Identification of an IL-1 receptor mutation driving autoinflammation directs IL-1-targeted drug design.

The interleukin 1 (IL-1) pathway signals through IL-1 receptor type 1 (IL-1R1) and emerges as a central mediator for systemic inflammation. Aberrant IL-1 signaling leads to a range of autoinflammatory diseases. Here, we identified a de novo missense variant in IL-1R1 (p.Lys131Glu) in a patient with chronic recurrent multifocal osteomyelitis (CRMO). Patient PBMCs showed strong inflammatory signatures, particularly in monocytes and neutrophils. The p.Lys131Glu substitution affected a critical positively charged amino acid, which disrupted the binding of the antagonist ligand, IL-1Ra, but not IL-1α or IL-1ß. This resulted in unopposed IL-1 signaling. Mice with a homologous mutation exhibited similar hyperinflammation and greater susceptibility to collagen antibody-induced arthritis, accompanied with pathological osteoclastogenesis. Leveraging the biology of the mutation, we designed an IL-1 therapeutic, which traps IL-1ß and IL-1α, but not IL-1Ra. Collectively, this work provides molecular insights and a potential drug for improved potency and specificity in treating IL-1-driven diseases.

Clinical Implications of a New DDX58 Pathogenic Variant That Causes Lupus Nephritis due to RIG-I Hyperactivation.

BACKGROUND: Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus, with heterogeneous phenotypes and different responses to therapy. Identifying genetic causes of LN can facilitate more individual treatment strategies. METHODS: We performed whole-exome sequencing in a cohort of Chinese patients with LN and identified variants of a disease-causing gene. Extensive biochemical, immunologic, and functional analyses assessed the effect of the variant on type I IFN signaling. We further investigated the effectiveness of targeted therapy using single-cell RNA sequencing. RESULTS: We identified a novel DDX58 pathogenic variant, R109C, in five unrelated families with LN. The DDX58 R109C variant is a gain-of-function mutation, elevating type I IFN signaling due to reduced autoinhibition, which leads to RIG-I hyperactivation, increased RIG-I K63 ubiquitination, and MAVS aggregation. Transcriptome analysis revealed an increased IFN signature in patient monocytes. Initiation of JAK inhibitor therapy (baricitinib 2 mg/d) effectively suppressed the IFN signal in one patient. CONCLUSIONS: A novel DDX58 R109C variant that can cause LN connects IFNopathy and LN, suggesting targeted therapy on the basis of pathogenicity. PODCAST: This article contains a podcast at.

AMPK-Dependent Phosphorylation of GAPDH Triggers Sirt1 Activation and Is Necessary for Autophagy upon Glucose Starvation.

Eukaryotes initiate autophagy to cope with the lack of external nutrients, which requires the activation of the nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase Sirtuin 1 (Sirt1). However, the mechanisms underlying the starvation-induced Sirt1 activation for autophagy initiation remain unclear. Here, we demonstrate that glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a conventional glycolytic enzyme, is a critical mediator of AMP-activated protein kinase (AMPK)-driven Sirt1 activation. Under glucose starvation, but not amino acid starvation, cytoplasmic GAPDH is phosphorylated on Ser122 by activated AMPK. This causes GAPDH to redistribute into the nucleus. Inside the nucleus, GAPDH interacts directly with Sirt1, displacing Sirt1's repressor and causing Sirt1 to become activated. Preventing this shift of GAPDH abolishes Sirt1 activation and autophagy, while enhancing it, through overexpression of nuclear-localized GAPDH, increases Sirt1 activation and autophagy. GAPDH is thus a pivotal and central regulator of autophagy under glucose deficiency, undergoing AMPK-dependent phosphorylation and nuclear translocation to activate Sirt1 deacetylase activity.

Acetyltransferase GCN5 regulates autophagy and lysosome biogenesis by targeting TFEB.

Accumulating evidence highlights the role of histone acetyltransferase GCN5 in the regulation of cell metabolism in metazoans. Here, we report that GCN5 is a negative regulator of autophagy, a lysosome-dependent catabolic mechanism. In animal cells and Drosophila, GCN5 inhibits the biogenesis of autophagosomes and lysosomes by targeting TFEB, the master transcription factor for autophagy- and lysosome-related gene expression. We show that GCN5 is a specific TFEB acetyltransferase, and acetylation by GCN5 results in the decrease in TFEB transcriptional activity. Induction of autophagy inactivates GCN5, accompanied by reduced TFEB acetylation and increased lysosome formation. We further demonstrate that acetylation at K274 and K279 disrupts the dimerization of TFEB and the binding of TFEB to its target gene promoters. In a Tau-based neurodegenerative Drosophila model, deletion of dGcn5 improves the clearance of Tau protein aggregates and ameliorates the neurodegenerative phenotypes. Together, our results reveal GCN5 as a novel conserved TFEB regulator, and the regulatory mechanisms may be involved in autophagy- and lysosome-related physiological and pathological processes.

Non-thermal plasma promotes boar sperm quality through increasing AMPK methylation.

Boar sperm quality, as an important indicator of reproductive efficiency, directly affects the efficiency of livestock production. Here, this study was conducted to improve the boar sperm quality by using a non-thermal dielectric barrier discharge (DBD) plasma. Our results showed that DBD plasma exposure at 2.1 W for 15 s could improve boar sperm quality by increasing exon methylation level of adenosine monophosphate-activated protein kinase (AMPK) and thus improving the glycolytic flux, mitochondrial function, and antioxidant capacity without damaging the integrity of sperm DNA and acrosome. In addition, DBD plasma could rescue DNA methyltransferase inhibitor decitabine-caused low sperm quality through reducing the oxidative stress and mitochondrial damage. Therefore, the application of non-thermal plasma provides a new strategy for reducing sperm oxidative damage and improving sperm quality, which shows a great potential in assisted reproduction to solve the problem of male infertility.

Identification and functional prediction of miRNAs that regulate ROS levels in dielectric barrier discharge plasma-treated boar spermatozoa.

Dielectric barrier discharge (DBD) plasma regulates the levels of reactive oxygen species (ROS), which are critical for sperm quality. MicroRNAs (miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes, which regulate post-transcriptional gene expression in animals. At present, it is unknown whether DBD plasma can regulate sperm ROS levels through miRNAs. To further understand the regulatory mechanism of DBD plasma on sperm ROS levels, miRNAs in fresh boar spermatozoa were detected using Illumina deep sequencing technology. We found that 25 known miRNAs and 50 novel miRNAs were significantly upregulated, and 14 known miRNAs and 74 novel miRNAs were significantly downregulated in DBD plasma-treated spermatozoa. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that target genes of differentially expressed miRNAs were involved in many activities and pathways associated with antioxidants. We verified that DBD plasma significantly increased boar sperm quality and reduced ROS levels. These results suggest that DBD plasma can improve sperm quality by regulating ROS levels via miRNAs. Our findings provide a potential strategy to improve sperm quality through miRNA-targeted regulation of ROS, which helps to increase male reproduction and protect cryopreserved semen in clinical practice.

Pathogenic Gene Spectrum and Clinical Implication in Chinese Patients with Lupus Nephritis.

BACKGROUND: Lupus nephritis is a rare immunological disorder. Genetic factors are considered important in its causation. We aim to systematically investigate the rare pathogenic gene variants in patients with lupus nephritis. METHODS: Whole-exome sequencing was used to screen pathogenic gene variants in 1886 probands with lupus nephritis. Variants were interpreted on the basis of known pathogenic variants or the American College of Medical Genetics and Genomics guidelines and studied by functional analysis, including RNA sequencing, quantitative PCR, cytometric bead array, and Western blotting. RESULTS: Mendelian form of lupus nephritis was confirmed in 71 probands, involving 63 variants in 39 pathogenic genes. The detection yield was 4%. The pathogenic genes enriched in nuclear factor kappa-B (NF-κB), type I interferon, phosphatidylinositol-3-kinase/serine/threonine kinase Akt (PI3K/AKT), Ras GTPase/mitogen-activated protein kinase (RAS/MAPK), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways. Clinical manifestation patterns were diverse among different signaling pathways. More than 50% of the pathogenic gene variants were reported to be associated with lupus or lupus nephritis for the first time. The identified pathogenic gene variants of lupus nephritis overlapped with those of autoinflammatory and immunodeficiency diseases. Inflammatory signatures, such as cytokine levels of IL-6, IL-8, IL-1 ß , IFN α , IFN γ , and IP10 in serum and transcriptional levels of interferon-stimulated genes in blood, were significantly higher in patients with pathogenic gene variants compared with controls. The overall survival rate of patients with pathogenic gene variants was lower than those without pathogenic gene variants. CONCLUSIONS: A small fraction of patients with lupus nephritis had identifiable pathogenic gene variants, primarily in NF-κB, type I interferon, PI3K/AKT, JAK/STAT, RAS/MAPK, and complement pathways.

Therapeutic implications of the tumor microenvironment in ovarian cancer patients receiving PD-1/PD-L1 therapy.

Epithelial ovarian cancer (EOC) ranks as the second most common cause of gynecologic cancer death. The conventional treatment for patients with EOC is postoperative therapy along with platinum chemotherapy. However, a more efficient treatment regimen is of great need for these patients diagnosed with advanced disease (FIGO stages III-IV), whose survival is approximately 29%. Immunotherapy seems to be an encouraging therapeutic strategy for EOC. Given the crucial role in the complicated interactions between tumor cells and other cells, the tumor microenvironment (TME) influences the response to immunotherapy. In this review, we discuss feasible strategies for EOC immunotherapy by exploiting the reciprocity of cancer cells and the constituents of the TME.

Plant communities exhibit low resource partitioning for pollinator guilds under sub-tropical conditions of Pakistan.

Assessment of resource partitioning in pollinators at a particular place can be used to conserve plant communities by minimizing their inter-specific competition. Current study was conducted to investigate the occurrence of this phenomenon among plant communities under sub-tropical conditions for the first time in Pakistan. We considered the entire available flowering plant and floral visitor communities in the study area-Lal Suhanra forest of Bahawalpur, Pakistan- along with different variations among them based on morphology, color and symmetry (functional groups) i.e. four functional groups among insects and nine among plants. Weekly floral visitor censuses were conducted during spring season -from the first week of March to the fourth week of May 2018. Thirty individuals of each plant species -in bloom- were observed for floral visitors in each census. Plant species with different floral shapes, colors and symmetry did not show any significant resource partitioning. The Non-metric multidimensional scaling analysis followed by one-way ANOSIM test showed non- significant differences among all the pair of floral shapes, colors (except white and yellow) and symmetry (R-value < 0.168). However, SIMPER test suggested that flies were the most common group that contributed more towards within group similarities of different floral shapes (19 to 21% similarity), colors (16 to 30%) and symmetry (19%) followed by long-tongue bees i.e. 14 to 21%, 9 to 19% and 18%, respectively. Our results suggest that plant communities under sub-tropical conditions of Pakistan exhibit a generalist pollination system with no significant resource partitioning in pollinator species. Therefore, plant communities may have high competition for pollinator species which exhibits fewer implications of species loss on overall pollination process. Our study provides the basis for understanding the partitioning of pollinator guilds under sub-tropical conditions. Future studies should focus on functional traits in more detail at the community and the population scales for their possible impact on resource partitioning.

Requirement for p62 acetylation in the aggregation of ubiquitylated proteins under nutrient stress.

Autophagy receptor p62/SQSTM1 promotes the assembly and removal of ubiquitylated proteins by forming p62 bodies and mediating their encapsulation in autophagosomes. Here we show that under nutrient-deficient conditions, cellular p62 specifically undergoes acetylation, which is required for the formation and subsequent autophagic clearance of p62 bodies. We identify K420 and K435 in the UBA domain as the main acetylation sites, and TIP60 and HDAC6 as the acetyltransferase and deacetylase. Mechanically, acetylation at both K420 and K435 sites enhances p62 binding to ubiquitin by disrupting UBA dimerization, while K435 acetylation also directly increases the UBA-ubiquitin affinity. Furthermore, we show that acetylation of p62 facilitates polyubiquitin chain-induced p62 phase separation. Our results suggest an essential role of p62 acetylation in the selective degradation of ubiquitylated proteins in cells under nutrient stress, by specifically regulating the assembly of p62 bodies.

Mammalian Atg9 contributes to the post-Golgi transport of lysosomal hydrolases by interacting with adaptor protein-1.

Accumulating evidence has indicated a role for autophagy-related (Atgs) proteins in cell regulation which is independent of their autophagic activities. As the only known transmembrane protein essential for autophagy, Atg9 cycles between the trans-Golgi network (TGN) and endosomes. Here, we report a function for mammalian Atg9 (mAtg9) in the transport of lysosomal hydrolases which impacts the lysosomal degradation capacity. Depletion of mAtg9 inhibits the degradation of epidermal growth factor receptor and the maturation of cathepsin D and cathepsin L. mAtg9 interacts with adaptor protein-1 (AP1) and the cation-independent mannose-6-phosphate receptor, facilitating AP1 polymerization and the transport of cathepsin D from the TGN. These results suggest that mAtg9 may serve as a coreceptor of lysosomal hydrolases for their TGN export by cycling between the TGN and endosomes.