Med23 deficiency reprograms the tumor microenvironment to promote lung tumorigenesis.

BACKGROUND: Lung cancer is the leading cause of cancer-related death worldwide. We previously found that Mediator complex subunit 23 (MED23) is important for the tumourigenicity of lung cancer cells with hyperactive Ras activity in vitro, although the in vivo function of MED23 in lung tumourigenesis remains to be explored. METHODS: In this study, we utilized well-characterized KrasG12D-driven non-small cell lung cancer mouse model to investigate the role of MED23 in lung cancer. The lung tumour progression was evaluated by H&E and IHC analysis. Western blotting and qRT-PCR assays were performed to detect changes in gene expression. Immune cells were analyzed by FACS technology. RNA-seq and reporter assays were conducted to explore the mechanism. RESULTS: We observed that lung epithelial Med23 deletion by adeno-Cre resulted in a significant increase in KrasG12D tumour number and size, which was further verified with another mouse model with Med23 specifically deleted in alveolar type II cells. Mice with lung-specific Med23 deficiency also exhibited accelerated tumourigenesis, and a higher proliferation rate for tumour cells, along with increased ERK phosphorylation. Notably, the numbers of infiltrating CD4+ T cells and CD8+ T cells were significantly reduced in the lungs of Med23-deficient mice, while the numbers of myeloid-derived suppressor cells (MDSCs) and Treg cells were significantly increased, suggesting the enhanced immune escape capability of the Med23-deficient lung tumours. Transcriptomic analysis revealed that the downregulated genes in Med23-deficient lung tumour tissues were associated with the immune response. Specifically, Med23 deficiency may compromise the MHC-I complex formation, partially through down-regulating B2m expression. CONCLUSIONS: Collectively, these findings revealed that MED23 may negatively regulate Kras-induced lung tumourigenesis in vivo, which would improve the precise classification of KRAS-mutant lung cancer patients and provide new insights for clinical interventions.

CD169+ Skin Macrophages Function as a Specialized Subpopulation in Promoting Psoriasis-like Skin Disease in Mice.

Skin macrophages are critical to maintain and restore skin homeostasis. They serve as major producers of cytokines and chemokines in the skin, participating in diverse biological processes such as wound healing and psoriasis. The heterogeneity and functional diversity of macrophage subpopulations endow them with multifaceted roles in psoriasis development. A distinct subpopulation of skin macrophages, characterized by high expression of CD169, has been reported to exist in both mouse and human skin. However, its role in psoriasis remains unknown. Here, we report that CD169+ macrophages exhibit increased abundance in imiquimod (IMQ) induced psoriasis-like skin lesions. Specific depletion of CD169+ macrophages in CD169-ditheria toxin receptor (CD169-DTR) mice inhibits IMQ-induced psoriasis, resulting in milder symptoms, diminished proinflammatory cytokine levels and reduced proportion of Th17 cells within the skin lesions. Furthermore, transcriptomic analysis uncovers enhanced activity in CD169+ macrophages when compared with CD169- macrophages, characterized by upregulated genes that are associated with cell activation and cell metabolism. Mechanistically, CD169+ macrophages isolated from IMQ-induced skin lesions produce more proinflammatory cytokines and exhibit enhanced ability to promote Th17 cell differentiation in vitro. Collectively, our findings highlight the crucial involvement of CD169+ macrophages in psoriasis development and offer novel insights into the heterogeneity of skin macrophages in the context of psoriasis.

Time-varying impacts of green credit on carbon productivity in China: New evidence from a non-parametric panel data model.

In the context of global climate change threatening human survival, and in a post-pandemic era that advocates for a global green and low-carbon economic recovery, conducting an in-depth analysis to assess whether green finance can effectively support low-carbon economic development from a dynamic perspective is crucial. Unlike existing research, which focuses solely on the average effects of green credit (GC) on carbon productivity (CP), we introduce a non-parametric panel data model to investigate GC's impact on CP across 30 provinces in China from 2003 to 2021, verifying a significant time-varying effect. Specifically, during the first phase (2003-2008), GC negatively impacted CP. In the second phase (2009-2014), this negative influence gradually diminished and transformed into a positive effect. In the third phase (2015-2021), GC continued to positively influence CP, although this effect became insignificant during the pandemic. Further subgroup analysis reveals that in the regions with low environmental regulations, GC did not significantly boost CP throughout the sample period. In contrast, in the regions with high environmental regulations, GC's positive effect persisted in the mid to late stages of the sample period. Additionally, compared to the regions with low levels of marketization, the impact of GC on CP was more pronounced in highly marketized regions. This indicates that the promoting effect of GC on CP depends on strong support from environmental regulations and well-functioning market mechanisms. By adopting a non-parametric approach, this study reveals variations in the impact of GC on CP across different stages and under the influence of the pandemic shock, offering new insights into the relationship between GC and China's CP.

CD169+ subcapsular sinus macrophage-derived microvesicles are associated with light zone follicular dendritic cells.

Follicular dendritic cells (FDCs) are a specialized type of stromal cells that exclusively reside in B-cell follicles. When inflammation occurs, the FDC network is reorganized to support germinal center (GC) polarization into the light zone (LZ) and dark zone (DZ). Despite the indispensable role of FDCs in supporting humoral responses, the FDC regulatory requirements remain incompletely defined. In this study, we unexpectedly observed an accumulation of CD169+ subcapsular sinus macrophage (SSM)-derived microvesicles (MVs) in the B-cell zone, which were tightly associated with the FDC network. Interestingly, a selective deposition of CD169+ MVs was detected in both GC LZ FDCs in secondary follicles and on predetermined LZ FDCs in primary follicles. The ablation of CD169+ MVs, resulting from SSM depletion, resulted in significantly decreased expression of LZ-related genes in FDCs. In addition, we found that CD169+ MVs could colocalize with fluorescently tagged antigen-containing immune complexes (ICs), supporting a possible role of CD169+ MVs in transporting antigens to the FDC network. Thus, our data reveal intimate crosstalk between FDCs and SSMs located outside B-cell follicles via SSM-released MVs, providing a novel perspective on the mechanisms underlying the regulation of FDC maturation and polarization.

Microenvironment modulation by key regulators of RNA N6-methyladenosine modification in respiratory allergic diseases.

BACKGROUND: RNA N6-methyladenosine (m6A) regulators are considered post-transcriptional regulators that affect several biological functions, and their role in immunity, in particular, is emerging. However, the role of m6A regulators in respiratory allergic diseases remains unclear. Therefore, we aimed to investigate the role of key m6A regulators in mediating respiratory allergic diseases and immune microenvironment infiltration characteristics. METHODS: We downloaded gene expression profiles of respiratory allergies from the Gene Expression Omnibus (GEO) database and we performed hierarchical clustering, difference analysis, and construction of predictive models to identify hub m6A regulators that affect respiratory allergies. Next, we investigate the underlying biological mechanisms of key m6A regulators by performing PPI network analysis, functional enrichment analysis, and immune microenvironment infiltration analysis. In addition, we performed a drug sensitivity analysis on the key m6A regulator, hoping to be able to provide some implications for clinical medication. RESULTS: In this study, we identified four hub m6A regulators that affect the respiratory allergy and investigated the underlying biological mechanisms. In addition, studies on the characteristics of immune microenvironment infiltration revealed that the expression of METTL14, METTL16, and RBM15B correlated with the infiltration of the mast and Th2 cells in respiratory allergy, and METTL16 expression was found to be significantly negatively correlated with macrophages for the first time (R = -0.53, P < 0.01). Finally, a key m6A regulator, METTL14, was screened by combining multiple algorithms. In addition, by performing a drug sensitivity analysis on METTL14, we hypothesized that it may play an important role in the improvement of allergic symptoms in the upper and lower airways with topical nasal glucocorticoids. CONCLUSIONS: Our findings suggest that m6A regulators, particularly METTL14, play a crucial role in the development of respiratory allergic diseases and the infiltration of immune cells. These results may provide insight into the mechanism of action of methylprednisolone in treating respiratory allergic diseases.

Discovery of novel 2-aminopyridine derivatives as ROS1 and ALK dual inhibitors to combat drug-resistant mutants including ROS1G2032R and ALKG1202R.

Clinical treatment by FDA-approved ROS1/ALK inhibitor Crizotinib significantly improved the therapeutic outcomes. However, the emergence of drug resistance, especially driven by acquired mutations, have become an inevitable problem and worsened the clinical effects of Crizotinib. To combat drug resistance, some novel 2-aminopyridine derivatives were designed rationally based on molecular simulation, then synthesised and subjected to biological test. The preferred spiro derivative C01 exhibited remarkable activity against CD74-ROS1G2032R cell with an IC50 value of 42.3 nM, which was about 30-fold more potent than Crizotinib. Moreover, C01 also potently inhibited enzymatic activity against clinically Crizotinib-resistant ALKG1202R, harbouring a 10-fold potency superior to Crizotinib. Furthermore, molecular dynamic disclosed that introducing the spiro group could reduce the steric hindrance with bulky side chain (Arginine) in solvent region of ROS1G2032R, which explained the sensitivity of C01 to drug-resistant mutant. These results indicated a path forward for the generation of anti Crizotinib-resistant ROS1/ALK dual inhibitors.

Deficiency of astrocyte CysLT1R ameliorates depression-like behaviors in mice by modulating glutamate synaptic transmission.

Our previous study suggests that hippocampal cysteinyl leukotriene receptor 1 (CysLT1R) could be involved in depression. Herein we hypothesize that CysLT1R may regulate depression by affecting synaptic glutamate cycling based on existence of CysLT1R in the astrocytes that participate in occurrence of depression. We found that CysLT1R expression was significantly increased in the astrocyte of chronic unpredictable mild stress (CUMS)-induced depression-like mice, CysLT1R astrocyte-specific conditional knockout (AcKO) significantly improved depression-like behaviors, as indicated by decreased immobility time in the forced swimming test and tail suspension test and increased sucrose preference in the sucrose preference test, and knockdown of CysLT1R in the astrocyte of dentate gyrus (DG), the region with the most significant increase of CysLT1R in the astrocyte of depression-like mice, produced similar effects. Correspondingly, overexpression of CysLT1R in the astrocyte of DG induced depression-like behaviors in mice. The further study showed that CysLT1R AcKO ameliorated synaptic plasticity impairment, as reflected by increased synapse, LTP and PSD95, and promoted glutamate transporter 1 (GLT-1) expression by inhibiting NF-κB p65 nuclear translocation mediated by ß-arestin2 and clatrhin, subsequently decreased glutamate in synaptic cleft and GluN2B on postsynaptic membrane in depression-like mice. The present study also showed that GLT-1 agonist or NF-κB inhibitor ameliorated depressive-like behaviors induced by overexpression of the astrocyte CysLT1R of DG. Our study demonstrated that astrocyte CysLT1R regulated depression by modulating glutamate synaptic transmission, suggesting that CysLT1R could be a potential target for developing novel drugs of anti-depression.

Orbits of charged particles trapped in a dipole magnetic field.

Motion of a test charged particle in a dipole magnetic field can be reduced to a two degree-of-freedom Hamiltonian system due to the axisymmetry of the dipole field. We carried out a systematic study of orbits of low-energy trapped charged particles in the dipole field via calculation of their Lyapunov characteristic exponents (LCEs) with random initial conditions in the four-dimensional phase space. Since there is at most one positive LCE, these orbits are classified as chaotic ones with one positive LCE and quasi-periodic ones with vanishing LCEs. The dependence of the fraction of quasi-periodic orbits in the phase space on the particle energy is given, which reveals a discrete spectrum, confirming the results of earlier studies. It is also found that most quasi-periodic orbits are confined near the equatorial plane and away from the dipole except for some at very low energies, while chaotic ones are ergodic. The distribution of the maximum LCE (mLCE) appears to vary gradually in the phase space and chaotic orbits with very low values of the mLCE wander near quasi-periodic orbits for a significant amount of time before merging into the sea of chaos.

From period to quasiperiod to chaos: A continuous spectrum of orbits of charged particles trapped in a dipole magnetic field.

Via evaluation of the Lyapunov exponent, we report the discovery of three prominent sets of phase space regimes of quasiperiodic orbits of charged particles trapped in a dipole magnetic field. Besides the low energy regime that has been studied extensively and covers more than ∼10% in each dimension of the phase space of trapped orbits, there are two sets of high energy regimes, the largest of which covers more than ∼4% in each dimension of the phase space of trapped orbits. Particles in these high-energy orbits may be observed in space and be realized in plasma experiments on the earth.

Horizontal gene transfer is more frequent with increased heterotrophy and contributes to parasite adaptation.

Horizontal gene transfer (HGT) is the transfer of genetic material across species boundaries and has been a driving force in prokaryotic evolution. HGT involving eukaryotes appears to be much less frequent, and the functional implications of HGT in eukaryotes are poorly understood. We test the hypothesis that parasitic plants, because of their intimate feeding contacts with host plant tissues, are especially prone to horizontal gene acquisition. We sought evidence of HGTs in transcriptomes of three parasitic members of Orobanchaceae, a plant family containing species spanning the full spectrum of parasitic capabilities, plus the free-living Lindenbergia Following initial phylogenetic detection and an extensive validation procedure, 52 high-confidence horizontal transfer events were detected, often from lineages of known host plants and with an increasing number of HGT events in species with the greatest parasitic dependence. Analyses of intron sequences in putative donor and recipient lineages provide evidence for integration of genomic fragments far more often than retro-processed RNA sequences. Purifying selection predominates in functionally transferred sequences, with a small fraction of adaptively evolving sites. HGT-acquired genes are preferentially expressed in the haustorium-the organ of parasitic plants-and are strongly biased in predicted gene functions, suggesting that expression products of horizontally acquired genes are contributing to the unique adaptive feeding structure of parasitic plants.

Lipid-based DNA/siRNA transfection agents disrupt neuronal bioenergetics and mitophagy.

A multitude of natural and artificial compounds have been recognized to modulate autophagy, providing direct or, through associated pathways, indirect entry points to activation and inhibition. While these pharmacological tools are extremely useful in the study of autophagy, their abundance also suggests the potential presence of unidentified autophagic modulators that may interfere with experimental designs if applied unknowingly. Here, we report unanticipated effects on autophagy and bioenergetics in neuronal progenitor cells (NPCs) incubated with the widely used lipid-based transfection reagent lipofectamine (LF), which induced mitochondria depolarization followed by disruption of electron transport. When NPCs were exposed to LF for 5 h followed by 24, 48, and 72 h in LF-free media, an immediate increase in mitochondrial ROS production and nitrotyrosine formation was observed. These events were accompanied by disrupted mitophagy (accumulation of dysfunctional and damaged mitochondria, and of LC3II and p62), in an mTOR- and AMPK-independent manner, and despite the increased mitochondrial PINK1 (PTEN-inducible kinase 1) localization. Evidence supported a role for a p53-mediated abrogation of parkin translocation and/or abrogation of membrane fusion between autophagosome and lysosomes. While most of the outcomes were LF-specific, only two were shared by OptiMEM exposure (with no serum and reduced glucose levels) albeit at lower extents. Taken together, our findings show that the use of transfection reagents requires critical evaluation with respect to consequences for overall cellular health, particularly in experiments designed to address autophagy-inducing effects and/or energy stress.

Bit-based support vector machine nonlinear detector for millimeter-wave radio-over-fiber mobile fronthaul systems.

An effective bit-based support vector machine (SVM) is proposed as a non-parameter nonlinear mitigation approach in the millimeter-wave radio-over-fiber (RoF) mobile fronthaul (MFH) system for various modulation formats. First, we analyze the impairments originated from nonlinearities in the millimeter-wave RoF system. Then we introduce the operation principle of the bit-based SVM detector. As a classifier, the SVM can create nonlinear decision boundaries by kernel function to mitigate the distortions caused by both linear and nonlinear noise. In our design, SVM can learn and capture the link characteristics from only a few training data without requiring the prior estimation of the system link. The bit-based SVM only needs log2M SVMs to detect the signal of M-order modulation format. Experimental results have been obtained to verify the feasibility of the proposed method. The sensitivities are improved by 1.2-dB for 16-QAM, 1.3-dB for 64-QAM, 1.8-dB for 16-APSK and 1.3-dB for 32-APSK at BER = 1E-3 with SVM detector, respectively. The proposed bit-based SVM gains a large improvement in the nonlinear system tolerance and outperforms the system employing k-means algorithm.

Molecular Dynamics Study to Investigate the Dimeric Structure of the Full-Length α-Synuclein in Aqueous Solution.

The mechanisms of dimerization of α-synuclein from full-length monomers and their structural features have been investigated through molecular dynamics simulations in this study. The dimerization of α-syn plays a critical role in the fibrillogenesis mechanism and could initiate and trigger α-syn to aggregate by conformational transforming. According to the alignment between three regions of α-syn monomer, eight diverse starting structures have been constructed. However, only five configurations show the dimeric structures, and the detailed properties of three dimers of them are discussed. During the simulations, both identical α-syn peptides (P1 and P2) of these three dimers reduce the high contents of α-helix from their native folded structures, while the contents of ß-sheet increase. Antiparallel ß-hairpin motifs within the α-syn peptide are formed by intramolecular interactions. The ß-hairpin regions are adjacent to the nonamyloid ß component (NAC) of α-syn, and these structural features are consistent with the experimental observation. Moreover, intermolecular ß-sheets also are generated between P1 and P2 through hydrogen bonding interactions. The dimers produce both intramolecular ß-hairpin and intermolecular ß-sheet characters; the former is presented in monomer and oligomer of α-syn, and the latter occurs in the fibril structure. The simulations also show several other interactions such as hydrophobic interactions and salt-bridges, which would contribute to making the α-syn dimers more stable with the aforementioned effects. The results may pave the way to design small molecules to inhibit the dimerization in order to block the aggregation of α-syn in the future.

Altered redox mitochondrial biology in the neurodegenerative disorder fragile X-tremor/ataxia syndrome: use of antioxidants in precision medicine.

A 55-200 expansion of the CGG nucleotide repeat in the 5'-UTR of the fragile X mental retardation 1 gene (FMR1) is the hallmark of the triplet nucleotide disease known as the "premutation" as opposed to those with >200 repeats, known as the full mutation or fragile X syndrome. Originally, premutation carriers were thought to be free of phenotypic traits; however, some are diagnosed with emotional and neurocognitive issues and, later in life, with the neurodegenerative disease fragile X-associated tremor/ataxia syndrome (FXTAS). Considering that mitochondrial dysfunction has been observed in fibroblasts and post-mortem brain samples from carriers of the premutation, we hypothesized that mitochondrial dysfunction-derived ROS may result in cumulative oxidative-nitrative damage. Fibroblasts from premutation carriers (n=31, all FXTAS-free except 8), compared to age- and sex-matched controls (n=25), showed increased mitochondrial ROS production, impaired Complex I activity, lower expression of MIA40 (rate-limiting step of the redox-regulated mitochondrial-disulfide-relay-system), increased mtDNA deletions, and increased biomarkers of lipid and protein oxidative-nitrative damage. Most of the outcomes were more pronounced in FXTAS-affected individuals. Significant recovery of mitochondrial mass and/or function was obtained with superoxide or hydroxyl radicals' scavengers, a glutathione peroxidase analog, or by overexpressing MIA40. The effects of ethanol (a hydroxyl radical scavenger) were deleterious, while others (by N-acetyl-cysteine, quercetin and epigallocatechin-3-gallate) were outcome- and/or carrier-specifics. The use of antioxidants in the context of precision medicine is discussed with the goal of improving mitochondrial function in carriers with the potential of decreasing the morbidity and/or delaying FXTAS onset.

Special cascade LMS equalization scheme suitable for 60-GHz RoF transmission system.

We design a specific cascade least mean square (LMS) equalizer and to the best of our knowledge, it is the first time this kind of equalizer has been employed for 60-GHz millimeter-wave (mm-wave) radio over fiber (RoF) system. The proposed cascade LMS equalizer consists of two sub-equalizers which are designated for optical and wireless channel compensations, respectively. We control the linear and nonlinear factors originated from optical link and wireless link separately. The cascade equalization scheme can keep the nonlinear distortions of the RoF system in a low degree. We theoretically and experimentally investigate the parameters of the two sub-equalizers to reach their best performances. The experiment results show that the cascade equalization scheme has a faster convergence speed. It needs a training sequence with a length of 10000 to reach its stable status, which is only half as long as the traditional LMS equalizer needs. With the utility of a proposed equalizer, the 60-GHz RoF system can successfully transmit 5-Gbps BPSK signal over 10-km fiber and 1.2-m wireless link under forward error correction (FEC) limit 10-3. An improvement of 4dBm and 1dBm in power sensitivity at BER 10-3 over traditional LMS equalizer can be observed when the signals are transmitted through Back-to-Back (BTB) and 10-km fiber 1.2-m wireless links, respectively.

Downregulation of long noncoding RNA NONHSAT037832 in papillary thyroid carcinoma and its clinical significance.

Long noncoding RNA (lncRNA) is a kind of RNA that is longer than 200 nucleotides with limited or no protein-coding potential. Studies have proved that lncRNAs play important regulatory roles in gene expression and contribute to oncogenesis and cancer metastasis. However, the expression level of lncRNAs and their clinicopathologic significance in papillary thyroid carcinoma (PTC) have not been well studied. In this study, we investigated the expression level of a novel lncRNA NONHSAT037832 in PTC and paired noncancerous thyroid tissues as well as some cell lines by quantitative real-time polymerase chain reaction. The association between the expression level of NONHSAT037832 and clinicopathologic characteristics of patients with PTC was further analyzed. Three receiver operating characteristic curves (ROCs) were established to evaluate the diagnostic value of NONHSAT037832. The results suggested that the expression level of NONHSAT037832 was significantly decreased in PTC compared with paired noncancerous tissues (P < 0.01). And, NONHSAT037832 was also significantly downregulated in two PTC cell lines (K1 and IHH-4) compared to normal thyroid follicular epithelial cell line Nthy-ori 3-1 (P < 0.01). Downregulated NONHSAT037832 was significantly associated with lymph node metastasis (P = 0.015) and tumor size (P = 0.032). The ROCs revealed that NONHSAT037832 had a high diagnostic value for differentiating between PTC and noncancerous diseases as well as identifying PTC with lymph node metastasis and larger tumors (≥3 cm). The area under curve was up to 0.897 (95%CI = 0.852-0.942, P = 0.000), 0.641 (95%CI = 0.519-0.762, P = 0.033), and 0.702 (95%CI = 0.567-0.827, P = 0.008), respectively. This study indicated that NONHSAT037832 might serve as a potential biomarker of PTC.

Pancreatic T cell protein-tyrosine phosphatase deficiency affects beta cell function in mice.

AIMS/HYPOTHESIS: T cell protein tyrosine phosphatase (TCPTP, encoded by PTPN2) regulates cytokine-induced pancreatic beta cell apoptosis and may contribute to the pathogenesis of type 1 diabetes. However, the role of TCPTP in pancreatic endocrine function and insulin secretion remains largely unknown. METHODS: To investigate the endocrine role of pancreatic TCPTP we generated mice with pancreas Ptpn2/TCPTP deletion (panc-TCPTP KO). RESULTS: When fed regular chow, panc-TCPTP KO and control mice exhibited comparable glucose tolerance. However, when challenged with prolonged high fat feeding panc-TCPTP KO mice exhibited impaired glucose tolerance and attenuated glucose-stimulated insulin secretion (GSIS). The defect in GSIS was recapitulated in primary islets ex vivo and after TCPTP pharmacological inhibition or lentiviral-mediated TCPTP knockdown in the glucose-responsive MIN6 beta cells, consistent with this being cell autonomous. Reconstitution of TCPTP in knockdown cells reversed the defect in GSIS demonstrating that the defect was a direct consequence of TCPTP deficiency. The reduced insulin secretion in TCPTP knockdown MIN6 beta cells was associated with decreased insulin content and glucose sensing. Furthermore, TCPTP deficiency led to enhanced tyrosyl phosphorylation of signal transducer and activator of transcription 1 and 3 (STAT 1/3), and substrate trapping studies in MIN6 beta cells identified STAT 1/3 as TCPTP substrates. STAT3 pharmacological inhibition and small interfering RNA-mediated STAT3 knockdown in TCPTP deficient cells restored GSIS to control levels, indicating that the effects of TCPTP deficiency were mediated, at least in part, through enhanced STAT3 phosphorylation and signalling. CONCLUSIONS/INTERPRETATION: These studies identify a novel role for TCPTP in insulin secretion and uncover STAT3 as a physiologically relevant target for TCPTP in the endocrine pancreas.

Protein tyrosine phosphatase 1B regulates pyruvate kinase M2 tyrosine phosphorylation.

Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and adiposity and is a drug target for the treatment of obesity and diabetes. Here we identify pyruvate kinase M2 (PKM2) as a novel PTP1B substrate in adipocytes. PTP1B deficiency leads to increased PKM2 total tyrosine and Tyr(105) phosphorylation in cultured adipocytes and in vivo. Substrate trapping and mutagenesis studies identify PKM2 Tyr-105 and Tyr-148 as key sites that mediate PTP1B-PKM2 interaction. In addition, in vitro analyses illustrate a direct effect of Tyr-105 phosphorylation on PKM2 activity in adipocytes. Importantly, PTP1B pharmacological inhibition increased PKM2 Tyr-105 phosphorylation and decreased PKM2 activity. Moreover, PKM2 Tyr-105 phosphorylation is regulated nutritionally, decreasing in adipose tissue depots after high-fat feeding. Further, decreased PKM2 Tyr-105 phosphorylation correlates with the development of glucose intolerance and insulin resistance in rodents, non-human primates, and humans. Together, these findings identify PKM2 as a novel substrate of PTP1B and provide new insights into the regulation of adipose PKM2 activity.

Potential drug targets for asthma identified in the plasma and brain through Mendelian randomization analysis.

Background: Asthma is a heterogeneous disease, and the involvement of neurogenic inflammation is crucial in its development. The standardized treatments focus on alleviating symptoms. Despite the availability of medications for asthma, they have proven to be inadequate in controlling relapses and halting the progression of the disease. Therefore, there is a need for novel drug targets to prevent asthma. Methods: We utilized Mendelian randomization to investigate potential drug targets for asthma. We analyzed summary statistics from the UK Biobank and then replicated our findings in GWAS data by Demenais et al. and the FinnGen cohort. We obtained genetic instruments for 734 plasma and 73 brain proteins from recently reported GWAS. Next, we utilized reverse causal relationship analysis, Bayesian co-localization, and phenotype scanning as part of our sensitivity analysis. Furthermore, we performed a comparison and protein-protein interaction analysis to identify causal proteins. We also analyzed the possible consequences of our discoveries by the given existing asthma drugs and their targets. Results: Using Mendelian randomization analysis, we identified five protein-asthma pairs that were significant at the Bonferroni level (P < 6.35 × 10-5). Specifically, in plasma, we found that an increase of one standard deviation in IL1R1 and ECM1 was associated with an increased risk of asthma, while an increase in ADAM19 was found to be protective. The corresponding odds ratios were 1.03 (95% CI, 1.02-1.04), 1.00 (95% CI, 1.00-1.01), and 0.99 (95% CI, 0.98-0.99), respectively. In the brain, per 10-fold increase in ECM1 (OR, 1.05; 95% CI, 1.03-1.08) and PDLIM4 (OR, 1.05; 95% CI, 1.04-1.07) increased the risk of asthma. Bayesian co-localization found that ECM1 in the plasma (coloc.abf-PPH4 = 0.965) and in the brain (coloc.abf-PPH4 = 0.931) shared the same mutation with asthma. The target proteins of current asthma medications were found to interact with IL1R1. IL1R1 and PDLIM4 were validated in two replication cohorts. Conclusion: Our integrative analysis revealed that asthma risk is causally affected by the levels of IL1R1, ECM1, and PDLIM4. The results suggest that these three proteins have the potential to be used as drug targets for asthma, and further investigation through clinical trials is needed.