A Monte Carlo simulation-based health risk assessment of heavy metals in soils of the tropical region in southern China.

The disturbance of ecological stability may take place in tropical regions due to the elevated biomass density resulting from heavy metal and other contaminant pollution. In this study, 62 valid soil samples were collected from Sanya. Source analysis of heavy metals in the area was carried out using absolute principal component-multiple linear regression receptor modelling (APCS-MLR); the comprehensive ecological risk of the study area was assessed based on pollution sources; the Monte-Carlo model was used to accurately predict the health risk of pollution sources in the study area. The results showed that: The average contents of soil heavy metals Cu, Ni and Cd in Sanya were 5.53, 6.56 and 11.66 times higher than the background values of heavy metals. The results of soil geo-accumulation index (Igeo) showed that Cr, Mo, Mn and Zn were unpolluted to moderately polluted, Cu and Ni were moderately polluted, and Cd was moderately polluted to strongly polluted. The main sources of heavy metal pollution were natural sources (57.99%), agricultural sources (38.44%) and traffic sources (3.57%). Natural and agricultural sources were jointly identified as priority control pollution sources and Cd was the priority control pollution element for soil ecological risk. Heavy metal content in Sanya did not pose a non-carcinogenic risk to the population, but there was a carcinogenic risk to children. The element Zn had a high carcinogenic risk to children, and was a priority controlling pollutant element for the risk of human health, with agricultural sources as the priority controlling pollutant source.

A CD36-dependent non-canonical lipid metabolism program promotes immune escape and resistance to hypomethylating agent therapy in AML.

Environmental lipids are essential for fueling tumor energetics, but whether these exogenous lipids transported into cancer cells facilitate immune escape remains unclear. Here, we find that CD36, a transporter for exogenous lipids, promotes acute myeloid leukemia (AML) immune evasion. We show that, separately from its established role in lipid oxidation, CD36 on AML cells senses oxidized low-density lipoprotein (OxLDL) to prime the TLR4-LYN-MYD88-nuclear factor κB (NF-κB) pathway, and exogenous palmitate transfer via CD36 further potentiates this innate immune pathway by supporting ZDHHC6-mediated MYD88 palmitoylation. Subsequently, NF-κB drives the expression of immunosuppressive genes that inhibit anti-tumor T cell responses. Notably, high-fat-diet or hypomethylating agent decitabine treatment boosts the immunosuppressive potential of AML cells by hijacking CD36-dependent innate immune signaling, leading to a dampened therapeutic effect. This work is of translational interest because lipid restriction by US Food and Drug Administration (FDA)-approved lipid-lowering statin drugs improves the efficacy of decitabine therapy by weakening leukemic CD36-mediated immunosuppression.

Association of Human Whole-blood NAD + Levels with Nabothian Cyst.

Objective: Little is known about the association between whole-blood nicotinamide adenine dinucleotide (NAD +) levels and nabothian cysts. This study aimed to assess the association between NAD + levels and nabothian cysts in healthy Chinese women. Methods: Multivariate logistic regression analysis was performed to analyze the association between NAD + levels and nabothian cysts. Results: The mean age was 43.0 ± 11.5 years, and the mean level of NAD + was 31.3 ± 5.3 µmol/L. Nabothian cysts occurred in 184 (27.7%) participants, with single and multiple cysts in 100 (15.0%) and 84 (12.6%) participants, respectively. The total nabothian cyst prevalence gradually decreased from 37.4% to 21.6% from Q1 to Q4 of NAD + and the prevalence of single and multiple nabothian cysts also decreased across the NAD + quartiles. As compared with the highest NAD + quartile (≥ 34.4 µmol/L), the adjusted odds ratios with 95% confidence interval of the NAD + Q1 was 1.89 (1.14-3.14) for total nabothian cysts. The risk of total and single nabothian cysts linearly decreased with increasing NAD + levels, while the risk of multiple nabothian cysts decreased more rapidly at NAD + levels of 28.0 to 35.0 µmol/L. Conclusion: Low NAD + levels were associated with an increased risk of total and multiple nabothian cysts.

First report of Corynespora cassiicola causing leaf spot on Nanhaia speciosa in China.

Nanhaia speciosa, commonly known as Niudali, is a medicinal woody vine belonging to the Leguminosae family. Valued for its culinary and medicinal properties, it is extensively cultivated, covering approximately 5,973 hm2 in the Guangxi Zhuang Autonomous Region of China. The edible tubers of this plant are reported to possess antibacterial and antioxidant effects (Luo et al., 2023; Shu et al., 2020). In July 2021, a Niudali plantation in Yulin, Guangxi, China (22°64'N; 110°29'E) exhibited leaf spot symptoms, with an incidence rate exceeding 40% across a 46,690 m2 area. Initially, small circular, pale yellow spots appeared on the leaves, which subsequently evolved into dark brown lesions surrounded by yellow halos, ultimately leading to foliage wilting. Leaves exhibiting typical symptoms were collected for pathogen investigation. The leaves were thoroughly washed with sterile water and small tissue fragments (5×5 mm) were excised from the lesion periphery. These fragments were surface-sterilized with 75% ethanol and 1% NaClO, rinsed three times with sterile water, and subsequently cultured on potato dextrose agar (PDA) at 28 °C in darkness for 7 days. Through single-spore isolation, seven isolates with similar morphological traits were obtained. After 7 days of incubation on PDA at 28 °C in dark, the colonies exhibited a white to grey coloration on the upper surface with abundant aerial hyphae, while the underside appeared dark black. The conidia, cylindrical or obclavate in shape, were straight, pale brown, and measured 30.1-128.9 µm × 4.8-15.0 µm (n=50). The morphological characteristics matched those of Corynespora sp.(Wang et al. 2021). For molecular identification, the isolate N5-2 underwent DNA sequence analysis using genomic DNA and primers ITS1/ITS4 and EF1-688F/EF1-1251R. The sequences (ITS: OP550425; TEF1-α: OQ117118) were deposited in GenBank, exhibiting 98% identity to C. cassiicola (OP981637) for TEF1-α and 99% homology to C. cassiicola (OP957070) for ITS. Based on the concatenated ITS and TEF1-α, a maximum likelihood phylogenetic analyses using MEGA7.0 clustered the isolate with C. cassiicola. Consequently, the fungus was identified as C. cassiicola based on its morphological and molecular features. In the pathogenicity test on 1-year-old Nanhaia speciosa seedlings, leaves were gently scratched and inoculated with mycelial plugs (5 mm). Control seedlings received PDA plugs. Five leaves per plant and five plants per treatment were selected for assessment. All seedling were maintained in a greenhouse (12/12h light/dark cycle, 25 ± 2°C, 90% humidity). After a 7-day incubation period, all leaves subjected to fungal inoculation exhibited symptoms consistent with those observed in the field, while control plants remained symptom-free. The fungus was successfully reisolated from the infected leaves in three successive trials, fulfilling Koch's postulates. While C. cassiicola is well-documented for inducing leaf spots on various plant species, including Jasminum nudiflorum, Strobilanthes cusia, Acanthus ilicifolius, Syringa species (Hu et al., 2023; Liu et al., 2023; Xie et al., 2021; Wang et al., 2021), this study represents the first report of C. cassiicola causing leaf spots on Nanhaia speciosa in China. The identification of this pathogen in Nanhaia speciosa has significant implications for future epidemiological investigations and serves as a valuable reference for controlling leaf spot disease in Nanhaia speciosa.

The mechanoreceptor Piezo is required for spermatogenesis in Bombyx mori.

BACKGROUND: The animal sperm shows high diversity in morphology, components, and motility. In the lepidopteran model insect, the silkworm Bombyx mori, two types of sperm, including nucleate fertile eupyrene sperm and anucleate unfertile apyrene sperm, are generated. Apyrene sperm assists fertilization by facilitating the migration of eupyrene spermatozoa from the bursa copulatrix to the spermatheca. During spermatogenesis, eupyrene sperm bundles extrude the cytoplasm by peristaltic squeezing, while the nuclei of the apyrene sperm bundles are discarded with the same process, forming matured sperm. RESULTS: In this study, we describe that a mechanoreceptor BmPiezo, the sole Piezo ortholog in B. mori, plays key roles in larval feeding behavior and, more importantly, is essential for eupyrene spermatogenesis and male fertility. CRISPR/Cas9-mediated loss of BmPiezo function decreases larval appetite and subsequent body size and weight. Immunofluorescence analyses reveal that BmPiezo is intensely localized in the inflatable point of eupyrene sperm bundle induced by peristaltic squeezing. BmPiezo is also enriched in the middle region of apyrene sperm bundle before peristaltic squeezing. Cytological analyses of dimorphic sperm reveal developmental arrest of eupyrene sperm bundles in BmPiezo mutants, while the apyrene spermatogenesis is not affected. RNA-seq analysis and q-RT-PCR analyses demonstrate that eupyrene spermatogenic arrest is associated with the dysregulation of the actin cytoskeleton. Moreover, we show that the deformed eupyrene sperm bundles fail to migrate from the testes, resulting in male infertility due to the absence of eupyrene sperm in the bursa copulatrix and spermatheca. CONCLUSIONS: In conclusion, our studies thus uncover a new role for Piezo in regulating spermatogenesis and male fertility in insects.

GASZ is indispensable for gametogenesis in the silkworm, Bombyx mori.

The prominent role of the P-element induced wimpy testis (PIWI)-interacting RNA (piRNA) pathway in animals is to silence transposable elements and maintain genome stability, ensuring proper gametogenesis in gonads. GASZ (Germ cell protein with Ankyrin repeats, Sterile alpha motif, and leucine Zipper) is an evolutionarily conserved protein located on the outer mitochondrial membrane of germ cells and plays vital roles in the piRNA pathway and spermatogenesis in mammals. In the model insect Drosophila melanogaster, GASZ is essential for piRNA biogenesis and oogenesis, whereas its biological functions in non-drosophilid insects are still unknown. Here, we describe a comprehensive investigation of GASZ functions in the silkworm, Bombyx mori, a lepidopteran model insect, by using a binary transgenic CRISPR/Cas9 system. The BmGASZ mutation did not affect growth and development, but led to sterility in both males and females. Eupyrene sperm bundles of mutant males exhibited developmental defects, while the apyrene sperm bundles were normal, which were further confirmed through double copulation experiments with sex-lethal mutants, which males possess functional eupyrene sperm and abnormal apyrene sperm. In female mutant moths, ovarioles were severely degenerated and the eggs in ovarioles were deformed compared with that of wild type (WT). Further RNA-seq and RT-qPCR analysis revealed that amounts of piRNAs and transposon expression were dysregulated in gonads of mutants. In summary, this study has demonstrated vital roles of BmGASZ in gametogenesis through regulating the piRNA pathway in B. mori.

Correlation analysis of phosphorylation of myofibrillar protein and muscle quality of tilapia during storage in ice.

In this study, the correlation between protein phosphorylation and deterioration in the quality of tilapia during storage in ice was examined by assessing changes in texture, water-holding capacity (WHC), and biochemical characteristics of myofibrillar protein throughout 7 days of storage. The hardness significantly decreased from 471.50 to 252.17 g, whereas cooking and drip losses significantly increased from 26.5% to 32.6% and 2.9% to 9.1%, respectively (P < 0.05). Myofibril fragmentation increased, while myofibrillar protein sulfhydryl content and Ca2+-ATPase activity decreased from 119.33 to 89.29 µmol/g prot and 0.85 to 0.46 µmolPi/mg prot/h, respectively (P < 0.05). Correlation analysis revealed that the myofibrillar protein phosphorylation level was positively correlated with hardness and Ca2+-ATPase activity but negatively correlated with WHC. Myofibrillar protein phosphorylation affects muscle contraction by influencing the dissociation of actomyosin, thereby regulating hardness and WHC. This study provides novel insights for the establishment of quality control strategies for tilapia storage based on protein phosphorylation.

Impact of Various Ration Energy Levels on the Slaughtering Performance, Carcass Characteristics, and Meat Qualities of Honghe Yellow Cattle.

Consumers are increasing their daily demand for beef and are becoming more discerning about its nutritional quality and flavor. The present objective was to evaluate how the ration energy content (combined net energy, Nemf) impacts the slaughter performance, carcass characteristics, and meat qualities of Honghe yellow cattle raised in confinement. Fifteen male Honghe yellow cattle were divided into three groups based on a one-way design: a low-energy group (LEG, 3.72 MJ/kg), a medium-energy group (MEG, 4.52 MJ/kg), and a high-energy group (HEG, 5.32 MJ/kg). After a period of 70 days on these treatments, the animals were slaughtered and their slaughter performance was determined, and the longissimus dorsi muscle (LD) and biceps femoris (BF) muscles were gathered to evaluate meat quality and composition. Increasing the dietary energy concentration led to marked improvements (p < 0.05) in the live weight before slaughter (LWBS), weight of carcass, backfat thickness, and loin muscle area. HEG also improved the yield of high-grade commercial cuts (13.47% vs. 10.39%) (p < 0.05). However, meat quality traits were not affected by treatment except for shear force, which was affected by dietary energy. A significant improvement (p < 0.05) in the intramuscular fat (IMF) content was observed in the HEG. Little effect on the amino acid profile was observed (p > 0.05), except for a tendency (p = 0.06) to increase the histidine concentration in the BF muscle. Increasing dietary energy also reduced C22:6n-3 and saturated fatty acids (SFAs) and enhanced C18:1 cis-9 and monounsaturated fatty acids (MUFAs, p < 0.05). Those results revealed that increasing energy levels of diets could enhance slaughter traits and affect the meat quality and fatty acid composition of different muscle tissues of Honghe yellow cattle. These results contribute to the theoretical foundation to formulate nutritional standards and design feed formulas for the Honghe yellow cattle.

Custom-designed, mass silk production in genetically engineered silkworms.

Genetically engineered silkworms have been widely used to obtain silk with modified characteristics especially by introducing spider silk genes. However, these attempts are still challenging due to limitations in transformation strategies and difficulties in integration of the large DNA fragments. Here, we describe three different transformation strategies in genetically engineered silkworms, including transcription-activator-like effector nuclease (TALEN)-mediated fibroin light chain (FibL) fusion (BmFibL-F), TALEN-mediated FibH replacement (BmFibH-R), and transposon-mediated genetic transformation with the silk gland-specific fibroin heavy chain (FibH) promoter (BmFibH-T). As the result, the yields of exogenous silk proteins, a 160 kDa major ampullate spidroin 2 (MaSp2) from the orb-weaving spider Nephila clavipes and a 226 kDa fibroin heavy chain protein (EvFibH) from the bagworm Eumeta variegate, reach 51.02 and 64.13% in BmFibH-R transformed cocoon shells, respectively. Moreover, the presence of MaSp2 or EvFibH significantly enhances the toughness of genetically engineered silk fibers by ∼86% in BmFibH-T and ∼80% in BmFibH-R silkworms, respectively. Structural analysis reveals a substantial ∼40% increase in fiber crystallinity, primarily attributed to the presence of unique polyalanines in the repetitive sequences of MaSp2 or EvFibH. In addition, RNA-seq analysis reveals that BmFibH-R system only causes minor impact on the expression of endogenous genes. Our study thus provides insights into developing custom-designed silk production using the genetically engineered silkworm as the bioreactor.

Effects of dietary energy levels on microorganisms and short-chain fatty acids of rumen and tight junction proteins in Honghe Yellow cattle.

This study was conducted to investigate the effects of dietary energy levels on microorganisms and short-chain fatty acids (SCFAs) of rumen and the expression of tight junction proteins in Honghe Yellow cattle. A total of fifteen male Honghe Yellow cattle were randomly divided into three treatments (five replicates per treatment), consisting of formulated energy concentrations of 5.90 MJ/kg (high-energy diet, group H), 5.60 MJ/kg (medium-energy diet, group M) and 5.30 MJ/kg (low-energy diet, group L). The results showed that compared with group H, the expression of Claudin-1 in rumen epithelium of groups M and L was increased, but the expression of ZO-1 was decreased (p < 0.05). Moreover, compared with group H, group M down-regulated the expression of Occludin and Claudin-1 in the brain (p < 0.05). For rumen bacteria, the dominant phyla included Bacteroidetes and Firmicutes, the abundance of Actinobacteriota in groups M and L was significantly increased compared with group H (p < 0.05). At the genus level, the relative abundance of Corynebacterium, Eubacterium_nodatum_group and Neisseraceae in groups M and L was significantly decreased compared with group H (p < 0.05). For rumen fungi, the dominant phyla included Basidiomycota, Ascomycota and Neocariastigomycota, the relative abundance of Ascomycetes was significantly higher than that of groups M and L compared with group H (p < 0.05). At the genus level, the relative abundance of Neocelimastigaceae and Myceliophthora in groups M and L was significantly reduced compared with group H (p < 0.05). Furthermore, the expression of Claudin-1 in rumen epithelium was significantly positively correlated with Actinobacteriota, Corynebacterium and Neisseriaceae. The expression of ZO-1 in the spinal cord was significantly positively correlated with Myceliophthora. The expression of Occludin in brain was positively correlated with valerate content (p < 0.05). In summary, dietary energy levels affected the rumen microbiota of Honghe Yellow cattle. The expression of Claudin-1 in rumen epithelium and the total SCFAs concentration were increased with decreasing dietary energy levels, but the expression of Claudin-1 in brain and ZO-1 in the spinal cord were reduced with decreasing dietary energy levels. Meanwhile, the rumen microbiota and SCFAs were significantly correlated with the expression of TJP.

Protective effects of sodium butyrate on fluorosis in rats by regulating bone homeostasis and serum metabolism.

Fluorosis due to high fluoride levels in drinking water profoundly affects the development of human skeletal and dental structures. Sodium butyrate (NaB) has been found to regulate overall bone mass and prevent pathological bone loss. However, the mechanism of NaB action on fluorosis remains unclear. In this study, a rat model of fluorosis induced by 100 mg/L sodium fluoride was used to investigate the impact of NaB on bone homeostasis and serum metabolomics. It was found that NaB significantly reduced the levels of bone resorption markers CTX-Ⅰ and TRACP-5B in fluorosis rats. Moreover, NaB increased calcium and magnesium levels in bone, while decreasing phosphorus levels. In addition, NaB improved various bone microstructure parameters, including bone mineral density (BMD), trabecular thickness (Tb. Th), trabecular bone separation (Tb. SP), and structural model index (SMI) in the femur. Notably, NaB intervention also enhanced the antioxidant capacity of plasma in fluorosis rats. Furthermore, a comprehensive analysis of serum metabolomics by LC-MS revealed a significant reversal trend of seven biomarkers after the intervention of NaB. Finally, pathway enrichment analysis based on differential metabolites indicated that NaB exerted protective effects on fluorosis by modulating arginine and proline metabolic pathways. These findings suggest that NaB has a beneficial effect on fluorosis and can regulate bone homeostasis by ameliorating metabolic disorders.

Structural insights into the orthosteric inhibition of P2X receptors by non-ATP analog antagonists.

P2X receptors are extracellular ATP-gated ion channels that form homo- or heterotrimers and consist of seven subtypes. They are expressed in various tissues, including neuronal and nonneuronal cells, and play critical roles in physiological processes such as neurotransmission, inflammation, pain, and cancer. As a result, P2X receptors have attracted considerable interest as drug targets, and various competitive inhibitors have been developed. However, although several P2X receptor structures from different subtypes have been reported, the limited structural information of P2X receptors in complex with competitive antagonists hampers the understanding of orthosteric inhibition, hindering the further design and optimization of those antagonists for drug discovery. We determined the cryogenic electron microscopy (cryo-EM) structures of the mammalian P2X7 receptor in complex with two classical competitive antagonists of pyridoxal-5'-phosphate derivatives, pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) (PPNDS) and pyridoxal phosphate-6-azophenyl-2',5'-disulfonic acid (PPADS), and performed structure-based mutational analysis by patch-clamp recording as well as molecular dynamics (MD) simulations. Our structures revealed the orthosteric site for PPADS/PPNDS, and structural comparison with the previously reported apo- and ATP-bound structures showed how PPADS/PPNDS binding inhibits the conformational changes associated with channel activation. In addition, structure-based mutational analysis identified key residues involved in the PPNDS sensitivity of P2X1 and P2X3, which are known to have higher affinity for PPADS/PPNDS than other P2X subtypes.

TRPV1 analgesics disturb core body temperature via a biased allosteric mechanism involving conformations distinct from that for nociception.

Efforts on developing transient receptor potential vanilloid 1 (TRPV1) drugs for pain management have been hampered by deleterious hypo- or hyperthermia caused by TRPV1 agonists/antagonists. Here, we compared the effects of four antagonists on TRPV1 polymodal gating and core body temperature (CBT) in Trpv1+/+, Trpv1-/-, and Trpv1T634A/T634A. Neither the effect on proton gating nor drug administration route, hair coverage, CBT rhythmic fluctuations, or inflammation had any influence on the differential actions of TRPV1 drugs on CBT. We identified the S4-S5 linker region exposed to the vanilloid pocket of TRPV1 to be critical for hyperthermia associated with certain TRPV1 antagonists. PSFL2874, a TRPV1 antagonist we discovered, is effective against inflammatory pain but devoid of binding to the S4-S5 linker and inducing CBT changes. These findings implicate that biased allosteric mechanisms exist for TRPV1 coupling to nociception and CBT regulation, opening avenues for the development of non-opioid analgesics without affecting CBT.

Analysis and Compensation of Phase Current Measuring Error Caused by Sensing Resistor in PMSM Application.

Field Oriented Control (FOC) effectively realizes independent control of flux linkage and torque, and is widely used in application of Permanent Magnet Synchronous Motor (PMSM). However, it is necessary to detect the phase current information of the motor to realize the current closed-loop control. The phase current detection method based on a sampling resistor will cause a measurement error due to the influence of parasitic parameters of the sampling resistor, which will lead to the decrease in PMSM control performance. This paper reveals the formation mechanism of the current sampling error caused by parasitic inductance and capacitance of the sampling resistor, and further confirms that the above error will lead to the fluctuation of the electromagnetic torque output by simulation. Moreover, we propose an approach for online observation and compensation of the current sampling error based on PI-type observer to suppresses the torque pulsation of PMSM. The phase current sampling error is estimated by the proportional and integral (PI) observer, and the deviation value of current sampling is obtained by low-pass filter (LPF). The above deviation value is further injected into the phase current close-loop for error compensation. The PI observer continues to work to keep the current sampling error close to zero. The simulation platform of Matlab/Simulink (Version: R2021b) is established to verify the effectiveness of online error observation and compensation. Further experiments also prove that the proposed method can effectively improve the torque fluctuation of the PMSM and enhance its control accuracy performance of rotation speed.

Lipid homeostasis is essential for oogenesis and embryogenesis in the silkworm, Bombyx mori.

Reproduction, a fundamental feature of all known life, closely correlates with energy homeostasis. The control of synthesizing and mobilizing lipids are dynamic and well-organized processes to distribute lipid resources across tissues or generations. However, how lipid homeostasis is precisely coordinated during insect reproductive development is poorly understood. Here we describe the relations between energy metabolism and reproduction in the silkworm, Bombyx mori, a lepidopteran model insect, by using CRISPR/Cas9-mediated mutation analysis and comprehensively functional investigation on two major lipid lipases of Brummer (BmBmm) and hormone-sensitive lipase (BmHsl), and the sterol regulatory element binding protein (BmSrebp). BmBmm is a crucial regulator of lipolysis to maintain female fecundity by regulating the triglyceride (TG) storage among the midgut, the fat body, and the ovary. Lipidomics analysis reveals that defective lipolysis of females influences the composition of TG and other membrane lipids in the BmBmm mutant embryos. In contrast, BmHsl mediates embryonic development by controlling sterol metabolism rather than TG metabolism. Transcriptome analysis unveils that BmBmm deficiency significantly improves the expression of lipid synthesis-related genes including BmSrebp in the fat body. Subsequently, we identify BmSrebp as a key regulator of lipid accumulation in oocytes, which promotes oogenesis and cooperates with BmBmm to support the metabolic requirements of oocyte production. In summary, lipid homeostasis plays a vital role in supporting female reproductive success in silkworms.

gp120-derived amyloidogenic peptides form amyloid fibrils that increase HIV-1 infectivity.

Apart from mediating viral entry, the function of the free HIV-1 envelope protein (gp120) has yet to be elucidated. Our group previously showed that EP2 derived from one ß-strand in gp120 can form amyloid fibrils that increase HIV-1 infectivity. Importantly, gp120 contains ~30 ß-strands. We examined whether gp120 might serve as a precursor protein for the proteolytic release of amyloidogenic fragments that form amyloid fibrils, thereby promoting viral infection. Peptide array scanning, enzyme degradation assays, and viral infection experiments in vitro confirmed that many ß-stranded peptides derived from gp120 can indeed form amyloid fibrils that increase HIV-1 infectivity. These gp120-derived amyloidogenic peptides, or GAPs, which were confirmed to form amyloid fibrils, were termed gp120-derived enhancers of viral infection (GEVIs). GEVIs specifically capture HIV-1 virions and promote their attachment to target cells, thereby increasing HIV-1 infectivity. Different GAPs can cross-interact to form heterogeneous fibrils that retain the ability to increase HIV-1 infectivity. GEVIs even suppressed the antiviral activity of a panel of antiretroviral agents. Notably, endogenous GAPs and GEVIs were found in the lymphatic fluid, lymph nodes, and cerebrospinal fluid (CSF) of AIDS patients in vivo. Overall, gp120-derived amyloid fibrils might play a crucial role in the process of HIV-1 infectivity and thus represent novel targets for anti-HIV therapeutics.

Realization of Gapped and Ungapped Photonic Topological Anderson Insulators.

It is commonly believed that topologically nontrivial one-dimensional systems support edge states rather than bulk states at zero energy. In this work, we find an unanticipated case of topological Anderson insulator (TAI) phase where two bulk modes are degenerate at zero energy, in addition to degenerate edge modes. We term this "ungapped TAI" to distinguish it from the previously known gapped TAIs. Our experimental realization of both gapped and ungapped TAIs relies on coupled photonic resonators, in which the disorder in coupling is judiciously engineered by adjusting the spacing between the resonators. By measuring the local density of states both in the bulk and at the edges, we demonstrate the existence of these two types of TAIs, together forming a TAI plateau in the phase diagram. Our experimental findings are well supported by theoretical analysis. In the ungapped TAI phase, we observe stable coexistence of topological edge states and localized bulk states at zero energy, highlighting the distinction between TAIs and traditional topological insulators.

ERK/STAT3 activation through CCL17/CCR4 axis-mediated type 2 cytokine-involved signaling pathways in Th2 cells regulates cutaneous drug reactions.

Cutaneous drug reactions (CDRs) are common drug-induced allergic reactions that cause severe consequences in HIV/AIDS patients. The CCL17/CCR4 axis is involved in the immune mechanism of allergic diseases, but its role in the CDRs has not been determined. Here, we aimed to determine the role of the CCL17/CCR4 axis and the underlying mechanism involved in CDRs. In this study, the serum cytokine levels in patients with CDR and healthy controls were measured. The CCL17-triggered allergic profile was screened via a PCR array. Apoptosis of keratinocytes cocultured with CCL17-stimulated Th2 cells was analyzed by flow cytometry. An NVP-induced rat CDR model was established, and dynamic inflammatory factor levels and Th2 cells in the peripheral blood of the rats were measured. Rat skin lesions and signaling pathways in Th2 cells were also analyzed. We showed that the serum CCL17 level was significantly upregulated in CDR patients (P = 0.0077), and the Th2 cell subgroup was also significantly elevated in the CDR rats. The CCL17/CCR4 axis induces Th2 cells to release IL-4 and IL-13 via the ERK/STAT3 pathway. The CCR4 antagonist compound 47 can alleviate rash symptoms resulting from NVP-induced drug eruption, Th2 cell subgroup, IL-4, and IL-13 and inhibit keratinocyte apoptosis. Taken together, these findings indicate that the CCL17/CCR4 axis mediates CDR via the ERK/STAT3 pathway in Th2 cells and type 2 cytokine-induced keratinocyte apoptosis.

Comparative skin histological and transcriptomic analysis of Rana kukunoris with two different skin colors.

This study compares the skin structures of Rana kukunoris with two different skin colors living in the same area of Haibei in the Northeastern Qinghai-Tibet Plateau. The skin thickness of the khaki R. kukunoris was significantly greater than that of the brown R. kukunoris (P < 0.01), and significantly more mucous and granular glands were present on the dorsal skin of the khaki frog (P < 0.05). Meanwhile, the melanocytes on the dorsal skin of the brown frog were significantly larger than those on the khaki one (P < 0.05). Morphological changes in the expansion and aggregation of melanocytes seemed to deepen the skin color of R. kukunoris. Moreover, transcriptome sequencing identified tyrosine metabolism, melanogenesis, and riboflavin metabolism as the main pathways involved in melanin formation and metabolism in brown R. kukunoris. TYR, MC1R was upregulated as the skin color of R. kukunoris was deepened and contributed to melanin production and metabolism. In contrast, the khaki frog had significantly more upregulated genes and metabolic pathways related to autoimmunity. The khaki frog appeared to defend against ultraviolet (UV) radiation-induced damage by secreting mucus and small molecular peptides, whereas the brown frog protected itself by distributing a large amount of melanin. Hence, the different skin colors of R. kukunoris might represent different adaptation strategies for survival in the intense UV radiation environment of the Qinghai-Tibet Plateau.

Long-term exposure to the mixture of phthalates induced male reproductive toxicity in rats and the alleviative effects of quercetin.

Phthalates (PEs), such as di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP) could cause reproductive and developmental toxicities, while human beings are increasingly exposed to them at low-doses. Phytochemical quercetin (Que) is a flavonoid that has estrogenic effect, anti-inflammatory and anti-oxidant effects. This study was conducted to assess the alleviative effect of Que. on male reproductive toxicity induced by the mixture of three commonly used PEs (MPEs) at low-dose in rats, and explore the underlying mechanism. Male rats were treated with MPEs (16 mg/kg/day) and/or Que. (50 mg/kg/d) for 91 days. The results showed that MPEs exposure caused male reproductive injuries, such as decreased serum sex hormones levels, abnormal testicular pathological structure, increased abnormal sperm rate and changed expressions of PIWIL1 and PIWIL2. Furthermore, MPEs also changed the expression of steroidogenic proteins in steroid hormone metabolism, including StAR, CYP11A1, CYP17A1, 17ß-HSD, CYP19A1. However, the alterations of these parameters were reversed by Que. MPEs caused male reproductive injuries in rats; Que. inhibited MPEs' male reproductive toxicity, which might relate to the improvement of testosterone biosynthesis.