CXCL5 is required for angiogenesis, but not structural adaptation after small bowel resection

ALK1 Signaling in Human Cardiac Progenitor Cells Promotes a Pro-angiogenic Secretome

Pro-angiogenic paracrine/autocrine signaling impacts myocardial repair in cell-based therapies. Activin A receptor-like type 1 (ACVRL1, ALK1) signaling plays a pivotal role in cardiovascular development and maintenance, but its importance in human-derived therapeutic cardiac cells is not well understood. Here, we isolated a subpopulation of human highly proliferative cells (hHiPCs) from adult epicardial tissue and found that they express ALK1, a high affinity receptor for bone morphogenetic protein-9 (BMP9), which signals via SMAD1/5 to regulate paracrine/autocrine signaling and angiogenesis. We show that in humans, circulating BMP9 level is negatively associated with the number of epicardial hHiPC and positively associated with endothelial cell (EC) number in the adult heart, implicating the potential importance of this signaling pathway in cardiac cell fate and vascular maintenance. To investigate BMP9/ALK1 signaling in hHiPCs, we selected a primary cell population of hHiPC from each of 3 individuals and studied their responses to BMP9 and BMP10 treatment in vitro. Proteins were collected in conditioned media (CM) for mass spectrometry and cell-based assays on human ECs and hHiPCs. Proteomic analysis of the hHiPC secretome following BMP9 or BMP10 treatment demonstrates that the secreted proteins, sclerostin (SOST), meflin/immunoglobulin superfamily containing leucine rich repeat (ISLR), and insulin-like growth factor binding protein-3 (IGFBP3), are novel regulated targets of BMP9/ALK1 signaling. Lentiviral shRNA and pharmacological inhibition of ALK1 in hHiPCs suppressed transcription and secretion of SOST, ISLR, and IGFBP3 following BMP9 treatment. Moreover, the BMP9-treated secretome of hHiPC increased capillary-like tube formation of ECs and hHiPCs. Treatment of hHiPCs with recombinant SOST increased VEGF-a expression, increased tube formation and enhanced expression of EC receptor marker annexin A2 (ANXA2). These data provide the first proteomic characterization of hHiPC, identifying BMP9/ALK1-mediated target protein secretion in hHiPCs, and underscore the complex role of BMP9/ALK1 signaling in paracrine/autocrine mediated angiogenesis. Data are available via ProteomeXchange with identifier PXD055302.

CXCL5 and CXCL14, but not CXCL16 as potential biomarkers of colorectal cancer

Experts emphasize that colorectal cancer (CRC) incidence and mortality are increasing. That is why its early detection is of the utmost importance. Patients with cancer diagnosed in earlier stages have a better prognosis and a chance for faster implementation of treatment. Consequently, it is vital to search for new parameters that could be useful in its diagnosis. Therefore, we evaluated the usefulness of CXCL5, CXCL14 and CXCL16 in serum of 115 participants (75 CRC patients and 40 healthy volunteers). Concentrations of all parameters were measured using Luminex. CRP (C-reactive protein) levels were determined by immunoturbidimetry, while levels of classical tumor markers were measured using CMIA (Chemiluminescence Microparticle Immunoassay). Concentrations of CXCL5 were statistically higher in the CRC group when compared to healthy controls. The diagnostic sensitivity, specificity, positive and negative predictive value, and area under the ROC curve (AUC) of CXCL5 and CXCL14 were higher than those of CA 19-9. Obtained results suggest the usefulness of CXCL5 and CXCL16 in the determination of distant metastases and differentiation between TNM (Tumor-Node-Metastasis) stages, as well as the usefulness of CXCL14 and CRP combination in CRC detection (primary or recurrence). However, further studies concerning their role in CRC progression are crucial to confirm and explain their diagnostic utility and clinical application as biomarkers.

Chemokine signaling in cancer-stroma communications

Cancer is a multi-faceted disease in which spontaneous mutation(s) in a cell leads to the growth and development of a malignant new organ that if left undisturbed will grow in size and lead to eventual death of the organism. During this process, multiple cell types are continuously releasing signaling molecules into the microenvironment, which results in a tangled web of communication that both attracts new cell types into and reshapes the tumor microenvironment as a whole. One prominent class of molecules, chemokines, bind to specific receptors and trigger directional, chemotactic movement in the receiving cell. Chemokines and their receptors have been demonstrated to be expressed by almost all cell types in the tumor microenvironment, including epithelial, immune, mesenchymal, endothelial, and other stromal cells. This results in chemokines playing multifaceted roles in facilitating context-dependent intercellular communications. Recent research has started to shed light on these ligands and receptors in a cancer-specific context, including cell-type specificity and drug targetability. In this review, we summarize the latest research with regards to chemokines in facilitating communication between different cell types in the tumor microenvironment.

Corneal angiogenic privilege and its failure

The cornea actively maintains its own avascular status to preserve its ultimate optical function. This corneal avascular state is also defined as "corneal angiogenic privilege", which results from a critical and sensitive balance between anti-angiogenic and pro-angiogenic mechanisms. In our review, we aim to explore the complex equilibrium among multiple mediators which prevents neovascularization in the resting cornea, as well as to unveil the evolutive process which leads to corneal angiogenesis in response to different injuries.

EGFR in enterocytes & endothelium and HIF1α in enterocytes are dispensable for massive small bowel resection induced angiogenesis

Background

Short bowel syndrome (SBS) results from significant loss of small intestinal length. In response to this loss, adaptation occurs, with Epidermal Growth Factor Receptor (EGFR) being a key driver. Besides enhanced enterocyte proliferation, we have revealed that adaptation is associated with angiogenesis. Further, we have found that small bowel resection (SBR) is associated with diminished oxygen delivery and elevated levels of hypoxia-inducible factor 1-alpha (HIF1α).

Methods

We ablated EGFR in the epithelium and endothelium as well as HIF1α in the epithelium, ostensibly the most hypoxic element. Using these mice, we determined the effects of these genetic manipulations on intestinal blood flow after SBR using photoacoustic microscopy (PAM), intestinal adaptation and angiogenic responses. Then, given that endothelial cells require a stromal support cell for efficient vascularization, we ablated EGFR expression in intestinal subepithelial myofibroblasts (ISEMFs) to determine its effects on angiogenesis in a microfluidic model of human small intestine.

Results

Despite immediate increased demand in oxygen extraction fraction measured by PAM in all mouse lines, were no differences in enterocyte and endothelial cell EGFR knockouts or enterocyte HIF1α knockouts by POD3. Submucosal capillary density was also unchanged by POD7 in all mouse lines. Additionally, EGFR silencing in ISEMFs did not impact vascular network development in a microfluidic device of human small intestine.

Conclusions

Overall, despite the importance of EGFR in facilitating intestinal adaptation after SBR, it had no impact on angiogenesis in three cell types–enterocytes, endothelial cells, and ISEMFs. Epithelial ablation of HIF1α also had no impact on angiogenesis in the setting of SBS.

Angiogenic effect of platelet-rich concentrates on dental pulp stem cells in inflamed microenvironment

OBJECTIVE

In this study, we aimed to determine the suitable concentrations of human platelet lysate (HPL) and platelet-rich plasma (PRP) for maintaining the in vitro proliferative and angiogenic potential of inflamed dental pulp stem cells.

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-induced inflamed dental pulp-derived stem cells (iDPSCs) were treated with different concentrations of HPL and PRP (10% and 20%) followed by determination of viability using Alamar Blue assay. Expression of angiogenesis-, adhesion-, and inflammation-regulating genes was also analyzed using RT-qPCR array. Furthermore, expression of growth factors at protein level in the cell culture microenvironment was measured using multiplex assay.

RESULTS

Viability of iDPSCs was significantly (p < 0.05) higher in 20% HPL-supplemented media compared to iDPSCs. Expression of 10 out of 12 selected angiogenic genes, four out of seven adhesion molecules, and seven out of nine cytokine-producing genes were significantly (p < 0.05) higher in cells maintained in 20% HPL-supplemented media compared to that in FBS-supplemented media. Furthermore, expression of all the selected growth factors was significantly higher (p < 0.05) in the supernatants from 20% HPL media at 12 and 24 h post-incubation.

CONCLUSION

This study suggests that 20% HPL could be optimum to stimulate angiogenesis-related factors in iDPSCs while maintaining their viability.

CLINICAL RELEVANCE

This data may suggest the potential use of 20% HPL for expanding DPSCs scheduled for clinical trials for regenerative therapies including dental pulp regeneration.

Selective IKK2 inhibitor IMD0354 disrupts NF-κB signaling to suppress corneal inflammation and angiogenesis

Corneal neovascularization is a sight-threatening condition caused by angiogenesis in the normally avascular cornea. Neovascularization of the cornea is often associated with an inflammatory response, thus targeting VEGF-A alone yields only a limited efficacy. The NF-κB signaling pathway plays important roles in inflammation and angiogenesis. Here, we study consequences of the inhibition of NF-κB activation through selective blockade of the IKK complex IκB kinase β (IKK2) using the compound IMD0354, focusing on the effects of inflammation and pathological angiogenesis in the cornea. In vitro, IMD0354 treatment diminished HUVEC migration and tube formation without an increase in cell death and arrested rat aortic ring sprouting. In HUVEC, the IMD0354 treatment caused a dose-dependent reduction in VEGF-A expression, suppressed TNFα-stimulated expression of chemokines CCL2 and CXCL5, and diminished actin filament fibers and cell filopodia formation. In developing zebrafish embryos, IMD0354 treatment reduced expression of Vegf-a and disrupted retinal angiogenesis. In inflammation-induced angiogenesis in the rat cornea, systemic selective IKK2 inhibition decreased inflammatory cell invasion, suppressed CCL2, CXCL5, Cxcr2, and TNF-α expression and exhibited anti-angiogenic effects such as reduced limbal vessel dilation, reduced VEGF-A expression and reduced angiogenic sprouting, without noticeable toxic effect. In summary, targeting NF-κB by selective IKK2 inhibition dampened the inflammatory and angiogenic responses in vivo by modulating the endothelial cell expression profile and motility, thus indicating an important role of NF-κB signaling in the development of pathologic corneal neovascularization.

Transcriptome analysis of human colorectal cancer biopsies reveals extensive expression correlations among genes related to cell proliferation, lipid metabolism, immune response and collagen catabolism

Precise characterization of biological processes critical to proliferation and metastasis of colorectal cancer should facilitate the development of diagnostic and prognostic biomarkers as well as novel treatments. Using mRNA-Seq, we examined the protein coding messenger RNA (mRNA) expression profiles across different histologically defined stages of primary colon cancers and compared them to their patient matched normal tissue controls. In comparing 79 colorectal cancers to their matched normal mucosa, tumors were distinguished from normal non-malignant tissues not only in the upregulation of biological processes pertaining to cell proliferation, inflammation, and tissue remodeling, but even more strikingly, in downregulated biological processes including fatty acid beta oxidization for ATP production and epithelial cell differentiation and function. A network analysis of deregulated genes revealed newly described cancer networks and putative hub genes.

Taken together, our findings suggest that, within an inflammatory microenvironment, invasive, dedifferentiated and rapidly dividing tumor cells divert the oxidation of fatty acids and lipids from energy production into lipid components of cell membranes and organelles to support tumor proliferation. A gene co-expression network analysis provides a clear and broad picture of biological pathways in tumors that may significantly enhance or supplant current histopathologic studies.

CXCL5 Plays a Promoting Role in Osteosarcoma Cell Migration and Invasion in Autocrine- and Paracrine-Dependent Manners

CXCL5, a CXC-type chemokine, is an important attractant for granulocytic immune cells by binding to its receptor CXCR2. Recently, CXCL5/CXCR2 has been found to play an oncogenic role in many human cancers. However, the exact role of CXCL5 in osteosarcoma cell migration and invasion has not been revealed. Here we found that the protein expression of CXCL5 was significantly increased in osteosarcoma tissues compared with that in matched adjacent nontumor tissues. Moreover, the expression of CXCL5 was significantly associated with advanced clinical stage and metastasis. Further investigation showed that the CXCL5 expression levels were also significantly increased in osteosarcoma cell lines, including Saos-2, MG63, U2OS, and SW1353, when compared with those in normal osteoblast hFoB1.19 cells. U2OS cells were further transfected with CXCL5-specific siRNA or overexpression plasmid. Knockdown of CXCL5 significantly suppressed U2OS cell migration and invasion. On the contrary, overexpression of CXLC5 remarkably promoted the migration and invasion of U2OS cells. Interestingly, both exogenous CXCL5 treatment and the conditioned medium of CXCL5-overexpressing hFoB1.19 cells could also enhance the migration and invasion of U2OS cells, suggesting that the promoting role of CXCL5 in U2OS cell migration and invasion is also in a paracrine-dependent manner. According to these data, our study demonstrates that CXCL5 is upregulated in osteosarcoma and may play an oncogenic role in osteosarcoma metastasis. Therefore, CXCL5 may become a potential therapeutic target for osteosarcoma treatment.

CXCL5 promotes the proliferation and migration of glioma cells in autocrine- and paracrine-dependent manners

CXCL5 and its receptor CXCR2 have been found to be involved in tumorigenesis and cancer progression. Recent studies have shown that CXCR2 is upregulated in glioma tissues, and associated with poor prognosis and recurrence. However, the role of CXCL5/CXCR2 signaling in mediating the malignant phenotypes of glioma cells, as well as the underlying mechanism, still remains unclear. In the present study, we found that CXCL5 was upregulated in glioma tissues compared to that noted in normal brain tissues. High CXCL5 levels were significantly associated with higher tumor grade, advanced clinical stage, and shorter survival time of glioma patients. In vitro studies indicated that the protein expression levels of CXCL5 and CXCR2 were markedly higher in human glioma cell lines (U87, U251, U373 and A172), when compared with those in normal human gliocyte HEB cells. Overexpression of CXLC5 significantly promoted the proliferation and migration of U87 cells, while knockdown of CXCL5 by small interfering RNA markedly inhibited U87 cell proliferation and migration. Moreover, both exogenous CXCL5 treatment and the conditioned medium of CXCL5-overexpressing HEB cells also enhanced the proliferation and migration of U87 cells. Molecular mechanism investigation revealed that CXLC5 activated the ERK, JNK, p38 MAPK signaling pathways, which play key roles in tumor growth and metastasis. According to these data, our study suggests that CXCL5 plays a promoting role in glioma in autocrine- and paracrine-dependent manners.

Nutritional strategies to enhance adaptation in intestinal failure

PURPOSE OF REVIEW

This article summarizes the current and potential future nutritional approaches to stimulate adaptation in intestinal failure. Adaptation in this context usually refers to intestinal adaptation but also involves changes in whole body physiology as well as in eating/drinking behavior.

RECENT FINDINGS

Adaptation largely depends on residual functional anatomy. Luminal exposure to complex nutrients is the most important trigger for intestinal adaptation. Enteral fat as well as enteral or parenteral short chain fatty acids have a specific stimulatory effect. Zinc and vitamin A status need to be optimized for adaptation to proceed and be maintained. In the context of maintaining sodium and water homeostasis, flushing the remnant intestine because of uncontrolled thirst/drinking must be avoided. Complications of nutritional care such as malnutrition, intestinal failure-associated liver disease, and recurrent line sepsis also need optimal management.

SUMMARY

Stimulation by luminal nutrients as well as prophylaxis against and treatment of (nutritional) complications are the cornerstones of adaptation to the short bowel situation. Based on ample data from animal studies but only limited evidence in humans specific nutritional stimulators need to be studied more rigorously. As long as such data are missing they can be tried on an individual basis.

Increased plasma levels of epithelial neutrophil-activating peptide 78/CXCL5 during the remission of Neuromyelitis optica

BACKGROUND

In neuromyelitis optica (NMO), one of the underlying pathogenic mechanisms is the formation of antigen-antibody complexes which can trigger an inflammatory response by inducing the infiltration of neutrophils in lesions. Epithelial neutrophil-activating peptide 78 (ENA 78), known as Chemokine (C-X-C motif) ligand 5 (CXCL5), belongs to the ELR-CXCL family. It recruits and activates neutrophils. The aim of this study was to evaluate ENA 78, IL-1β and TNF-α plasma levels in multiple sclerosis (MS) and neuromyelitis optica (NMO) patients.

METHODS

ENA 78, IL-1β and TNF-α plasma levels were detected in 20 healthy controls (HC), 25 MS and 25 NMO patients using MILLIPLEX® map Human High Sensitivity Cytokine/Chemokine Panels.

RESULTS

Plasma levels of ENA 78 were significantly higher in NMO patients than in HC (P < 0.001) and MS patients (P < 0.05). The NMO patients showed higher plasma levels of IL-1β compared with HC (P < 0.01). Further, increased plasma levels of TNF-α were found in the MS (P < 0.05) and NMO patients (P < 0.001). In addition, NMO patients had higher Expanded Disability Status Scale (EDSS) scores compared with MS patients (P < 0.05). EDSS scores were correlated with plasma levels of ENA 78 in NMO patients (P < 0.05). There were no significant correlations between EDSS scores and plasma levels of ENA 78 in MS patients (P > 0.05).

CONCLUSIONS

The overproduction of pro-inflammatory cytokines such as IL-1β and TNF-α during the remission of NMO activates ENA 78, which in turn leads to neutrophil infiltration in lesions. ENA 78 plasma levels were correlated with EDSS scores in NMO patients. Elevated secretion of ENA 78 may be a critical step in neutrophil recruitment during the remission of NMO.

The Pathogenesis of Resection-Associated Intestinal Adaptation

After massive small-bowel resection, the remnant bowel compensates by a process termed adaptation. Adaptation is characterized by villus elongation and crypt deepening, which increases the capacity for absorption and digestion per unit length. The mechanisms/mediators of this important response are multiple. The purpose of this review is to highlight the major basic contributions in elucidating a more comprehensive understanding of this process.

Both epidermal growth factor and insulin-like growth factor receptors are dispensable for structural intestinal adaptation

PURPOSE

Intestinal adaptation structurally represents increases in crypt depth and villus height in response to small bowel resection (SBR). Previously, we found that neither epidermal growth factor receptor (EGFR) nor insulin-like growth factor 1 receptor (IGF1R) function was individually required for normal adaptation. In this study, we sought to determine the effect of disrupting both EGFR and IGF1R expression on resection-induced adaptation.

METHODS

Intestinal-specific EGFR and IGF1R double knockout mice (EGFR/IGF1R-IKO) (n=6) and wild-type (WT) control mice (n=7) underwent 50% proximal SBR. On postoperative day (POD) 7, structural adaptation was scored by measuring crypt depth and villus height. Rates of crypt cell proliferation, apoptosis, and submucosal capillary density were also compared.

RESULTS

After 50% SBR, normal adaptation occurred in both WT and EGFR/IGF1R-IKO. Rates of proliferation and apoptosis were no different between the two groups. The angiogenic response was less in the EGFR/IGF1R-IKO compared to WT mice.

CONCLUSION

Disrupted expression of EGFR and IGF1R in the intestinal epithelial cells does not affect resection-induced structural adaptation but attenuates angiogenesis after SBR. These findings suggest that villus growth is driven by receptors and pathways that occur outside the epithelial cell component, while angiogenic responses may be influenced by epithelial-endothelial crosstalk.

The effect of impaired angiogenesis on intestinal function following massive small bowel resection

PURPOSE

Intestinal adaptation involves villus lengthening, crypt deepening, and increased capillary density following small bowel resection (SBR). Mice lacking the proangiogenic chemokine CXCL5 have normal structural adaptation but impaired angiogenesis. This work evaluates the impact of incomplete adaptive angiogenesis on the functional capacity of the intestine after SBR.

METHODS

CXCL5 knockout (KO) and C57BL/6 wild-type (WT) mice underwent 50% SBR. Magnetic resonance imaging measured weekly body composition. Intestinal absorptive capacity was evaluated through fecal fat analysis. Gene expression profiles for select macronutrient transporters were measured via RT-PCR. Postoperative crypt and villus measurements were assessed for structural adaptation. Submucosal capillary density was measured through CD31 immunohistochemistry.

RESULTS

Comparable postoperative weight gain occurred initially. Diminished weight gain, impaired fat absorption, and elevated steatorrhea occurred in KO mice after instituting high-fat diet. Greater postoperative upregulation of ABCA1 fat transporter occurred in WT mice, while PEPT1 protein transporter was significantly downregulated in KO mice. KO mice had impaired angiogenesis but intact structural adaptation.

CONCLUSION

After SBR, KO mice display an inefficient intestinal absorption profile with perturbed macronutrient transporter expression, impaired fat absorption, and slower postoperative weight gain. In addition to longer villi and deeper crypts, an intact angiogenic response may be required to achieve functional adaptation to SBR.