PLS-based gene subset augmentation and tumor-specific gene identification.

In the study of tumor disease pathogenesis, the identification of genes specifically expressed in disease states is pivotal, yet challenges arise from high-dimensional datasets with limited samples. Conventional gene (feature) selection methods often fall short of capturing the complexity of gene-phenotype and gene-gene interactions, necessitating a more robust analysis method. To address these challenges, a gene subset augmentation strategy is proposed in this paper. Our approach introduces diverse perturbation mechanisms to generate distinct gene subsets. The partial least squares-based multiple gene measurement algorithm considers gene-phenotype and gene-gene correlations, identifying differentially expressed genes, including those with weak signals. The constructed gene networks derived from the augmented subsets unveil regulatory patterns, enabling association analysis to explore gene associations comprehensively. Our algorithm excels in identifying small-sized gene subsets with strong discriminative power, surpassing traditional methods that yield a single gene subset. Unlike conventional approaches, our algorithm reveals a spectrum of different gene subsets and their weakly differentially expressed genes. This nuanced perspective aids in unraveling the molecular characteristics and specific expression patterns of tumor genes. The versatility of our approach not only contributes to the advancement of tumor-specific gene identification but also holds promise for addressing challenges in various fields characterized by high-dimensional datasets and limited samples. The Python implementation is available at http://github.com/wenjieyou/PLSGSA.

Elafibranor emerged as a potential chemotherapeutic drug for non-muscle invasive bladder cancer.

Intravesical infusion of chemotherapeutics is highly recommended by several clinical guidelines for treating nonmuscle invasive bladder cancer (NMIBC). However, cytotoxic chemotherapeutics can cause a series of side effects, which greatly limits their application. Herein, a starvation therapy strategy was proposed, and elafibranor (ELA) was validated as a safe chemotherapeutic for NMIBC. The results showed that 20 µM ELA was sufficient to inhibit the proliferation and migration of bladder cancer cells and increase the level of intracellular reactive oxygen species (ROS). Furthermore, 2 mg/kg ELA treatment blocked the growth of primary tumors in an immunodeficient model by inhibiting proliferation and inducing apoptosis and improved the survival time of immunocompetent model mice. ELA treatment up to 10 mg/kg met the general safety requirements. We also established a patient-derived conditional reprogramming cell (CRC) model to assess the clinical translational potential of ELA. The antitumor effect and antitumor specificity of ELA treatment were confirmed. This work not only identified a promising chemotherapeutic for NMIBC but also provided a potential methodological system for drug discovery.

Farnesoid X receptor promotes non-small cell lung cancer metastasis by activating Jak2/STAT3 signaling via transactivation of IL-6ST and IL-6 genes.

Metastasis accounts for the majority of cases of cancer recurrence and death in patients with advanced non-small cell lung cancer (NSCLC). Farnesoid X Receptor (FXR) is a bile acid nuclear receptor that was recently found to be upregulated in NSCLC tissues. However, whether and how FXR regulates NSCLC metastasis remains unclear. In the present study, it was found that FXR promoted the migration, invasion, and angiogenic ability of NSCLC cells in vitro, and increased NSCLC metastasis in a mouse model in vivo. Mechanistic investigation demonstrated that FXR specifically bound to the promoters of IL-6ST and IL-6 genes to upregulate their transcription, thereby leading to activation of the Jak2/STAT3 signaling pathway, which facilitated tumor migration, invasion, and angiogenesis in NSCLC. Notably, Z-guggulsterone, a natural FXR inhibitor, significantly reduced FXRhigh NSCLC metastasis, and decreased the expression of FXR, IL-6, IL-6ST, and p-STAT3 in the mouse model. Clinical analysis verified that FXR was positively correlated with IL-6, IL-6ST and p-STAT3 expression in NSCLC patients, and was indicative of a poor prognosis. Collectively, these results highlight a novel FXR-induced IL-6/IL-6ST/Jak2/STAT3 axis in NSCLC metastasis, and a promising therapeutic means for treating FXRhigh metastatic NSCLC.

Immune checkpoint inhibitor-associated toxicity in advanced non-small cell lung cancer: An updated understanding of risk factors.

Immune checkpoint inhibitors (ICIs), such as programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T lymphocyte antigen 4 (CTLA-4) antibodies, etc, have revolutionized cancer treatment strategies, including non-small cell lung cancer (NSCLC). While these immunotherapy agents have achieved durable clinical benefits in a subset of NSCLC patients, they bring in a variety of immune-related adverse events (irAEs), which involve cardiac, pulmonary, gastrointestinal, endocrine and dermatologic system damage, ranging from mild to life-threatening. Thus, there is an urgent need to better understand the occurrence of irAEs and predict patients who are susceptible to those toxicities. Herein, we provide a comprehensive review of what is updated about the clinical manifestations, mechanisms, predictive biomarkers and management of ICI-associated toxicity in NSCLC. In addition, this review also provides perspective directions for future research of NSCLC-related irAEs.

Delicaflavone reactivates anti-tumor immune responses by abrogating monocytic myeloid cell-mediated immunosuppression.

BACKGROUND: Myeloid cell-mediated immunosuppression is a major obstacle to checkpoint blockade immunotherapy. We previously reported that total biflavonoids extract from Selaginella doederleinii (TBESD) and a flavone monomer isolated from TBESD, named Delicaflavone, have favorable anti-tumor activity. However, whether TBESD and Delicaflavone could affect the tumor microenvironment (TME) remains unclear. PURPOSE: In this study, we focused on the TME to determine whether TBESD and Delicaflavone could restore anti-tumor immune response. METHODS: 4T1 tumor-bearing immunocompetent BALB/c mice and T cell-deficient nude mice were used to examine the effect of TBESD on T cell-mediated immunity in vivo. Multi-parameter flow cytometry was conducted to evaluate the impacts of TBESD on TME. Primary cells, including murine CD8+ T cells, tumor associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) were prepared to investigate the modulatory activities of TBESD on immune cells. It was further determined whether Delicaflavone or Amentoflavone, two typical functional biflavones from TBESD, mediated those effects of TBESD. Finally, the impacts of TBESD and Delicaflavone on Jak1/STAT6 signaling pathway were explored via western blot. RESULTS: We found that TBESD significantly reduced 4T1 tumor growth in immunocompetent BALB/c mice, but not in nude mice. This effect was associated with the regulation of TME, shown as an increase in functional T cells and M1 phenotype TAMs (M1-TAMs), and a decrease in M2 phenotype TAMs (M2-TAMs), monocytic-MDSCs (M-MDSCs) and regulatory T cells (Tregs) in TBESD-treated BALB/c mouse 4T1 tumors. It was found ex vivo that TBESD restrained the viability and immunosuppressive properties of M2-TAMs and M-MDSCs, especially for the loss of arginase-1 expression. Additionally, TBESD re-educated M2-TAMs to an M1 like phenotype. Further investigations determined that Delicaflavone predominantly mediated the immuno-modulatory activities of TBESD both ex vivo and in vivo. Finally, Delicaflavone and TBESD blocked Jak1/STAT6 signaling pathway in M2-TAMs and MDSCs. CONCLUSION: The present study suggests Delicaflavone as a potent natural inhibitor of M2-TAMs and MDSCs, which fills the gap in knowledge on the immuno-modulatory effects of TBESD and Delicaflavone, and could have translational implications to improve the efficacy of cancer immunotherapy.

GABAA(δ) receptor hypofunction in the amygdala-hippocampal circuit underlies stress-induced anxiety.

Dysregulated GABAergic inhibition in the amygdala has long been implicated in stress-related neuropsychiatric disorders. However, the molecular and circuit mechanisms underlying the dysregulation remain elusive. Here, by using a mouse model of chronic social defeat stress (CSDS), we observed that the dysregulation varied drastically across individual projection neurons (PNs) in the basolateral amygdala (BLA), one of the kernel amygdala subregions critical for stress coping. While persistently reducing the extrasynaptic GABAA receptor (GABAAR)-mediated tonic current in the BLA PNs projecting to the ventral hippocampus (BLA â†’ vHPC PNs), CSDS increased the current in those projecting to the anterodorsal bed nucleus of stria terminalis (BLA â†’ adBNST PNs), suggesting projection-based dysregulation of tonic inhibition in BLA PNs by CSDS. Transcriptional and electrophysiological analysis revealed that the opposite CSDS influences were mediated by loss- and gain-of-function of δ-containing GABAARs (GABAA(δ)Rs) in BLA â†’ vHPC and BLA â†’ adBNST PNs, respectively. Importantly, it was the lost inhibition in the former population but not the augmentation in the latter population that correlated with the increased anxiety-like behavior in CSDS mice. Virally mediated maintenance of GABAA(δ)R currents in BLA â†’ vHPC PNs occluded CSDS-induced anxiety-like behavior. These findings clarify the molecular substrate for the dysregulated GABAergic inhibition in amygdala circuits for stress-associated psychopathology.

Prefrontal GABAA(δ)R Promotes Fear Extinction through Enabling the Plastic Regulation of Neuronal Intrinsic Excitability.

Extinguishing the previously acquired fear is critical for the adaptation of an organism to the ever-changing environment, a process requiring the engagement of GABAA receptors (GABAARs). GABAARs consist of tens of structurally, pharmacologically, and functionally heterogeneous subtypes. However, the specific roles of these subtypes in fear extinction remain largely unexplored. Here, we observed that in the medial prefrontal cortex (mPFC), a core region for mood regulation, the extrasynaptically situated, δ-subunit-containing GABAARs [GABAA(δ)Rs], had a permissive role in tuning fear extinction in male mice, an effect sharply contrasting to the established but suppressive role by the whole GABAAR family. First, the fear extinction in individual mice was positively correlated with the level of GABAA(δ)R expression and function in their mPFC. Second, knockdown of GABAA(δ)R in mPFC, specifically in its infralimbic (IL) subregion, sufficed to impair the fear extinction in mice. Third, GABAA(δ)R-deficient mice also showed fear extinction deficits, and re-expressing GABAA(δ)Rs in the IL of these mice rescued the impaired extinction. Further mechanistic studies demonstrated that the permissive effect of GABAA(δ)R was associated with its role in enabling the extinction-evoked plastic regulation of neuronal excitability in IL projection neurons. By contrast, GABAA(δ)R had little influence on the extinction-evoked plasticity of glutamatergic transmission in these cells. Altogether, our findings revealed an unconventional and permissive role of extrasynaptic GABAA receptors in fear extinction through a route relying on nonsynaptic plasticity.SIGNIFICANCE STATEMENT The medial prefrontal cortex (mPFC) is one of the kernel brain regions engaged in fear extinction. Previous studies have repetitively shown that the GABAA receptor (GABAAR) family in this region act to suppress fear extinction. However, the roles of specific GABAAR subtypes in mPFC are largely unknown. We observed that the GABAAR-containing δ-subunit [GABAA(δ)R], a subtype of GABAARs exclusively situated in the extrasynaptic membrane and mediating the tonic neuronal inhibition, works oppositely to the whole GABAAR family and promotes (but does not suppress) fear extinction. More interestingly, in striking contrast to the synaptic GABAARs that suppress fear extinction by breaking the extinction-evoked plasticity of glutamatergic transmission, the GABAA(δ)R promotes fear extinction through enabling the plastic regulation of neuronal excitability in the infralimbic subregion of mPFC. Our findings thus reveal an unconventional role of GABAA(δ)R in promoting fear extinction through a route relying on nonsynaptic plasticity.

High farnesoid X receptor expression predicts favorable clinical outcomes in PD­L1low/negative non­small cell lung cancer patients receiving anti­PD­1­based chemo­immunotherapy.

Anti­programmed death­1 (PD­1)/programmed death­ligand 1 (PD­L1)­directed immunotherapy has revolutionized the treatment of advanced non­small cell lung cancer (NSCLC). However, predictive biomarkers are still lacking, particularly in identifying PD­L1low/negative patients who will benefit from immunotherapy. It was previously reported that farnesoid X receptor (FXR) downregulated PD­L1 expression in NSCLC, and that FXRhighPD­L1low mouse Lewis lung carcinoma tumors showed an increased susceptibility to PD­1 blockade compared with mock tumors. At present, whether the FXRhighPD­L1low phenotype predicts clinical response to immunotherapy in patients with NSCLC remains unclear. Herein, a retrospective study was conducted to examine the expression levels of FXR, PD­L1 and CD8+ T cells by immunohistochemistry in a cohort of 149 patients with NSCLC receiving anti­PD­1­based chemo­immunotherapy. The results revealed that high FXR and PD­L1 expression levels were associated with higher objective response rates (ORR) in all patients. High PD­L1 expression also indicated superior progression­free survival (PFS). Interestingly, an inverse correlation was identified between FXR and PD­L1 expression in specimens with NSCLC. Subgroup analysis revealed that high FXR expression was associated with a higher ORR, as well as longer PFS and overall survival (OS) in PD­L1low patients. Cox multivariate analysis revealed that high FXR expression was an independent predictor for PFS and OS in PD­L1low patients. Tumor microenvironment evaluation revealed a statistically significant decrease of infiltrating CD8+ T cells in FXRhigh specimens with NSCLC. Overall, the present study proposed an FXRhighPD­L1low signature as a candidate predictor of response to anti­PD­1­based chemo­immunotherapy in PD­L1low/negative patients with NSCLC, providing evidence that could be used to broaden the patients benefitting from immunotherapy.

Inhaled mRNA Nanoformulation with Biogenic Ribosomal Protein Reverses Established Pulmonary Fibrosis in a Bleomycin-Induced Murine Model.

Idiopathic pulmonary fibrosis (IPF), a lethal respiratory disease with few treatment options, occurs due to repetitive microinjuries to alveolar epithelial cells (AECs) and progresses with an overwhelming deposition of extracellular matrix (ECM), ultimately resulting in fibrotic scars and destroyed the alveolar architecture. Here, an inhaled ribosomal protein-based mRNA nanoformulation is reported for clearing the intrapulmonary ECM and re-epithelializing the disrupted alveolar epithelium, thereby reversing established fibrotic foci in IPF. The nanoformulation is sequentially assembled by a ribosomal protein-condensed mRNA core, a bifunctional peptide-modified corona and keratinocyte growth factor (KGF) with a PEGylated shielding shell. When inhaled via a nebulizer, the nanoformulations carried by microdrops are deposited in the alveoli, and penetrate into fibrotic foci, where the outer KGFs are detached after matrix metalloproteinase 2 (MMP2) triggering. The RGD motif-grafted cores then expose and specifically target the integrin-elevated cells for the intracellular delivery of mRNA. Notably, repeated inhalation of the nanoformulations accelerates the clearance of locoregional collagen by boosting the intralesional expression of MMP13 and alveolar re-epithelialization mediated by KGFs, which synergistically ameliorates the lung function of a bleomycin-induced murine model. Therefore, this work provides an alternative mRNA-inhalation delivery strategy, which shows great potential for the treatment of IPF.

Z-guggulsterone induces PD-L1 upregulation partly mediated by FXR, Akt and Erk1/2 signaling pathways in non-small cell lung cancer.

Programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule, that is overexpressed in non-small cell lung cancer (NSCLC) and has been associated with the response to anti-PD-1/PD-L1 immunotherapy. Z-guggulsterone (Z-GS), an active compound extracted from the gumresin of the Commiphora mukul tree, has been shown to have anti-tumor effects in NSCLC in our previous study. However, whether Z-GS could affect PD-L1 expression levels in tumor cells remains unknown. In this study, we verified the inhibitory effects of Z-GS on NSCLC cell viability and cell cycle progression in vitro, and mouse Lewis lung carcinoma (LLC) tumor growth in vivo. Notably, Z-GS treatment increased PD-L1 surface and mRNA expression levels, and gene transcription in NSCLC cells, in a dose- and time-dependent manner. Mechanistic experiments showed that the upregulation of PD-L1 was mediated, partly by farnesoid X receptor inhibition, and partly by the activation of the Akt and Erk1/2 signaling pathways in Z-GS-treated NSCLC cells. In vivo, Z-GS treatment dose-dependently increased PD-L1 expression levels in mouse LLC tumor models. Overall, our findings demonstrated a promoting role for Z-GS in PD-L1 expression in NSCLC and provided mechanistic insights, that may be used for further investigation into synergistic combined therapies.

Suppressive effects of plumbagin on the growth of human bladder cancer cells via PI3K/AKT/mTOR signaling pathways and EMT.

BACKGROUND: Novel chemotherapeutic drugs with good anti-tumor activity are of pressing need for bladder cancer treatment. In this study, plumbagin (PL), a natural plant-derived drug extracted from Chinese herbals, was identified as a promising candidate for human bladder cancer (BCa) chemotherapy. METHODS: The anti-tumor activity of PL was evaluated using a series of in vitro experiments, such as MTT, transwell assay, flow cytometry, quantitative real-time PCR (qRT-PCR) and western blotting. We established xenograft tumors in nude mice by subcutaneous injection with the human bladder cancer T24 cells. RESULTS: The results showed that PL could inhibit the proliferation, migration and survival of BCa cells (T24 and UMUC3 cells) in a time- and dose-dependent way. We found PL promotes the cell cycle arrest and apoptosis by inhibiting PI3K/AKT/mTOR signaling pathway, which inhibits cell proliferation. In vivo, anti-tumor activity of PL was further investigated using a BCa cell xenograft mice model. To simulate clinical chemotherapy, the PL were intravenously injected with a dose of 10 mg/kg for 10 times. Compared with the blank control, the tumor weight in PL treated group decreased significantly from 0.57 ± 0.04 g to 0.21 ± 0.06 g (P < 0.001). CONCLUSIONS: In our study. We found PL inhibits the proliferation of T24 and UMUC3 cells in vivo and in vitro, which may play a role through several downstream effectors of PI3K/AKT/mTOR signaling pathway to promote the cell cycle arrest and apoptosis. Meanwhile, we consider that PL may inhibit the migration of bladder cancer cells via EMT suppression and induce ROS generation to make cell apoptosis. This work screened out a novel chemotherapeutic drug (plumbagin) with relatively good anti-tumor activity, which possessed great potential in BCa chemotherapy.

SMYD3 overexpression indicates poor prognosis and promotes cell proliferation, migration and invasion in non­small cell lung cancer.

SET and MYND domain­containing protein 3 (SMYD3) is a lysine methyltransferase, and its aberrant expression has been implicated in several malignancies. However, its clinical and biological roles in non­small cell lung cancer (NSCLC) remain unclear. In the present study, it was revealed that SMYD3 was significantly upregulated in NSCLC tissues, as compared with paired adjacent normal tissues. A high SMYD3 expression was associated with aggressive clinicopathological characteristics, as well as poor disease­free survival and overall survival (OS) in NSCLC patients. Multivariate analysis revealed that SMYD3 overexpression was an independent predictor of poor OS in NSCLC patients. In addition, SMYD3 knockdown inhibited cell proliferation, triggered apoptosis, and blocked migration and invasion in NSCLC cells in vitro, whereas stable SMYD3 overexpression promoted NSCLC cell proliferation. Furthermore, the SMYD3­silenced NSCLC cells became more sensitive, whereas the SMYD3­overexpressed NSCLC cells became more resistant to the apoptosis induced by cisplatin. Mechanistic analysis revealed that SMYD3 knockdown led to the upregulation of Bim, Bak and Bax, and the downregulation of Bcl­2, Bcl­xl, MMP­2 and MMP­9 in NSCLC cells. In combination, the present findings indicated that SMYD3 has oncogenic potential in the context of NSCLC, providing evidence that may be exploited for both prognostic and therapeutic purposes in the future.

Mechanistic insight of predictive biomarkers for antitumor PD­1/PD­L1 blockade: A paradigm shift towards immunome evaluation (Review).

Checkpoint inhibitor­based immunotherapy has exhibited unprecedented success in the treatment of advanced­stage cancer in recent years. Several therapeutic antibodies targeting programmed death­1 (PD­1) or its ligand (PD­L1) have received regulatory approvals for the treatment of multiple malignancies, including melanoma, non­small cell lung cancer, kidney cancer and Hodgkin's lymphoma. However, a substantial proportion of patients still do not benefit from these agents, let alone the risk of immune­associated toxicities and financial burden. Therefore, it is imperative to identify valid predictive biomarkers which can help optimize the selection of patients. In this review, a mechanism­based interpretation of tumor PD­L1 expression and other candidate biomarkers of response to antitumor PD­1/PD­L1 blockade was provided, particularly for the tumor microenvironment­derived 'immunomes', and the challenges faced in their clinical use was addressed. Directions for future biomarker development and the potential of combined biomarker strategies were also proposed.

Identification of a prefrontal cortex-to-amygdala pathway for chronic stress-induced anxiety.

Dysregulated prefrontal control over amygdala is engaged in the pathogenesis of psychiatric diseases including depression and anxiety disorders. Here we show that, in a rodent anxiety model induced by chronic restraint stress (CRS), the dysregulation occurs in basolateral amygdala projection neurons receiving mono-directional inputs from dorsomedial prefrontal cortex (dmPFC→BLA PNs) rather than those reciprocally connected with dmPFC (dmPFC↔BLA PNs). Specifically, CRS shifts the dmPFC-driven excitatory-inhibitory balance towards excitation in the former, but not latter population. Such specificity is preferential to connections made by dmPFC, caused by enhanced presynaptic glutamate release, and highly correlated with the increased anxiety-like behavior in stressed mice. Importantly, low-frequency optogenetic stimulation of dmPFC afferents in BLA normalizes the enhanced prefrontal glutamate release onto dmPFC→BLA PNs and lastingly attenuates CRS-induced increase of anxiety-like behavior. Our findings thus reveal a target cell-based dysregulation of mPFC-to-amygdala transmission for stress-induced anxiety.

High Flexible and Broad Antibacterial Nanodressing Induces Complete Skin Repair with Angiogenic and Follicle Regeneration.

Complete skin reconstruction is a hierarchically physiological assembly involving epidermis, dermis, vasculature, innervation, hair follicles, and sweat glands. Despite various wound dressings having been developed for skin regeneration, few works refer to the complete skin regeneration, particularly lacking for vasculatures and hair follicles. Herein, an instructive wound dressing that integrates the antibacterial property of quaternized chitin and the mechanical strength and biological multifunction of silk fibroin through layer-by-layer electrostatic self-assembly is designed and reported. The resultant dressings exhibit a nanofibrous structure ranging from 471.5 ± 212.1 to 756.9 ± 241.8 nm, suitable flexibility with tensile strength up to 4.47 ± 0.29 MPa, and broad-spectrum antibacterial activity against Escherichia coli and Staphylococcus aureus. More interestingly, the current dressing system remarkably accelerates in vivo vascular reconstruction within 15 days, and the number of regenerated hair follicles reaches up to 22 ± 4 mm-2 , which is comparable to the normal tissue (27 ± 2 mm-2 ). Those crucial functions might originate from the combination between quaternized chitin and silk fibroin and the hierarchical structure of electrospun nanofiber. This work establishes an easy but effective pathway to design a multifunctional wound dressing for the complete skin regeneration.

Glycyrrhizin suppresses epithelial-mesenchymal transition by inhibiting high-mobility group box1 via the TGF-ß1/Smad2/3 pathway in lung epithelial cells.

BACKGROUND: Epithelial-mesenchymal transition (EMT) plays an important role in fibrosis, chronic inflammation, tumor metastasis, etc. Glycyrrhizin, an active component extracted from licorice plant, has been reported to treat a variety of inflammatory reactions through inhibiting high-mobility group box1 (HMGB1), which has been suggested to be a significant mediator in EMT process. However, whether glycyrrhizin affects the EMT process or not remains unclear. METHODS: Human alveolar epithelial cell line A549 and normal human bronchial epithelial cell line BEAS-2B were treated with extrinsic TGF-ß1 to induce EMT. Elisa was used to detect HMGB1 concentrations in cell supernatant. RNA interference and lentivirus infection experiments were performed to investigate the involvement of HMGB1 in EMT process. Cell Counting Kit-8 (CCK-8) was used to detect the viability of A549 and BEAS-2B cells treated with glycyrrhizin. Finally, the effects of glycyrrhizin on EMT changes, as well as the underlying mechanisms, were evaluated via Western blot, immunofluorescence and transwell assays. RESULTS: Our results showed that HMGB1 expression was increased by TGF-ß1, and knockdown of HMGB1 expression reversed TGF-ß1-induced EMT in A549 and BEAS-2B cells. Ectopic HMGB1 expression or TGF-ß1 treatment caused a significant increase in HMGB1 release. Notably, we found that glycyrrhizin treatment effectively suppressed TGF-ß1-induced EMT process by inhibiting HMGB1. Also, glycyrrhizin significantly inhibited the migration of both A549 and BEAS-2B cells promoted by TGF-ß1. Mechanistically, HMGB1 overexpression could activate Smad2/3 signaling in A549 and BEAS-2B cells. Glycyrrhizin significantly blocked the phosphorylation of Smad2/3 stimulated either by TGF-ß1 or by ectopic HMGB1 in A549 and BEAS-2B cells. CONCLUSIONS: HMGB1 is a vital mediator of EMT changes induced by TGF-ß1 in lung epithelial cells. Importantly, glycyrrhizin can effectively block Smad2/3 signaling pathway through inhibiting HMGB1, thereby suppressing the EMT progress.

Gender-dependent regulation of anxiety-like behavior by δ subunit-containing GABAA receptor during postnatal development.

The δ subunit-containing GABAA receptor [GABAA(δ)R], which is exclusively situated in the extrasynaptic space, has considerable influence on emotion and behavior. Although the expression of this receptor experiences dramatic fluctuation during postnatal development, it remains unknown whether it regulates emotion in a development-dependent manner. Here, by using mice with genetic deletion of GABAA(δ)R (knockout) and their wild-type littermates, we examined the role of GABAA(δ)R in regulating anxiety-like behavior, as measured with open field test (OFT) and elevated plus maze during the transition from puberty to adulthood. We observed that for female mice, the knockout ones at puberty but not adulthood showed increased anxiety-like behavior in the OFT relative to their wild-type littermates. However, such increase was not observed in elevated plus maze. For male mice, no between-genotype differences were observed in both tests at the above two developmental stages. Our results suggest that GABAA(δ)R preferentially affects the anxiety-like behavior in OFT in a development-dependent manner, but only in female mice.

Farnesoid X Receptor Constructs an Immunosuppressive Microenvironment and Sensitizes FXRhighPD-L1low NSCLC to Anti-PD-1 Immunotherapy.

The farnesoid X receptor (FXR) regulates inflammation and immune responses in a subset of immune-mediated diseases. We previously reported that FXR expression promotes tumor cell proliferation in non-small cell lung cancer (NSCLC). Here we study the relevance of FXR to the immune microenvironment of NSCLC. We found an inverse correlation between FXR and PD-L1 expression in a cohort of 408 NSCLC specimens; from this, we identified a subgroup of FXRhighPD-L1low patients. We showed that FXR downregulates PD-L1 via transrepression and other mechanisms in NSCLC. Cocultured with FXRhighPD-L1low NSCLC cell lines, effector function and proliferation of CD8+ T cell in vitro are repressed. We also detected downregulation of PD-L1 in FXR-overexpressing Lewis lung carcinoma (LLC) mouse syngeneic models, indicating an FXRhighPD-L1low subtype in which FXR suppresses tumor-infiltrating immune cells. Anti-PD-1 therapy was effective against FXRhighPD-L1low mouse LLC tumors. Altogether, our findings demonstrate an immunosuppressive role for FXR in the FXRhighPD-L1low NSCLC subtype and provide translational insights into therapeutic response in PD-L1low NSCLC patients treated with anti-PD-1. We recommend FXRhighPD-L1low as a biomarker to predict responsiveness to anti-PD-1 immunotherapy.

Chronic Stress Causes Projection-Specific Adaptation of Amygdala Neurons via Small-Conductance Calcium-Activated Potassium Channel Downregulation.

BACKGROUND: The role of the amygdala in mediating stress coping has been long appreciated. However, basolateral amygdala (BLA) projection neurons (PNs) are organized into discrete output circuits, and it remains unclear whether stress differentially impacts these circuits. METHODS: Mice were exposed to acute restraint stress or chronic restraint stress (CRS), and c-fos expression was measured as a proxy for neuronal activation in Retrobead retrogradely labeled dorsomedial prefrontal cortex-targeting PNs (BLA→dmPFC) and non-dmPFC-targeting PNs (BLA↛dmPFC). Next, the effects of CRS on neuronal firing and membrane potassium channel current were examined via ex vivo electrophysiology in these neuronal populations and correlated with anxiety-like behavior, as measured in the elevated plus maze and novel open field tests. Lastly, the ability of virus-mediated overexpression of subtype 2 of small-conductance, calcium-activated potassium (SK2) channel in BLA↛dmPFC PNs to negate the anxiety-related effects of CRS was assessed. RESULTS: BLA→dmPFC PNs were transiently activated after CRS, whereas BLA↛dmPFC showed sustained c-fos expression and augmented firing to external input. CRS led to a loss of SK2 channel-mediated currents in BLA↛dmPFC PNs, which correlated with heightened anxiety-like behavior. Virus-mediated maintenance of SK2 channel currents in BLA↛dmPFC PNs prevented CRS-induced anxiety-like behavior. Finally, CRS produced persistent activation of BLA PNs targeting the ventral hippocampus, and virally overexpressing SK2 channels in this projection population were sufficient to prevent CRS-induced anxiety-like behavior. CONCLUSIONS: The current data reveal that chronic stress produces projection-specific functional adaptations in BLA PNs. These findings offer new insight into the neural circuits that contribute to stress-induced psychopathology.