A Drosophila Model Reveals the Potential Role for mtt in Retinal Disease.

Congenital stationary night blindness (CSNB) is a genetically heterogeneous inherited retinal disorder, caused by over 300 mutations in 17 different genes. While there are numerous fly models available for simulating ocular diseases, most are focused on mimicking retinitis pigmentosa (RP), with animal models specifically addressing CSNB limited to mammals. Here, we present a CSNB fly model associated with the mtt gene, utilizing RNA interference (RNAi) to silence the mtt gene in fly eyes (homologous to the mammalian GRM6 gene) and construct a CSNB model. Through this approach, we observed significant defects in the eye structure and function upon reducing mtt expression in fly eyes. This manifested as disruptions in the compound eye lens structure and reduced sensitivity to light responses. These results suggest a critical role for mtt in the function of fly adult eyes. Interestingly, we found that the mtt gene is not expressed in the photoreceptor neurons of adult flies but is localized to the inner lamina neurons. In summary, these results underscore the crucial involvement of mtt in fly retinal function, providing a framework for understanding the pathogenic mechanisms of CSNB and facilitating research into potential therapeutic interventions.

Efficacy of 75% alcohol in pretreatment of the Andersen sampler in trapping maximum airborne microbes.

The present study was conducted to evaluate the effects of the pretreatment methods and sampling time on the sampling of airborne bacteria in hospitals. Methods for the pretreatment of Andersen samplers, namely, non-sterilized, 75% ethanol and autoclaving sampled for 5 min, 10 min and 15 min in the general ward and class 1000 clean operating department, respectively, were studied. Statistical analysis was used to compare the differences in sampling results of airborne bacteria under different pretreatment methods, sampling time and environmental conditions. In the first test, the sampling results of the airborne bacteria obtained by pretreatment of the sampler with 75% ethanol and without pre-treatment were not very different, and the sampling results showed a certain declining trend with the extension of the sampling time. In the second test, the pretreatment effect of autoclaving was significantly better than that of 75% ethanol, and the sampling time had no effect on the sampling results. After removing the influencing factors of the environment, the results were consistent with the results of the second test. It was observed that the Andersen samplers should not be pretreated with 75% ethanol before airborne microbes sampling. The pretreatment should be carried out by autoclaving, and the sampling time has little effect on the sampling results.

Comparative analysis of locomotor behavior and head diurnal transcriptome regulation by PERIOD and CRY2 in the diamondback moth.

Earth's rotation shapes a 24-h cycle, governing circadian rhythms in organisms. In mammals, the core clock genes, CLOCK and BMAL1, are regulated by PERIODs (PERs) and CRYPTOCHROMEs (CRYs), but their roles remain unclear in the diamondback moth, Plutella xylostella. To explore this, we studied P. xylostella, which possesses a simplified circadian system compared to mammals. In P. xylostella, we observed rhythmic expressions of the Pxper and Pxcry2 genes in their heads, with differing phases. In vitro experiments revealed that PxCRY2 repressed monarch butterfly CLK:BMAL1 transcriptional activation, while PxPER and other CRY-like proteins did not. However, PxPER showed an inhibitory effect on PxCLK/PxCYCLE. Using CRISPR/Cas9, we individually and in combination knocked out Pxper and Pxcry2, then conducted gene function studies and circadian transcriptome sequencing. Loss of either Pxper or Pxcry2 eliminated the activity peak after lights-off in light-dark cycles, and Pxcry2 loss reduced overall activity. Pxcry2 was crucial for maintaining endogenous rhythms in constant darkness. Under light-dark conditions, 1 098 genes exhibited rhythmic expression in wild-type P. xylostella heads, with 749 relying on Pxper and Pxcry2 for their rhythms. Most core clock genes lost their rhythmicity in Pxper and Pxcry2 mutants, while Pxcry2 sustained rhythmic expression, albeit with reduced amplitude and altered phase. Additionally, rhythmic genes were linked to biological processes like the spliceosome and Toll signaling pathway, with these rhythms depending on Pxper or Pxcry2 function. In summary, our study unveils differences in circadian rhythm regulation by Pxper and Pxcry2 in P. xylostella. This provides a valuable model for understanding circadian clock regulation in nocturnal animals.

Research progress on photocatalytic reduction of CO2 based on ferroelectric materials.

Transforming CO2 into renewable fuels or valuable carbon compounds could be a practical means to tackle the issues of global warming and energy crisis. Photocatalytic CO2 reduction is more energy-efficient and environmentally friendly, and offers a broader range of potential applications than other CO2 conversion techniques. Ferroelectric materials, which belong to a class of materials with switchable polarization, are attractive candidates as catalysts due to their distinctive and substantial impact on surface physical and chemical characteristics. This review provides a concise overview of the fundamental principles underlying photocatalysis and the mechanism involved in CO2 reduction. Additionally, the composition and properties of ferroelectric materials are introduced. This review expands on the research progress in using ferroelectric materials for photocatalytic reduction of CO2 from three perspectives: directly as a catalyst, by modification, and construction of heterojunctions. Finally, the future potential of ferroelectric materials for photocatalytic CO2 reduction is presented. This review may be a valuable guide for creating reasonable and more effective photocatalysts based on ferroelectric materials.

miR-106b-5p protects against drug-induced liver injury by targeting vimentin to stimulate liver regeneration.

Understanding the endogenous mechanism of adaptive response to drug-induced liver injury (arDILI) may discover innovative strategies to manage DILI. To gain mechanistic insight into arDILI, we investigated exosomal miRNAs in the adaptive response to toosendanin-induced liver injury (TILI) of mice. Exosomal miR-106b-5p was identified as a specific regulator of arDILI by comprehensive miRNA profiling. Outstandingly, miR-106b-5p agomir treatment alleviated TILI and other DILI by inhibiting apoptosis and promoting hepatocyte proliferation. Conversely, antagomir treatments had opposite effects, indicating that miR-106b-5p protects mice from liver injury. Injured hepatocytes released miR-106b-5p-enriched exosomes taken up by surrounding hepatocytes. Vim (encodes vimentin) was identified as an important target of miR-106b-5p by dual luciferase reporter and siRNA assays. Furthermore, single-cell RNA-sequencing analysis of toosendanin-injured mouse liver revealed a cluster of Vim + hepatocytes; nonetheless declined following miR-106b-5p cotreatment. More importantly, Vim knockout protected mice from acetaminophen poisoning and TILI. In the clinic, serum miR-106b-5p expression levels correlated with the severity of DILI. Indeed, liver biopsies of clinical cases exposed to different DILI causing drugs revealed marked vimentin expression among harmed hepatocytes, confirming clinical relevance. Together, we report mechanisms of arDILI whereby miR-106b-5p safeguards restorative tissue repair by targeting vimentin.

CRISPR/Cas9-mediated knockout of period reveals its function in the circadian rhythms of the diamondback moth Plutella xylostella.

Circadian clocks control the rhythmicity of many behaviors and physiological features of insects. To study the circadian clock of the moth Plutella xylostella, we employed CRISPR/Cas9-mediated genome editing to investigate the effect of loss of the clock gene period on the circadian rhythms. P. xylostella harbors a single copy of period. Phylogenetic analysis showed that P. xylostella PERIOD is more homologous to mouse PERIOD than the PERIOD proteins from bees, flies, mosquitos, and many other Lepidoptera, such as Danaus plexippus and Bombyx mori. The circadian rhythms in adult locomotor activity were altered in the period knockout strain of P. xylostella under light-dark (LD) and continuous dark (DD) conditions. Under the LD cycle, the wild-type moths displayed nocturnal activity with activity peaking very early after lights off and quickly declining after lights on. In contrast, the period knockout strain had no peak in activity when the lights were turned off and exhibited steady activity throughout the hours of darkness. Interestingly, under DD conditions, our results showed that the locomotor rhythm can be maintained without period gene, but at a lower rhythmicity ratio than wild-type. In addition, knockout of period in P. xylostella changed circadian rhythms patterns related to pupal eclosion, mating, egg-laying, and egg hatching. Mechanistically, loss of PERIOD disrupted the molecular rhythm of period and changed the clock transcription rhythm in the heads of the moths under LD and DD conditions. Together, our study indicates that the PERIOD is required for normal expression of many behavioral rhythms in P. xylostella.

Single-cell RNA sequencing reveals the dynamics of hepatic non-parenchymal cells in autoprotection against acetaminophen-induced hepatotoxicity.

Gaining a better understanding of autoprotection against drug-induced liver injury (DILI) may provide new strategies for its prevention and therapy. However, little is known about the underlying mechanisms of this phenomenon. We used single-cell RNA sequencing to characterize the dynamics and functions of hepatic non-parenchymal cells (NPCs) in autoprotection against DILI, using acetaminophen (APAP) as a model drug. Autoprotection was modeled through pretreatment with a mildly hepatotoxic dose of APAP in mice, followed by a higher dose in a secondary challenge. NPC subsets and dynamic changes were identified in the APAP (hepatotoxicity-sensitive) and APAP-resistant (hepatotoxicity-resistant) groups. A chemokine (C-C motif) ligand 2+ endothelial cell subset almost disappeared in the APAP-resistant group, and an R-spondin 3+ endothelial cell subset promoted hepatocyte proliferation and played an important role in APAP autoprotection. Moreover, the dendritic cell subset DC-3 may protect the liver from APAP hepatotoxicity by inducing low reactivity and suppressing the autoimmune response and occurrence of inflammation. DC-3 cells also promoted angiogenesis through crosstalk with endothelial cells via vascular endothelial growth factor-associated ligand-receptor pairs and facilitated liver tissue repair in the APAP-resistant group. In addition, the natural killer cell subsets NK-3 and NK-4 and the Sca-1-CD62L+ natural killer T cell subset may promote autoprotection through interferon-γ-dependent pathways. Furthermore, macrophage and neutrophil subpopulations with anti-inflammatory phenotypes promoted tolerance to APAP hepatotoxicity. Overall, this study reveals the dynamics of NPCs in the resistance to APAP hepatotoxicity and provides novel insights into the mechanism of autoprotection against DILI at a high resolution.

De novo analysis of bulk RNA-seq data at spatially resolved single-cell resolution.

Uncovering the tissue molecular architecture at single-cell resolution could help better understand organisms' biological and pathological processes. However, bulk RNA-seq can only measure gene expression in cell mixtures, without revealing the transcriptional heterogeneity and spatial patterns of single cells. Herein, we introduce Bulk2Space ( https://github.com/ZJUFanLab/bulk2space ), a deep learning framework-based spatial deconvolution algorithm that can simultaneously disclose the spatial and cellular heterogeneity of bulk RNA-seq data using existing single-cell and spatial transcriptomics references. The use of bulk transcriptomics to validate Bulk2Space unveils, in particular, the spatial variance of immune cells in different tumor regions, the molecular and spatial heterogeneity of tissues during inflammation-induced tumorigenesis, and spatial patterns of novel genes in different cell types. Moreover, Bulk2Space is utilized to perform spatial deconvolution analysis on bulk transcriptome data from two different mouse brain regions derived from our in-house developed sequencing approach termed Spatial-seq. We have not only reconstructed the hierarchical structure of the mouse isocortex but also further annotated cell types that were not identified by original methods in the mouse hypothalamus.

High-Salt Diet Impairs the Neurons Plasticity and the Neurotransmitters-Related Biological Processes.

Salt, commonly known as sodium chloride, is an important ingredient that the body requires in relatively minute quantities. However, consuming too much salt can lead to high blood pressure, heart disease and even disruption of circadian rhythms. The biological process of the circadian rhythm was first studied in Drosophila melanogaster and is well understood. Their locomotor activity gradually increases before the light is switched on and off, a phenomenon called anticipation. In a previous study, we showed that a high-salt diet (HSD) impairs morning anticipation behavior in Drosophila. Here, we found that HSD did not significantly disrupt clock gene oscillation in the heads of flies, nor did it disrupt PERIOD protein oscillation in clock neurons or peripheral tissues. Remarkably, we found that HSD impairs neuronal plasticity in the axonal projections of circadian pacemaker neurons. Interestingly, we showed that increased excitability in PDF neurons mimics HSD, which causes morning anticipation impairment. Moreover, we found that HSD significantly disrupts neurotransmitter-related biological processes in the brain. Taken together, our data show that an HSD affects the multiple functions of neurons and impairs physiological behaviors.

Integrating serum exosomal microRNA and liver microRNA profiles disclose the function role of autophagy and mechanisms of Fructus Meliae Toosendan-induced hepatotoxicity in mice.

Herb-induced liver injury (HILI) is a growing clinical and economic problem worldwide. However, the underlying mechanism of HILI remains largely unknown, which hinders the prevention and treatment of this disease. Recently evidence supports that microRNAs (miRNAs) in circulating exosomes and cells play an important role in the pathology of liver diseases. Thus, using Fructus Meliae Toosendan (FMT) as an example of hepatoxic herbal medicine, the aim of this study was to reveal the mechanisms of FMT-induced liver injury (FILI) through integrated analysis of serum exosomal miRNAs and liver miRNAs profiles on FMT ethyl acetate extract (FMT for short)-exposed mice. Two dosages of FMT (20 and 40 g/kg) were involved in this study, while only high-dose exposure induced obvious liver injury in mice. Pathway analysis of 209 differentially expressed miRNAs (DEMs) in serum exosomes between high-dose FMT and control groups exhibited that FILI might be regulated by apoptosis-related pathways, such as p53 signaling, PI3K/Akt signaling, and PTEN signaling. Integrated analysis of the mRNA targets of serum exosomal DEMs and liver DEMs of high-dose FMT group showed that autophagy was significantly enriched as one of the top canonical pathways in FILI. Hepatocyte apoptosis was then proved by TUNEL assay in the liver tissue of high-dose FMT-treated mice. Moreover, in vivo validation studies suggested that the protein expression levels of PTEN, p-AKT, p53, and BAX were indeed regulated in the mouse liver after high-dose FMT administration, indicating hepatocyte apoptosis may be mediated by these three pathways mentioned above. Intriguingly, PINK1/Parkin-mediated mitophagy was activated in high-dose FMT-treated mouse liver and the protective effect of autophagy in FILI was validated in vitro with an autophagic flux inhibitor. In addition, serum exosomal miR-222, the most downregulated miRNAs between low- and high-dose FMT treatments, might be an important event in the hepatocyte apoptosis by regulating PTEN and PPP2R2A. In conclusion, integrated analysis of microRNA profiles in mouse serum exosomes and liver cells provides insights into the hepatotoxicity mechanisms of FMT and discloses the protective role of autophagy in FILI, suggesting this method could contribute to deeply understand the mechanism of HILI and activation of autophagy may be a potentially therapeutic strategy for FILI even HILI.

Circulating exosomal microRNAs reveal the mechanism of Fructus Meliae Toosendan-induced liver injury in mice.

The toxicological mechanisms of liver injury caused by most traditional Chinese medicine (TCM) remain largely unknown. Due to the unique features, exosomal microRNAs (miRNAs) are currently attracting major interests to provide further insights into toxicological mechanisms. Thus, taking Fructus Meliae Toosendan as an example of hepatoxic TCM, this study aimed to elucidate its hepatotoxicity mechanisms through profiling miRNAs in circulating exosomes of Fructus Meliae Toosendan water extract (FMT)-exposed mice. Biological pathway analysis of the 64 differentially expressed exosomal miRNAs (DEMs) showed that hepatic dysfunction induced by FMT likely related to apoptosis, mitochondrial dysfunction, and cell cycle dysregulation. Integrated analysis of serum exosomal DEMs and hepatic differentially expressed mRNAs further enriched oxidative stress and apoptosis related pathways. In vitro validation studies for omics results suggested that FMT-induced DNA damage was mediated by generating intracellular reactive oxygen species, leading to cell apoptosis through p53-dependent mitochondrial damage and S-phase arrest. Nrf2-mediated antioxidant response was activated to protect liver cells. Moreover, serum exosomal miR-370-3p, the most down-regulated miRNA involving in these pathways, might be the momentous event in aggravating cytotoxic effect of FMT by elevating p21 and Cyclin E. In conclusion, circulating exosomal miRNAs profiling could contribute to deepen the understanding of TCM-induced hepatotoxicity.

Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures.

JOURNAL/nrgr/04.03/01300535-202501000-00034/figure1/v/2024-05-14T021156Z/r/image-tiff Certain amino acids changes in the human Na+/K+-ATPase pump, ATPase Na+/K+ transporting subunit alpha 1 (ATP1A1), cause Charcot-Marie-Tooth disease type 2 (CMT2) disease and refractory seizures. To develop in vivo models to study the role of Na+/K+-ATPase in these diseases, we modified the Drosophila gene homolog, Atpα, to mimic the human ATP1A1 gene mutations that cause CMT2. Mutations located within the helical linker region of human ATP1A1 (I592T, A597T, P600T, and D601F) were simultaneously introduced into endogenous DrosophilaAtpα by CRISPR/Cas9-mediated genome editing, generating the AtpαTTTF model. In addition, the same strategy was used to generate the corresponding single point mutations in flies (AtpαI571T, AtpαA576T, AtpαP579T, and AtpαD580F). Moreover, a deletion mutation (Atpαmut) that causes premature termination of translation was generated as a positive control. Of these alleles, we found two that could be maintained as homozygotes (AtpαI571T and AtpαP579T). Three alleles (AtpαA576T, AtpαP579 and AtpαD580F) can form heterozygotes with the Atpαmut allele. We found that the Atpα allele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila. Flies heterozygous for AtpαTTTF mutations have motor performance defects, a reduced lifespan, seizures, and an abnormal neuronal morphology. These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.