Molecular mechanism for target recognition, dimerization, and activation of Pyrococcus furiosus Argonaute.

The Argonaute nuclease from the thermophilic archaeon Pyrococcus furiosus (PfAgo) contributes to host defense and represents a promising biotechnology tool. Here, we report the structure of a PfAgo-guide DNA-target DNA ternary complex at the cleavage-compatible state. The ternary complex is predominantly dimerized, and the dimerization is solely mediated by PfAgo at PIWI-MID, PIWI-PIWI, and PAZ-N interfaces. Additionally, PfAgo accommodates a short 14-bp guide-target DNA duplex with a wedge-type N domain and specifically recognizes 5'-phosphorylated guide DNA. In contrast, the PfAgo-guide DNA binary complex is monomeric, and the engagement of target DNA with 14-bp complementarity induces sufficient dimerization and activation of PfAgo, accompanied by movement of PAZ and N domains. A closely related Argonaute from Thermococcus thioreducens adopts a similar dimerization configuration with an additional zinc finger formed at the dimerization interface. Dimerization of both Argonautes stabilizes the catalytic loops, highlighting the important role of Argonaute dimerization in the activation and target cleavage.

Knockdown of the salivary protein gene NlG14 caused displacement of the lateral oviduct secreted components and inhibited ovulation in Nilaparvata lugens.

Saliva plays important roles in insect feeding, but its roles in insect reproduction were rarely reported. Here we reported that the knockdown of a salivary gland-specific gene NlG14 disrupted the reproduction through inhibiting the ovulation of the brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most devastating rice pests in Asia. NlG14 knockdown caused the displacement of the lateral oviduct secreted components (LOSC), leading to the ovulation disorder and the accumulation of mature eggs in the ovary. The RNAi-treated females laid much less eggs than their control counterparts, though they had the similar oviposition behavior on rice stems as controls. NlG14 protein was not secreted into the hemolymph, indicating an indirect effect of NlG14 knockdown on BPH reproduction. NlG14 knockdown caused the malformation of A-follicle of the principal gland and affected the underlying endocrine mechanism of salivary glands. NlG14 reduction might promote the secretion of insulin-like peptides NlILP1 and NlILP3 from the brain, which up-regulated the expression of Nllaminin gene and then caused the abnormal contraction of lateral oviduct muscle. Another explanation was NlG14 reduction disrupted the ecdysone biosynthesis and action through the insulin-PI3K-Akt signaling in ovary. Altogether, this study indicated that the salivary gland specific protein NlG14 indirectly mediated BPH ovulation process, which established a connexon in function between insect salivary gland and ovary.

Multi-omics reveals the role of MCM2 and hnRNP K phosphorylation in mouse renal aging through genomic instability.

The process of aging is characterized by structural degeneration and functional decline, as well as diminished adaptability and resistance. The aging kidney exhibits a variety of structural and functional impairments. In aging mice, thinning and graying of fur were observed, along with a significant increase in kidney indices compared to young mice. Biochemical indicators revealed elevated levels of creatinine, urea nitrogen and serum uric acid, suggesting impaired kidney function. Histological analysis unveiled glomerular enlargement and sclerosis, severe hyaline degeneration, capillary occlusion, lymphocyte infiltration, tubular and glomerular fibrosis, and increased collagen deposition. Observations under electron microscopy showed thickened basement membranes, altered foot processes, and increased mesangium and mesangial matrix. Molecular marker analysis indicated upregulation of aging-related ß-galactosidase, p16-INK4A, and the DNA damage marker γH2AX in the kidneys of aged mice. In metabolomics, a total of 62 significantly different metabolites were identified, and 10 pathways were enriched. We propose that citrulline, dopamine, and indoxyl sulfate have the potential to serve as markers of kidney damage related to aging in the future. Phosphoproteomics analysis identified 6656 phosphosites across 1555 proteins, annotated to 62 pathways, and indicated increased phosphorylation at the Ser27 site of Minichromosome maintenance complex component 2 (Mcm2) and decreased at the Ser284 site of heterogeneous nuclear ribonucleoprotein K (hnRNP K), with these modifications being confirmed by western blotting. The phosphorylation changes in these molecules may contribute to aging by affecting genome stability. Eleven common pathways were detected in both omics, including arginine biosynthesis, purine metabolism and biosynthesis of unsaturated fatty acids, etc., which are closely associated with aging and renal insufficiency.

Effect of isoproterenol, a ß-adrenergic agonist, on the differentiation of insulin-producing pancreatic ß cells derived from human pluripotent stem cells.

Research on islet replacement through the differentiation of functionally matured insulin-producing ß-like cells for the treatment of diabetes presents a significant challenge. Neural signals in ß cell differentiation significantly impact the pancreatic microenvironment in glucose metabolism, but they are not fully understood. In this study, isoproterenol, a ß adrenoreceptor agonist, was introduced into pancreatic progenitor cells, derived from human pluripotent stem cells in vitro, undergoing endocrine differentiation, using 2-dimensional (2D) and 3-dimensional (3D) differentiation protocols. This resulted in increased insulin and C-peptide secretion, along with elevated expression of key pancreatic beta cell transcription factors, including PDX-1, NKX6.1, and MAFA, and improved function, demonstrated by increased responsiveness to glucose determined via a glucose-stimulated insulin secretion test. Moreover, RNA transcriptome analysis of isoproterenol-treated endocrine progenitors facilitated the identification of biological pathways and genes that contribute to mature beta cell differentiation efficiency correlated with neural signals, such as adrenoceptor beta 1, calcium/calmodulin dependent protein kinase II alpha, phospholipase C delta 4, and neurotrophic receptor tyrosine kinase 1. Among those genes, calcium/calmodulin dependent protein kinase II alpha was suggested as the most notable gene involved in the isoproterenol mechanism through inhibitor assays. This study illustrates that isoproterenol significantly enhances endocrine differentiation and underscores its effects on stem cell-derived beta cell maturation, emphasizing its therapeutic potential for the treatment of diabetes.

Proteomics and ß-hydroxybutyrylation Modification Characterization in the Hearts of Naturally Senescent Mice.

Aging is widely accepted as an independent risk factor for cardiovascular disease (CVD), which contributes to increasing morbidity and mortality in the elderly population. Lysine ß-hydroxybutyrylation (Kbhb) is a novel post-translational modification (PTM), wherein ß-hydroxybutyrate is covalently attached to lysine ε-amino groups. Recent studies have revealed that histone Kbhb contributes to tumor progression, diabetic cardiomyopathy progression, and postnatal heart development. However, no studies have yet reported a global analysis of Kbhb proteins in aging hearts or elucidated the mechanisms underlying this modification in the process. Herein, we conducted quantitative proteomics and Kbhb PTM omics to comprehensively elucidate the alterations of global proteome and Kbhb modification in the hearts of aged mice. The results revealed a decline in grip strength and cardiac diastolic function in 22-month-old aged mice compared to 3-month-old young mice. High-throughput liquid chromatogram-mass spectrometry analysis identified 1710 ß-hydroxybutyrylated lysine sites in 641 proteins in the cardiac tissue of young and aged mice. Additionally, 183 Kbhb sites identified in 134 proteins exhibited significant differential modification in aged hearts (fold change (FC) > 1.5 or <1/1.5, p < 0.05). Notably, the Kbhb-modified proteins were primarily detected in energy metabolism pathways, such as fatty acid elongation, glyoxylate and dicarboxylate metabolism, tricarboxylic acid cycle, and oxidative phosphorylation. Furthermore, these Kbhb-modified proteins were predominantly localized in the mitochondria. The present study, for the first time, provides a global proteomic profile and Kbhb modification landscape of cardiomyocytes in aged hearts. These findings put forth novel possibilities for treating cardiac aging and aging-related CVDs by reversing abnormal Kbhb modifications.

Quantification and Proteomic Characterization of ß-Hydroxybutyrylation Modification in the Hearts of AMPKα2 Knockout Mice.

AMP-activated protein kinase alpha 2 (AMPKα2) regulates energy metabolism, protein synthesis, and glucolipid metabolism myocardial cells. Ketone bodies produced by fatty acid ß-oxidation, especially ß-hydroxybutyrate, are fatty energy-supplying substances for the heart, brain, and other organs during fasting and long-term exercise. They also regulate metabolic signaling for multiple cellular functions. Lysine ß-hydroxybutyrylation (Kbhb) is a ß-hydroxybutyrate-mediated protein posttranslational modification. Histone Kbhb has been identified in yeast, mouse, and human cells. However, whether AMPK regulates protein Kbhb is yet unclear. Hence, the present study explored the changes in proteomics and Kbhb modification omics in the hearts of AMPKα2 knockout mice using a comprehensive quantitative proteomic analysis. Based on mass spectrometry (LC-MS/MS) analysis, the number of 1181 Kbhb modified sites in 455 proteins were quantified between AMPKα2 knockout mice and wildtype mice; 244 Kbhb sites in 142 proteins decreased or increased after AMPKα2 knockout (fold change >1.5 or <1/1.5, p < 0.05). The regulation of Kbhb sites in 26 key enzymes of fatty acid degradation and tricarboxylic acid cycle was noted in AMPKα2 knockout mouse cardiomyocytes. These findings, for the first time, identified proteomic features and Kbhb modification of cardiomyocytes after AMPKα2 knockout, suggesting that AMPKα2 regulates energy metabolism by modifying protein Kbhb.

Cellular and molecular mechanisms of gastrointestinal cancer liver metastases and drug resistance.

Distant metastases and drug resistance account for poor survival of patients with gastrointestinal (GI) malignancies such as gastric cancer, pancreatic cancer, and colorectal cancer. GI cancers most commonly metastasize to the liver, which provides a unique immunosuppressive tumour microenvironment to support the development of a premetastatic niche for tumor cell colonization and metastatic outgrowth. Metastatic tumors often exhibit greater resistance to drugs than primary tumors, posing extra challenges in treatment. The liver metastases and drug resistance of GI cancers are regulated by complex, intertwined, and tumor-dependent cellular and molecular mechanisms that influence tumor cell behavior (e.g. epithelial-to-mesenchymal transition, or EMT), tumor microenvironment (TME) (e.g. the extracellular matrix, cancer-associated fibroblasts, and tumor-infiltrating immune cells), tumor cell-TME interactions (e.g. through cytokines and exosomes), liver microenvironment (e.g. hepatic stellate cells and macrophages), and the route and mechanism of tumor cell dissemination (e.g. circulating tumor cells). This review provides an overview of recent advances in the research on cellular and molecular mechanisms that regulate liver metastases and drug resistance of GI cancers. We also discuss recent advances in the development of mechanism-based therapy for these GI cancers. Targeting these cellular and molecular mechanisms, either alone or in combination, may potentially provide novel approaches to treat metastatic GI malignancies.

Targeting DKK1 enhances the antitumor activity of paclitaxel and alleviates chemotherapy-induced peripheral neuropathy in breast cancer.

Chemotherapy in combination with immunotherapy has gradually shown substantial promise to increase T cell infiltration and antitumor efficacy. However, paclitaxel in combination with immune checkpoint inhibitor targeting PD-1/PD-L1 was only used to treat a small proportion of metastatic triple-negative breast cancer (TNBC), and the clinical outcomes was very limited. In addition, this regimen cannot prevent paclitaxel-induced peripheral neuropathy. Therefore, there was an urgent need for a novel target to enhance the antitumor activity of paclitaxel and alleviate chemotherapy-induced peripheral neuropathy in breast cancer. Here, we found that Dickkopf-1 (DKK1) expression was upregulated in multiply subtypes of human breast cancer specimens after paclitaxel-based chemotherapy. Mechanistic studies revealed that paclitaxel promoted DKK1 expression by inducing EGFR signaling in breast cancer cells, and the upregulation of DKK1 could hinder the therapeutic efficacy of paclitaxel by suppressing the infiltration and activity of CD8+ T cells in tumor microenvironment. Moreover, paclitaxel treatment in tumor-bearing mice also increased DKK1 expression through the activation of EGFR signaling in the primary sensory dorsal root ganglion (DRG) neurons, leading to the development of peripheral neuropathy, which is charactered by myelin damage in the sciatic nerve, neuropathic pain, and loss of cutaneous innervation in hindpaw skin. The addition of an anti-DKK1 antibody not only improved therapeutic efficacy of paclitaxel in two murine subtype models of breast cancer but also alleviated paclitaxel-induced peripheral neuropathy. Taken together, our findings providing a potential chemoimmunotherapy strategy with low neurotoxicity that can benefit multiple subtypes of breast cancer patients.

Andrographolide sensitizes glioma to temozolomide by inhibiting DKK1 expression.

BACKGROUND: Temozolomide (TMZ) is the first-line chemotherapeutic drug for gliomas treatment. However, the clinical efficacy of TMZ in glioma patients was very limited. Therefore, it is urgently needed to discover a novel approach to increase the sensitivity of glioma cells to TMZ. METHODS: Western blot, immunohistochemical staining, and qRT-PCR assays were used to explore the mechanisms underlying TMZ promoting DKK1 expression and andrographolide (AND) inhibiting DKK1 expression. HPLC was used to detect the ability of andrographolide (AND) to penetrate the blood-brain barrier. MTT assay, bioluminescence images, magnetic resonance imaging (MRI) and H&E staining were employed to measure the proliferative activity of glioma cells and the growth of intracranial tumors. RESULTS: TMZ can promote DKK1 expression in glioma cells and brain tumors of an orthotopic model of glioma. DKK1 could promote glioma cell proliferation and tumor growth in an orthotopic model of glioma. Mechanistically, TMZ increased EGFR expression and subsequently induced the activation of its downstream MEK-ERK and PI3K-Akt pathways, thereby promoting DKK1 expression in glioma cells. Andrographolide inhibited TMZ-induced DKK1 expression through inactivating MEK-ERK and PI3K-Akt pathways. Andrographolide can cross the blood-brain barrier, the combination of TMZ and andrographolide not only improved the anti-tumor effects of TMZ but also showed a survival benefit in an orthotopic model of glioma. CONCLUSION: Andrographolide can enhance anti-tumor activity of TMZ against glioma by inhibiting DKK1 expression.

Enhancing the Efficiency of Flexible, Large-Area, ITO-Free Organic Photovoltaic Devices.

The development of flexible ITO-free devices is crucial for the industrial advancement of organic photovoltaic (OPV) technology. Here, a novel ITO-free device architecture is proposed, and ITO-free OPV devices are realized on glass substrates with performance comparable to that of ITO-based devices. It is also demonstrated that the performance of ITO-free devices on polyethylene terephthalate (PET) substrates is limited due to the higher surface roughness of PET, leading to high voltage losses, low device quantum efficiency, and high device leakage current. To address the issue of high roughness on the PET surface, a polyimide (PI) modification strategy is developed and the PI-modified PET is employed as the substrate to construct flexible ITO-free OPV devices and large-area modules with an active area of up to 16.5 cm2. This approach leads to decreased trap-assisted recombination losses, enhanced exciton dissociation efficiency, and a reduced density of pinholes in flexible OPV devices, resulting in improved photovoltaic performance under both strong and weak illumination conditions. The outcomes of this work are expected to advance the industrial development of flexible organic photovoltaic technology.

Pressure-Induced Re-Entrant Superconductivity in Transition Metal Dichalcogenide TiSe2.

Transition metal dichalcogenide TiSe2 exhibits a superconducting dome within a low pressure range of 2-4 GPa, which peaks with the maximal transition temperature Tc of ≈1.8 K. Here it is reported that applying high pressure induces a new superconducting state in TiSe2, which starts at ≈16 GPa with a substantially higher Tc that reaches 5.6 K at ≈21.5 GPa with no sign of decline. Combining high-throughput first-principles structure search, X-ray diffraction, and Raman spectroscopy measurements up to 30 GPa, It is found that TiSe2 undergoes a first-order structural transition from the 1T phase under ambient pressure to a new 4O phase under high pressure. Comparative ab initio calculations reveal that while the conventional phonon-mediated pairing mechanism may account for the superconductivity observed in 1T-TiSe2 under low pressure, the electron-phonon coupling of 4O-TiSe2 is too weak to induce a superconducting state whose transition temperature is as high as 5.6 K under high pressure. The new superconducting state found in pressurized TiSe2 requires further study on its underlying mechanism.

An OBP gene highly expressed in non-chemosensory tissues affects the phototaxis and reproduction of Spodoptera frugiperda.

Insect odorant binding proteins (OBPs) were initially regarded as carriers of the odorants involved in chemosensation. However, it had been observed that a growing number of OBP genes exhibited broad expression patterns beyond chemosensory tissues. Here, an OBP gene (OBP31) was found to be highly expressed in the larval ventral nerve cord, adult brain and male reproductive organ of Spodoptera frugiperda. An OBP31 knockout strain (OBP31-/- ) was generated by CRISPR/Cas9 mutagenesis. For OBP31-/- , the larvae needed longer time to pupate, but there was no difference in the pupal weight between OBP31-/- and wild type (WT). OBP31-/- larvae showed stronger phototaxis than the WT larvae, indicating the importance of OBP31 in light perception. For mating rhythm of adults, OBP31-/- moths displayed an earlier second mating peak. In the cross-pairing of OBP31-/- and WT moths, the mating duration was longer, and hatchability was lower in OBP31-/- group and OBP31+/- ♂ group than that in the WT group. These results suggested that OBP31 played a vital role in larval light perception and male reproductive process and could provide valuable insights into understanding the biological functions of OBPs that were not specific in chemosensory tissues.

Characterization and Dissolution Mechanism of Low-Molecular-Weight Organic Acids or Inorganic Mesoporous Particle-Based Piperine Amorphous Solid Dispersions.

The objective of the current study is to prepare amorphous solid dispersions (ASDs) containing piperine (PIP) by utilizing organic acid glycyrrhizic acid (GA) and inorganic disordered mesoporous silica 244FP (MSN/244FP) as carriers and to investigate their dissolution mechanism. The physicochemical properties of ASDs were characterized with scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) and one-dimensional proton nuclear magnetic resonance (1H NMR) studies collectively proved that strong hydrogen-bonding interactions formed between PIP and the carriers in ASDs. Additionally, molecular dynamic (MD) simulation was conducted to simulate and predict the physical stability and dissolution mechanisms of the ASDs. Interestingly, it revealed a significant increase in the dissolution of amorphous PIP in ASDs in in vitro dissolution studies. Rapid dissolution of GA in pH 6.8 medium resulted in the immediate release of PIP drugs into a supersaturated state, acting as a dissolution-control mechanism. This exhibited a high degree of fitting with the pseudo-second-order dynamic model, with an R2 value of 0.9996. Conversely, the silanol groups on the outer surface of the MSN and its porous nanostructures enabled PIP to display a unique two-step drug release curve, indicating a diffusion-controlled mechanism. This curve conformed to the Ritger-Peppas model, with an R2 > 0.9. The results obtained provide a clear evidence of the proposed transition of dissolution mechanism within the same ASD system, induced by changes in the properties of carriers in a solution medium of varying pH levels.

Aberrant phenotypes of circulating γδ-T cells may be involved in the onset of systemic lupus erythematosus.

OBJECTIVE: Human gamma-delta T cells (γδ-T cells) play crucial roles in both innate and adaptive immune responses. However, much less is known about the immune status of γδT cells in systemic lupus erythematosus (SLE) patients. The objective of this study was to explore potential relationships between the frequency of γδ-T-cell subpopulations and disease activity, autoantibody titres and renal involvement in patients with SLE. METHODS: Circulating γδ-T cells and their subsets (Vδ1+ T cells, Vδ2+ T cells and γδ-T-cell subpopulations defined by expression of surface receptors, including NKG2D, NKp30, NKp46 and PD-1), were identified via flow cytometry. Sixty active SLE patients were selected, including 41 new-onset and 19 relapsing cases. One hundred healthy controls (HCs) were enrolled as the control group. Percentages of these cell subsets in SLE patients and HCs and their relationships with disease activity were analysed. Twenty-two of the 41 new-onset SLE patients were assessed before and after treatment. Changes in the frequencies of these cell subsets and their relationships with renal involvement were also analysed. RESULTS: Compared with that in HCs, the percentage of total γδ-T cells among CD3+ T cells in SLE patients was significantly lower. An imbalance in the proportions of Vδ1+ and Vδ2+ T cells among γδ-T cells was observed. The proportion of Vδ1+ T cells among γδ-T cells was significantly greater in SLE patients than in HCs, while the proportion of Vδ2+ T cells was significantly lower. Expression levels of PD-1, NKG2D, NKp30 and NKp46 in Vδ1+ T cells and Vδ2+ T cells from SLE patients were generally significantly increased, except for expression of NKG2D in Vδ2+ T cells. Moreover, Vδ2+ T cells, Vδ1+ T cells and Vδ1+PD-1+ T cells were associated with disease activity, and an increase in Vδ2+ T-cell frequency and a decrease in PD-1 expression by γδ-T cells might be associated with effective treatment. Interestingly, our results indicated that Vδ2+ T cells and their Vδ2+NKp30+ T-cell subpopulation might be associated with renal involvement in SLE. CONCLUSION: A broad range of anomalies in the proportions of γδ-T-cell subsets and γδ-T cells in SLE patients may be involved in the pathogenesis of SLE. There is a strong association between Vδ2+ T cells and their Vδ2+NKp30+ T-cell subpopulation and LN occurrence. Our results indicate that γδ-T cells and their subpopulations might be key players in disease immunopathology and renal involvement in SLE.

Integrated metabolomics and phosphoproteomics reveal the protective role of exosomes from human umbilical cord mesenchymal stem cells in naturally aging mouse livers.

BACKGROUND: Aging is characterized by a general decline in cellular function, which ultimately affects whole body homeostasis. This study aimed to investigate the effects and underlying mechanisms of exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSC-exos) on the livers of naturally aging mice. METHOD: Twenty-two-month-old C57BL6 mice were used as a natural aging animal model, divided into a saline-treated wild-type aged control group (WT-AC) and a hUCMSC-exo-treated group (WT-AEX), and then detected by morphology, metabolomics and phosphoproteomics. RESULTS: Morphological analysis showed that hUCMSC-exos ameliorated structural disorder and decreased markers of senescence and genome instability in aging livers. Metabolomics showed that hUCMSC-exos decreased the contents of saturated glycerophospholipids, palmitoyl-glycerols and eicosanoid derivatives associated with lipotoxicity and inflammation, consistent with the decreased phosphorylation of metabolic enzymes, such as propionate-CoA ligase (Acss2), at S267 detected by phosphoproteomics. Moreover, phosphoproteomics indicated that hUCMSC-exos reduced the phosphorylation of proteins participating in nuclear transport and cancer signaling, such as heat shock protein HSP90-beta (Hsp90ab1) at S226 and nucleoprotein TPR (Tpr) at S453 and S379, while increasing those involved in intracellular communication, such as calnexin (Canx) at S563 and PDZ domain-containing protein 8 (Pdzd8). Finally, phosphorylated HSP90ß and Tpr were verified predominantly in hepatocytes. CONCLUSION: HUCMSC-exos improved metabolic reprogramming and genome stability mainly associated with phosphorylated HSP90ß in hepatocytes in natural aging livers. This work provides a comprehensive resource of biological data by omics to support future investigations of hUCMSC-exos in aging.

Investigating the optimal maximum diameter of benign thyroid nodules for thermal ablation on the basis of complete disappearance rate.

OBJECTIVE: Thermal ablation (TA) is a safe and effective treatment for benign thyroid nodules (BTNs). However, there has been no consensus on the optimal maximum diameter (MD) of BTNs for TA. This study aimed to identify the optimal MD of BTNs for TA based on complete disappearance rate after TA. MATERIALS AND METHODS: This retrospective study included 639 BTNs treated with TA from June 2014 to January 2022. The complete disappearance rate of BTNs after TA was summarized, related influencing factors were explored, and the optimal MD of BTNs for TA was identified. RESULTS: At the final follow-up (median: 40 months, range: 24-95 months), the overall volume reduction rate was 95.4 ± 9.0%, and 50.5% of the BTNs (323/639) completely disappeared. The MD was significantly negatively correlated with complete disappearance (odds ratio 0.89, 95% confidence interval 0.87-0.92; p < 0.001). Calcification, comet-tail artifacts, multilocular cysts, and composition of BTNs, as well as diabetes were negatively correlated with complete disappearance. Restricted cubic spline indicated that an MD of 25.0 mm was the optimal threshold of BTNs for TA, which was confirmed by subgroup logistic regression analysis. Compared with BTNs with MD ≤ 25.0 mm, those with MD > 25.0 mm had a greater complication rate (6.5% vs. 2.4%, p = 0.012). CONCLUSIONS: The MD of BTNs was negatively correlated with complete disappearance after TA; an MD > 25.0 mm indicated a reduced likelihood of complete disappearance compared with an MD ≤ 25.0 mm. An MD of 25.0 mm is an appropriate threshold of BTNs for TA on the basis of complete disappearance rate.

Quantitative evaluation of morphological and functional changes in meibomian glands and lipid layer thickness in patients with and without keratoconus.

PURPOSE: To quantitatively evaluate the morphological parameters of meibomian glands (MGs) and lipid layer thickness (LLT) in patients with keratoconus (KC). METHODS: In this prospective, cross-sectional study, 164 eyes of 164 keratoconus patients and 64 eyes of 64 age-matched control subjects were included. An advanced automatic MG analyzer was used to quantitatively measure the morphological and functional parameters of MGs. Morphological and functional parameters of MGs, LLT, and other ocular surface parameters were compared between the control and KC groups. RESULTS: The mean meibomian gland diameter, length, square, and gland area ratio (GA) were all significantly decreased in the KC group (all P < 0.05), while no significant difference was observed in the gland tortuosity index (TI) and gland signal index (SI) between the KC and control groups (all P > 0.05). There was no significant difference in the number of total and incomplete blinking among patients with different stages of keratoconus (all P > 0.05). The gland diameter, square, and TI were all negatively associated with KC severity (all P < 0.05), while no significant difference was observed among all stages of KC in gland length, GA, and SI (all P > 0.05). Moreover, the LLTs were positively correlated with the gland diameter, square, GA, and TI and negatively correlated with anterior corneal curvature or KC severity (all P < 0.05). CONCLUSIONS: Atrophic morphological changes in the meibomian glands were closely correlated with the severity of keratoconus. Gland diameter may be a sensitive functional morphology metric of meibomian glands in patients with keratoconus.

Comparative analysis of child injuries in passenger vehicles and school buses: a multicentre cross-sectional study.

OBJECTIVE: This study investigated the differences in injury profiles and safety device effectiveness among children with road traffic injuries (RTIs) involving passenger vehicles and school buses. METHODS: Using data from the Emergency Department-based Injury In-depth Surveillance database, this multicentre cross-sectional study investigated the injury profiles of 14 669 children aged 12 years old and younger who experienced RTIs from 2011-2021. Demographic factors, injury distribution, severity and effect of safety device use between RITs involving passenger vehicles and school buses were compared. RESULTS: RTIs in children most frequently occurred between 12:00 and 18:00 hours (46.9%). School bus-related RTIs peaked during school commute hours, that is, from 06:00 to 12:00 hours, and were associated with a higher prevalence of head (63.1% vs 58.9%, p<0.05) and extremity injuries (upper extremity: 8.0% vs 6.4% and lower extremity: 11.1% vs 7.6 %, p<0.05) compared with those involving passenger vehicles. However, passenger vehicle crashes showed higher proportions of neck and chest injuries, along with injuries requiring hospitalisation and intensive care. Safety devices exhibited preventive effects against head and lower extremity injuries in both vehicle types. While safety devices showed effective in reducing hospital admissions and severe injuries in passenger vehicles, their effectiveness in school buses was not observed. CONCLUSION: This study highlights the different epidemiology and injury profiles of RTIs among children involving passenger vehicles and school buses. Improved safety devices, particularly in school buses, are necessary to ensure the comprehensive protection of child passengers and reduce the risk of severe injuries during road traffic incidents.

Insecticidal activity of the spider neurotoxin PPTX-04 through modulating insect voltage-gated sodium channel.

Ion channels on cell membrane are molecular targets of more than half peptide neurotoxins from spiders. From Pardosa pseudoannulata, a predatory spider on a range of insect pests, we characterized a peptide neurotoxin PPTX-04 with an insecticidal activity. PPTX-04 showed high toxicity to Nilaparvata lugens, a main prey of P. pseudoannulata, and the toxicity was not affected by the resistance to etofenprox (IUPAC chemical name:1-ethoxy-4-[2-methyl-1-[(3-phenoxyphenyl)methoxy]propan-2-yl]benzene, purity: 99%). On N. lugens voltage-gated sodium channel NlNav1 expressed in Xenopus oocytes, PPTX-04 prolonged the channel opening and induced tail currents, which is similar to pyrethroid insecticides. However, PPTX-04 potency on NlNav1 was not affected by mutations conferring pyrethroid resistance in insects, which revealed that PPTX-04 and pyrethroids should act on different receptors in NlNav1. In contrast, two mutations at the extracellular site 4 significantly reduced PPTX-04 potency, which indicated that PPTX-04 would act on a potential receptor containing the site 4 in NlNav1. The result from the molecular docking supported the conclusion that the binding pocket of PPTX-04 in NlNav1 should contain the site 4. In summary, PPTX-04 had high insecticidal activity through acting on a distinct receptor site in insect Nav, and was a potential resource to control insect pests and manage resistance to pyrethroids.

Development of a Convenient and Quantitative Method for Evaluating Photosensitizing Activity Using Thiazolyl Blue Formazan Dye.

Photosensitizers cause oxidative damages in various biological systems under light. In this study, the method for analyzing photosensitizing activity of various dietary and medicinal sources was developed using 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (thiazolyl blue formazan; MTT-F) as a probe. Significant and quantitative decolorization of MTT-F was observed in the presence of photosensitizers used in this study under light but not under dark conditions. The decolorization of MTT-F occurred irradiation time-, light intensity-, and photosensitizer concentration-dependently. The decolorized MTT-F was reversibly reduced by living cells; the LC-MS/MS results indicated the formation of oxidized products with -1 m/z of base peak from MTT-F, suggesting that MTT-F decolorized by photosensitizers was its corresponding tetrazolium. The present results indicate that MTT-F is a reliable probe for the quantitative analysis of photosensitizing activities, and the MTT-F-based method can be an useful tool for screening and evaluating photosensitizing properties of various compounds used in many industrial purposes.