Thalidomide targets EGFL6 to inhibit EGFL6/PAX6 axis-driven angiogenesis in small bowel vascular malformation

Rescue Blood Contamination in scRNA-Seq Data by Originator, a Computational Deciphering Tool using Genetic and Contextual Information

Single-cell RNA sequencing (scRNA-Seq) data from complex human tissues have prevalent blood cell contamination due to the sample preparation process and may comprise cells of different genetic makeups. To reveal such complexity and annotate cells appropriately, we propose the first-of-its-kind computational framework, Originator, which deciphers single cells by genetic origin and separates blood cells from tissue-resident cells. We show that blood contamination is widely spread in scRNA-Seq data from a variety of tissues. We warn of the significant biases in downstream analysis without considering blood contamination and genetic contexts using pancreatic ductal adenocarcinoma and placenta data, respectively.

Hypoxia and low-glucose environments co-induced HGDILnc1 promote glycolysis and angiogenesis

Small bowel vascular malformation disease (SBVM) commonly causes obscure gastrointestinal bleeding (OGIB). However, the pathogenetic mechanism and the role of lncRNAs in SBVM remain largely unknown. Here, we found that hypoxia and low-glucose environments co-augment angiogenesis and existed in SBVM. Mechanistically, hypoxia and low-glucose environments supported angiogenesis via activation of hypoxia and glucose deprivation-induced lncRNA (HGDILnc1) transcription by increasing binding of the NeuroD1 transcription factor to the HGDILnc1 promoter. Raised HGDILnc1 acted as a suppressor of α-Enolase 1 (ENO1) small ubiquitin-like modifier modification (SUMOylation)-triggered ubiquitination, and an activator of transcription of Aldolase C (ALDOC) via upregulation of Histone H2B lysine 16 acetylation (H2BK16ac) level in the promoter of ALDOC, and consequently promoting glycolysis and angiogenesis. Moreover, HGDILnc1 was clinically positively correlated with Neurogenic differentiation 1 (NeuroD1), ENO1, and ALDOC in SBVM tissues, and could function as a biomarker for SBVM diagnosis and therapy. These findings suggest that hypoxia and low-glucose environments were present in SBVM tissues, and co-augmented angiogenesis. Hypoxia and low-glucose environments co-induced HGDILnc1, which is higher expressed in SBVM tissue compared with normal tissue, could promoted glycolysis and angiogenesis.

Thalidomide for Recurrent Bleeding Due to Small-Intestinal Angiodysplasia

BACKGROUND

Recurrent bleeding from the small intestine accounts for 5 to 10% of cases of gastrointestinal bleeding and remains a therapeutic challenge. Thalidomide has been evaluated for the treatment of recurrent bleeding due to small-intestinal angiodysplasia (SIA), but confirmatory trials are lacking.

METHODS

We conducted a multicenter, double-blind, randomized, placebo-controlled trial to investigate the efficacy and safety of thalidomide for the treatment of recurrent bleeding due to SIA. Eligible patients with recurrent bleeding (at least four episodes of bleeding during the previous year) due to SIA were randomly assigned to receive thalidomide at an oral daily dose of 100 mg or 50 mg or placebo for 4 months. Patients were followed for at least 1 year after the end of the 4-month treatment period. The primary end point was effective response, which was defined as a reduction of at least 50% in the number of bleeding episodes that occurred during the year after the end of thalidomide treatment as compared with the number that occurred during the year before treatment. Key secondary end points were cessation of bleeding without rebleeding, blood transfusion, hospitalization because of bleeding, duration of bleeding, and hemoglobin levels.

RESULTS

Overall, 150 patients underwent randomization: 51 to the 100-mg thalidomide group, 49 to the 50-mg thalidomide group, and 50 to the placebo group. The percentages of patients with an effective response in the 100-mg thalidomide group, 50-mg thalidomide group, and placebo group were 68.6%, 51.0%, and 16.0%, respectively (P<0.001 for simultaneous comparison across the three groups). The results of the analyses of the secondary end points supported those of the primary end point. Adverse events were more common in the thalidomide groups than in the placebo group overall; specific events included constipation, somnolence, limb numbness, peripheral edema, dizziness, and elevated liver-enzyme levels.

CONCLUSIONS

In this placebo-controlled trial, treatment with thalidomide resulted in a reduction in bleeding in patients with recurrent bleeding due to SIA. (Funded by the National Natural Science Foundation of China and the Shanghai Municipal Education Commission, Gaofeng Clinical Medicine; ClinicalTrials.gov number, NCT02707484.).

Single-Cell Transcriptomics Reveals Cellular Heterogeneity and Complex Cell-Cell Communication Networks in the Mouse Cornea

Purpose

To generate a single-cell RNA-sequencing (scRNA-seq) map and construct cell-cell communication networks of mouse corneas.

Methods

C57BL/6 mouse corneas were dissociated to single cells and subjected to scRNA-seq. Cell populations were clustered and annotated for bioinformatic analysis using the R package "Seurat." Differential expression patterns were validated and spatially mapped with whole-mount immunofluorescence staining. Global intercellular signaling networks were constructed using CellChat.

Results

Unbiased clustering of scRNA-seq transcriptomes of 14,732 cells from 40 corneas revealed 17 cell clusters of six major cell types: nine epithelial cell, three keratocyte, two corneal endothelial cell, and one each of immune cell, vascular endothelial cell, and fibroblast clusters. The nine epithelial cell subtypes included quiescent limbal stem cells, transit-amplifying cells, and differentiated cells from corneas and two minor conjunctival epithelial clusters. CellChat analysis provided an atlas of the complex intercellular signaling communications among all cell types.

Conclusions

We constructed a complete single-cell transcriptomic map and the complex signaling cross-talk among all cell types of the cornea, which can be used as a foundation atlas for further research on the cornea. This study also deepens the understanding of the cellular heterogeneity and heterotypic cell-cell interaction within corneas.

Thalidomide upper limb embryopathy - pathogenesis, past and present management and future considerations

This review article provides a comprehensive overview of thalidomide upper limb embryopathy including updates about its pathogenesis, a historical account of the management of the paediatric thalidomide patient, experience with management of the adult patient, as well as creating awareness about early onset age-related changes associated with limb differences. Despite its withdrawal from the market in November 1961, novel discoveries have meant thalidomide is licensed again and currently still in use to treat a variety of conditions, including inflammatory disorders and some cancers. Yet, if not used safely, thalidomide still has the potential to cause damage to the embryo. Recent work identifying thalidomide analogues that retain clinical benefits yet without the harmful effects are showing great promise. Understanding the problems thalidomide survivors face as they age can allow surgeons to support their unique healthcare issues and translate these principles of care to other congenital upper limb differences.

Thalidomide interaction with inflammation in idiopathic pulmonary fibrosis

The "Thalidomide tragedy" is a landmark in the history of the pharmaceutical industry. Despite limited clinical trials, there is a continuous effort to investigate thalidomide as a drug for cancer and inflammatory diseases such as rheumatoid arthritis, lepromatous leprosy, and COVID-19. This review focuses on the possibilities of targeting inflammation by repurposing thalidomide for the treatment of idiopathic pulmonary fibrosis (IPF). Articles were searched from the Scopus database, sorted, and selected articles were reviewed. The content includes the proven mechanisms of action of thalidomide relevant to IPF. Inflammation, oxidative stress, and epigenetic mechanisms are major pathogenic factors in IPF. Transforming growth factor-β (TGF-β) is the major biomarker of IPF. Thalidomide is an effective anti-inflammatory drug in inhibiting TGF-β, interleukins (IL-6 and IL-1β), and tumour necrosis factor-α (TNF-α). Thalidomide binds cereblon, a process that is involved in the proposed mechanism in specific cancers such as breast cancer, colon cancer, multiple myeloma, and lung cancer. Cereblon is involved in activating AMP-activated protein kinase (AMPK)-TGF-β/Smad signalling, thereby attenuating fibrosis. The past few years have witnessed an improvement in the identification of biomarkers and diagnostic technologies in respiratory diseases, partly because of the COVID-19 pandemic. Hence, investment in clinical trials with a systematic plan can help repurpose thalidomide for pulmonary fibrosis.

Tranexamic acid may be a useful pharmacotherapy for endoscopically resistant small bowel angiodysplasia

Small bowel angiodysplasia (SBAD) is reported to account for nearly 50% of cases of small bowel bleeding. When SBAD occurs frequently, it is difficult to treat all the angiodysplasias endoscopically, and gastrointestinal bleeding often recurs. Hormone therapy, somatostatin analogs, thalidomide and vascular endothelial growth factor (VEGF)-neutralizing antibodies have been reported to reduce gastrointestinal angiodysplasia (GIAD) bleeding. However, there is no strong evidence to recommend them. Also, there are no guidelines for their use. Hereditary hemorrhagic telangiectasia (HHT) is a hereditary disease caused by abnormalities in VEGF, resulting in multiple GIADs. A treatment guideline has been created for GIAD in HHT, and the use of tranexamic acid, an antifibrinolytic agent, is the first recommendation pharmacotherapy for GIAD with gastrointestinal bleeding that is difficult to treat endoscopically. It has been reported that fibrinolysis is accelerated in GIAD patients who are not HHT, similar to HHT patients. The use of tranexamic acid for gastric antral vascular ectasia in GIAD has been reported to be useful. However, there are very few reports of its use for SBAD. There are concerns with tranexamic acid use regarding the development of thrombosis/embolism, but there are few reports of such side effects. Future clinical trials including tranexamic acid for SBAD are desired.

Progress of EGFL6 in angiogenesis and tumor development

The epidermal growth factor (EGF) superfamily includes the protein 6 with an epidermal growth factor-like protein (EGFL6). EGFL6 has a signal peptide domain with an amino terminus and a MAM domain with a carboxy terminus. There are four whole EGF-like repeat regions and one partial EGF-like repeat region. Three of these regions include calcium-binding structures and an arg-gly-asp (RGD) integrin interaction motif. The epidermal growth factor-like (EGFL) and EGF domains have identical amino acid residues. Cell division, differentiation, mortality, cell adhesion, and migration are all affected by EGFL6. EGFL proteins are involved in a broad range of biological activities, making it important in tumor development and angiogenesis. We highlighted the latest development of EGFL6 research on tumor proliferation, invasion, and migration in this review.

EGFL6 regulates angiogenesis and osteogenesis in distraction osteogenesis via Wnt/β-catenin signaling

Background

Osteogenesis is tightly coupled with angiogenesis during bone repair and regeneration. However, the underlying mechanisms linking these processes remain largely undefined. The present study aimed to test the hypothesis that epidermal growth factor-like domain-containing protein 6 (EGFL6), an angiogenic factor, also functions in bone marrow mesenchymal stem cells (BMSCs), playing a key role in the interaction between osteogenesis and angiogenesis.

Methods

We evaluated how EGFL6 affects angiogenic activity of human umbilical cord vein endothelial cells (HUVECs) via proliferation, transwell migration, wound healing, and tube-formation assays. Alkaline phosphatase (ALP) and Alizarin Red S (AR-S) were used to assay the osteogenic potential of BMSCs. qRT-PCR, western blotting, and immunocytochemistry were used to evaluate angio- and osteo-specific markers and pathway-related genes and proteins. In order to determine how EGFL6 affects angiogenesis and osteogenesis in vivo, EGFL6 was injected into fracture gaps in a rat tibia distraction osteogenesis (DO) model. Radiography, histology, and histomorphometry were used to quantitatively evaluate angiogenesis and osteogenesis.

Results

EGFL6 stimulated both angiogenesis and osteogenic differentiation through Wnt/β-catenin signaling in vitro. Administration of EGFL6 in the rat DO model promoted CD31^hiEMCN^hi type H-positive capillary formation associated with enhanced bone formation. Type H vessels were the referred subtype involved during DO stimulated by EGFL6.

Conclusion

EGFL6 enhanced the osteogenic differentiation potential of BMSCs and accelerated bone regeneration by stimulating angiogenesis. Thus, increasing EGFL6 secretion appeared to underpin the therapeutic benefit by promoting angiogenesis-coupled bone formation. These results imply that boosting local concentrations of EGFL6 may represent a new strategy for the treatment of compromised fracture healing and bone defect restoration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02487-3.

Multiple toxicity of propineb in developing zebrafish embryos: Neurotoxicity, vascular toxicity, and notochord defects in normal vertebrate development

A dithiocarbamate (DTC) fungicide, propineb, affects thyroid function and exerts immunotoxicity, cytotoxicity, and neurotoxicity in humans. Long-term exposure to propineb is associated with carcinogenicity, teratogenicity, malfunction of the reproductive system, and abnormalities in vital signs during organ development. However, there is no evidence of acute toxicity attributable to propineb in zebrafish. Therefore, in the present study, we assessed the toxicity of propineb in zebrafish by studying its adverse effects on embryo development, angiogenesis, and notochord development. Embryos with propineb exposure developed morphological and physiological defects and in larvae, apoptosis and notochord defects were induced in the early development stage. Transgenic fli1:eGFP zebrafish exposed to propineb showed abnormal larval development with defects in angiogenesis and deformed vasculature. Propineb induced irreversible damage to the neural development of embryos and neurogenic defects in developing zebrafish in transgenic olig2:dsRED zebrafish. These results show that exposure to propineb triggers abnormalities in different organ systems of zebrafish and suggests the physiological complexity of the response to propineb.

Dynamic Enhancement Pattern on CT for Predicting Pancreatic Neuroendocrine Neoplasms with Low PAX6 Expression: A Retrospective Observational Study

Paired box 6 (PAX6) is a transcription factor that plays a critical role in tumor suppression, implying that the downregulation of PAX6 promotes tumor growth and invasiveness. This study aimed to examine dynamic computed tomography (CT) features for predicting pancreatic neuroendocrine neoplasms (Pan-NENs) with low PAX6 expression. We retrospectively evaluated 51 patients with Pan-NENs without synchronous liver metastasis to assess the pathological expression of PAX6. Two radiologists analyzed preoperative dynamic CT images to determine morphological features and enhancement patterns. We compared the CT findings between low and high PAX6 expression groups. Pathological analysis identified 11 and 40 patients with low and high PAX6 expression, respectively. Iso- or hypoenhancement types in the arterial and portal phases were significantly associated with low PAX6 expression (p = 0.009; p = 0.001, respectively). Low PAX6 Pan-NENs showed a lower portal enhancement ratio than high PAX6 Pan-NENs (p = 0.044). The combination based on enhancement types (iso- or hypoenhancement during arterial and portal phases) and portal enhancement ratio (≤1.22) had 54.5% sensitivity, 92.5% specificity, and 84.3% accuracy in identifying low PAX6 Pan-NENs. Dynamic CT features, including iso- or hypoenhancement types in the arterial and portal phases and lower portal enhancement ratio may help predict Pan-NENs with low PAX6 expression.