The extracellular matrix protein mindin serves as an integrin ligand and is critical for inflammatory cell recruitment

Characterizing immune variation and diagnostic indicators of preeclampsia by single-cell RNA sequencing and machine learning

Preeclampsia is a multifactorial and heterogeneous complication of pregnancy. Here, we utilize single-cell RNA sequencing to dissect the involvement of circulating immune cells in preeclampsia. Our findings reveal downregulation of immune response in lymphocyte subsets in preeclampsia, such as reduction in natural killer cells and cytotoxic genes expression, and expansion of regulatory T cells. But the activation of naïve T cell and monocyte subsets, as well as increased MHC-II-mediated pathway in antigen-presenting cells were still observed in preeclampsia. Notably, we identified key monocyte subsets in preeclampsia, with significantly increased expression of angiogenesis pathways and pro-inflammatory S100 family genes in VCAN+ monocytes and IFN+ non-classical monocytes. Furthermore, four cell-type-specific machine-learning models have been developed to identify potential diagnostic indicators of preeclampsia. Collectively, our study demonstrates transcriptomic alternations of circulating immune cells and identifies immune components that could be involved in pathophysiology of preeclampsia.

Systematic identification of key basement membrane related genes as potential new biomarkers in Alzheimer's disease

OBJECTIVE

The study aimed to identify biomarkers associated with basement membranes (BMs)-related genes (BMGs) in Alzheimer's disease (AD) and investigate their potential role in the progression of AD pathology.

METHODS

Gene expression profiles were retrieved from Gene Expression Omnibus database. 222 human BMGs were collected from the relevant literature. Subsequently, the differentially expressed BMGs (DE-BMGs) were filtered, and the key DE-BMGs were identified using weighted gene correlation network analysis (WGCNA) and two machine learning algorithms. The expression levels, diagnostic values, clinical significances, enrichment analyses and regulatory networks of these candidate biomarkers were further examined.

RESULTS

A total of 44 DE-BMGs were acquired by comparing AD temporal cortex with nondemented controls. Using WGCNA and machine learning, versiscan (VCAN), tissue inhibitor of metalloproteinase 1 (TIMP1), structural maintenance of chromosome 3 (SMC3), and laminin β2 (LAMB2) were ultimately identified as candidate biomarkers, and they were verified in a murine model. These biomarkers had high diagnostic value (area under the curve (AUC)＞0.8). The diagnostic value of the four gene combination was then evaluated in multiple databases, yielding AUCs ranging from 0.688 to 1. Furthermore, a meaningful correlation between these biomarkers and AD pathology progression was observed. Finally, comprehensive analyses involving Hallmark pathway enrichment, immune cell infiltration analysis, transcriptional regulatory, and competitive endogenous RNA networks indicated that key DE-BMGs closely correlated with oxidative stress and immune dysfunction.

CONCLUSION

Our study comprehensively identified four candidate BMGs and their combination model that play a crucial part in the diagnosis and pathogenesis of AD.

Peripheral Blood Single-Cell Sequencing Uncovers Common and Specific Immune Aberrations in Fibrotic Lung Diseases

Rationale and Objectives

The extent and commonality of peripheral blood immune aberrations in fibrotic interstitial lung diseases are not well characterized. In this study, we aimed to identify common and distinct immune aberrations in patients with idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (FHP) using cutting-edge single-cell profiling technologies.

Methods

Single-cell RNA sequencing was performed on patients and healthy controls' peripheral blood and bronchoalveolar lavage samples using 10X Genomics 5' gene expression and V(D)J profiling. Cell type composition, transcriptional profiles, cellular trajectories and signaling, and T and B cell receptor repertoires were studied. The standard Seurat R pipeline was followed for cell type composition and differential gene expression analyses. Transcription factor activity was imputed using the DoRothEA-VIPER algorithm. Pseudotime analyses were conducted using Monocle3, while RNA velocity analyses were performed with Velocyto, scVelo, and CellRank. Cell-cell connectomics were assessed using the Connectome R package. V(D)J analyses were conducted using CellRanger and Immcantation frameworks. Across all analyses, disease group differences were assessed using the Wilcoxon rank-sum test.

Measurements and Main Results

327,990 cells from 83 samples were profiled. Overall, changes in monocytes were common to IPF and FHP, whereas lymphocytes exhibited disease-specific aberrations. Both diseases displayed enrichment of CCL3 hi /CCL4 hi CD14+ monocytes (p<2.2e-16) and S100A hi CD14+ monocytes (p<2.2e-16) versus controls. Trajectory and RNA velocity analysis suggested that pro-fibrotic macrophages observed in BAL originated from peripheral blood monocytes. Lymphocytes exhibited disease-specific aberrations, with CD8+ GZMK hi T cells and activated B cells primarily enriched in FHP patients. V(D)J analyses revealed unique T and B cell receptor complementarity-determining region 3 (CDR3) amino acid compositions (p<0.05) in FHP and significant IgA enrichment in IPF (p<5.2e-7).

Conclusions

We identified common and disease-specific immune mechanisms in IPF and FHP; S100A hi monocytes and SPP1 hi macrophages are common to IPF and FHP, whereas GMZK hi T lymphocytes and T and B cell receptor repertoires were unique in FHP. Our findings open novel strategies for the diagnosis and treatment of IPF and FHP.

Comprehensive analysis of the oncogenic and immunological role of SPON2 in human tumors

BACKGROUND

Sapiens spondin-2 (SPON2) is a protein found in the extracellular matrix that plays a role in a number of processes, including immune reactions and cell adhesion, and is closely linked to the emergence of a number of tumor types. However, we know very little about Sapiens spondin-2. Therefore, we performed a systematic pan-carcinogenic analysis to explore the relationship between Sapiens spondin-2 and cancers.

MATERIALS AND METHODS

By comprehensive use of datasets from TCGA, GEO, GTEx, HPA, CPTAC, GEPIA2, TIMER2, cBioPortal, STRING, we adopted bioinformatics methods to dig up the potential carcinogenesis of SPON2, including dissecting the correlation between SPON2 and gene expression, prognosis, gene mutation, Immunohistochemistry staining, immune cell infiltration, and constructed the interaction network of a total of 54 SPON2-binding proteins as well as explored the enrichment analysis of SPON2-related partners.

RESULTS

The expression of Sapiens spondin-2 in most tumor tissues was higher than that of normal tissues. In addition, SPON2 showed the early diagnostic value in 33 kinds of tumors and was positively or negatively associated with the prognosis of different tumors. It also validates that SPON2 is the gene associated with the majority of immune-infiltrating cells in pan-cancer. High SPON2 expression is associated with tumor progression related pathways.

CONCLUSION

We found and validated the potential use of SPON2 in cancer detection for the first time through pan-cancer analysis. The expression levels of SPON2 in various tumors were quite different from those in normal tissues. Furthermore, the performance of SPON2 in tumorigenesis and tumor immunity verified our hypothesis. At the same time, it has high specificity and sensitivity in cancer detection. Therefore, SPON2 can be employed as an auxiliary index for the initial diagnosis of tumors and a prognostic marker for various types of tumors.

A Wrinkle in TIME: How Changes in the Aging ECM Drive the Remodeling of the Tumor Immune Microenvironment

SUMMARY

Cancer is an age-related disease, with the majority of patients receiving their diagnosis after the age of 60 and most mortality from cancer occurring after this age. The tumor microenvironment changes drastically with age, which in turn affects cancer progression and treatment efficacy. Age-related changes to individual components of the microenvironment have received well-deserved attention over the past few decades, but the effects of aging at the interface of two or more microenvironmental components have been vastly understudied. In this perspective, we discuss the relationship between the aging extracellular matrix and the aging immune system, how they affect the tumor microenvironment, and how these multidisciplinary studies may open avenues for new therapeutics. Cancer is a disease of aging. With a rapidly aging population, we need to better understand the age-related changes that drive tumor progression, ranging from secreted changes to biophysical and immune changes.

MACC1-induced migration in tumors: Current state and perspective

Malignant tumors are still a global, heavy health burden. Many tumor types cannot be treated curatively, underlining the need for new treatment targets. In recent years, metastasis associated in colon cancer 1 (MACC1) was identified as a promising biomarker and drug target, as it is promoting tumor migration, initiation, proliferation, and others in a multitude of solid cancers. Here, we will summarize the current knowledge about MACC1-induced tumor cell migration with a special focus on the cytoskeletal and adhesive systems. In addition, a brief overview of several in vitro models used for the analysis of cell migration is given. In this context, we will point to issues with the currently most prevalent models used to study MACC1-dependent migration. Lastly, open questions about MACC1-dependent effects on tumor cell migration will be addressed.

Mindin Activates Autophagy for Lipid Utilization and Facilitates White Spot Syndrome Virus Infection in Shrimp

Mindin is a secreted extracellular matrix protein that is involved in regulating cellular events through interacting with integrin. Studies have demonstrated its role in host immunity, including phagocytosis, cell migration, and cytokine production. However, the function of Mindin in the host-virus interaction is largely unknown. In the present study, we report that Mindin facilitates virus infection by activating lipid utilization in an arthropod, kuruma shrimp (Marsupenaeus japonicus). Shrimp Mindin facilitates white spot syndrome virus infection by facilitating viral entry and replication. By activating autophagy, Mindin induces lipid droplet consumption, the hydrolysis of triglycerides into free fatty acids, and ATP production, ultimately providing energy for virus infection. Moreover, integrin is essential for Mindin-mediated autophagy and lipid utilization. Therefore, by revealing the mechanism by which Mindin facilitates virus infection through regulating lipid metabolism, the present study reveals the significance of Mindin in the host-virus interaction. IMPORTANCE White spot syndrome virus (WSSV) is an enveloped double-stranded DNA virus that has had a serious influence on worldwide shrimp farming in the last 30 years. We have demonstrated that WSSV hijacks host autophagy and lipid metabolism for reproduction in kuruma shrimp (Marsupenaeus japonicus). These findings revealed the mechanism by which WSSV exploits host machinery for its infection and provided serial targets for WSSV prevention and control in shrimp farming.

Knockdown of SPON2 inhibits the growth of triple-negative breast cancer

Objective

Spondin-2 (SPON2) is highly expressed in a variety of tumors and has been associated with poor prognosis, but the relationship to triple-negative breast cancer (TNBC) is unclear. The aim of this study is to investigate the expression of SPON2 in TNBC and its function.

Methods

Immunohistochemistry was used to detect the expression of the SPON2 protein in TNBC and in normal tissue adjacent to cancer and breast fibroadenoma. The GEO database GSE76275 dataset was used to study the expression of SPON2 mRNA in TNBC and non-TNBC. ​The expression of SPON2 mRNA was detected by qPCR in TNBC cells MDA-MB-231, non-TNBC breast cancer cells MCF-7, and normal breast cells MCF-10A. ​Kaplan Meier-Plotter database was used to analyze the relationship between SPON2 expression and TNBC prognosis. ​ShRNA lentivirus was used to knock down high expression of SPON2 in TNBC cells. The effects of knockdown of SPON2 expression on the proliferation, migration, invasion, apoptosis, and subcutaneous tumorigenic ability of TNBC cells in nude mice were analyzed using CCK8, clone formation assay, scratch assay, transwell migration assay, transwell invasion assay, Hoechst apoptosis assay, and tumorigenic ability in nude mice. Transcriptome sequencing of TNBC cells with knockdown SPON2 expression. ​In combination with the GEO database, GO and KEGG analyses were performed, and psychophysiological interaction Protein-Protein Interaction Networks (PPI) analysis was performed for transcriptome sequencing of the differentially expressed genes. ​The changes in the expression of PI3K-ATK pathway proteins after SPON2 knockdown were detected by Western blot.

Results

Our study shows that upregulation of SPON2 in TNBC is associated with poorer patient outcomes. Knockdown of SPON2 inhibited TNBC cell proliferation, clone formation, migration, invasion, and tumorigenic ability and promoted apoptosis. Knockdown of SPON2 up-regulated TNBC cell adhesion and down-regulated PI3K-ATK pathway, and PPI results showed that CCL2 was the key protein.

Conclusions

SPON2 may be a valuable biomarker for the diagnosis and prognosis of TNBC and is a potential therapeutic target for TNBC.

In situ assessment of Mindin as a biomarker of podocyte lesions in diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of chronic kidney disease and end-stage renal failure worldwide. Several mechanisms are involved in the pathogenesis of this disease, which culminate in morphological changes such as podocyte injury. Despite the complex diagnosis and pathogenesis, limited attempts have been made to establish new biomarkers for DN. The higher concentration of Mindin protein in the urine of patients with type 2 diabetes mellitus suggests that it plays a role in DN. Therefore, this study investigated whether in situ protein expression of Mindin can be considered a potential DN biomarker. Fifty renal biopsies from patients diagnosed with DN, 57 with nondiabetic glomerular diseases, including 17 with focal segmental glomerulosclerosis (FSGS), 14 with minimal lesion disease (MLD) and 27 with immunoglobulin A nephropathy (IgAN), and 23 adult kidney samples from autopsies (control group) were evaluated for Mindin expression by immunohistochemistry. Podocyte density was inferred by Wilms' tumor 1 (WT1) immunostaining, while foot process effacement was assessed by transmission electron microscopy. Receiver operative characteristic (ROC) analysis was performed to determine the biomarker sensitivity/specificity. Low podocyte density and increased Mindin expression were observed in all cases of DN, regardless of their class. In the DN group, Mindin expression was significantly higher than that in the FSGS, MCD, IgAN and control groups. Higher Mindin expression was significantly positively correlated with foot process effacement only in class III DN cases. Furthermore, Mindin protein presented high specificity in the biopsies of patients with DN (p < 0.0001). Our data suggest that Mindin may play a role in DN pathogenesis and is a promising biomarker of podocyte lesions.

Mindin (SPON2) Is Essential for Cutaneous Fibrogenesis in a Mouse Model of Systemic Sclerosis

Systemic sclerosis is a fibrotic disease that initiates in the skin and progresses to internal organs, leading to a poor prognosis. Unraveling the etiology of a chronic, multifactorial disease such as systemic sclerosis has been aided by various animal models that recapitulate certain aspects of the human pathology. We found that the transcription factor SNAI1 is overexpressed in the epidermis of patients with systemic sclerosis, and a transgenic mouse recapitulating this expression pattern is sufficient to induce many clinical features of the human disease. Using this mouse model as a discovery platform, we have uncovered a critical role for the matricellular protein Mindin (SPON2) in fibrogenesis. Mindin is produced by SNAI1 transgenic skin keratinocytes and aids fibrogenesis by inducing early inflammatory cytokine production and collagen secretion in resident dermal fibroblasts. Given the dispensability of Mindin in normal tissue physiology, targeting this protein holds promise as an effective therapy for fibrosis.

Snail maintains the stem/progenitor state of skin epithelial cells and carcinomas through the autocrine effect of matricellular protein Mindin

Preservation of a small population of cancer stem cells (CSCs) within a heterogeneous carcinoma serves as a paradigm to understand how select cells in a tissue maintain their undifferentiated status. In both embryogenesis and cancer, Snail has been correlated with stemness, but the molecular underpinning of this phenomenon remains largely ill-defined. In models of cutaneous squamous cell carcinoma (cSCC), we discovered a non-epithelial-mesenchymal transition function for the transcription factor Snail in maintaining the stemness of epidermal keratinocytes. Snail-expressing cells secrete the matricellular protein Mindin, which functions in an autocrine fashion to activate a Src-STAT3 pathway to reinforce their stem/progenitor phenotype. This pathway is activated by the engagement of Mindin with the leukocyte-specific integrin, CD11b (ITGAM), which is also unexpectedly expressed by epidermal keratinocytes. Interestingly, disruption of this signaling module in human cSCC attenuates tumorigenesis, suggesting that targeting Mindin would be a promising therapeutic approach to hinder cancer recurrence.

Endothelial inflammation and neutrophil transmigration are modulated by extracellular matrix composition in an inflammation-on-a-chip model

Inflammatory diseases are often characterised by excessive neutrophil infiltration from the blood stream to the site of inflammation, which damages healthy tissue and prevents resolution of inflammation. Development of anti-inflammatory drugs is hindered by lack of in vitro and in vivo models which accurately represent the disease microenvironment. In this study, we used the OrganoPlate to develop a humanized 3D in vitro inflammation-on-a-chip model to recapitulate neutrophil transmigration across the endothelium and subsequent migration through the extracellular matrix (ECM). Human umbilical vein endothelial cells formed confluent vessels against collagen I and geltrex mix, a mix of basement membrane extract and collagen I. TNF-α-stimulation of vessels upregulated inflammatory cytokine expression and promoted neutrophil transmigration. Intriguingly, major differences were found depending on the composition of the ECM. Neutrophils transmigrated in higher number and further in geltrex mix than collagen I, and did not require an N-formyl-methionyl-leucyl-phenylalanine (fMLP) gradient for transmigration. Inhibition of neutrophil proteases inhibited neutrophil transmigration on geltrex mix, but not collagen I. These findings highlight the important role of the ECM in determining cell phenotype and response to inhibitors. Future work could adapt the ECM composition for individual diseases, producing accurate models for drug development.

Tumor cell-derived SPON2 promotes M2-polarized tumor-associated macrophage infiltration and cancer progression by activating PYK2 in CRC

Background

Tumor-associated macrophages (TAMs) are key regulators of the complex interplay between cancer and the immune microenvironment. Tumor cell-derived spondin 2 (SPON2) is an extracellular matrix glycoprotein that has complicated roles in recruitment of macrophages and neutrophils during inflammation. Overexpression of SPON2 has been shown to promote tumor cell migration in colorectal cancer (CRC). However, the mechanism by which SPON2 regulates the accumulation of TAMs in the tumor microenvironment (TME) of CRC is unknown.

Methods

Immunohistochemistry was used to examine SPON2 expression in clinical CRC tissues. In vitro migration assays, transendothelial migration assays (iTEM), and cell adhesion assays were used to investigate the effects of SPON2 on monocyte/macrophage migration. Subcutaneous tumor formation and orthotopic implantation assays were performed in C57 BL/6 mice to confirm the effects of SPON2 on TAM infiltration in tumors.

Results

SPON2 expression is positively correlated with M2-TAM infiltration in clinical CRC tumors and poor prognosis of CRC patients. In addition, SPON2 promotes cytoskeletal remodeling and transendothelial migration of monocytes by activating integrin β1/PYK2 axis. SPON2 may indirectly induce M2-polarization through upregulating cytokines including IL10, CCL2 and CSF1 expression in tumor cells. Blocking M2 polarization and Macrophage depletion inhibited the SPON2-induced tumors growth and invasion. Furthermore, blocking the SPON2/integrin β1/PYK2 axis impairs the transendothelial migration of monocytes and cancer-promoting functions of TAMs in vivo.

Conclusions

Our findings demonstrate that SPON2-driven M2-TAM infiltration plays an important role during CRC tumor growth and metastasis. SPON2 may be a valuable biomarker guiding the use of macrophage-targeting strategies and a potential therapeutic target in advanced CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02108-0.

Comparative Expression Analysis of Innate Immune Markers and Phagocytic Activity in Peripheral Blood of Dogs with Mammary Tumors

Canine innate immune system role in cancer prevention and progression remains poorly understood. It has been revealed that innate immune cells could play a dual role in cancer immunology promoting or inhibiting tumor development and growth. Current immunotherapies target mainly the adaptive anti-tumor response and that may be a reason why they remain ineffective in a majority of patients. It is important to acquire detailed knowledge about innate immune mechanisms to broaden the diagnostic and therapeutic options and employ innate immune cells in anti-cancer therapies. In the present study, 21 female dogs of different breeds and types of spontaneous mammary tumors were investigated. The study aimed to find simple and cheap markers that can be used for preliminary diagnosis, prior to the surgical resection of the tumor. The differences in innate immune cell quantity and function were investigated between female dogs with malignant mammary tumors of epithelial and mesenchymal origin. Flow cytometry was used to evaluate the percentages of CD5+ lymphocytes including CD5low lymphocytes, CD11b integrin expression on leukocytes, phagocytosis, and oxidative burst. The number of CD11b lymphocytes was increased in tumors with epithelial origin compared to the control group. No significant differences were found between the percentages of phagocytic cells neither for granulocytes nor for monocytes. However, the phagocytes of canine patients with tumors of epithelial origin showed increased phagocytosis compared to the control group. The percentages of granulocytes that produced reactive oxygen species (ROS) in response to E.coli and PMA were not altered in patients with malignant tumors compared to control. A statistically significant difference between the number of ROS produced by the single granulocyte was demonstrated only between the group of bitches with epithelial tumors and the control group in case of E. coli stimulation. The obtained results suggest that some innate immune cells may be involved in anti-tumor immune mechanisms and have the potential to be supportive diagnostic markers in canine mammary tumors.

Integrative Analysis of DNA Methylation and Transcriptome Identifies a Predictive Epigenetic Signature Associated With Immune Infiltration in Gliomas

Glioma is the most common primary brain tumor with poor prognosis and high mortality. The purpose of this study was to use the epigenetic signature to predict prognosis and evaluate the degree of immune infiltration in gliomas. We integrated gene expression profiles and DNA methylation data of lower-grade glioma and glioblastoma to explore epigenetic differences and associated differences in biological function. Cox regression and lasso analysis were used to develop an epigenetic signature based on eight DNA methylation sites to predict prognosis of glioma patients. Kaplan–Meier analysis showed that the overall survival time of high- and low-risk groups was significantly separated, and ROC analysis verified that the model had great predictive ability. In addition, we constructed a nomogram based on age, sex, 1p/19q status, glioma type, and risk score. The epigenetic signature was obviously associated with tumor purity, immune checkpoints, and tumor-immune infiltrating cells (CD8+ T cells, gamma delta T cells, M0 macrophages, M1 macrophages, M2 macrophages, activated NK cells, monocytes, and activated mast cells) and thus, it may find application as a guide for the evaluation of immune infiltration or in treatment decisions in immunotherapy.

Long-Term Effects of Very Low Dose Particle Radiation on Gene Expression in the Heart: Degenerative Disease Risks

Compared to low doses of gamma irradiation (γ-IR), high-charge-and-energy (HZE) particle IR may have different biological response thresholds in cardiac tissue at lower doses, and these effects may be IR type and dose dependent. Three- to four-month-old female CB6F1/Hsd mice were exposed once to one of four different doses of the following types of radiation: γ-IR ¹³⁷Cs (40-160 cGy, 0.662 MeV), ¹⁴Si-IR (4-32 cGy, 260 MeV/n), or ²²Ti-IR (3-26 cGy, 1 GeV/n). At 16 months post-exposure, animals were sacrificed and hearts were harvested and archived as part of the NASA Space Radiation Tissue Sharing Forum. These heart tissue samples were used in our study for RNA isolation and microarray hybridization. Functional annotation of twofold up/down differentially expressed genes (DEGs) and bioinformatics analyses revealed the following: (i) there were no clear lower IR thresholds for HZE- or γ-IR; (ii) there were 12 common DEGs across all 3 IR types; (iii) these 12 overlapping genes predicted various degrees of cardiovascular, pulmonary, and metabolic diseases, cancer, and aging; and (iv) these 12 genes revealed an exclusive non-linear DEG pattern in ¹⁴Si- and ²²Ti-IR-exposed hearts, whereas two-thirds of γ-IR-exposed hearts revealed a linear pattern of DEGs. Thus, our study may provide experimental evidence of excess relative risk (ERR) quantification of low/very low doses of full-body space-type IR-associated degenerative disease development.

MINDIN Exerts Protumorigenic Actions on Primary Prostate Tumors via Downregulation of the Scaffold Protein NHERF-1

Advanced prostate cancer preferential metastasis to bone is associated with osteomimicry. MINDIN is a secreted matrix protein upregulated in prostate tumors that overexpresses bone-related genes during prostate cancer progression. Na+/H+ exchanger regulatory factor (NHERF-1) is a scaffold protein that has been involved both in tumor regulation and osteogenesis. We hypothesize that NHERF-1 modulation is a mechanism used by MINDIN to promote prostate cancer progression. We analyzed the expression of NHERF-1 and MINDIN in human prostate samples and in a premetastatic prostate cancer mouse model, based on the implantation of prostate adenocarcinoma TRAMP-C1 (transgenic adenocarcinoma of the mouse prostate) cells in immunocompetent C57BL/6 mice. The relationship between NHERF-1 and MINDIN and their effects on cell proliferation, migration, survival and osteomimicry were evaluated. Upregulation of MINDIN and downregulation of NHERF-1 expression were observed both in human prostate cancer samples and in the TRAMP-C1 model. MINDIN silencing restored NHERF-1 expression to control levels in the mouse model. Stimulation with MINDIN reduced NHERF-1 expression and triggered its mobilization from the plasma membrane to the cytoplasm in TRAMP-C1 cells. MINDIN-dependent downregulation of NHERF-1 promoted tumor cell migration and proliferation without affecting osteomimicry and adhesion. We propose that MINDIN downregulates NHERF-1 expression leading to promotion of processes involved in prostate cancer progression.

Autism spectrum disorders and natural killer cells: a review on pathogenesis and treatment

Introduction: Autism spectrum disorder (ASD), as a wide spectrum of neurodevelopmental disorders, is characterized by early-onset impairments in social-communication, repetitive behaviors, and restrictive interests.Areas covered: Although still unknown, there are some pieces of evidence suggesting altered immune function in the etiology of ASD. This review aims to summarize studies linking Natural Killer (NK) cells to ASD by searching through databases like MEDLINE and Scopus up to October 2020. NK cells play important roles in the innate immune system and immune regulation. As parts of the immune system, they interact with the neural system as well. Immune dysregulations such as autoimmunity and improper immune responses to both internal and external stimulations, especially in early developmental stages of the brain, may induce neurodevelopmental disorders. NK cells' dysfunction in children with ASD as well as their parents have been highlighted in many studies.Expert opinion: Changes in the frequency, gene expressions, cytotoxicity features, and receptors of NK cells are reported in children with ASD. Immune therapy for children with ASD with immune abnormality has shown promising results. However, further studies are needed to elucidate the exact role of NK cells in the pathogenesis of ASD providing future treatment options for these children.

Overexpression of Spondin-2 Is Associated with Recurrence-Free Survival in Patients with Localized Clear Cell Renal Cell Carcinoma

Background

The spondin-2 (SPON2) gene is overexpressed in multiple malignant tumors and may promote tumor aggressiveness. However, its expression profile and functional roles in clear cell renal cell carcinoma (ccRCC) are still unclear.

Methods

SPON2 expression in ccRCC was evaluated using expression data from TCGA and GEO databases, then confirmed by local patient population (94 patients). The clinical significance of SPON2 expression was evaluated. Downregulation of SPON2 was performed using small-interfering RNA (siRNA). The effects of SPON2 silencing on cell proliferation, apoptosis, invasion, and migration in vitro were investigated.

Results

SPON2 was overexpressed in the majority of the ccRCC at both mRNA and protein levels. SPON2 expression was significantly correlated with stage, grade, and recurrence (all P < 0.05) in patients with localized ccRCC. The receiver operating characteristic (ROC) curve showed that SPON2 expression could serve as a predictor of recurrence. SPON2 expression was significantly associated with recurrence-free survival (RFS) in patients with localized ccRCC. Knocking down SPON2 resulted in suppressed cell invasion and migration in vitro.

Conclusion

SPON2 expression might function as a prognostic biomarker in patients with localized ccRCC.

Transcriptional Activation of Matricellular Protein Spondin2 (SPON2) by BRG1 in Vascular Endothelial Cells Promotes Macrophage Chemotaxis

The matricellular protein SPON2 plays diverse roles in the development of cardiovascular diseases. SPON2 is expressed in endothelial cells, but its transcription regulation in the context of atherogenesis remains incompletely appreciated. Here we report that SPON2 expression was up-regulated by pro-atherogenic stimuli (oxLDL and TNF-α) in vascular endothelia cells. In addition, endothelial SPON2 was elevated in Apoe^–/– mice fed on a Western diet compared to the control mice. Induction of SPON2 in endothelial cells by pro-atherogenic stimuli was mediated by BRG1, a chromatin remodeling protein, both in vitro and in vivo. Further analysis revealed that BRG1 interacted with the sequence-specific transcription factor Egr-1 to activate SPON2 transcription. BRG1 contributed to SPON2 trans-activation by modulating chromatin structure surrounding the SPON2 promoter. Functionally, activation of SPON2 transcription by the Egr-1/BRG1 complex provided chemoattractive cues for macrophage trafficking. SPON2 depletion abrogated the ability of BRG1 or Egr-1 to stimulate endothelial derived chemoattractive cue for macrophage migration. On the contrary, recombinant SPON2 rescued endothelial chemo-attractability in the absence of BRG1 or Egr-1. In conclusion, our data have identified a novel transcriptional cascade in endothelial cells that may potentially promote macrophage recruitment and vascular inflammation leading to atherogenesis.

Mindin serves as a tumour suppressor gene during colon cancer progression through MAPK/ERK signalling pathway in mice

Mindin is important in broad spectrum of immune responses. On the other hand, we previously reported that mindin attenuated human colon cancer development by blocking angiogenesis through Egr-1-mediated regulation. However, the mice original mindin directly suppressed the syngenic colorectal cancer (CRC) growth in our recent study and we aimed to further define the role of mindin during CRC development in mice. We established the mouse syngeneic CRC CMT93 and CT26 WT cell lines with stable mindin knock-down or overexpression. These cells were also subcutaneously injected into C57BL/6 and BALB/c mice as well as established a colitis-associated colorectal cancer (CAC) mouse model treated with lentiviral-based overexpression and knocked-down of mindin. Furthermore, we generated mindin knockout mice using a CRISPR-Cas9 system with CAC model. Our data showed that overexpression of mindin suppressed cell proliferation in both of CMT93 and CT26 WT colon cancer cell lines, while the silencing of mindin promoted in vitro cell proliferation via the ERK and c-Fos pathways and cell cycle control. Moreover, the overexpression of mindin significantly suppressed in vivo tumour growth in both the subcutaneous transplantation and the AOM/DSS-induced CAC models. Consistently, the silencing of mindin reversed these in vivo observations. Expectedly, the tumour growth was promoted in the CAC model on mindin-deficient mice. Thus, mindin plays a direct tumour suppressive function during colon cancer progression and suggesting that mindin might be exploited as a therapeutic target for CRC.

Targeting miR-27a/VE-cadherin interactions rescues cerebral cavernous malformations in mice

Cerebral cavernous malformations (CCMs) are vascular lesions predominantly developing in the central nervous system (CNS), with no effective treatments other than surgery. Loss-of-function mutation in CCM1/krev interaction trapped 1 (KRIT1), CCM2, or CCM3/programmed cell death 10 (PDCD10) causes lesions that are characterized by abnormal vascular integrity. Vascular endothelial cadherin (VE-cadherin), a major regulator of endothelial cell (EC) junctional integrity is strongly disorganized in ECs lining the CCM lesions. We report here that microRNA-27a (miR-27a), a negative regulator of VE-cadherin, is elevated in ECs isolated from mouse brains developing early CCM lesions and in cultured ECs with CCM1 or CCM2 depletion. Furthermore, we show miR-27a acts downstream of kruppel-like factor (KLF)2 and KLF4, two known key transcription factors involved in CCM lesion development. Using CD5-2 (a target site blocker [TSB]) to prevent the miR-27a/VE-cadherin mRNA interaction, we present a potential therapy to increase VE-cadherin expression and thus rescue the abnormal vascular integrity. In CCM1- or CCM2-depleted ECs, CD5-2 reduces monolayer permeability, and in Ccm1 heterozygous mice, it restores dermal vessel barrier function. In a neonatal mouse model of CCM disease, CD5-2 normalizes vasculature and reduces vascular leakage in the lesions, inhibits the development of large lesions, and significantly reduces the size of established lesions in the hindbrain. Furthermore, CD5-2 limits the accumulation of inflammatory cells in the lesion area. Our work has established that VE-cadherin is a potential therapeutic target for normalization of the vasculature and highlights that targeting miR-27a/VE-cadherin interaction by CD5-2 is a potential novel therapy for the devastating disease, CCM.

Cerebral cavernous malformation (CCM) is a disease for which, hitherto, surgery has been the only option. This study shows that a potential therapeutic, CD5-2, inhibits lesion development and vascular leak in the brains of CCM neonatal mice by targeting the endothelial cell–specific adhesion molecule VE-cadherin and restoring the vascular integrity of CCM lesions.

Role of extra cellular proteins in gastric cancer progression and metastasis: an update

Background

Gastric cancer (GC) is one of the most common cancers in the world with a high ratio of mortality. Regarding the late diagnosis, there is a high ratio of distant metastasis among GC cases. Despite the recent progresses in therapeutic modalities, there is not still an efficient therapeutic method to increase survival rate of metastatic GC cases.

Main body

Apart from the various intracellular signaling pathways which are involved in tumor cell migration and metastasis, the local microenvironment is also a critical regulator of tumor cell migration. Indeed, the intracellular signaling pathways also exert their final metastatic roles through regulation of extra cellular matrix (ECM). Therefore, it is required to assess the role of extra cellular components in biology of GC.

Conclusion

In the present review, we summarize 48 of the significant ECM components including 17 ECM modifying enzymes, seven extracellular angiogenic factors, 13 cell adhesion and cytoskeletal organizers, seven matricellular proteins and growth factors, and four proteoglycans and extra cellular glycoproteins. This review paves the way of determination of a specific extra cellular diagnostic and prognostic panel marker for the GC patients.

The secreted matrix protein mindin increases prostate tumor progression and tumor-bone crosstalk via ERK 1/2 regulation

Advanced prostate cancer cells preferentially metastasize to bone by acquiring a bone phenotype that allows metastatic cells to thrive in the skeletal environment. Identification of factors that promote the expression of ectopic bone genes-process known as osteomimicry-leading to tumor progression is crucial to prevent and treat metastatic prostate cancer and prolong life expectancy for patients. Here, we identify the extracelular matrix protein mindin in the secretome of prostate adenocarcinoma cells and show that mindin overexpression in human and mouse TRAMP-C1-induced prostate tumors correlates with upregulated levels of bone-related genes in the tumorigenic prostate tissues. Moreover, mindin silencing decreased osteomimicry in adenocarcinoma cells and in the prostate tumor mice model, as well as reduced tumor cell proliferation, migration and adhesion to bone cells. Inhibition of the extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation decreased the proliferative, migratory and pro-adhesion actions of mindin on prostate tumor cells. In addition, conditioned media obtained by crosstalk stimulation of either osteocytes or osteoblasts with the secretome of TRAMP-C1 cells promoted osteomimicry in prostate tumor cells; an effect inhibited by mindin silencing of TRAMP-C1 cells. In vivo, tibiae of primary tumor-bearing mice overexpressed the pro-angiogenic and pro-metastattic factor vascular endothelial growth factor receptor 2 (VEGFR2) in a mindin-dependent manner. Our findings indicate that mindin is a novel regulator of osteomimicry in prostate tumors and potentially mediates tumor-bone cell crosstalk, suggesting its promising role as a target to inhibit bone metastases.

Mindin deficiency alleviates renal fibrosis through inhibiting NF-κB and TGF-β/Smad pathways

Renal fibrosis acts as a clinical predictor in patients with chronic kidney disease and is characterized by excessive extracellular matrix (ECM) accumulation. Our previous study suggested that mindin can function as a mediator for liver steatosis pathogenesis. However, the role of mindin in renal fibrosis remains obscure. Here, tumour necrosis factor (TGF)‐β‐treated HK‐2 cells and global mindin knockout mouse were induced with renal ischaemia reperfusion injury (IRI) to test the relationship between mindin and renal fibrosis. In vitro, mindin overexpression promoted p65—the hub subunit of the NF‐κB signalling pathway—translocation from the cytoplasm into the nucleus, resulting in NF‐κB pathway activation in TGF‐β‐treated HK‐2 cells. Meanwhile, mindin activated the TGF‐β/Smad pathway, thereby causing fibrotic‐related protein expression in vitro. Mindin^−/− mice exhibited less kidney lesions than controls, with small renal tubular expansion, inflammatory cell infiltration, as well as collagen accumulation, following renal IRI. Mechanistically, mindin^−/− mice suppressed p65 translocation and deactivated NF‐κB pathway. Simultaneously, mindin disruption inhibited the TGF‐β/Smad pathway, alleviating the expression of ECM‐related proteins. Hence, mindin may be a novel target of renal IRI in the treatment of renal fibrogenesis.

Single-cell transcriptomics of blood reveals a natural killer cell subset depletion in tuberculosis

Background

Tuberculosis (TB) continues to be a critical global health problem, which killed millions of lives each year. Certain circulating cell subsets are thought to differentially modulate the host immune response towards Mycobacterium tuberculosis (Mtb) infection, but the nature and function of these subsets is unclear.

Methods

Peripheral blood mononuclear cells (PBMC) were isolated from healthy controls (HC), latent tuberculosis infection (LTBI) and active tuberculosis (TB) and then subjected to single-cell RNA sequencing (scRNA-seq) using 10 × Genomics platform. Unsupervised clustering of the cells based on the gene expression profiles using the Seurat package and passed to tSNE for clustering visualization. Flow cytometry was used to validate the subsets identified by scRNA-Seq.

Findings

Cluster analysis based on differential gene expression revealed both known and novel markers for all main PBMC cell types and delineated 29 cell subsets. By comparing the scRNA-seq datasets from HC, LTBI and TB, we found that infection changes the frequency of immune-cell subsets in TB. Specifically, we observed gradual depletion of a natural killer (NK) cell subset (CD3-CD7+GZMB+) from HC, to LTBI and TB. We further verified that the depletion of CD3-CD7+GZMB+ subset in TB and found an increase in this subset frequency after anti-TB treatment. Finally, we confirmed that changes in this subset frequency can distinguish patients with TB from LTBI and HC.

Interpretation

We propose that the frequency of CD3-CD7+GZMB+ in peripheral blood could be used as a novel biomarker for distinguishing TB from LTBI and HC.

Fund

The study was supported by Natural Science Foundation of China (81770013, 81525016, 81772145, 81871255 and 91942315), National Science and Technology Major Project (2017ZX10201301), Science and Technology Project of Shenzhen (JCYJ20170412101048337) and Guangdong Provincial Key Laboratory of Regional Immunity and Diseases (2019B030301009). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Deconvolution of RNA-Seq Analysis of Hyperbaric Oxygen-Treated Mice Lungs Reveals Mesenchymal Cell Subtype Changes

Hyperbaric oxygen (HBO) is widely applied to treat several hypoxia-related diseases. Previous studies have focused on the immediate effect of HBO-exposure induced oxidative stress on the lungs, but knowledge regarding the chronic effects from repetitive HBO exposure is limited, especially at the gene expression level. We found that repetitive HBO exposure did not alter the morphology of murine lungs. However, by deconvolution of RNA-seq from those mice lungs using CIBERSORTx and the expression profile matrices of 8 mesenchymal cell subtypes obtained from bleomycin-treated mouse lungs, we identify several mesenchymal cell subtype changes. These include increases in Col13a1 matrix fibroblasts, mesenchymal progenitors and mesothelial cell populations and decreases in lipofibroblasts, endothelial and Pdgfrb high cell populations. Our data suggest that repetitive HBO exposure may affect biological processes in the lungs such as response to wounding, extracellular matrix, vasculature development and immune response.

Fibroblastic Reticular Cells Control Conduit Matrix Deposition during Lymph Node Expansion

Lymph nodes (LNs) act as filters, constantly sampling peripheral cues. This is facilitated by the conduit network, a tubular structure of aligned extracellular matrix (ECM) fibrils ensheathed by fibroblastic reticular cells (FRCs). LNs undergo rapid 3- to 5-fold expansion during adaptive immune responses, but these ECM-rich structures are not permanently damaged. Whether conduit flow or filtering function is affected during LN expansion is unknown. Here, we show that conduits are partially disrupted during acute LN expansion, but FRC-FRC contacts remain connected. We reveal that polarized FRCs deposit ECM basolaterally using LL5-β and that ECM production is regulated at transcriptional and secretory levels by the C-type lectin CLEC-2, expressed by dendritic cells. Inflamed LNs maintain conduit size exclusion, and flow is disrupted but persists, indicating the robustness of this structure despite rapid tissue expansion. We show how dynamic communication between peripheral tissues and LNs provides a mechanism to prevent inflammation-induced fibrosis in lymphoid tissue.

A bigenic mouse model of FSGS reveals perturbed pathways in podocytes, mesangial cells and endothelial cells

Focal segmental glomerulosclerosis is a major cause of end stage renal disease. Many patients prove unresponsive to available therapies. An improved understanding of the molecular basis of the disease process could provide insights leading to novel therapeutic approaches. In this study we carried out an RNA-seq analysis of the altered gene expression patterns of podocytes, mesangial cells and glomerular endothelial cells of the bigenic Cd2ap+/-, Fyn-/- mutant mouse model of FSGS. In the podocytes we observed upregulation of many genes related to the Tgfβ family/pathway, including Gdnf, Tgfβ1, Tgfβ2, Snai2, Vegfb, Bmp4, and Tnc. The mutant podocytes also showed upregulation of Acta2, a marker of smooth muscle and associated with myofibroblasts, which are implicated in driving fibrosis. GO analysis of the podocyte upregulated genes identified elevated protein kinase activity, increased expression of growth factors, and negative regulation of cell adhesion, perhaps related to the observed podocyte loss. Both podocytes and mesangial cells showed strong upregulation of aldehyde dehydrogenase genes involved in the synthesis of retinoic acid. Similarly, the Cd2ap+/-, Fyn-/- mesangial cells, as well as podocytes in other genetic models, and the glomeruli of human FSGS patients, all show upregulation of the serine protease Prss23, with the common thread suggesting important functionality. Another gene with strong upregulation in the Cd2ap+/-, Fyn-/- mutant mesangial cells as well as multiple other mutant mouse models of FSGS was thrombospondin, which activates the secreted inactive form of Tgfβ. The Cd2ap+/-, Fyn-/- mutant endothelial cells showed elevated expression of genes involved in cell proliferation, angioblast migration, angiogenesis, and neovasculature, all consistent with the formation of new blood vessels in the diseased glomerulus. The resulting global definition of the perturbed molecular pathways in the three major cell types of the mutant glomerulus provide deeper understanding of the molecular pathogenic pathways.

Cellular and Molecular Mechanisms in the Pathogenesis of Classical, Vascular, and Hypermobile Ehlers‒Danlos Syndromes

The Ehlers‒Danlos syndromes (EDS) constitute a heterogenous group of connective tissue disorders characterized by joint hypermobility, skin abnormalities, and vascular fragility. The latest nosology recognizes 13 types caused by pathogenic variants in genes encoding collagens and other molecules involved in collagen processing and extracellular matrix (ECM) biology. Classical (cEDS), vascular (vEDS), and hypermobile (hEDS) EDS are the most frequent types. cEDS and vEDS are caused respectively by defects in collagen V and collagen III, whereas the molecular basis of hEDS is unknown. For these disorders, the molecular pathology remains poorly studied. Herein, we review, expand, and compare our previous transcriptome and protein studies on dermal fibroblasts from cEDS, vEDS, and hEDS patients, offering insights and perspectives in their molecular mechanisms. These cells, though sharing a pathological ECM remodeling, show differences in the underlying pathomechanisms. In cEDS and vEDS fibroblasts, key processes such as collagen biosynthesis/processing, protein folding quality control, endoplasmic reticulum homeostasis, autophagy, and wound healing are perturbed. In hEDS cells, gene expression changes related to cell-matrix interactions, inflammatory/pain responses, and acquisition of an in vitro pro-inflammatory myofibroblast-like phenotype may contribute to the complex pathogenesis of the disorder. Finally, emerging findings from miRNA profiling of hEDS fibroblasts are discussed to add some novel biological aspects about hEDS etiopathogenesis.

The pattern-recognition molecule mindin binds integrin Mac-1 to promote macrophage phagocytosis via Syk activation and NF-κB p65 translocation

Mindin has a broad spectrum of roles in the innate immune system, including in macrophage migration, antigen phagocytosis and cytokine production. Mindin functions as a pattern‐recognition molecule for microbial pathogens. However, the underlying mechanisms of mindin‐mediated phagocytosis and its exact membrane receptors are not well established. Herein, we generated mindin‐deficient mice using the CRISPR‐Cas9 system and show that peritoneal macrophages from mindin‐deficient mice were severely defective in their ability to phagocytize E  coli. Phagocytosis was enhanced when E  coli or fluorescent particles were pre‐incubated with mindin, indicating that mindin binds directly to bacteria or non‐pathogen particles and promotes phagocytosis. We defined that ¹³¹I‐labelled mindin binds with integrin Mac‐1 (CD11b/CD18), the F‐spondin (FS)‐fragment of mindin binds with the α_M‐I domain of Mac‐1 and that mindin serves as a novel ligand of Mac‐1. Blockade of the α_M‐I domain of Mac‐1 using either a neutralizing antibody or si‐Mac‐1 efficiently blocked mindin‐induced phagocytosis. Furthermore, mindin activated the Syk and MAPK signalling pathways and promoted NF‐κB entry into the nucleus. Our data indicate that mindin binds with the integrin Mac‐1 to promote macrophage phagocytosis through Syk activation and NF‐κB p65 translocation, suggesting that the mindin/Mac‐1 axis plays a critical role during innate immune responses.

Study of Human T21 Placenta Suggests a Potential Role of Mesenchymal Spondin-2 in Placental Vascular Development

Placental development is particularly altered in trisomy of chromosome 21 (T21)-affected pregnancies. We previously described in T21-affected placentae an abnormal paracrine crosstalk between the villus mesenchymal core and villus trophoblasts. T21-affected placentae are known to be characterized by their hypovascularity. However, the causes of this anomaly remain not fully elucidated. Therefore, the hypothesis of an abnormal paracrine crosstalk between fetal mesenchymal core and placental endothelial cells (PLECs) was evocated. Villus mesenchymal cells from control (CMCs) and T21 placentae (T21MCs) were isolated and grown in culture to allow their characterization and collection of conditioned media for functional analyses (CMC-CM and T21MC-CM, respectively). Interestingly, PLEC proliferation and branching ability were less stimulated by T21MC-CM than by CMC-CM. Protein array analysis identified secreted proangiogenic growth factors in CMC-CM, which were reduced in T21MC-CM. Combined mass spectrometry and biochemical analysis identified spondin-2 as a factor decreased in T21MC-CM compared with CMC-CM. We found that exogenous spondin-2 stimulated PLEC proliferation and established that T21MC-CM supplemented with spondin-2 recovered conditioned media ability to induce PLEC proliferation and angiogenesis. Hence, this study demonstrates a crosstalk between villus mesenchymal and fetal endothelial cells, in which spondin-2 secreted from mesenchymal cells plays a central role in placental vascular functions. Furthermore, our results also suggest that a reduction in spondin-2 secretion may contribute to the pathogenesis of T21 placental hypovascularity.

Hyperlipidemia and Allograft Rejection

Purpose of review

Advances in the development of immunosuppressive drug regimens have led to impressive survival rates in the year following organ transplantation. However rates of long-term graft dysfunction remain undesirably high. Recently it has been shown that co-morbidities in the patient population may affect graft survival. In mouse models, hyperlipidemia, a co-morbidity present in the majority of cardiac transplant patients, can significantly alter T cell responses to cardiac and skin allografts, and accelerate graft rejection. Here we review recent advances in our understanding of how alterations in lipids affect immune function and graft survival.

Recent Findings

Recent work in humans has highlighted the importance of controlling low density lipoprotein (LDL) levels in transplant recipients to reduce the development of chronic allograft vasculopathy (CAV). High serum levels of cholesterol containing particles leads to extensive immune system changes to T cell proliferation, differentiation and suppression. Changes in B cell subsets, and the ability of antigen presenting cells to stimulate T cells in hyperlipidemic animals may also contribute to increased organ allograft rejection.

Summary

Cholesterol metabolism is a critical cellular pathway for proper control of immune cell homeostasis and activation. Increasing evidence in both human, and in mouse models shows that elevated levels of serum cholesterol can have profound impact on the immune system. Hyperlipidemia has been shown to increase T cell activation, alter the development of T helper subsets, increase the inflammatory capacity of antigen presenting cells (APC) and significantly accelerate graft rejection in several models.

Spondin-2 is a novel diagnostic biomarker for laryngeal squamous cell carcinoma

Spondin-2, belongs to the SOX (SRY-related HMG box) gene family, plays a vital role in the development of malignancy, however, the role of Spondin-2 in laryngeal squamous cell carcinoma (LSCC) remains unknown. The aim of this study is to investigate the prognostic significance of and probable mechanism of Spondin-2 in LSCC. qRT-PCR, western blotting assays and IHC analysis demonstrated that Spondin-2 was significantly increased in LSCC tissues compared with adjacent non-tumorous tissues. In addition, high levels of Spondin-2 was associated with clinical stage, lymph node metastasis and pathology grade of LSCC patients (P ＜0.05). Kaplan-Meier analysis showed that patients with high expression of Spondin-2 had a lower overall survival rate (P＜0.05) than that with low expression of Spondin-2. Moreover, spondin-2 silencing inhibited the proliferation of LSCC cells through inhibiting the activation of PI3K/AKT signaling. In conclusion, spondin-2 might be a novel therapeutic target and prognostic biomarker for LSCC patients.

Relation of serum spondin-2 levels with cardiac morphology and inflammatory parameters in hemodialysis patients

PURPOSE

Cardiovascular diseases are the leading causes of mortality in chronic kidney disease. Spondin-2 (SP-2), an intrinsic cardio-protective factor, prevents maladaptive remodeling. We aimed to determine the relation between serum SP-2 levels and cardiac morphology along with inflammatory parameters in hemodialysis (HD) patients.

METHOD

The study comprised a total of 95 patients (61 females) receiving HD treatment three times a week for at least 6 months, and a control group consisting of age and gender matched 62 subjects (34 females). SP-2 levels were determined by ELISA. Echocardiography, 24-h ambulatory blood pressure monitoring, and carotid artery intima-media thickness (CIMT) measurement were performed in all subjects. The relation of serum SP-2 levels with CIMT, echocardiographic parameters, CRP, and absolute neutrophil-to-lymphocyte count ratio (NLR) was evaluated by correlation analysis.

RESULTS

SP-2 levels were found to be significantly higher in the HD group than the control group (16.660 [8.719-20.938] vs. 3.988 [2.702-8.042] ng/L; P < 0.001). CIMT, CRP, and NLR were also higher in HD group (P < 0.005, P < 0.001, and P < 0.001, respectively). Significantly positive correlation was found between SP-2 and left ventricular mass, left ventricular mass index, CRP, and NLR, but no correlation was determined between SP-2 and CIMT. SP-2 was not statistically significant variable for the determination of LVH in univariate logistic regression analysis [Wald = 2.375; OR (95% CI) = 1.000 (0.999-1.000), P = 0.123].

CONCLUSION

Serum SP-2 levels were higher in HD patients compared to the population with normal renal functions. The results suggest that SP-2, an uremic toxin, might be effective over a complex pathway in the inflammatory process and in the pathogenesis of cardiovascular diseases of patients under HD treatment.

Upregulation of Spondin-2 protein expression correlates with poor prognosis in hepatocellular carcinoma

OBJECTIVE

The aim of this study was to measure the extracellular matrix protein Spondin-2 (SPON2) in hepatocellular carcinoma (HCC) tissues and to determine its potential value as a prognostic indicator by assessing its correlation with clinicopathological variables and survival.

METHODS

SPON2 mRNA expression was assessed in 20 matched pairs of HCC and non-cancerous liver tissues by quantitative reverse transcription-polymerase chain reaction analysis. SPON2 protein expression was determined in 107 matched pairs of HCC and normal liver tissue by immunohistochemical staining of tissue microarrays.

RESULTS

Analysis of patient tissues and Oncomine datasets showed that SPON2 mRNA and SPON2 protein expression were both significantly upregulated in HCC tissues, compared with non-cancerous liver tissue; moreover, both correlated significantly with tumor size. Kaplan-Meier analysis revealed that HCC patients who showed high levels of cytoplasmic SPON2 protein had poorer survival following curative resection, compared with HCC patients who exhibited low protein expression levels. Multivariate Cox regression analysis showed that tumor thrombus and SPON2 protein expression both independently correlated with reduced survival in HCC patients.

CONCLUSION

Upregulated expression of SPON2 protein in tumor tissue could be an effective prognostic indicator for patients with HCC.

'Blow my mind(in)' - mindin neutralization for the prevention of atherosclerosis?

The hallmark features of atherosclerosis include accumulation of low-density lipoprotein (LDL) carrying cholesterol in the vessel wall, formation of lipid-laden foam cells, and the creation of a pro-inflammatory microenvironment. To date, no effective treatments are clinically available for increasing cholesterol efflux from vascular macrophages and inducing reverse cholesterol transport (RCT). In an article published recently in Clinical Science (vol 132, issue 6, 1199-1213), Zhang and colleagues identified the extracellular matrix protein mindin/spondin 2 as a positive regulator of atherosclerosis. Genetic knockout of mindin in apolipoprotein-E (apoE)^-/- mice attenuated atherosclerosis, foam cell formation, and inflammation within the vessel wall. Conversely, selective overexpression of mindin in macrophages in apoE^-/- mice was sufficient to promote the greater severity of atherosclerosis. Interestingly, foam cell formation was closely associated with the expression of cholesterol transporters (ABCA1 and ACBG1) that facilitate cholesterol efflux. Liver X receptor (LXR)-β is a key modulator of cholesterol transporter expression and formed direct interactions with mindin. Furthermore, the protective effects of mindin deficiency on foam cell formation were blocked by inhibition of LXR-β. This article highlights a novel role of mindin in modulating foam cell formation and atherosclerosis development in mice through direct regulation of LXR-β. Thus far, direct targetting of LXR-β via pharmacological agonists has proven to be problematic due to the lack of subtype selective inhibitors and associated adverse effects. Indirect targetting of LXR-β, therefore, via mindin inhibition offers a new therapeutic strategy for increasing LXR-β induced cholesterol efflux, reducing foam cell formation, and preventing or treating atherosclerosis.

Mindin deficiency in macrophages protects against foam cell formation and atherosclerosis by targeting LXR-β

Mindin, which is a highly conserved extracellular matrix protein, has been documented to play pivotal roles in regulating angiogenesis, inflammatory processes, and immune responses. The aim of the present study was to assess whether mindin contributes to the development of atherosclerosis. A significant up-regulation of Mindin expression was observed in the serum, arteries and atheromatous plaques of ApoE−/− mice after high-fat diet treatment. Mindin−/−ApoE−/− mice and macrophage-specific mindin overexpression in ApoE−/− mice (Lyz2-mindin-TG) were generated to evaluate the effect of mindin on the development of atherosclerosis. The Mindin−/−ApoE−/− mice exhibited significantly ameliorated atherosclerotic burdens in the entire aorta and aortic root and increased atherosclerotic plaque stability. Moreover, bone marrow transplantation further demonstrated that mindin deficiency in macrophages was largely responsible for the alleviated atherogenesis. The Lyz2-mindin-TG mice exhibited the opposite phenotype. Mindin deficiency enhanced foam cell formation by increasing the expression of cholesterol effectors, including ABCA1 and ABCG1. The mechanistic study indicated that mindin ablation promoted LXR-β expression via a direct interaction. Importantly, LXR-β inhibition largely reversed the ameliorating effect of mindin deficiency on foam cell formation and ABCA1 and ABCG1 expression. The present study demonstrated that mindin deficiency serves as a novel mediator that protects against foam cell formation and atherosclerosis by directly interacting with LXR-β.

Elevated spondin-2 expression correlates with progression and prognosis in gastric cancer

The spondin-2 correlated with tumor progression in many malignancies. However, the role of spondin-2 in gastric cancer has not been thoroughly elucidated. Spondin-2 and matrix metallopeptidase 9 (MMP-9) expression was detected by immunohistochemistry in 174 gastric carcinoma tissues. The relationship between the expression of spondin-2 and MMP-9, clinicopathological/prognostic value in gastric cancer was examined. Spondin-2 was significantly higher in gastric cancer than that in adjacent non-tumorous tissues. Spondin-2 overexpression was significantly associated with well differentiation, depth of invasion, lymph node metastasis, and advanced TNM stages. The expression levels of spondin-2 were increasing in both prominent serosal invasion group and lymph node metastasis group. In addition, spondin-2 was positively correlated with MMP-9 among 174 gastric cancer samples. In univariate and multivariate analyses, spondin-2 was an independent prognostic factor for both recurrence-free survival (RFS) and overall survival (OS). Moreover, spondin-2 overexpression was associated with poor prognosis in patients with gastric cancer in different risk groups. In conclusion, Spondin-2 overexpression contributes to tumor aggressiveness and prognosis, and could be a promising target for prognostic prediction in gastric cancer patients.

SPON2 Promotes M1-like Macrophage Recruitment and Inhibits Hepatocellular Carcinoma Metastasis by Distinct Integrin-Rho GTPase-Hippo Pathways

Tumor-associated macrophages (TAM) represent key regulators of the complex interplay between cancer and the immune microenvironment. Matricellular protein SPON2 is essential for recruiting lymphocytes and initiating immune responses. Recent studies have shown that SPON2 has complicated roles in cell migration and tumor progression. Here we report that, in the tumor microenvironment of hepatocellular carcinoma (HCC), SPON2 not only promotes infiltration of M1-like macrophages but also inhibits tumor metastasis. SPON2-α4β1 integrin signaling activated RhoA and Rac1, increased F-actin reorganization, and promoted M1-like macrophage recruitment. F-Actin accumulation also activated the Hippo pathway by suppressing LATS1 phosphorylation, promoting YAP nuclear translocation, and initiating downstream gene expression. However, SPON2-α5β1 integrin signaling inactivated RhoA and prevented F-actin assembly, thereby inhibiting HCC cell migration; the Hippo pathway was not noticeably involved in SPON2-mediated HCC cell migration. In HCC patients, SPON2 levels correlated positively with prognosis. Overall, our findings provide evidence that SPON2 is a critical factor in mediating the immune response against tumor cell growth and migration in HCC.Significance: Matricellular protein SPON2 acts as an HCC suppressor and utilizes distinct signaling events to perform dual functions in HCC microenvironment.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/9/2305/F1.large.jpg Cancer Res; 78(9); 2305-17. ©2018 AACR.

Characterization of the early molecular changes in the glomeruli of Cd151 -/- mice highlights induction of mindin and MMP-10

In humans and FVB/N mice, loss of functional tetraspanin CD151 is associated with glomerular disease characterised by early onset proteinuria and ultrastructural thickening and splitting of the glomerular basement membrane (GBM). To gain insight into the molecular mechanisms associated with disease development, we characterised the glomerular gene expression profile at an early stage of disease progression in FVB/N Cd151 ^-/- mice compared to Cd151 ^+/+ controls. This study identified 72 up-regulated and 183 down-regulated genes in FVB/N Cd151 ^-/- compared to Cd151 ^+/+ glomeruli (p < 0.05). Further analysis highlighted induction of the matrix metalloprotease MMP-10 and the extracellular matrix protein mindin (encoded by Spon2) in the diseased FVB/N Cd151 ^-/- GBM that did not occur in the C57BL/6 diseased-resistant strain. Interestingly, mindin was also detected in urinary samples of FVB/N Cd151 ^-/- mice, underlining its potential value as a biomarker for glomerular diseases associated with GBM alterations. Gene set enrichment and pathway analysis of the microarray dataset showed enrichment in axon guidance and actin cytoskeleton signalling pathways as well as activation of inflammatory pathways. Given the known function of mindin, its early expression in the diseased GBM could represent a trigger of both further podocyte cytoskeletal changes and inflammation, thereby playing a key role in the mechanisms of disease progression.

The extracellular matrix protein mindin attenuates colon cancer progression by blocking angiogenesis via Egr-1-mediated regulation

Mindin, a secreted, highly conserved extracellular matrix (ECM) protein, exerts a broad spectrum of effects on the innate immune system. However, its function in colorectal cancer (CRC) progression is not well established, and its upstream regulation mechanisms remain unclear. Contrary to previous reports, this study used two different enzyme-linked immunosorbent assay (ELISA) kits to show that the serum level of mindin was significantly decreased in CRC patients and that this decreased level is more significantly associated with the early stages of the disease. To explore the regulation of mindin, we used a bioinformatics approach to predict potential transcription factors and determined that early growth response factor (Egr)-1 directly regulates mindin expression at the transcriptional level using dual luciferase, chromatin immunoprecipitation (ChIP) DNA and electrophoretic mobility shift assay (EMSA) methods. Egr-1 regulates mindin mRNA and protein expression in CRC cells, and the protein expression of both Egr-1 and mindin was significantly decreased in tumor lesions of patients compared with adjacent control tissues. Mindin is essential for Egr-1-mediated inhibition of endothelial cell tube formation, and mindin inhibits endotheliocyte proliferation, migration and angiogenic sprouts in vitro. Overexpression of mindin suppressed xenograft tumor growth by blocking angiogenesis instead of directly suppressing CRC cell proliferation. Mechanically, mindin inhibits the hypoxia-induced HIF-1a and VEGFA protein expression in CRC cells and the phosphorylation of VEGFR-2 in endothelial cells. The results suggest that the serum level of mindin can be used as a novel biomarker for early detection of CRC and that the Egr-1/mindin axis is a potential therapeutic target for the inhibition of angiogenesis in CRC development.

Spondin2 is a new prognostic biomarker for lung adenocarcinoma

Spondin 2 (SPON2) is a member of the F-spondin superfamily of genes that encode an extracellular matrix protein. SPON2 has been identified by mRNA differential display screening of cancerous and noncancerous lung cell lines in vitro [1], however, its role in pulmonary adenocarcinoma (ADC) patients remains unclear. In our study, we evaluated whether SPON2 can be used as a biomarker for the diagnosis of pulmonary ADC and any association between SPON2 protein levels and clinicopathological characteristics. Firstly, the mRNA levels of SPON2 in pulmonary ADCs and normal adjacent tissue samples were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n = 60) assay and the expression of SPON2 protein were detected by tissue microarray immunohistochemistry analysis (TMA-IHC) (n = 280). Overexpression of SPON2 protein in cancerous tissues was associated with the clinical characteristics of ADC patients and their overall survival. Levels of SPON2 mRNA and protein were significantly expressed higher in ADC tissues than in adjacent normal tissues. Finally, through univariate and multivariate regression analysis, we found that overexpression of SPON2 protein levels correlates with differentiation, positive lymph nodes metastasis, higher serum carcinoembryonic antigen (CEA) level and poor overall survival. Overexpression of SPON2 protein is an independent prognostic biomarker in ADC patients. Our data revealed that SPON2 played an oncogene role in ADC development and progression. Inhibiting SPON2 might represent a new strategy for pulmonary ADC.

C-type lectin interacting with β-integrin enhances hemocytic encapsulation in the cotton bollworm, Helicoverpa armigera

The encapsulation reaction in invertebrates is analogous to granuloma formation in vertebrates, and this reaction is severely compromised when ecdysone signaling is blocked. However, the molecular mechanism underlying the encapsulation reaction and its regulation by ecdysone remains obscure. In our previous study, we found that the C-type lectin HaCTL3, from the cotton bollworm Helicoverpa armigera, is involved in anti-bacterial immune response, acting as a pattern recognition receptor (PRR). In the current study, we demonstrate that HaCTL3 is involved in defense against parasites and directly binds to the surface of nematodes. Our in vitro and in vivo studies indicate that HaCTL3 enhances hemocytic encapsulation and melanization, whereas H. armigera β-integrin (Haβ-integrin), located on the surface of hemocytes, participates in encapsulation. Additionally, co-immunoprecipitation experiments reveal HaCTL3 interacts with Haβ-integrin, and knockdown of Haβ-integrin leads to reduced encapsulation of HaCTL3-coated beads. These results indicate that Haβ-integrin serves as a hemocytic receptor of HaCTL3 during the encapsulation reaction. Furthermore, we demonstrate that 20-hydroxyecdysone (20E) treatment dramatically induces the expression of HaCTL3, and knockdown of the 20E receptor (EcR)/ultraspiracle (USP), abrogates this response. Overall, this study provides the first evidence of the presence of a hemocytic receptor (Haβ-integrin), that interacts with the PRR HaCTL3 to facilitate encapsulation reaction in insects and demonstrates the regulation of this process by the steroid hormone ecdysone.

Endotoxin-induced autocrine ATP signaling inhibits neutrophil chemotaxis through enhancing myosin light chain phosphorylation

Although the neutrophil recruitment cascade during inflammation has been well described, the molecular players that halt neutrophil chemotaxis remain unclear. In this study, we found that lipopolysaccharide (LPS) was a potent stop signal for chemotactic neutrophil migration. Treatment with an antagonist of the ATP receptor (P2X1) in primary human neutrophils or knockout of the P2X1 receptor in neutrophil-like differentiated HL-60 (dHL-60) cells recovered neutrophil chemotaxis. Further observations showed that LPS-induced ATP release through connexin 43 (Cx43) hemichannels was responsible for the activation of the P2X1 receptor and the subsequent calcium influx. Increased intracellular calcium stopped neutrophil chemotaxis by activating myosin light chain (MLC) through the myosin light chain kinase (MLCK)-dependent pathway. Taken together, these data identify a previously unknown function of LPS-induced autocrine ATP signaling in inhibiting neutrophil chemotaxis by enhancing MLC phosphorylation, which provides important evidence that stoppage of neutrophil chemotaxis at infectious foci plays a key role in the defense against invading pathogens.

WITHDRAWN: C-type lectin interacting with β-integrin enhances hemocytic encapsulation in the cotton bollworm, Helicoverpa armigera

This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error. The article was subsequently accepted and published and can be viewed here: https://doi.org/10.1016/j.ibmb.2017.05.005 The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Akt: A Therapeutic Target in Hepatic Ischemia-Reperfusion Injury

BACKGROUND

Liver transplantation is the second most common transplant procedure in the United States. A leading cause of post-transplantation organ dysfunction is I/R injury. During I/R injury, the serine/threonine kinase Akt is activated, stimulating downstream mediators to promote cellular survival. Due to the cellular effects of Akt, therapeutic manipulation of the Akt pathway can help reduce cellular damage during hepatic I/R that occurs during liver transplantation.

OBJECTIVE

A full description of therapeutic options available that target Akt to reduce hepatic I/R injury has not been addressed within the literature. The purpose of this review is to illuminate advances in the manipulation of Akt that can be used to therapeutically target I/R injury in the liver.

METHODS

An in depth literature review was performed using the Scopus and PubMed databases. A total of 75 published articles were utilized for this manuscript. Terminology searched includes a combination of "hepatic ischemia/reperfusion injury", "Akt/PKB", "preconditioning" and "postconditioning."

RESULTS

Four principal methods that reduce I/R injury include hepatic pre- and postconditioning, pharmacological intervention and future miRNA/gene therapy. Discussed therapies used serum alanine aminotransferase levels, liver histology and phosphorylation of downstream mediators to confirm the Akt protective effect.

CONCLUSION

The activation of Akt from the reviewed therapies has resulted in predictable reduction in hepatocyte damage using the previously mentioned measurements. In a clinical setting, these therapies could potentially be used in combination to achieve better outcomes in hepatic transplant patients. Evidence supporting reduced I/R injury through Akt activation warrants further studies in human clinical trials.

Non-genotoxic conditioning for hematopoietic stem cell transplantation using a hematopoietic-cell-specific internalizing immunotoxin

Hematopoietic stem cell transplantation (HSCT) offers curative therapy for patients with hemoglobinopathies, congenital immunodeficiencies, and other conditions, possibly including AIDS. Autologous HSCT using genetically corrected cells would avoid the risk of graft-versus-host disease (GVHD), but the genotoxicity of conditioning remains a substantial barrier to the development of this approach. Here we report an internalizing immunotoxin targeting the hematopoietic-cell-restricted CD45 receptor that effectively conditions immunocompetent mice. A single dose of the immunotoxin, CD45-saporin (SAP), enabled efficient (>90%) engraftment of donor cells and full correction of a sickle-cell anemia model. In contrast to irradiation, CD45-SAP completely avoided neutropenia and anemia, spared bone marrow and thymic niches, enabling rapid recovery of T and B cells, preserved anti-fungal immunity, and had minimal overall toxicity. This non-genotoxic conditioning method may provide an attractive alternative to current conditioning regimens for HSCT in the treatment of non-malignant blood diseases.

SPON2, a newly identified target gene of MACC1, drives colorectal cancer metastasis in mice and is prognostic for colorectal cancer patient survival

MACC1 (metastasis associated in colon cancer 1) is a prognostic biomarker for tumor progression, metastasis and survival of a variety of solid cancers including colorectal cancer (CRC). Here we aimed to identify the MACC1-induced transcriptome and key players mediating the MACC1-induced effects in CRC. We performed microarray analyses using CRC cells ectopically overexpressing MACC1. We identified more than 1300 genes at least twofold differentially expressed, including the gene SPON2 (Spondin 2) as 90-fold upregulated transcriptional target of MACC1. MACC1-dependent SPON2 expression regulation was validated on mRNA and protein levels in MACC1 high (endogenously or ectopically) and low (endogenously or by knockdown) expressing cells. Chromatin immunoprecipitation analysis demonstrated the binding of MACC1 to the gene promoter of SPON2. In cell culture, ectopic SPON2 overexpression induced cell viability, migration, invasion and colony formation in endogenously MACC1 and SPON2 low expressing cells, whereas SPON2 knockdown reduced proliferative, migratory and invasive abilities in CRC cells with high endogenous MACC1 and SPON2 expression. In intrasplenically transplanted NOD/SCID mice, metastasis induction was analyzed with control or SPON2-overexpressing CRC cells. Tumors with SPON2 overexpression induced liver metastasis (vs control animals without any metastases, P=0.0036). In CRC patients, SPON2 expression was determined in primary tumors (stages I-III), and survival time was analyzed by Kaplan-Meier method. CRC patients with high SPON2 expressing primary tumors demonstrated 8 months shorter metastasis-free survival (MFS) compared with patients with low SPON2 levels (P=0.053). Combining high levels of SPON2 and MACC1 improved the identification of high-risk patients with a 20-month shorter MFS vs patients with low biomarker expression. In summary, SPON2 is a transcriptional target of the metastasis gene MACC1. SPON2 induces cell motility in vitro and CRC metastasis in mice. In patients, SPON2 serves as prognostic indicator for CRC metastasis and survival, and might represent a promising target for therapeutic approaches.