rod. The defecator is then slowly rotated and inserted into the anus, with careful attention to any changes in resistance. Once the spiral rod is fully inserted, the patient is instructed to inhale and defecate while the defecator is slowly withdrawn, carrying the dislodged fecal matter, and depositing it into the sealed bag. This operation is repeated 2 to 3 times, followed by the injection of either 100 ml of 36°C normal saline or 60 ml of liquid paraffin into the rectum. After a 5 to 8-minute wait, the patient assumes a squatting position to expel any remaining feces from the rectum. The study assessed the operation time, single treatment success rate, pain levels during treatment, and the occurrence of complications. Results: All 42 patients successfully underwent treatment with the new defecator device, achieving a single treatment success rate of 100%. The average operation time was 11.0 minutes (range: 9.0 to 13.3 minutes). During treatment, 20 cases (47.6%) reported moderate to severe anal pain, with 1 case (2.4%) experiencing anal fissure bleeding, and 6 cases (14.3%) reporting discomfort such as palpitations and sweating. No serious complications, including rectal perforation, were observed in any case. Conclusion: The new defecator device demonstrates ease of use and safety, making it a feasible option for treating acute rectal fecal impaction.

Estrogen as a guardian of auditory health: Tsp1-CD47 axis regulation and noise-induced hearing loss

OBJECTIVES

This study aimed to analyze the role of estrogen in noise-induced hearing loss (NIHL) and uncover underlying mechanisms.

METHODS

An ovariectomized Sprague-Dawley rat model (OVX) was constructed to investigate the hearing threshold and auditory latency before and after noise exposure using the auditory brainstem response (ABR) test. The morphological changes were assessed using immunofluorescence, scanning electron microscopy and transmission electron microscopy. Proteomics and bioinformatics were used to analyze the mechanism. The findings were further verified through western blot and Luminex liquid suspension chip technology.

RESULTS

After noise exposure, OVX rats exhibited substantially elevated hearing thresholds. A conspicuous delay in ABR wave I latency was observed, alongside increased loss of outer hair cells, severe collapse of stereocilia and pronounced deformation of the epidermal plate. Accordingly, OVX rats with estrogen supplementation exhibited tolerance to NIHL. Additionally, a remarkable upregulation of the thrombospondin 1 (Tsp1)-CD47 axis in OVX rats was discovered and verified.

CONCLUSIONS

OVX rats were more susceptible to NIHL, and the protective effect of estrogen was achieved through regulation of the Tsp1-CD47 axis. This study presents a novel mechanism through which estrogen regulates NIHL and offers a potential intervention strategy for the clinical treatment of NIHL.

Managing nitrogen for sustainable crop production with reduced hydrological nitrogen losses under a winter wheat-summer maize rotation system: an eight-season field study

Excessive nitrogen (N) application in wheat-maize cropping systems was adjusted towards more sustainable practices to reduce hydrological N losses while maintaining crop yield. In comprehensive quantification of N management effects on crop yield, N use efficiency (NUE), hydrological N losses, and soil nitrate residual across eight seasons, we have added to growing evidence of strategies beneficial for sustainable crop production with lower hydrological N losses. The results show that adjusted N practices enhanced crop yield and NUE, as compared to farmer's practices, but benefits varied with N rates and types. Optimized N treatment (OPT, 180 kg N ha-1 in both maize and wheat seasons) with or without straw returning produced the most crop yield. They increased maize yield by 5.5% and 7.3% and wheat yield by 6.2% and 3.2% on average, as compared to farmer's practice with huge N application (FP, 345 kg N ha-1 and 240 kg N ha-1 in maize and wheat). Regulation of N release through amendment with controlled release urea at a rate of 144 kg N ha-1 crop-1 (CRU treatment) obtained 4.4% greater maize yield than FP, and sustained a similar wheat yield with less N input, resulting in the highest crop NUE. Additionally, CRU was most effective in mitigating hydrological N loss, with 39.5% and 45.5% less leachate N and 31.9% and 35.9% less runoff N loss than FP in maize and wheat seasons. Synthetic N input correlated significantly and positively with runoff and leachate N losses, indicating it was one of the dominant factors driving hydrological N losses. Moreover, compared to OPT, additional straw returning (STR) or substituting 20% of the nutrients by duck manure (DMS) further reduced runoff N discharges due to the fact that organic matter incorporation increased resilience to rainfall. N over-application in FP caused considerable nitrate accumulation in the 0-90-cm soil profile, while the adjusted N practices, i.e., OPT, STR, CRU, and DMS treatments effectively controlled it to a range of 79.6-92.9 kg N ha-1. This study suggests that efforts using optimized N treatment integrated with CRU or straw returning should be encouraged for sustainable crop production in this region.

Evaluation of neurotoxicity and the role of oxidative stress of cobalt nanoparticles, titanium dioxide nanoparticles, and multiwall carbon nanotubes in Caenorhabditis elegans

The widespread use of nanomaterials in daily life has led to increased concern about their potential neurotoxicity. Therefore, it is particularly important to establish a simple and reproducible assessment system. Representative nanomaterials, including cobalt nanoparticles (CoNPs), titanium dioxide nanoparticles (TiO2-NPs), and multiwall carbon nanotubes (MWCNTs), were compared in terms of their neurotoxicity and underlying mechanisms. In 0, 25, 50, and 75 μg/ml of these nanomaterials, the survival, locomotion behaviors, acetylcholinesterase (AchE) activity, reactive oxygen species production, and glutathione-S transferase 4 (Gst-4) activation in wildtype and transgenic Caenorhabditis elegans (C. elegans) were evaluated. All nanomaterials induced an imbalance in oxidative stress, decreased the ratio of survival, impaired locomotion behaviors, as well as reduced the activity of AchE in C. elegans. Interestingly, CoNPs and MWCNTs activated Gst-4, but not TiO2-NPs. The reactive oxygen species scavenger, N-acetyl-l-cysteine, alleviated oxidative stress and Gst-4 upregulation upon exposure to CoNPs and MWCNTs, and rescued the locomotion behaviors. MWCNTs caused the most severe damage, followed by CoNPs and TiO2-NPs. Furthermore, oxidative stress and subsequent activation of Gst-4 were involved in nanomaterials-induced neurotoxicity. Our study provides a comprehensive comparison of the neurotoxicity and mechanisms of typical nanomaterials, which could serve as a model for hazard assessment of environmental pollutants using C. elegans as an experimental model system.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

The impact of social media on guideline-concordant cervical cancer-screening: insights from a national survey

OBJECTIVES

Cervical cancer is one of the leading causes of cancer mortality in women, yet routine screenings lead to early detection and sometimes even prevention. Screening is an effective way to prevent cervical cancer, and it has been implemented in many countries and regions worldwide, especially in developed countries. However, the incidence of cervical cancer remains a public health problem due to screening disparities in the population. Social media engagement and overloading of online health information may be the cause of this disparity.

STUDY DESIGN

Cross-sectional study.

METHODS

Data from the Health Information National Trends Survey (a national survey conducted by the National Cancer Institute) was used to characterise cervical cancer screening into two dimensions; namely, high-frequency screening and guideline-concordant screening. The differences between these two screening frequency behaviours were compared by applying ordered logistic regression and binary logistic regression, and the mechanisms of guideline-concordant screening were explored.

RESULTS

The factors influencing high-frequency screening and guideline-concordant screening were different. Only self-efficacy (odds ratio [OR] = 1.16; 95% confidence interval [CI] = 0.98, 1.37) had a significant positive association with the high-frequency screening behaviour. Social media engagement (OR = 0.57; 95% CI = 0.33, 0.96) was shown to have a significant negative impact on guideline-concordant screening. A theory-based mechanism of screening behaviour found that traditional health perception factors no longer influence guideline-concordant screening behaviour, whereas environmental factors (e.g., social media) significantly reduce guideline-concordant screening behaviour.

CONCLUSIONS

The results from this study indicate that while the internet has become the main channel through which women acquire health resources, and social media has become a main platform for people to obtain health information, online information cannot guide people to engage in appropriate healthy behaviours. Overloading of online health information and the digital divide may lead to excessive screening. Consequently, it is important to address the screening disparity caused by health behaviours as a result of environmental factors and the digital divide.

Microglia-derived exosomal circZNRF1 alleviates paraquat-induced neuronal cell damage via miR-17-5p

Paraquat (PQ) is an environmental poison that causes clinical symptoms similar to those of Parkinson's disease (PD) in vitro and in rodents. It can lead to the activation of microglia and apoptosis of dopaminergic neurons. However, the exact role and mechanism of microglial activation in PQ-induced neuronal degeneration remain unknown. Here, we isolated the microglia-derived exosomes exposed with 0 and 40 μM PQ, which were subsequently co-incubated with PQ-exposed neuronal cells to simulate intercellular communication. First, we found that exosomes released from microglia caused a change in neuronal cell vitality and reversed PQ-induced neuronal apoptosis. RNA sequencing data showed that these activated microglia-derived exosomes carried large amounts of circZNRF1. Moreover, a bioinformatics method was used to study the underlying mechanism of circZNRF1 in regulating PD, and miR-17-5p was predicted to be its target. Second, an increased Bcl2/Bax ratio could play an anti-apoptotic role. Bcl2 was predicted to be a downstream target of miR-17-5p. Our results showed that circZNRF1 plays an anti-apoptotic role by absorbing miR-17-5p and regulating the binding of Bcl2 after exosomes are internalized by dopaminergic neurons. In conclusion, we demonstrated a new intercellular communication mechanism between microglia and neurons, in which circZNRF1 plays a key role in protecting against PQ-induced neuronal apoptosis through miR-17-5p to regulate the biological process of PD. These findings may offer a novel approach to preventing and treating PD.

The deficiency of N6-methyladenosine demethylase ALKBH5 enhances the neurodegenerative damage induced by cobalt

Cobalt exposure, even at low concentrations, induces neurodegenerative damage, such as Alzheimer's disease (AD). The specific underlying mechanisms remain unclear. Our previous study demonstrated that m⁶A methylation alteration is involved in cobalt-induced neurodegenerative damage, such as in AD. However, the role of m⁶A RNA methylation and its underlying mechanisms are poorly understood. In this study, both epidemiological and laboratory studies showed that cobalt exposure could downregulate the expression of the m⁶A demethylase ALKBH5, suggesting a key role for ALKBH5. Moreover, Methylated RNA immunoprecipitation and sequencing (MeRIP-seq) analysis revealed that ALKBH5 deficiency is associated with neurodegenerative diseases. KEGG pathway and Gene ontology analyses further revealed that the differentially m⁶A-modified genes resulting from ALKBH5 downregulation and cobalt exposure were aggregated in the pathways of proliferation, apoptosis, and autophagy. Subsequently, ALKBH5 deficiency was shown to exacerbate cell viability decline, motivate cell apoptosis and attenuate cell autophagy induced by cobalt with experimental techniques of gene overexpression/inhibition. In addition, morphological changes in neurons and the expression of AD-related proteins, such as APP, P-Tau, and Tau, in the cerebral hippocampus of wild-type and ALKBH5 knockout mice after chronic cobalt exposure were also investigated. Both in vitro and in vivo results showed that lower expression of ALKBH5 aggravated cobalt-induced neurodegenerative damage. These results suggest that ALKBH5, as an epigenetic regulator, could be a potential target for alleviating cobalt-induced neurodegenerative damage. In addition, we propose a novel strategy for the prevention and treatment of environmental toxicant-related neurodegeneration from an epigenetic perspective.

Cobalt induces neurodegeneration through FTO-triggered autophagy impairment by targeting TSC1 in an m6A-YTHDF2-dependent manner

Cobalt is the most widely used heavy metal pollutant in medicine and industry. Excessive cobalt exposure can adversely affect human health. Neurodegenerative symptoms have been observed in cobalt-exposed populations; however, the underlying mechanisms remain largely unknown. In this study, we demonstrate that the N6-methyladenosine (m⁶A) demethylase fat mass and obesity-associated gene (FTO) mediates cobalt-induced neurodegeneration by impairing autophagic flux. Cobalt-induced neurodegeneration was exacerbated through FTO genetic knockdown or repression of demethylase activity, but was alleviated by FTO overexpression. Mechanistically, we showed that FTO regulates TSC1/2-mTOR signaling pathway by targeting TSC1 mRNA stability in an m⁶A-YTHDF2 manner, which resulted in autophagosome accumulation. Furthermore, FTO decreases lysosome-associated membrane protein-2 (LAMP2) to inhibit the integration of autophagosomes and lysosomes, leading to autophagic flux damage. In vivo experiments further identified that central nervous system (CNS)-Fto-specific knockout resulted in serious neurobehavioral and pathological damage as well as TSC1-related autophagy impairment in cobalt-exposed mice. Interestingly, FTO-regulated autophagy impairment has been confirmed in patients with hip replacement. Collectively, our results provide novel insights into m⁶A-modulated autophagy through FTO-YTHDF2 targeted TSC1 mRNA stability, revealing cobalt is a novel epigenetic hazard that induces neurodegeneration. These findings suggest the potential therapeutic targets for hip replacement in patients with neurodegenerative damage.

[Targeting microRNA-125b inhibited the metastasis of Alisertib resistance cells through mediating p53 pathway]

Objective: To clarify the mechanisms involvement in Alisertib-resistant colorectal cells and explore a potential target to overcome Alisertib-resistance. Methods: Drug-resistant colon cancer cell line (named as HCT-8-7T cells) was established and transplanted into immunodeficient mice. The metastasis in vivo were observed. Proliferation and migration of HCT-8-7T cells and their parental cells were assessed by colony formation and Transwell assay, respectively. Glycolytic capacity and glutamine metabolism of cells were analyzed by metabolism assays. The protein and mRNA levels of critical factors which are involved in mediating glycolysis and epithelial-mesenchymal transition (EMT) were examined by western blot and reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR), respectively. Results: In comparison with the mice transplanted with HCT-8 cells, which were survival with limited metastatic tumor cells in organs, aggressive metastases were observed in liver, lung, kidney and ovary of HCT-8-7T transplanted mice (P<0.05). The levels of ATP [(0.10±0.01) mmol/L], glycolysis [(81.77±8.21) mpH/min] and the capacity of glycolysis [(55.50±3.48) mpH/min] in HCT-8-7T cells were higher than those of HCT-8 cells [(0.04±0.01) mmol/L, (27.77±2.55) mpH/min and(14.00±1.19) mpH/min, respectively, P<0.05]. Meanwhile, the levels of p53 protein and mRNA in HCT-8-7T cells were potently decreased as compared to that in HCT-8 cells (P<0.05). However, the level of miRNA-125b (2.21±0.12) in HCT-8-7T cells was significantly elevated as compared to that in HCT-8 cells (1.00±0.00, P<0.001). In HCT-8-7T cells, forced-expression of p53 reduced the colon number (162.00±24.00) and the migration [(18.53±5.67)%] as compared with those in cells transfected with control vector [274.70±40.50 and (100.00±29.06)%, P<0.05, respectively]. Similarly, miR-125b mimic decreased the glycolysis [(25.28±9.51) mpH/min] in HCT-8-7T cells as compared with that [(54.38±12.70)mpH/min, P=0.003] in HCT-8-7T cells transfected with control. Meanwhile, in comparison with control transfected HCT-8-7T cells, miR-125b mimic also significantly led to an increase in the levels of p53 and β-catenin, in parallel with a decrease in the levels of PFK1 and HK1 in HCT-8-7T cells (P<0.05). Conclusions: Silencing of p53 by miR-125b could be one of the mechanisms that contributes to Alisertib resistance. Targeting miR-125b could be a strategy to overcome Alisertib resistance.

Toxicity of Copper and Zinc alone and in combination in Caenorhabditis elegans model of Huntington's disease and protective effects of rutin

Copper (Cu) and Zinc (Zn) are required in small concentrations for metabolic functions, but are also toxic. There is a great concern about soil pollution by heavy metals, which may exposure the population to these toxicants, either by inhalation of dust or exposure to toxicants through ingestion of food derived from contaminated soils. In addition, the toxicity of metals in combination is questionable, as soil quality guidelines only assess them separately. It is well known that metal accumulation is often found in the pathologically affected regions of many neurodegenerative diseases, including Huntington's disease (HD). HD is caused by an autosomal dominantly inherited CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. This results in the formation of a mutant huntingtin (mHTT) protein with an abnormally long polyglutamine (polyQ) repeat. The pathology of HD results in loss of neuronal cells, motor changes, and dementia. Rutin is a flavonoid found in various food sources, and previous studies indicate it has protective effects in HD models and acts as a metal chelator. However, further studies are needed to unravel its effects on metal dyshomeostasis and to discern the underlying mechanisms. In the present study, we investigated the toxic effects of long-term exposure to copper, zinc, and their mixture, and the relationship with the progression of neurotoxicity and neurodegeneration in a C. elegans-based HD model. Furthermore, we investigated the effects of rutin post metal exposure. Overall, we demonstrate that chronic exposure to the metals and their mixture altered body parameters, locomotion, and developmental delay, in addition to increasing polyQ protein aggregates in muscles and neurons causing neurodegeneration. We also propose that rutin has protective effects acting through mechanisms involving antioxidant and chelating properties. Altogether, our data provides new indications about the higher toxicity of metals in combination, the chelating potential of rutin in the C. elegans model of HD and possible strategies for future treatments of neurodegenerative diseases caused by the aggregation of proteins related to metals.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

High species diversity in Diaporthe associated with citrus diseases in China

Species in Diaporthe have broad host ranges and cosmopolitan geographic distributions, occurring as endophytes, saprobes and plant pathogens. Previous studies have indicated that many Diaporthe species are associated with Citrus. To further determine the diversity of Diaporthe species associated with citrus diseases in China, we conducted extensive surveys in major citrus-producing areas from 2017-2020. Diseased tissues were collected from leaves, fruits, twigs, branches and trunks showing a range of symptoms including melanose, dieback, gummosis, wood decay and canker. Based on phylogenetic comparisons of DNA sequences of the internal transcribed spacer regions (ITS), calmodulin (cal), histone H3 (his3), translation elongation factor 1-alpha (tef1) and beta-tubulin (tub2), 393 isolates from 10 provinces were identified as belonging to 36 species of Diaporthe, including 32 known species, namely D. apiculata, D. biconispora, D. biguttulata, D. caryae, D. citri, D. citriasiana, D. compacta, D. discoidispora, D. endophytica, D. eres, D. fusicola, D. fulvicolor, D. guangxiensis, D. hongkongensis, D. hubeiensis, D. limonicola, D. litchii, D. novem, D. passifloricola, D. penetriteum, D. pescicola, D. pometiae, D. sackstonii, D. sennicola, D. sojae, D. spinosa, D. subclavata, D. tectonae, D. tibetensis, D. unshiuensis, D. velutina and D. xishuangbanica, and four new species, namely D. gammata, D. jishouensis, D. ruiliensis and D. sexualispora. Among the 32 known species, 14 are reported for the first time on Citrus, and two are newly reported from China. Among the 36 species, D. citri was the dominant species as exemplified by its high frequency of isolation and virulence. Pathogenicity tests indicated that most Diaporthe species obtained in this study were weakly aggressive or non-pathogenic to the tested citrus varieties. Only D. citri produced the longest lesion lengths on citrus shoots and induced melanose on citrus leaves. These results further demonstrated that a rich diversity of Diaporthe species occupy Citrus, but only a few species are harmful and D. citri is the main pathogen for Citrus in China. The present study provides a basis from which targeted monitoring, prevention and control measures can be developed. Citation: Xiao XE, Liu YD, Zheng F, et al. 2023. High species diversity in Diaporthe associated with citrus diseases in China. Persoonia 51: 229-256. doi: 10.3767/persoonia.2023.51.06.

The interplay between lncRNA NR_030777 and SF3B3 in neuronal damage caused by paraquat

Paraquat (PQ) has been widely acknowledged as an environmental risk factor for Parkinson's disease (PD). However, the interaction between splicing factor and long non-coding RNA (lncRNA) in the process of PQ-induced PD has rarely been studied. Based on previous research, this study focused on splicing factor 3 subunit 3 (SF3B3) and lncRNA NR_030777. After changing the target gene expression level by lentiviral transfection technology, the related gene expression was detected by western blot and qRT-PCR. The expression of SF3B3 protein was reduced in Neuro-2a cells after PQ exposure, and the reactive oxygen species (ROS) scavenger N-acetylcysteine prevented this decline. Knockdown of SF3B3 reduced the PQ-triggered NR_030777 expression increase, and overexpression of NR_030777 reduced the transcriptional and translational level of Sf3b3. Then, knockdown of SF3B3 exacerbated the PQ-induced decrease in cell viability and aggravated the reduction of tyrosine hydroxylase (TH) protein expression. Overexpressing SF3B3 reversed the reduction of TH expression caused by PQ. Moreover, after intervention with the autophagy inhibitor Bafilomycin A1, LC3B-II protein expression was further increased in Neuro-2a cells with the knockdown of SF3B3, indicating that autophagy was enhanced. In conclusion, PQ modulated the interplay between NR_030777 and SF3B3 through ROS production, thereby impairing autophagic flux and causing neuronal damage.

[Effects and mechanism of astragalus polysaccharide on wound healing of deep partial-thickness burns in rats]

Objective: To investigate the effects and mechanism of astragalus polysaccharide (APS) on wound healing of deep partial-thickness burns in rats. Methods: The experimental study method was used. Fifty 7-week-old male Sprague-Dawley rats were divided into normal group, simple burn group, APS group, inhibitor group, and inhibitor+APS group according to the random number table, with 10 rats in each group. Except for normal group, rats in the other 4 groups were inflicted with a deep partial-thickness burn wound on the back. Rats in normal group and simple burn group were intraperitoneally injected with normal saline, and rats in the other three groups were injected with APS and/or integrin-linked kinase (ILK) inhibitor, respectively. After 7 days of injection, the wound healing rate of rats with burns in the four groups was calculated, and the serum content of interferon-γ, interleukin-2 (IL-2), and tumor necrosis factor α (TNF-α) in rats in 5 groups was determined by enzyme-linked immunosorbent assay (ELISA). The normal skin tissue of rats in normal group and wound tissue of rats with burns in the four groups were taken, the water content was determined and the water ratio was calculated, the content of interferon-γ, IL-2, and TNF-α was detected by ELISA, the mRNA expressions of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and ILK were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction, and the protein expressions of ILK, protein kinase B (Akt), phosphorylated Akt (p-Akt), glycogen synthetic kinase-3β (GSK-3β), and phosphorylated GSK-3β (p-GSK-3β) were detected by Western blotting. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: After 7 days of injection, the wound healing rate of rats in APS group was (67±5)%, which was significantly higher than (52±4)% in simple burn group and (59±5)% in inhibitor+APS group (with all the P values <0.05). The wound healing rate of rats in inhibitor+APS group was significantly higher than (48±4)% in inhibitor group (P<0.05). After 7 days of injection, compared with those in serum or normal skin tissue of rats in normal group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in simple burn group were significantly increased (P<0.05); compared with those in APS group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in simple burn group and inhibitor+APS group were significantly increased (P<0.05); compared with those in inhibitor group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in inhibitor+APS group were significantly decreased (P<0.05). After 7 days of injection, compared with that in normal skin tissue of rats in normal group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in simple burn group was significantly increased (P<0.05); compared with that in APS group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in simple burn group and inhibitor+APS group was significantly increased (P<0.05); compared with that in inhibitor group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in inhibitor+APS group was significantly decreased (P<0.05). After 7 days of injection, compared with those in normal skin tissue of rats in normal group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in simple burn group were significantly increased (P<0.05); compared with those in APS group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in simple burn group and inhibitor+APS group were significantly decreased (P<0.05); compared with those in inhibitor group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in inhibitor+APS group were significantly increased (P<0.05). There were no statistically significant differences in the protein expressions of Akt and GSK-3β in normal skin tissue of rats in normal group and wound tissue of rats with burns in the four groups (P>0.05). Conclusions: APS can alleviate systemic and local inflammation, alleviate tissue edema, and promote the expressions of healing factors in rats with deep partial-thickness burns, thus to promote the wound healing, possibly by activating ILK/Akt/GSK-3β signaling pathway.

Cobalt nanoparticles induce mitochondrial damage and β-amyloid toxicity via the generation of reactive oxygen species

Exposure to cobalt nanoparticles (CoNPs) has been associated with neurodegenerative disorders, while the mitochondrial-associated mechanisms that mediate their neurotoxicity have yet to be fully characterized. In this study, we reported that CoNPs exposure reduced the survival and lifespan in the nematodes, Caenorhabditis elegans (C. elegans). Moreover, exposure to CoNPs aggravated the induction of paralysis and the aggregation of β-amyloid (Aβ). These effects were accompanied by reactive oxygen species (ROS) overproduction, ATP reduction as well as mitochondrial fragmentation. Dynamin-related protein 1 (drp-1) activation and ensuing mitochondrial fragmentation have been shown to be associated with CoNPs-reduced survival. In order to address the role of mitochondrial damage and ROS production in CoNPs-induced Aβ toxicity, the mitochondrial reactive oxygen species scavenger mitoquinone (Mito Q) was used. Our results showed that Mito Q pretreatment alleviated CoNPs-induced ROS generation, rescuing mitochondrial dysfunction, thereby lessening the CoNPs-induced Aβ toxicity. Taken together, we show for the first time, that increasing of ROS and the upregulation of drp-1 lead to CoNPs-induced Aβ toxicity. Our novel findings provide in vivo evidence for the mechanisms of environmental toxicant-induced Aβ toxicity, and can afford new modalities for the prevention and treatment of CoNPs-induced neurodegeneration.

Age-related adiposity and beta-cell function: impact on prediabetes and diabetes prevalence in middle-aged and older Han Chinese adults

PURPOSE

To investigate the effect of aging on the prevalence of prediabetes and diabetes, and the influence of aging on the associations among adipose mass, redistribution, β cell function, and the prevalence of hyperglycaemia.

METHOD

This urban-based cross-sectional study included 1033 Chinese Han people, aged 40-65 years. The abdominal subcutaneous fat area (SFA) and visceral fat area (VFA) were determined by magnetic resonance imaging. The prevalence rates of prediabetes and diabetes were analyzed according to age group (40-49, 50-59, and 60-65 years). The effects of aging on abdominal fat mass, adipose distribution, insulin action indexes were also assessed.

RESULTS

Prediabetes and diabetes prevalence gradually increased with age. Both SFA and VFA increased, while SFA/VFA decreased, in the 50-59 and 60-65 years age groups compared to the 40-49 years group. Homeostatic model assessment of insulin resistance (HOMA-IR) increased with fat mass. Homeostatic model assessment of beta-cell function (HOMA-β) and early-phase insulin secretion (∆I30/∆G30) were decreased in the 60-65 years group compared to the younger age groups. Increased age, VFA, and HOMA-IR, as well as decreased HOMA-β, were risk factors for the development of prediabetes and diabetes. The associations between central obesity and the development of prediabetes and diabetes, but not the associations of SFA/VFA, HOMA-IR, and HOMA-β with hyperglycaemia prevalence, weakened with age.

CONCLUSIONS

The prevalence of prediabetes and diabetes increased with age. Central obesity may be related stronger to the development of hyperglycaemia in younger people.

Cobalt induces neurodegenerative damages through impairing autophagic flux by activating hypoxia-inducible factor-1α triggered ROS overproduction

Cobalt is an environmental toxicant, and excessive bodily exposure can damage the nervous system. Particularly, our previous study reported that low-dose cobalt (significantly less than the safety threshold) is still able to induce neurodegenerative changes. However, the underlying molecular mechanism is still insufficient revealed. Herein, we further investigate the molecular mechanism between cobalt-induced neurodegeneration and autophagy, as well as explore the interplay between hypoxia-inducible factor-1α (HIF-1α), reactive oxygen species (ROS), and autophagy in cobalt-exposed mice and human neuroglioma cells. We first reveal cobalt as an environmental toxicant to severely induce β amyloid (Aβ) deposition, tau hyperphosphorylation, and dysregulated autophagy in the hippocampus and cortex of mice. In particular, we further identify that cobalt-induced neurotoxicity is triggered by the impairment of autophagic flux in vitro experiments. Moreover, the mechanistic study reveals that cobalt exposure extremely activates HIF-1α expression to facilitate the overproduction of ROS. Then, elevated ROS can target the amino-threonine kinase (AKT)-mammalian target of rapamycin (mTOR)-Unc-51 like autophagy activating kinase 1 (ULK1) signaling pathway to participate in cobalt-induced impairment of autophagic flux. Subsequently, defected autophagy further exacerbates cobalt-induced neurotoxicity for its unable to eliminate the deposition of pathological protein. Therefore, our data provide scientific evidence for cobalt safety evaluation and risk assessment and propose a breakthrough for understanding the regulatory relationship between HIF-1α, ROS, and autophagy in cobalt-induced neurodegeneration.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

BTBD9 attenuates manganese-induced oxidative stress and neurotoxicity by regulating insulin growth factor signaling pathway

Manganese (Mn) is an essential mineral, but excess exposure can cause dopaminergic neurotoxicity. Restless legs syndrome (RLS) is a common neurological disorder, but the etiology and pathology remain largely unknown. The purpose of this study was to identify the role of Mn in the regulation of an RLS genetic risk factor BTBD9, characterize the function of BTBD9 in Mn-induced oxidative stress and dopaminergic neuronal dysfunction. We found that human subjects with high blood Mn levels were associated with decreased BTBD9 mRNA levels, when compared with subjects with low blood Mn levels. In A549 cells, Mn exposure decreased BTBD9 protein levels. In Caenorhabditis elegans, loss of hpo-9 (BTBD9 homolog) resulted in more susceptibility to Mn-induced oxidative stress and mitochondrial dysfunction, as well as decreased dopamine levels and alternations of dopaminergic neuronal morphology and behavior. Overexpression of hpo-9 in mutant animals restored these defects and the protection was eliminated by mutation of the forkhead box O (FOXO). In addition, expression of hpo-9 upregulated FOXO protein levels and decreased protein kinase B levels. These results suggest that elevated Mn exposure might be an environmental risk factor for RLS. Furthermore, BTBD9 functions to alleviate Mn-induced oxidative stress and neurotoxicity via regulation of insulin/insulin-like growth factor signaling pathway.

Neurotoxicity Evaluation of Nanomaterials Using C. elegans: Survival, Locomotion Behaviors, and Oxidative Stress

Nanomaterials are broadly used in a variety of industries and consumer products. However, studies have demonstrated that many nanomaterials, including metal-containing nanoparticles and nanoplastics, have neurotoxic effects. Caenorhabditis elegans (C. elegans) is a widely used model organism with numerous advantages for research, including transparency, short life span, well-characterized nervous system, complete connectome, available genome, and numerous genetic tools. C. elegans has been extensively used to assess the neurotoxicity of multiple chemicals via survival assays, behavioral tests, neuronal morphology studies, and various molecular and mechanistic analyses. However, detailed protocols describing general assays in C. elegans to examine the neurotoxic effects of nanomaterials are limited. Here, we describe protocols for assessing nanomaterial neurotoxicity in C. elegans. We describe the steps for exposure and subsequent evaluation of survival, locomotion behavior, and oxidative stress. Survival and locomotion behavior are measured in wild-type N2 strains to assess acute neurotoxicity. Oxidative stress is used as an endpoint here since it is one of the most predominant and common changes induced by nanomaterials. VP596 nematodes, which express GFP upon activation of skn-1 (the worm homolog of Nrf2), are evaluated for assays of oxidative stress in response to test nanomaterials. These assays can be readily used to quickly examine the neurotoxicity of nanomaterials in vivo, laying the foundation for mechanistic studies of nanomaterials and their impacts on health and physiology. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Exposure of C. elegans to nanomaterials Basic Protocol 2: Survival assessment Basic Protocol 3: Assessment of locomotion behavior Basic Protocol 4: Analysis of oxidative stress.

Paraquat-induced oxidative stress regulates N6-methyladenosine (m6A) modification of long noncoding RNAs in Neuro-2a cells

Paraquat (PQ) is a ubiquitously applied herbicide. Long-term PQ exposure with low dose has been reported to induce abnormal expression of long non-coding RNAs (lncRNAs) in brain nerve cells, which could further lead to Parkinson's disease (PD). N6-methyladenosine (m⁶A) modification has recently been identified as having an important role in regulating the function of lncRNAs. However, how m⁶A modification regulates lncRNAs following PQ exposure remains largely unknown. Herein, this study reported m⁶A modification of lncRNAs in mouse neuroblastoma cells (Neuro-2a) following PQ induced reactive oxide species (ROS). M⁶A sequencing was performed to explore the m⁶A modificated pattern of lncRNAs in Neuro-2a cells which were treated with 200 μM PQ for 3 h. It was found that PQ hypermethylated total RNA and changed the expression of m⁶A methyltransferase and demethylase proteins, which leading to the alteration of m⁶A modification of lncRNAs. Furthermore, the functional analysis further revealed that N-acetyl-L-cysteine (NAC)，a ROS scavengers, partly reversed PQ-induced distinct m⁶A modificated pattern of lncRNAs. In addition, tow specific m⁶A modified lncRNAs were identified: cell division cycle 5-like (lncRNA CDC5L) and signal transducer and activator of transcription 3 (lncRNA STAT3), which could influence downstream autophagy related biological function. In summary, this work could potentially contribute to the new insight of lncRNAs m⁶A modification mechanism in the field of environmental toxicology.

Oxidation and Antioxidation of Natural Products in the Model Organism Caenorhabditiselegans

Natural products are small molecules naturally produced by multiple sources such as plants, animals, fungi, bacteria and archaea. They exert both beneficial and detrimental effects by modulating biological targets and pathways involved in oxidative stress and antioxidant response. Natural products’ oxidative or antioxidative properties are usually investigated in preclinical experimental models, including virtual computing simulations, cell and tissue cultures, rodent and nonhuman primate animal models, and human studies. Due to the renewal of the concept of experimental animals, especially the popularization of alternative 3R methods for reduction, replacement and refinement, many assessment experiments have been carried out in new alternative models. The model organism Caenorhabditis elegans has been used for medical research since Sydney Brenner revealed its genetics in 1974 and has been introduced into pharmacology and toxicology in the past two decades. The data from C. elegans have been satisfactorily correlated with traditional experimental models. In this review, we summarize the advantages of C. elegans in assessing oxidative and antioxidative properties of natural products and introduce methods to construct an oxidative damage model in C. elegans. The biomarkers and signaling pathways involved in the oxidative stress of C. elegans are summarized, as well as the oxidation and antioxidation in target organs of the muscle, nervous, digestive and reproductive systems. This review provides an overview of the oxidative and antioxidative properties of natural products based on the model organism C. elegans.

N6-methyladenosine(m6A) demethylase FTO regulates cellular apoptosis following cobalt-induced oxidative stress

Cobalt is an environmental toxicant that is known to damage human health. However, the molecular mechanisms underlying cobalt-induced neurotoxicity have not been elucidated in detail. In the present research, we used human neuroglioma H4 cells as an in vitro model. Cells were exposed to CoCl₂ (0, 100, 200, 400 μM) for 24 h. We performed m⁶A sequencing techniques and constructed FTO-knockdown/FTO-overexpressing cells to investigate the role of FTO-mediated m⁶A modification in regulating apoptosis following CoCl₂ induced oxidative stress. Our study has shown CoCl₂ exposure led to the decrease of demethylase FTO as well as elevated oxidative stress. However, NAC treatment could partly reverse the reduction of FTO expression as well as the degree of ROS via eliminating oxidative stress. Meanwhile, MeRIP-seq and RNA-seq further revealed the potential function m⁶A modification in regulating apoptosis. More importantly, KEGG pathway and Gene ontology (GO) analyses further elucidated that the differentially m⁶A-modified genes were aggregated in apoptosis-related pathways. Mechanistic analysis indicated that knockdown of FTO facilitated CoCl₂-induced apoptosis via caspase activation and G1/S cell cycle arrest. Nevertheless, overexpression of FTO partly attenuated the increased apoptosis following CoCl₂ exposure. More notably, we observed that FTO regulated apoptosis in an m⁶A-dependent manner. Therefore, our findings reveal that CoCl₂ induced ROS affected the m⁶A modification of apoptosis-related genes by decreasing the expression of FTO, thereby resulting in the activation of apoptosis. These findings provide important insights into CoCl₂-induced apoptosis and m⁶A modification and propose a novel strategy for studying environmental toxicant-related neurodegeneration.

Acceleration of Brain Susceptibility-Weighted Imaging with Compressed Sensitivity Encoding: A Prospective Multicenter Study

BACKGROUND AND PURPOSE

While three-dimensional susceptibility-weighted imaging has been widely suggested for intracranial vessel imaging, hemorrhage detection, and other neuro-diseases, its relatively long scan time has necessitated the clinical verification of recent progresses of fast imaging techniques. Our aim was to evaluate the effectiveness of brain SWI accelerated by compressed sensitivity encoding to identify the optimal acceleration factors for clinical practice.

MATERIALS AND METHODS

Ninety-nine subjects, prospectively enrolled from 5 centers, underwent 8 brain SWI sequences: 5 different folds of compressed sensitivity encoding acceleration (CS2, CS4, CS6, CS8, and CS10), 2 different folds of sensitivity encoding acceleration (SF2 and SF4), and 1 without acceleration. Images were assessed quantitatively on both the SNR of the red nucleus and its contrast ratio to the CSF and, subjectively, with scoring on overall image quality; visibility of the substantia nigra-red nucleus, basilar artery, and internal cerebral vein; and diagnostic confidence of the cerebral microbleeds and other intracranial diseases.

RESULTS

Compressed sensitivity encoding showed a promising ability to reduce the acquisition time (from 202 to 41 seconds) of SWI while increasing the acceleration factor from 2 to 10, though at the cost of decreasing the SNR, contrast ratio, and the scores of visual assessments. The visibility of the substantia nigra-red nucleus and internal cerebral vein became unacceptable in CS6 to CS10. The basilar artery was well-distinguished, and diseases including cerebral microbleeds, cavernous angiomas, intracranial gliomas, venous malformations, and subacute hemorrhage were well-diagnosed in all compressed sensitivity encoding sequences.

CONCLUSIONS

Compressed sensitivity encoding factor 4 is recommended in routine practice. Compressed sensitivity encoding factor 10 is potentially a fast surrogate for distinguishing the basilar artery and detecting susceptibility-related abnormalities (eg, cerebral microbleeds, cavernous angiomas, gliomas, and venous malformation) at the sacrifice of visualization of the substantia nigra-red nucleus and internal cerebral vein.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Paraquat-induced oxidative stress regulates N6-methyladenosine (m6A) modification of circular RNAs

Paraquat (PQ), a widely used herbicide and well-known oxidative stress inducer, has been linked to numerous neurodegenerative diseases, but the underlying mechanism(s) remains unknown. Circular RNAs (circRNAs) have recently been reported to be associated with oxidative stress in Parkinson's disease. Herein, we performed methylated RNA immunoprecipitation and RNA sequencing assays for mouse neuroblastoma (Neuro-2a) cells and successfully established a positive link between the alteration of circRNAs driven by m⁶A modification and PQ-induced oxidative stress. We observed oxidative stress and antioxidative stress present distinct m⁶A modification pattern of circRNAs as well as biological effect. Gene ontology and pathway analysis predicted that differentially m⁶A-methylated and expressed circRNAs are highly clustered in pathways associated with function and development of nervous system, including axon cargo transport, nervous system development, long-term potentiation, and neurotrophic signaling pathways. Moreover, we demonstrated that the alteration of m⁶A-methylated circRNAs upon PQ exposure could be partially reversed by N-acetylcysteine pretreatment. The mechanistic analysis further demonstrated that N-acetylcysteine pretreatment attenuated the decreased expression of target genes (UBC and PPP2CA) induced by PQ. These findings revealed distinct patterns of differentially m⁶A-modified circRNAs, indicating that m⁶A could participate in a specific regulatory network of circRNAs to modulate the expression of downstream genes in response to PQ-induced oxidative stress. In conclusion, our work established a link between m⁶A modification of circRNAs and PQ-induced oxidative stress, and further studies are required to explore the underlying molecular mechanisms associated with PQ-induced neurotoxicity.

NOX2 activation contributes to cobalt nanoparticles-induced inflammatory responses and Tau phosphorylation in mice and microglia

Despite the wide application of cobalt nanoparticles (CoNPs), its neurotoxicity and the underlying mechanisms are not fully understood. In this study, CoNPs-induced toxic effect was examined in both C57BL/6J mice and microglial BV2 cells. CoNPs-induced brain weight loss and the reduction of Nissl bodies, assuring neural damage. Moreover, both total unphosphorylated Tau and phosphorylated Tau (pTau; T231 and S262) expressions in the hippocampus and cortex were upregulated, unveiling Tau phosphorylation. Besides, the increase in inflammation-related proteins NLRP3 and IL-1β were found in mice brain. Corroborating that, microglial marker Iba-1 expression was also increased, suggesting microglia-involved inflammation. Among the NADPH oxidase (NOX) family proteins tested, only NOX2 was activated by CoNPs in hippocampus. Therefore, BV2 cells were employed to further investigate the role of NOX2. In BV2 cells, NOX2 expression was upregulated, corresponding to the production of ROS. Moreover, similar induction in Tau phosphorylation and inflammation-related protein expressions were observed in CoNPs-exposed BV2 cells. Treatment of apocynin, a NOX2 inhibitor, reduced ROS generation and reversed Tau phosphorylation and inflammation caused by CoNPs. Thus, CoNPs induced ROS production, Tau phosphorylation and inflammation specially via NOX2 activation.

Intercellular transfer of mitochondria via tunneling nanotubes protects against cobalt nanoparticle-induced neurotoxicity and mitochondrial damage

Broad applications of cobalt nanoparticles (CoNPs) have raised increased concerns regarding their potential toxicity. However, the underlining mechanisms of their toxicity have yet to be characterized. Here, we demonstrated that CoNPs reduced cell viability and induced membrane leakage. CoNPs induced oxidative stress, as indicated by the generation of reactive oxygen species (ROS) secondary to the increased expression of hypoxia-induced factor 1 alpha. Moreover, CoNPs led to mitochondrial damage, including generation of mitochondrial ROS, reduction in ATP content, morphological damage and autophagy. Interestingly, exogenous mitochondria were observed between neurons and astrocytes upon CoNPs exposure. Concomitantly, tunneling nanotubes (TNTs)-like structures were observed between neurons and astrocytes upon CoNPs exposure. These structures were further verified to be TNTs as they were found to be F-actin rich and lacking tubulin. We then demonstrated that TNTs were utilized for mitochondrial transfer between neurons and astrocytes, suggesting a novel crosstalk phenomenon between these cells. Moreover, we found that the inhibition of TNTs (using actin-depolymerizing drug latrunculin B) intensified apoptosis triggered by CoNPs. Therefore, we demonstrate, for the first time, that the inhibition of intercellular mitochondrial transfer via TNTs aggravates CoNPs-induced cellular and mitochondrial toxicity in neuronal cells, implying a novel intercellular protection mechanism in response to nanoparticle exposure.

Cobalt induces neurodegenerative damages through Pin1 inactivation in mice and human neuroglioma cells

Cobalt is a hazardous material that has harmful effects on neurotoxicity. Excessive exposure to cobalt or inactivation of the unique proline isomerase Pin1 contributes to age-dependent neurodegeneration. However, nothing is known about the role of Pin1 in cobalt-induced neurodegeneration. Here we find that out of several hazardous materials, only cobalt dose-dependently decreased Pin1 expression and alterations in its substrates, including cis and trans phosphorylated Tau in human neuronal cells, concomitant with neurotoxicity. Cobalt-induced neurotoxicity was aggravated by Pin1 genetic or chemical inhibition, but rescued by Pin1 upregulation. Furthermore, less than 4 μg/l of blood cobalt induced dose- and age-dependent Pin1 downregulation in murine brains, ensuing neurodegenerative changes. These defects were corroborated by changes in Pin1 substrates, including cis and trans phosphorylated Tau, amyloid precursor protein, β amyloid and GSK3β. Moreover, blood Pin1 was downregulated in human hip replacement patients with median blood cobalt level of 2.514 μg/l, which is significantly less than the safety threshold of 10 μg/l, suggesting an early role Pin1 played in neurodegenerative damages. Thus, Pin1 inactivation by cobalt contributes to age-dependent neurodegeneration, revealing that cobalt is a hazardous material triggering AD-like neurodegenerative damages.

Meta-analyses of maternal exposure to atmospheric particulate matter and risk of congenital anomalies in offspring

Congenital anomalies are the main causes of infant death and disability. Previous studies have suggested that maternal exposure to particulate matter is related to congenital malformation. However, the conclusions of this study remain controversial. Hence, meta-analyses were performed to assess the relationship between maternal exposure to particulate matter and the risk of congenital anomalies. The Medline, Embase, and Web of Science databases were systemically searched from inception until August 2020 to find articles related to birth defects and particulate matter. The pooled risk estimated for the combination of pollution outcomes was calculated for each study by performing fixed effects or random effects models. The existence of heterogeneity and publication bias in relevant studies was also examined. Thirty studies were included in the analysis. A statistically increased summary risk valuation was found. PM₁₀ exposure was associated with an increased risk of congenital heart disease, neural tube defects, and cleft lip with or without cleft palate (OR per 10 μg/m³ = 1.05, 95% CI, 1.03-1.07; OR per 10 μg/m³ = 1.04, 95% CI, 1.01-1.06; OR per 10 μg/m³ = 1.03, 95% CI, 1.01-1.06). Maternal exposure to particulate matter might be associated with an increased risk of congenital anomalies. Our results indicate the dangers of particulate matter exposure on fetal development and the importance of protection against exposure to such particles during pregnancy. The schematic representation of the association between maternal exposure to PM_2.5/PM₁₀ and congenital anomalies in offspring, and geographic distribution of the included reports in the meta-analyses.

Evaluations of Environmental Pollutant-Induced Mitochondrial Toxicity Using Caenorhabditis elegans as a Model System

Environmental pollutants inevitably exert adverse effects on humans and other species. Quick identification and in-depth characterization of the pollutants are requisite objectives for clinicians and environmental health scientists. The nematode Caenorhabditis elegans has been utilized as a model organism for toxicity evaluation of environmental pollutants, due to its transparency, short lifespan, entire genome sequencing, and economical characteristics. However, few researchers have systematically addressed mitochondrial toxicity in response to toxicants, despite the critical role mitochondria play in energy production and respiration, as well as the generation of reactive oxygen species. Mitochondria are vulnerable to environmental pollutants, and their dysfunction contributes to cellular damage and toxicity in plethora of diseases. Here, we describe methods in step-by-step for mitochondrial toxicity evaluation in response to pollutants, including exposure of C. elegans to toxicants, mitochondrial ROS detection, mitochondrial morphology analysis, mitochondrial function analysis, such as ATP production and oxygen consumption, and gene expression studies, with the application of corresponding genetically modified strains.

LncRNA NR_030777 Alleviates Paraquat-Induced Neurotoxicity by Regulating Zfp326 and Cpne5

Paraquat (PQ) is herbicide widely used in agricultural production. It is identified as an environmental toxicant that could lead to neurodegeneration damage. Parkinson's disease (PD) is a central nervous system degenerative disease that occurs in the elderly. Main risk factors for PD include genetic and environmental variables, but its specific mechanism is still not well understood. Emerging evidence suggests that long noncoding RNAs (lncRNAs) play an important role in PD. LncRNA NR_030777 has a full length of 2208 bp and is highly conserved among species. RNA profiling showed a significant alteration in lncRNA NR_030777 expression upon PQ-induced neurotoxicity. However, little is known on the functional relevance of lncRNA NR_030777 in the development of PQ. In this study, we discovered a vital protective role of lncRNA NR_030777 in PQ-induced neurotoxicity. The expression of NR_030777 correlates with elevated level of reactive oxygen species induced by PQ. In addition, activated expression of NR_030777 alleviates neurotoxicity by regulating the expression of Zfp326 and Copine 5. We report that lncRNA NR_030777 has a vital protective role in neurotoxicity induced by environmental toxicants such as PQ. This study could serve as an exemplary case for lncRNAs to be considered as a potential target for the prevention and treatment of PQ-induced neurodegenerative disorders such as PD.

Drp-1-Dependent Mitochondrial Fragmentation Contributes to Cobalt Chloride-Induced Toxicity in Caenorhabditis elegans

Excess cobalt may lead to metallosis, characterized by sensorineural hearing loss, visual, and cognitive impairment, and peripheral neuropathy. In the present study, we sought to address the molecular mechanisms of cobalt-induced neurotoxicity, using Caenorhabditis elegans as an experimental model. Exposure to cobalt chloride for 2 h significantly decreased the survival rate and lifespan in nematodes. Cobalt chloride exposure led to increased oxidative stress and upregulation of glutathione S-transferase 4. Consistently, its upstream regulator skn-1, a mammalian homolog of the nuclear factor erythroid 2-related factor 2, was activated. Among the mRNAs examined by quantitative real-time polymerase chain reactions, apoptotic activator egl-1, proapoptotic gene ced-9, autophagic (bec-1 and lgg-1), and mitochondrial fission regulator drp-1 were significantly upregulated upon cobalt exposure, concomitant with mitochondrial fragmentation, as determined by confocal microscopy. Moreover, drp-1 inhibition suppressed the cobalt chloride-induced reactive oxygen species generation, growth defects, and reduced mitochondrial fragmentation. Our novel findings suggest that the acute toxicity of cobalt is mediated by mitochondrial fragmentation and drp-1 upregulation.