LC3-Associated Endocytosis Facilitates ß-Amyloid Clearance and Mitigates Neurodegeneration in Murine Alzheimer's Disease.

The expression of some proteins in the autophagy pathway declines with age, which may impact neurodegeneration in diseases, including Alzheimer's Disease. We have identified a novel non-canonical function of several autophagy proteins in the conjugation of LC3 to Rab5+, clathrin+ endosomes containing ß-amyloid in a process of LC3-associated endocytosis (LANDO). We found that LANDO in microglia is a critical regulator of immune-mediated aggregate removal and microglial activation in a murine model of AD. Mice lacking LANDO but not canonical autophagy in the myeloid compartment or specifically in microglia have a robust increase in pro-inflammatory cytokine production in the hippocampus and increased levels of neurotoxic ß-amyloid. This inflammation and ß-amyloid deposition were associated with reactive microgliosis and tau hyperphosphorylation. LANDO-deficient AD mice displayed accelerated neurodegeneration, impaired neuronal signaling, and memory deficits. Our data support a protective role for LANDO in microglia in neurodegenerative pathologies resulting from ß-amyloid deposition.

LC3-Associated Phagocytosis in Myeloid Cells Promotes Tumor Immune Tolerance.

Targeting autophagy in cancer cells and in the tumor microenvironment are current goals of cancer therapy. However, components of canonical autophagy play roles in other biological processes, adding complexity to this goal. One such alternative function of autophagy proteins is LC3-associated phagocytosis (LAP), which functions in phagosome maturation and subsequent signaling events. Here, we show that impairment of LAP in the myeloid compartment, rather than canonical autophagy, induces control of tumor growth by tumor-associated macrophages (TAM) upon phagocytosis of dying tumor cells. Single-cell RNA sequencing (RNA-seq) analysis revealed that defects in LAP induce pro-inflammatory gene expression and trigger STING-mediated type I interferon responses in TAM. We found that the anti-tumor effects of LAP impairment require tumor-infiltrating T cells, dependent upon STING and the type I interferon response. Therefore, autophagy proteins in the myeloid cells of the tumor microenvironment contribute to immune suppression of T lymphocytes by effecting LAP.

ESCRT-III Acts Downstream of MLKL to Regulate Necroptotic Cell Death and Its Consequences.

The activation of mixed lineage kinase-like (MLKL) by receptor-interacting protein kinase-3 (RIPK3) results in plasma membrane (PM) disruption and a form of regulated necrosis, called necroptosis. Here, we show that, during necroptosis, MLKL-dependent calcium (Ca2+) influx and phosphatidylserine (PS) exposure on the outer leaflet of the plasma membrane preceded loss of PM integrity. Activation of MLKL results in the generation of broken, PM "bubbles" with exposed PS that are released from the surface of the otherwise intact cell. The ESCRT-III machinery is required for formation of these bubbles and acts to sustain survival of the cell when MLKL activation is limited or reversed. Under conditions of necroptotic cell death, ESCRT-III controls the duration of plasma membrane integrity. As a consequence of the action of ESCRT-III, cells undergoing necroptosis can express chemokines and other regulatory molecules and promote antigenic cross-priming of CD8+ T cells.

BOK Is a Non-canonical BCL-2 Family Effector of Apoptosis Regulated by ER-Associated Degradation.

The mitochondrial pathway of apoptosis is initiated by mitochondrial outer membrane permeabilization (MOMP). The BCL-2 family effectors BAX and BAK are thought to be absolutely required for this process. Here, we report that BCL-2 ovarian killer (BOK) is a bona fide yet unconventional effector of MOMP that can trigger apoptosis in the absence of both BAX and BAK. However, unlike the canonical effectors, BOK appears to be constitutively active and unresponsive to antagonistic effects of the antiapoptotic BCL-2 proteins. Rather, BOK is controlled at the level of protein stability by components of the endoplasmic reticulum (ER)-associated degradation pathway. BOK is ubiquitylated by the AMFR/gp78 E3 ubiquitin ligase complex and targeted for proteasomal degradation in a VCP/p97-dependent manner, which allows survival of the cell. When proteasome function, VCP, or gp78 activity is compromised, BOK is stabilized to induce MOMP and apoptosis independently of other BCL-2 proteins.

O-GlcNAc Transferase Suppresses Inflammation and Necroptosis by Targeting Receptor-Interacting Serine/Threonine-Protein Kinase 3.

Elevated glucose metabolism in immune cells represents a hallmark feature of many inflammatory diseases, such as sepsis. However, the role of individual glucose metabolic pathways during immune cell activation and inflammation remains incompletely understood. Here, we demonstrate a previously unrecognized anti-inflammatory function of the O-linked ß-N-acetylglucosamine (O-GlcNAc) signaling associated with the hexosamine biosynthesis pathway (HBP). Despite elevated activities of glycolysis and the pentose phosphate pathway, activation of macrophages with lipopolysaccharide (LPS) resulted in attenuated HBP activity and protein O-GlcNAcylation. Deletion of O-GlcNAc transferase (OGT), a key enzyme for protein O-GlcNAcylation, led to enhanced innate immune activation and exacerbated septic inflammation. Mechanistically, OGT-mediated O-GlcNAcylation of the serine-threonine kinase RIPK3 on threonine 467 (T467) prevented RIPK3-RIPK1 hetero- and RIPK3-RIPK3 homo-interaction and inhibited downstream innate immunity and necroptosis signaling. Thus, our study identifies an immuno-metabolic crosstalk essential for fine-tuning innate immune cell activation and highlights the importance of glucose metabolism in septic inflammation.

cBAF complex components and MYC cooperate early in CD8+ T cell fate.

The identification of mechanisms to promote memory T (Tmem) cells has important implications for vaccination and anti-cancer immunotherapy1-4. Using a CRISPR-based screen for negative regulators of Tmem cell generation in vivo5, here we identify multiple components of the mammalian canonical BRG1/BRM-associated factor (cBAF)6,7. Several components of the cBAF complex are essential for the differentiation of activated CD8+ T cells into T effector (Teff) cells, and their loss promotes Tmem cell formation in vivo. During the first division of activated CD8+ T cells, cBAF and MYC8 frequently co-assort asymmetrically to the two daughter cells. Daughter cells with high MYC and high cBAF display a cell fate trajectory towards Teff cells, whereas those with low MYC and low cBAF preferentially differentiate towards Tmem cells. The cBAF complex and MYC physically interact to establish the chromatin landscape in activated CD8+ T cells. Treatment of naive CD8+ T cells with a putative cBAF inhibitor during the first 48 h of activation, before the generation of chimeric antigen receptor T (CAR-T) cells, markedly improves efficacy in a mouse solid tumour model. Our results establish cBAF as a negative determinant of Tmem cell fate and suggest that manipulation of cBAF early in T cell differentiation can improve cancer immunotherapy.

Mutation to a cytochrome P450 -like gene alters the leaf color by affecting the heme and chlorophyll biosynthesis pathways in Brassica napus.

The regulated biosynthesis of chlorophyll is important because of its effects on plant photosynthesis and dry biomass production. In this study, a map-based cloning approach was used to isolate the cytochrome P450 -like gene BnaC08g34840D (BnCDE1) from a chlorophyll-deficient mutant (cde1) of Brassica napus obtained by ethyl methanesulfonate (EMS) mutagenization. Sequence analyses revealed that BnaC08g34840D in the cde1 mutant (BnCDE1I320T ) encodes a substitution at amino acid 320 (Ile320Thr) in the conserved region. The over-expression of BnCDE1I320T in ZS11 (i.e., gene-mapping parent with green leaves) recapitulated a yellow-green leaf phenotype. The CRISPR/Cas9 genome-editing system was used to design two single-guide RNAs (sgRNAs) targeting BnCDE1I320T in the cde1 mutant. The knockout of BnCDE1I320T in the cde1 mutant via a gene-editing method restored normal leaf coloration (i.e., green leaves). These results indicate that the substitution in BnaC08g34840D alters the leaf color. Physiological analyses showed that the over-expression of BnCDE1I320T leads to decreases in the number of chloroplasts per mesophyll cell and in the contents of the intermediates of the chlorophyll biosynthesis pathway in leaves, while it increases heme biosynthesis, thereby lowering the photosynthetic efficiency of the cde1 mutant. The Ile320Thr mutation in the highly conserved region of BnaC08g34840D inhibited chlorophyll biosynthesis and disrupted the balance between heme and chlorophyll biosynthesis. Our findings may further reveal how the proper balance between the chlorophyll and heme biosynthesis pathways is maintained.

The influence of radiation-induced bystander effect in osteoblasts mediated by plasma-derived extracellular vesicles (EVs).

OBJECTIVES: Head and neck tumor patients may develop post-radiotherapy diseases after radiotherapy treatment. And radiotherapy can elicit radiation-induced bystander effect, wherein extracellular vesicles (EVs) play a crucial role. For normal parts of the body that have not been directly irradiated, the effect of EVs on them needs to be further explored. This study aims to investigate the functions of plasma-derived EVs in regulating normal osteoblasts during radiation-induced bystander effects. METHODS AND MATERIALS: Rat plasma-derived EVs were isolated and identified firstly, followed by an evaluation of their intracellular biological effects on normal osteoblasts in vitro. Transcriptome sequencing analysis and confirmations were performed to identify potential mechanisms. RESULTS: Irradiated plasma-derived EVs were found to enhance osteoblast proliferation, migration, and cell cycle progression, concurrently suppressing the expression of osteogenesis-related genes and proteins. Furthermore, these EVs attenuated the expression of osteogenesis and oxidative stress resistance related genes, while upregulating the PI3K-AKT pathway and intracellular reactive oxygen species in osteoblasts. CONCLUSIONS: Irradiated plasma-derived EVs could alter the biological effects in osteoblasts, which is closely associated with the levels of GPX1 and the PI3K-AKT signaling pathway. This suggests that plasma-derived EVs serve as a crucial factor contributing to radiation-induced bystander effect in osteoblasts.

Nature Products Chlorophyll Derivatives for NIR-II Fluorescence Bioimaging and Plant-Imaging.

The second near-infrared window (NIR-II, 1000-1700 nm) fluorescence imaging has attracted significant attention in research fields because of its unique advantages compared with conventional optical windows (400-900 nm). A variety of NIR-II fluorophores have been actively studied because they serve as a key component of fluorescence imaging. Among them, organic small molecule NIR-II fluorophores display outstanding imaging performance and many advantages, but types of small molecule NIR-II fluorophores with high biocompatibility are still quite limited. Novel molecular scaffolds based NIR-II dyes are highly desired. Herein, we hypothesized that chlorophyll is a new promising molecular platform for discovery NIR-II fluorophores. Thus, seven derivatives of derivatives were selected to characterize their optical properties. Interestingly, six chlorophyll derivatives displayed NIR-II fluorescence imaging capability. This characteristic allowed the successful NIR-II imaging of green leaves of various plants. Furthermore, most of these fluorophores showed capacity to monitor viscosity change because of their sensitive for viscosity. For demonstration of its biomedical applications, these probes were successfully used for NIR-II fluorescence-guided surgical resection of lymph nodes. In summary, chlorophylls are novel valuable tool molecules for NIR-II fluorescence imaging and have potential to expand their applications in biomedical field and plant science.

Oral vaccination with recombinant Saccharomyces cerevisiae expressing Micropterus salmoides rhabdovirus G protein elicits protective immunity in largemouth bass.

Micropterus salmoides rhabdovirus (MSRV) is one of the main pathogens of largemouth bass, leading to serious economic losses. The G protein, as the only envelope protein present on the surface of MSRV virion, contains immune-related antigenic determinants, thereby becoming the primary target for the design of MSRV vaccines. Here, we displayed the G protein on the surface of yeast cells (named EBY100/pYD1-G) and conducted a preliminary assessment of the protective efficacy of the recombinant yeast vaccine. Upon oral vaccination, a robust immune response was observed in systemic and mucosal tissue. Remarkably, following the MSRV challenge, the relative percent survival of EBY100/pYD1-G treated largemouth bass significantly increased to 66.7 %. In addition, oral administration inhibited viral replication and alleviated the pathological symptoms of MSRV-infected largemouth bass. These results suggest that EBY100/pYD1-G could be used as a potential oral vaccine against MSRV infection.

Advances in polysaccharides of natural source of anti-diabetes effect and mechanism.

PURPOSE: Diabetes is a chronic disease in metabolic disorder, and the pathology is characterized by insulin resistance and insulin secretion disorder in blood. In current, many studies have revealed that polysaccharides extracted from natural sources with significant anti-diabetic effects. Natural polysaccharides can ameliorate diabetes through different action mechanisms. All these polysaccharides are expected to have an important role in the clinic. METHODS: Existing polysaccharides for the treatment of diabetes are reviewed, and the mechanism of polysaccharides in the treatment of diabetes and its structural characteristics are described in detail. RESULTS: This article introduced the natural polysaccharide through different mechanisms of action in the treatment of diabetes, including oxidative stress, apoptosis, inflammatory response and regulation of intestinal bacteria. Natural polysaccharides can treat of diabetes by regulating signaling pathways is also a research hotspot. In addition, the structural characteristics of polysaccharides were explored. There are some structure-activity relationships between natural polysaccharides and the treatment of diabetes.

First report of Pseudopithomyces palmicola causing leaf spot on tobacco in China.

In July 2023, a new leaf spot disease emerged on tobacco leaves in Meitan County, Guizhou Province, China (27°20'18" - 28°12'30"N, 107°15'36" - 107°41'08"E, average altitude 972 meters). Initially, the symptoms showed raised yellow-brown spots; subsequently, the lesions expanded and became broken and perforated, leading to a significant loss of economic value, the prevalence rate exceeded 30%. For isolation, two tissue fragments (0.2 × 0.2 cm) of symptomatic leaves were sterilized in 75% ethanol for 30 s, 3% NaClO for 2 min, and were washed 3 times in sterilized distilled water, and were subsequently inoculated on potato dextrose agar (PDA), and incubated at 28°C for 9 days in the dark. The two strains CW16 and CW28 were isolated using the single hyphae method (Nouri et al. 2023). Both strains formed pale to yellow white colonies on PDA. Conidia had three constricted transverse septa and 1 to 2 longitudinal septa in the central cells, with thick and hyaline conidiophores and mostly globose, pale brown conidia with slightly constricted septa, their average size were measured as 13.4-22.4×8.358-13.347 µm (n = 50). Genomic DNA was extracted from the isolated strains CW16 and CW28. The internal transcribed spacer regions 1 and 2 as well as 5.8S nuclear ribosomal RNA (ITS), large subunit nrRNA (LSU), and partial DNA-directed RNA polymerase II second largest subunit (RPB2) genes were amplified using primers (Cui et al. 2023). The sequences had been deposited in GenBank under accession numbers ITS: PP024201, PP024205; LSU: PP024207, PP024209; RPB2: PP060480, PP060481. The sequences analysis revealed a high similarity of 99.74 to 100% between strains CW16 and CW28 with P. palmicola isolate KM42 (ITS OQ875842, LSU OQ875844, RPB2 OQ883943) in GenBank. Using BLAST for homology matching, two isolates (CW16, CW28) and with the sequences of the ten type isolates from GenBank, phylogenetic analysis was conducted using the Maximum Likelihood method in MEGA (11.0) software based on ITS, LSU and RPB2 sequences, which showed that strains CW16, CW28 clustered in the same score as the Pseudopithomyces palmicola, confirming the morphological and molecular characteristics identification. The pathogenicity tests were conducted on healthy tobacco plants with 4-5 leaves (Fig. S1B), the isolated strains, CW16 and CW28, were used to inoculate the healthy tobacco leaves, while blank PDA was used as a control. All plants were maintained in a greenhouse at 28°C with a relative humidity of 90%. After 9 days, necrotic spots were observed on all tobacco leaves inoculated with CW16 and CW28 fungal plugs, while the blank PDA-inoculated tobacco leaves showed no symptoms. Based on morphological and molecular characteristics, the same pathogen P. palmicola was identified from the inoculated leaves, fulfilling Koch's postulates. This study represents the first reported of tobacco leaf spot caused by P. palmicola in China and provides a theoretical basis for future prevention and control measures.

Dual strategy involving hospital-based study and community-based screening to eliminate hepatitis C in remote areas.

BACKGROUND: /Purpose: To achieve the World Health Organization goal of eliminating viral hepatitis by 2030, a key strategy in resource-limited areas is to identify the areas with high prevalence and to prioritize screening and treatment intervention. We hypothesized that a hospital-based laboratory database could be used to estimate the township- and village-specific anti-hepatitis C virus (HCV) prevalence. METHODS: Yunlin County Public Health Bureau has been collecting anti-HCV test data from eight major hospitals. Township- and village-specific screening testing rates and anti-HCV prevalence were calculated for residents 40 years or older. A township with a wide range of anti-HCV prevalence rates was selected for outreach universal screening and for validating the village-specific prevalence of anti-HCV in the analysis of the data from the hospitals. RESULTS: The overall anti-HCV screening testing rate in Yunlin County was 30.4 %, whereas the anti-HCV prevalence rate for persons 40 years or older was 15.4 %. The village-specific anti-HCV prevalence rates ranged from 3.8 % to 85.8 %. Community-based screening was conducted in Kouhu Township. The village-specific anti-HCV prevalence rates ranged from 0 % to 18.8 %. Three of the four villages had the highest village-specific anti-HCV prevalence in the community-based study and the hospital-based study. Additionally, 95.8 % of the new HCV cases detected by universal screening received anti-HCV therapy. CONCLUSION: The hospital-based database provided a framework for identifying the villages with high anti-HCV prevalence. Additionally, community-based universal screening should be prioritized for villages with high prevalence in hospital-based databases.

BnUC1 Is a Key Regulator of Epidermal Wax Biosynthesis and Lipid Transport in Brassica napus.

The bHLH (basic helix-loop-helix) transcription factor AtCFLAP2 regulates epidermal wax accumulation, but the underlying molecular mechanism remains unknown. We obtained BnUC1mut (BnaA05g18250D homologous to AtCFLAP2) from a Brassica napus mutant with up-curling leaves (Bnuc1) and epidermal wax deficiency via map-based cloning. BnUC1mut contains a point mutation (N200S) in the conserved dimerization domain. Overexpressing BnUC1mut in ZS11 (Zhongshuang11) significantly decreased the leaf epidermal wax content, resulting in up-curled and glossy leaves. In contrast, knocking out BnUC1mut in ZS11-NIL (Zhongshuang11-near-isogenic line) restored the normal leaf phenotype (i.e., flat) and significantly increased the leaf epidermal wax content. The point mutation weakens the ability of BnUC1mut to bind to the promoters of VLCFA (very-long-chain fatty acids) synthesis-related genes, including KCS (ß-ketoacyl coenzyme synthase) and LACS (long-chain acyl CoA synthetase), as well as lipid transport-related genes, including LTP (non-specific lipid transfer protein). The resulting sharp decrease in the transcription of genes affecting VLCFA biosynthesis and lipid transport disrupts the normal accumulation of leaf epidermal wax. Thus, BnUC1 influences epidermal wax formation by regulating the expression of LTP and genes associated with VLCFA biosynthesis. Our findings provide a foundation for future investigations on the mechanism mediating plant epidermal wax accumulation.

A small chromosomal inversion mediated by MITE transposons confers cleistogamy in Brassica napus.

Cleistogamy, self-pollination within closed flowers, can help maintain seed purity, accelerate breeding speed, and aid in the development of ornamental flowers. However, the mechanism underlying petal closing/opening behavior remains elusive. Here, we found that a Brassica napus petal closing/opening behavior was inherited in a Mendelian manner. Fine mapping and positional cloning experiments revealed that the Mendelian factor originated from a short (29.8 kb) inversion mediated by BnDTH9 miniature inverted-repeat transposable elements (MITEs) on chromosome C03. This inversion led to tissue-specific gene promoter exchange between BnaC03.FBA (BnaC03G0156800ZS encoding an F-Box-associated domain-containing protein) and BnaC03.EFO1 (BnaC03G0157400ZS encoding an EARLY FLOWERING BY OVEREXPRESSION 1 protein) positioned near the respective inversion breakpoints. Our genetic transformation work demonstrated that the cleistogamy originated from high tissue-specific expression of the BnaC03.FBA gene caused by promoter changes due to the MITE-mediated inversion. BnaC03.FBA is involved in the formation of an SCF (Skp1-Cullin-F-box) complex, which participates in ubiquitin-mediated protein targeting for degradation through the ubiquitin 26S-proteasome system. Our results shed light on a molecular model of petal-closing behavior.

Synthesis of Luminescent Indolo[2,1-b]quinazolin-6(12H)-ones via a Sequential Ugi/Iodine-Promoted Cyclization/Staudinger/Aza-Wittig Reaction.

A new efficient synthesis of indolo[2,1-b]quinazolin-6(12H)-ones via a sequential Ugi/iodine-promoted cyclization/Staudinger/aza-Wittig reaction was developed. The acid catalyzed three-component reactions of 2-azidobenzaldehydes, 2-[2-(trimethylsilyl)ethynyl]benzenamines (or o-aminoacetophenones), and isocyanides gave Ugi-3CR intermediates, which reacted subsequently with I2/DMSO and triphenylphosphine to produce indolo[2,1-b]quinazolin-6(12H)-ones in good overall yields. The obtained indolo[2,1-b]quinazolin-6(12H)-ones were all colored in bright red or orange. Their luminescent property was studied preliminarily and some of them showed high molar absorption coefficients, strong fluorescence emission intensity, and good absolute light quantum yields.

Stereoselective Synthesis of 12-Tetrazolyl Substituted (E)-5H-Quinazolino[3,2-a]quinazolines via Sequential Ugi-Azide/Staudinger/aza-Wittig/Addition/Ag(I)-Catalyzed Cyclization.

A new efficient and stereoselective synthesis of 12-tetrazolyl substituted (E)-5H-quinazolino[3,2-a]quinazolines via sequential Ugi-azide/Staudinger/aza-Wittig/addition/Ag(I)-catalyzed cyclization was developed. The four-component reactions of 2-azidobenzaldehyde, 2-(alkynyl)benzenamine, isocyanide, and trimethylsilyl azide gave Ugi-azide intermediates, which were subsequently treated with triphenylphosphine and isocyanate to produce 12-tetrazolyl substituted (E)-5H-quinazolino[3,2-a]quinazolines in the presence of Ag(I) catalyst and K2CO3.