Angiopoietin-Like Protein 7 Promotes an Inflammatory Phenotype in RAW264.7 Macrophages Through the P38 MAPK Signaling Pathway

Olink Profiling of Aqueous Humor Identifies Novel Biomarkers for Wet Age-Related Macular Degeneration

Metabolic dysfunction is recognized as a contributing factor in the pathogenesis of wet age-related macular degeneration (wAMD). However, the specific metabolism-related proteins implicated in wAMD remain elusive. In this study, we assessed the expression profiles of 92 metabolism-related proteins in aqueous humor (AH) samples obtained from 44 wAMD patients and 44 cataract control patients. Our findings revealed significant alterations in the expression of 60 metabolism-related proteins between the two groups. Notably, ANGPTL7 and METRNL displayed promising diagnostic potential for wAMD, as evidenced by area under the curve values of 0.88 and 0.85, respectively. Subsequent validation studies confirmed the upregulation of ANGPTL7 and METRNL in the AH of wAMD patients and in choroidal neovascularization (CNV) models. Functional assays revealed that increased ANGPTL7 and METRNL played a pro-angiogenic role in endothelial biology by promoting endothelial cell proliferation, migration, tube formation, and spouting in vitro. Moreover, in vivo studies revealed the pro-angiogenic effects of ANGPTL7 and METRNL in CNV formation. In conclusion, our findings highlight the association between elevated ANGPTL7 and METRNL levels and wAMD, suggesting their potential as novel predictive and diagnostic biomarkers for this condition. These results underscore the significance of ANGPTL7 and METRNL in the context of wAMD pathogenesis and offer new avenues for future research and therapeutic interventions.

The Emerging Evidence for a Protective Role of Fucoidan from Laminaria japonica in Chronic Kidney Disease-Triggered Cognitive Dysfunction

This study aimed to explore the mechanism of fucoidan in chronic kidney disease (CKD)-triggered cognitive dysfunction. The adenine-induced ICR strain CKD mice model was applied, and RNA-Seq was performed for differential gene analysis between aged-CKD and normal mice. As a result, fucoidan (100 and 200 mg kg-1) significantly reversed adenine-induced high expression of urea, uric acid in urine, and creatinine in serum, as well as the novel object recognition memory and spatial memory deficits. RNA sequencing analysis indicated that oxidative and inflammatory signaling were involved in adenine-induced kidney injury and cognitive dysfunction; furthermore, fucoidan inhibited oxidative stress via GSK3β-Nrf2-HO-1 signaling and ameliorated inflammatory response through regulation of microglia/macrophage polarization in the kidney and hippocampus of CKD mice. Additionally, we clarified six hallmarks in the hippocampus and four in the kidney, which were correlated with CKD-triggered cognitive dysfunction. This study provides a theoretical basis for the application of fucoidan in the treatment of CKD-triggered memory deficits.

ANGPTL7 is transcriptionally regulated by SP1 and modulates glucocorticoid-induced cross-linked actin networks in trabecular meshwork cells via the RhoA/ROCK pathway

Glaucoma is one of the leading causes of worldwide irreversible blindness. Lowering elevated intraocular pressure (IOP) is currently the only effective approach for controlling the progress of glaucoma. Angiopoietin-like 7 (ANGPTL7) takes a key part in elevated outflow resistance of aqueous humor in dysfunctional trabecular meshwork (TM), along with the formation of cross-linked actin networks (CLANs), leading to high IOP. In this study, we explored the role of the ANGPTL7 signaling pathway in CLAN formation. We detected the expression of ANGPTL7 in cultured primary TM cells treated with dexamethasone (DEX) and ethanol as a control using qRT-PCR and western blotting. Actin filaments were revealed by phalloidin staining. ANGPTL7 short hairpin RNA (shRNA) was applied to TM cells to examine the effect of ANGPTL7 on DEX-induced CLAN formation. Western blotting was used to assess the effect of ANGPTL7 on the RhoA/Rho-associated kinase (Rho-kinase/ROCK) signaling pathway. Bioinformatics, dual-luciferase reporter assays, and chromatin immunoprecipitation were employed to identify the transcription factors of ANGPTL7. Transcription factor specificity protein 1 (SP1) overexpression and silencing were performed to determine their roles in the modulation of ANGPTL7 expression. We found DEX-induced ANGPTL7 expression and stress fiber rearrangement in TM cells. ANGPTL7 knockdown effectively inhibited the formation of CLANs. Moreover, it was involved in the regulation of the RhoA/ROCK signaling pathway, further affecting DEX-induced CLAN formation. SP1 was identified as a transcription factor of ANGPTL7 which regulated ANGPTL7 level to mediate CLAN formation through the RhoA/ROCK signaling pathway. This study contributes to revealing the molecular mechanisms of ANGPTL7 in CLAN formation, which is involved in TM dysfunction and glaucoma pathogenesis.

Increased plasma ANGPTL7 levels with increased obstructive sleep apnea severity

BACKGROUND

Weight-loss surgery is one of the recommended methods for treating obstructive sleep apnea (OSA) in obese patients. While weight reduction is critical to relieve symptoms of OSA, the biochemical factors involved in post-surgery improvement are still unknown. We aimed to explore the link between ANGPTL7 and OSA in patients with different OSA severity. Furthermore, we examined the effect of treating OSA with bariatric surgery on ANGPTL7 level.

METHODS

We quantified levels of circulating ANGPTL7 in fasting plasma and adipose tissue samples of 88 participants before and after bariatric surgery. Confocal microscopy analyses were also performed to assess the ANGPTL7 expression in subcutaneous white adipose tissue biopsies obtained from people with moderate-to-severe OSA compared to those with none or mild OSA. The study involved 57 individuals with none or mild OSA and 31 patients with moderate-to-severe OSA.

RESULTS

Levels of circulating ANGPTL7 were significantly higher in people with moderate-to-severe OSA (1440 ± 1310 pg/ml) compared to the none or mild OSA group (734 ± 904 pg/ml, p = 0.01). The increase in ANGPTL7 correlated significantly and positively with the apnea-hypopnea index (AHI, r = .226, p = .037), and AHI-supine (r = .266, p = .019) in participants with moderate-to-severe OSA. Multivariate logistic regression analysis demonstrated an association between ANGPTL7 and OSA severity (log₂ ANGPTL7; OR =1.24, p = 0.024). ANGPTL7 levels exhibited significant positive correlations with the levels of TG and oxLDL (p-value = 0.002 and 0.01 respectively). Bariatric surgery reduced the levels of both ANGPTL7 and AHI significantly.

CONCLUSION

Here we report significantly increased levels of ANGPTL7 both in the circulation and in adipose tissue of patients with OSA, which concurred with increased inflammation and OSA severity. Levels of ANGPTL7 decreased significantly as OSA showed a significant improvement post-surgery supporting a potential role for ANGPTL7 in either OSA progression or a role in an OSA-related mechanism.

Identification of distinct and age-dependent p16High microglia subtypes

Cells expressing high levels of the cyclin‐dependent kinase (CDK)4/6 inhibitor p16 (p16^High) accumulate in aging tissues and promote multiple age‐related pathologies, including neurodegeneration. Here, we show that the number of p16^High cells is significantly increased in the central nervous system (CNS) of 2‐year‐old mice. Bulk RNAseq indicated that genes expressed by p16^High cells were associated with inflammation and phagocytosis. Single‐cell RNAseq of brain cells indicated p16^High cells were primarily microglia, and their accumulation was confirmed in brains of aged humans. Interestingly, we identified two distinct subpopulations of p16^High microglia in the mouse brain, with one being age‐associated and one present in young animals. Both p16^High clusters significantly differed from previously described disease‐associated microglia and expressed only a partial senescence signature. Taken together, our study provides evidence for the existence of two p16‐expressing microglia populations, one accumulating with age and another already present in youth that could positively and negatively contribute to brain homeostasis, function, and disease.

Ferroptosis-Related Gene Signature and Patterns of Immune Infiltration Predict the Overall Survival in Patients With Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is a malignant tumor with high heterogeneity and poor prognosis. Ferroptosis, a form of regulated cell-death–related iron, has been proven to trigger inflammation-associated immunosuppression in the tumor microenvironment, which promotes tumor growth. Therefore, the clinical prognostic value of ferroptosis-related genes in LUAD needs to be further explored.

Method: In this study, we downloaded the mRNA expression profiles and corresponding clinical data of LUAD patients from the Cancer Genome Atlas database. The least absolute shrinkage and selection operator (LASSO) Cox regression model was utilized to construct ferroptosis-related gene signature. Based on these, we established the nomograms for prognosis prediction and validated the model in the GSE72094 dataset. The cell type was identified using the CIBERSORT algorithm for estimating relative subsets of RNA transcripts, which was then used to screen significant tumor immune-infiltrating cells associated with the LUAD prognosis prediction model. Subsequently, we applied co-expression analysis to reveal the relationship between ferroptosis-related genes and significant immune cells.

Results: The univariate COX regression analysis showed that 20 genes were associated with the overall survival (OS) as prognostic differentially expressed genes (DEGs) (FDR <0.05). Patients were divided into two risk groups using a 13-gene signature, with the high-risk group having a significantly worse OS than their low-risk counterparts (p < 0.001). We used receiver operating characteristic (ROC) curve analysis to confirm the predictive capacity of the signature. Besides, we identified seven pairs of ferroptosis-related genes and tumor-infiltrating immune cells associated with the prognosis of LUAD patients.

Conclusion: In this study, we construct a ferroptosis-related gene signature that can be used for prognostic prediction in LUAD. In addition, we reveal a potential connection between ferroptosis and tumor-infiltrating immune cells.

Expression profiling of genes in rheumatoid fibroblast-like synoviocytes regulated by Fas ligand via cDNA microarray analysis

Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation in synovial tissues. Hyperplasia of synovial tissues leads to the formation of pannus that invades the joint cartilage and bone, resulting in joint destruction. Fas ligand (FasL), which is a member of the tumor necrosis factor superfamily, contributes to the pathogenesis of autoimmune diseases, including RA. The current study attempted to identify genes whose expressions in rheumatoid fibroblast-like synoviocytes (RA-FLS) were regulated by FasL, using cDNA microarray. A total of four individual lines of primary cultured RA-FLS were incubated either with recombinant human FasL protein or PBS as an unstimulated control for 12 h. Gene expression was detected using a microarray assay. The results revealed the expression profiles of genes in RA-FLS regulated by Fas and investigated the functions of the genes that were regulated. Among the genes in this profile, the mRNA expression changes of the following genes were indicated to be of note using RT-qPCR: Dual specificity phosphatase 6, epiregulin, interleukin 11, angiopoietin-like 7, protein inhibitor of activated STAT 2 and growth differentiation factor 5. These genes may affect the pathogenesis of RA by affecting apoptosis, proliferation, cytokine production, cytokine-induced inflammation, intracellular signaling, angiogenesis, bone destruction and chondrogenesis. To the best of our knowledge, the current study is the first study to reveal the expression profile of genes in RA-FLS regulated by FasL. The data demonstrated that FasL may regulate the expression of a number of key molecules in RA-FLS, thus affecting RA pathogenesis. Further studies of the genes detected may improve the understanding of RA pathogenesis and provide novel treatment targets for RA.

An Extracellular Matrix-Based Signature Associated With Immune Microenvironment Predicts the Prognosis and Therapeutic Responses of Patients With Oesophageal Squamous Cell Carcinoma

Evidence has suggested that the cancer-associated extracellular matrix (ECM) could be recognised as immune-related biomarkers that modulate tumour progression and expansion. However, the ECM-associated immune effect on esophageal squamous cell carcinoma (ESCC) prognosis and therapy has not been well characterised. In our study, we first constructed an ECM-related signature including four genes CST1, NELL2, ADAMTSL4, and ANGPTL7 by multivariate Cox regression analyses. This signature could serve as a marker to evaluate the prognosis of patients with ESCC and was successfully validated in testing and combined (training plus testing) cohorts. We also found that there were significant different therapeutic responses to chemotherapy and targeted drugs between the high-risk and low-risk groups of patients defined by the signature. Furthermore, the expression of four genes and immune function analysis suggested that this ECM-related signature gene might play important roles in the changes of the tumour microenvironment. In conclusion, our findings demonstrated that the ECM-related signature might serve as an independent prognostic factor and provide a potential biomarker for chemotherapy responses for patients with ESCC.

Cord Blood Levels of Angiopoietin-Like 7 (ANGPTL7) in Preterm Infants

Objective

ANGPTL7 is a member of the angiogenin-like protein family. Compared to other members, ANGPTL7 is the least known. Recent studies have explored the relationship between ANGPTL7 and multiple pathological processes and diseases. However, there is no research about ANGPTL7 in neonates. This study was designed to investigate the concentration of ANGPTL7 in cord blood of preterm infants.

Method

Singleton infants born in November 2017 to June 2019 in the study hospital were enrolled in the study. Maternal and neonatal clinical data were collected. ANGPTL7 levels in cord blood and serum on the third day after birth were measured by an enzyme-linked immunosorbent assay.

Result

A total of 182 infants were enrolled in this study. Patients were categorized into two groups by gestational age (102 preterm, 80 full-term). ANGPTL7 levels in preterm infants were significantly higher than that in full-term babies (t = 15.4, P < 0.001). In multiple line regression analysis, ANGPTL7 levels independently correlated with gestational age (β = −0.556, P < 0.001). There is also no correlation between preterm outcomes and ANGPTL7 levels. Cord blood levels of ANGPTL7 were significantly higher than those in serum on the third day after birth (t = 13.88, P < 0.001).

Conclusion

Cord blood ANGPTL7 levels are higher in preterm infants than full-term babies. The levels are independently influenced by gestational ages and attenuated significantly after birth. The underlying mechanism needs to be further studied.

Structural Characterization and Pro-inflammatory Activity of a Thaumatin-Like Protein from Pulp Tissues of Litchi chinensis

The objective of this study was to extract and purify proteins from the pulp tissues of litchi and evaluate their structure and pro-inflammatory activity. The results showed that a highly pure litchi protein was identified as the litchi thaumatin-like protein (LcTLP) by nano LC-MS/MS and verified by sequencing of the LcTLP gene. The molecular weight was 24 kDa, and the main secondary structure was a β sheet (33.00 ± 2.86%). Small-angle X-ray scattering results showed that LcTLP was a spherical particle (diameter of approximately 140 to 165 nm) with a close internal and rough surface in solution. The assay of pro-inflammatory activity in vitro revealed that the expression of inducible nitric oxide synthase and cyclooxygenase-2 genes reached 9.71 ± 0.64 and 7.05 ± 1.00 after 200 μg/mL LcTLP stimulation, which were 7.05-fold and 9.61-fold that of the blank control, respectively. LcTLP promoted the gene expression and production of pro-inflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, and it also enhanced the expression of p65, which is a key component of nuclear factor-κ B signaling pathways. Additionally, the levels of anti-inflammatory cytokines interleukin-10 and transforming growth factor-β1 increased after LcTLP stimulation.

Angiopoietin-Like Protein 7 and Short-Term Mortality in Acute Heart Failure

INTRODUCTION

Angiopoietin-like protein 7 (ANGPTL7) is involved in extracellular matrix expression and inflammatory responses. However, the prognostic utility of ANGPTL7 among patients with acute heart failure (AHF) remains unclear.

OBJECTIVE

To evaluate the association between ANGPTL7 and short-term mortality due to AHF.

METHODS AND RESULTS

Patients with AHF were prospectively studied. Serum levels of ANGPTL7 were measured by an enzyme-linked immunosorbent assay. Associations between 30- and 90-day mortality and tertiles of ANGPTL7 were assessed by multivariate logistic regression models. The study comprised 142 patients. Median patient age was 68 years, and 69.7% were male. There were 20 deaths within 30 days and 37 deaths within 90 days. Crude rates of 30-day mortality in low, intermediate, and high tertiles of ANGPTL7 were 4.6, 14.6, and 22.9%, respectively. Crude rates of 90-day mortality of corresponding tertiles were 15.2, 25.0, and 37.5%. After adjusting for potential confounders, including NT-proBNP, the high tertile of ANGPTL7 was associated with a significantly increased risk of both 30-day mortality (odds ratio [OR]: 6.77, 95% confidence interval [CI]: 1.41-32.61, p = 0.017) and 90-day mortality (OR: 3.78, 95% CI: 1.38-10.36, p = 0.010) compared with the low tertile of ANGPTL7. Although mortality risk tended to be higher in the intermediate tertile than the low tertile, it did not reach statistical significance (OR: 3.75, 95% CI: 0.73-19.14, p = 0.113 for 30-day mortality; OR: 1.88, 95% CI: 0.66-5.34, p = 0.236 for 90-day mortality).

CONCLUSIONS

Serum level of ANGPTL7 was independently associated with short-term mortality among patients with AHF.

The Roles of ANGPTL Families in Cancer Progression

Angiopoietins play important roles in angiogenesis and the maintenance of hematopoietic stem cells. Angiopoietin-like proteins (ANGPTLs) are identified as proteins structurally similar to angiopoietins, and the ANGPTL family now consists of eight members. ANGPTLs are secretary proteins, and some ANGPTLs are not only angiogenic factors but also proteins with multiple functions such as glucose metabolism, lipid metabolism, redox regulation and chronic inflammation. Chronic inflammation is one of the key factors in carcinogenesis and cancer growth, proliferation, invasion and metastasis. ANGPTL 2, 3, 4, 6 and 7 are pro-inflammatory factors and regulate cancer progression, while ANGPTL1 inhibits tumor angiogenesis and metastasis. In this review, we describe the roles of ANGPTLs in cancer progression and discuss the possibility of disturbing the progression of cancer by regulating ANGPTLs expression.