Milk Fat Globule-epidermal Growth Factor Research Articles

MFG-E8 regulated by miR-99b-5p protects against osteoarthritis by targeting chondrocyte senescence and macrophage reprogramming via the NF-\u03baB pathway

Milk fat globule-epidermal growth factor (EGF) factor 8 (MFG-E8), as a necessary bridging molecule between apoptotic cells and phagocytic cells, has been widely studied in various organs and diseases, while the effect of MFG-E8 in osteoarthritis (OA) remains unclear. Here, we identified MFG-E8 as a key factor mediating chondrocyte senescence and macrophage polarization and revealed its role in the pathology of OA. We found that MFG-E8 expression was downregulated both locally and systemically as OA advanced in patients with OA and in mice after destabilization of the medial meniscus surgery (DMM) to induce OA. MFG-E8 loss caused striking progressive articular cartilage damage, synovial hyperplasia, and massive osteophyte formation in OA mice, which was relieved by intra-articular administration of recombinant mouse MFG-E8 (rmMFG-E8). Moreover, MFG-E8 restored chondrocyte homeostasis, deferred chondrocyte senescence and reprogrammed macrophages to the M2 subtype to alleviate OA. Further studies showed that MFG-E8 was inhibited by miR-99b-5p, expression of which was significantly upregulated in OA cartilage, leading to exacerbation of experimental OA partially through activation of NF-κB signaling in chondrocytes. Our findings established an essential role of MFG-E8 in chondrocyte senescence and macrophage reprogramming during OA, and identified intra-articular injection of MFG-E8 as a potential therapeutic target for OA prevention and treatment.

MFGE8 mitigates brain injury in a rat model of SAH by maintaining vascular endothelial integrity via TIGβ5/PI3K/CXCL12 signaling.

Leaked blood components, injured endothelial cells, local inflammatory response and vasospasm may converge to promote microthrombosis following subarachnoid hemorrhage (SAH). Previously, we showed that the milk fat globule-epidermal growth factor 8 (MFGE8) can mitigate SAH-induced microthrombosis. This present study was aimed to explore the molecular pathway participated in MFGE8-dependent protection on vascular endothelium. Immunofluorescence, immunoblot and behavioral tests were used to determine the molecular partner and signaling pathway mediating the effect of MFGE8 in vascular endothelium in rats with experimental SAH and controls, together with the applications of RNA silencing and pharmacological intervention methods. Relative to control, recombinant human MFGE8 (rhMFGE8) treatment increased 5-bromo-2'-deoxyuridine (BrdU) labeled new endothelial cells, reduced TUNUL-positive endothelial cells and elevated the expression of phosphatidylinositol 3-kinase (PI3K) and chemokine (C-X-C motif) ligand 12 (CXCL12), in the brains of SAH rats. These effects were reversed by MFGE8 RNA silencing, as well as following cilengitide and wortmannin intervention. These results suggest that MFGE8 promotes endothelial regeneration and mitigates endothelial DNA damage through the activation of the TIGβ5/PI3K/CXCL12 signaling pathway.

Clinical implications of milk fat globule-epidermal growth factor 8 (MFG-E8) and vitamin D levels in patients with rheumatoid arthritis and primary knee osteoarthritis

Aimof the work to determine serum levels of vitamin D and Milk fat globule-epidermal growth factor 8 (MFG-E8) in rheumatoid arthritis (RA) and primary knee osteoarthritis (OA) compared to healthy controls and their possible associations. Patients and methods: The study included 30 RA and 30 primary knee OA patients as well as 25 control. The disease activity was measured by disease activity score 28 (DAS28) in RA. The functional status was estimated by Western Ontario and McMaster Universities index (WOMAC index) in OA. While the assessment of pain was measured by the visual analog scale (VAS) in both RA and OA. Serum vitamin D and MFG-E8 levels were measured using enzyme-linked immunosorbent assay (ELISA). Results: The mean age of RA patients was 41.1 ± 9.2 years; 25 females and 5 males (F:M 5:1) and a disease duration of 6.9 ± 4.6 years. The mean age of OA patients was 48.7 ± 8.3 years; 28 females and 2 males (F:M 14:1) and disease duration was 5.4 ± 3.3 years. The mean vitamin D was significantly lower in RA (9.7 ± 5.04 ng/ml) than OA (16.4 ± 4 ng/ml) and controls (17.7 ± 3.4 ng/ml), p < 0.0001. The mean MFG-E8 serum level was significantly lower in RA and OA patients (4.9 ± 2.4 ng/mland 5.3 ± 1.2 ng/ml) than in controls (9.1 ± 3 ng/ml), p < 0.0001.Vitamin D significantly correlated with MFG-E8 (r = 0.6, p = 0.002) in RA and both inversely correlated with DAS28 (r = -0.66, p < 0.0001 and r = -0.58, p < 0.0001 respectively). Vitamin D (9.7 ng/ml) and MFG-E8 (4.9 ng/ml) significantly predicted RA (p < 0.0001) at specificity (100%) and sensitivity (66.7%). MFG-E8 at cut-off 5.3 ng/ml significantly predicted OA at specificity of 88% and sensitivity 86.7%.Conclusion: An association between low serum vitamin D and MFG-E8 levels with RA and the disease activity has been determined. Low MFG-E8 was associated with OA.

Relationship Between Milk Fat Globule-Epidermal Growth Factor 8 and Intestinal Cytokines in Infants Born Preterm

To investigate the relationships between dietary intake and fecal concentrations of milk fat globule-epidermal growth factor 8 (MFG-E8), and between fecal concentrations of MFG-E8 and markers of intestinal inflammation in infants born preterm. Fecal samples were collected daily and enteral feedings were sampled weekly. MFG-E8 in enteral feedings and feces, and cytokine concentrations in feces were quantified by enzyme-linked immunosorbent assay. Milk MFG-E8 concentrations were significantly greater in unfortified mother's own milk (MOM) and MOM with human milk fortifier than either donor human milk or preterm formula. MFG-E8 concentrations in fecal samples were positively correlated with MFG-E8 concentrations in respective milks. High MFG-E8 exposure (≥60mL/kg/day of feedings that include MOM or MOM with human milk fortifier) was associated with lower concentrations of proinflammatory cytokines (interleukin-8, tumor necrosis factor-α, and monocyte chemoattractant protein-1) and higher concentrations of the anti-inflammatory cytokine interleukin-4 in feces, compared with low MFG-E8 exposure. Infants born preterm who were fed MOM had greater concentrations of MFG-E8 and lower concentrations of proinflammatory cytokines in fecal samples than other diets or no feedings. These data further support the protective role of MOM, possibly because of MFG-E8, against intestinal inflammation.

An injectable recombinant human milk fat globule–epidermal growth factor 8–loaded copolymer system for spinal cord injury reduces inflammation through NF-κB and neuronal cell death

Spinal cord injury (SCI) is a common disease and a major cause of paralysis, carrying much burden around the world. Despite the progress made with growth factors therapy, the response rate of acute SCI treatment still remains unsatisfactory, due largely to complex and severe inflammatory reactions. Herein, we prepare a MFG-E8–loaded copolymer system–based anti-inflammation therapy for SCI treatment. It is shown that the MFG-E8–loaded copolymer system can decrease pro-inflammatory cytokine expression and neuron death. In a rat model of crush-caused SCI, the copolymer system shows significant therapeutic efficacy by ameliorating inflammation, decreasing fibrotic scar, promoting myelin regeneration and suppressing overall SCI severity.

Milk Fat Globule-Epidermal Growth Factor VIII Ameliorates Brain Injury in the Subacute Phase of Cerebral Ischemia in an Animal Model.

ObjectiveMilk fat globule-epidermal growth factor VIII (MFG-E8) may play a key role in inflammatory responses and has the potential to function as a neuroprotective agent for ameliorating brain injury in cerebral infarction. This study aimed to determine the role of MFG-E8 in brain injury in the subacute phase of cerebral ischemia in a rat model. MethodsFocal cerebral ischemia was induced in rats by occluding the middle cerebral artery with the modified intraluminal filament technique. Twenty-four hours after ischemia induction, rats were randomly assigned to two groups and treated with either recombinant human MFG-E8 or saline. Functional outcomes were assessed using the modified Neurological Severity Score (mNSS), and infarct volumes were evaluated using histology. Anti-inflammation, angiogenesis, and neurogenesis were assessed using immunohistochemistry with antibodies against ionized calcium-binding adapter molecule 1 (Iba-1), rat endothelial cell antigen-1 (RECA-1), and bromodeoxyuridine (BrdU)/doublecortin (DCX), respectively. ResultsOur results showed that intravenous MFG-E8 treatment did not reduce the infarct volume; however, the mNSS test revealed that neurobehavioral deficits were significantly improved in the MFG-E8-treated group than in the vehicle group. Immunofluorescence staining revealed a significantly lower number of Iba-1-positive cells and higher number of RECA-1 in the peri-infarcted brain region, and significantly higher numbers of BrdU- and DCX-positive cells in the subventricular zone in the MFG-E8-treated group than in the vehicle group. ConclusionOur findings suggest that MFG-E8 improves neurological function by suppressing inflammation and enhancing angiogenesis and neuronal proliferation in the subacute phase of cerebral infarction.

A rare missense variant in the milk fat globule-EGF factor 8 (MFGE8) increases T2DM susceptibility and cardiovascular disease risk with population-specific effects.

The milk fat globule-epidermal growth factor 8 (MFGE8), also called lactadherin, is an integrin ligand and a known mediator of inflammation and atherosclerosis in T2DM in studies using animal models. However, its role in the pathophysiology of human T2DM, obesity, and cardiovascular disease has been poorly explored. Aim of thisstudy was toinvestigate the role ofa missense variant (rs371227978 C/T: Arg148His) in the MFGE8 gene identified through exome sequencing for its association with T2DM and cardiometabolic traits. Exome-wide sequencing was performed using DNA samples from 68 Sikh individuals from multi-generation pedigrees affected with diabetes onIllumina's GAIIx using "SureSelect Human All Exon" panels. We further replicated this variant by de novo genotyping in a total of 4242 individuals of the Asian Indian Diabetic Heart Study/Sikh Diabetes Study using custom TaqMan genotyping assay. We also measured circulating concentrations of Mfge8 using frozen serum aliquots by enzyme-linked immunosorbent assay. Overall, only 1.78% of 4242 individuals were carriers of this variant with MAF being 0.009. Except for the significant correlation of this variant with T2DM and triglycerides, no other quantitative risk phenotype was significant. The minor per allele-associated increased risk for T2DM showed odds ratio of 1.95 (95% CI 1.18-3.23; p = 0.008) in unadjusted model and was 1.73 (95% CI 1.02-2.93; p = 0.043) after adjusting for the age, gender, and BMI. However, there was a strong correlation between serum Mfge8 concentrations with T2DM, (r2 = 0.38; p = 0.001), fasting glucose (r2= 0.36; p = 0.002), and triglycerides (r2 = 0.33; p = 0.005). Our data revealed a significant dose-related increase in MFGE8 genotypes for affecting serum Mfge8 (p = 2.1 × 10-3) and triglyceride concentrations (p = 3.2 × 10-3). For a per riskallele-associated increase of 4.74ng/ml ± SD of 1.62ng/ml of the Mfge8 concentration was found to increase T2DM risk to 1.7 fold (95% CI from 1 to 3 fold). Here, we report for the first time a novel population-specific rare variant in the MFGE8 gene linked with the increased Mfge8 concentrations and the risk for developing T2DM and cardiovascular risk factors in a population of Punjabi Sikhs from India. In view of a strong evidence from animal studies supporting the role of Mfge8 in obesity, insulin resistance, and the development of atherosclerosis in T2DM, our findings are important and timely. If validated in a large independent dataset, early screening of Mfge8 in blood levels may especially benefit those patients with genetically elevated Mfge8 levels to preventing or reducing the risk of T2DM and cardiovascular disease.

Recombinant Human Milk Fat Globule-Epidermal Growth Factor 8 Attenuates Microthrombosis after Subarachnoid Hemorrhage in Rats

BackgroundMicrothrombosis after subarachnoid hemorrhage has an adverse effect on prognosis. Milk fat globule-epidermal growth factor 8 promotes phagocytosis of phagocytic cells and may reduce microthrombosis. This study investigated the effects of recombinant human milk fat globule-epidermal growth factor 8 on microthrombosis and neurological function after subarachnoid hemorrhage. MethodsRats subarachnoid hemorrhage model was induced by intravascular puncture method. Western blot was performed to measure the expression of endogenous milk fat globule-epidermal growth factor 8 after subarachnoid hemorrhage. Microthrombosis was quantified by microthrombi count using immunohistochemistry and immunofluorescence. The neuroprotective effect of recombinant human milk fat globule-epidermal growth factor 8 administration was evaluated by modified Garcia score, beam balance, Rotarod test, and Morris water maze. ResultsEndogenous milk fat globule-epidermal growth factor 8 protein level increased after subarachnoid hemorrhage. Microthrombosis was significantly increased in subarachnoid hemorrhage rats brain, while recombinant human milk fat globule-epidermal growth factor 8 dramatically reduced microthrombosis as well as improve short- and long- term neurobehavior after subarachnoid hemorrhage. ConclusionsRecombinant human milk fat globule-epidermal growth factor 8 reduces microthrombosis and improves neurological function after subarachnoid hemorrhage, which may be an effective strategy for treating subarachnoid hemorrhage.

P6010Deficiency in milk fat globule-epidermal growth factor 8 delays thrombus resolution

Abstract Background Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by the obstruction of pulmonary vessels by organized thrombotic and fibrotic lesions. Efferocytosis refers to the engulfment of apoptotic cells (ACs) by phagocytes, a process that is facilitated by bridging proteins. Milk fat globule-epidermal growth factor 8 (MFG-E8) connects phosphatidylserine on ACs with integrin alpha-v beta-III on phagocytes. MFG-E8-deficient mice develop auto-immune disease closely resembling systemic lupus erythematosus. In humans, decreased MFG-E8 levels were observed in patients with coronary heart disease and chronic obstructive pulmonary disease. Whether defective efferocytosis is involved in failure to resolve thrombi in CTEPH remains unknown. Purpose We aimed to assess whether deficiency in MFG-E8 is responsible for of chronic non-resolving thrombosis in CTEPH. Methods We employed a murine model of chronic thrombosis by inferior vena cava ligation, in MFG-E8 knockout (KO) or wild-type (WT) mice to assess thrombus formation and resolution. Thrombus size at days 3, 7, 14 and 28 after ligation was assessed using either histologic trichrome stainings (n=4–13 per group and time point) or in vivo high-frequency ultrasound (n=10 per group and time point). We furthermore recruited CTEPH patients (n=60, 53% female, mean age 56±11 years) and sex- and age-matched healthy controls for measurement of MFG-E8 plasma levels using ELISA. In CTEPH patients, hemodynamic measurements were performed. Human lung specimens harvested during surgery for CTEPH or from healthy controls, and isolated monocytes from whole blood of CTEPH patients or controls were analyzed using RT-qPCR. Results We observed substantially increased thrombus volume in MFG-E8 KO mice compared to WT, which persisted until day 14 after ligation. In human CTEPH patients, MFG-E8 in plasma was increased compared to healthy controls. Similarly, CTEPH monocytes displayed higher concentrations of MFG-E8 mRNA. Conversely, MFG-E8 expression of CTEPH pulmonary artery specimens was downregulated. No correlations between MFG-E8 levels and hemodynamic parameters were observed. Conclusion MFG-E8 plays an important role in thrombus resolution. In CTEPH, dysregulation of efferocytosis via impaired MFG-E8 expression in the pulmonary arteries, might drive persistence of thrombus in pulmonary arteries. The absence of a correlation between MFG-E8 and hemodynamic measures argues against pressure as a confounder of the observation.

Synovial fluid and plasma levels of milk fat globule-epidermal growth factor 8 are inversely correlated with radiographic severity of knee osteoarthritis.

ObjectiveMounting evidence demonstrates that inflammation plays an important role in the pathogenesis of osteoarthritis (OA). Milk fat globule–epidermal growth factor 8 (MFG-E8) is an important glycoprotein that is involved in anti-inflammatory responses. The present study was performed to assess the MFG-E8 levels in plasma and synovial fluid and explore the association between radiographic severity and MFG-E8 levels in patients with knee OA.MethodsThis study involved 138 healthy controls and 142 patients with knee OA. The MFG-E8 levels in plasma and synovial fluid were evaluated by enzyme-linked immunosorbent assay. The Kellgren and Lawrence classification was used for OA grading.ResultsThe plasma MFG-E8 level was significantly lower in patients with knee OA than in healthy controls. The synovial fluid MFG-E8 level was significantly lower than the plasma level in patients with knee OA. More importantly, the MFG-E8 levels in synovial fluid and plasma were significantly and inversely associated with radiographic severity among patients with knee OA.ConclusionsThese results demonstrate that the levels of MFG-E8 in synovial fluid and plasma are inversely correlated with the radiographic severity of knee OA.

Abstract 3146: MFG-E8: A novel prognostic marker for gastric cancer

Abstract Gastric cancer is one of the leading causes of cancer-related death all over the world. Milk fat globule-epidermal growth factor (EGF)-factor VIII (MFG-E8) was found to be highly unregulated in a variety of cancers, could induce phagocytosis of apoptotic cells and a significant factor in immune systems. However, its prognostic potential has not been evaluated in gastric cancer (GC). In our former proteomic study, MFG-E8 was found significantly overexpressed in gastric cancer tissues comparing with paired non-cancerous gastric tissues. This study aimed to analyze the association between the expression of MFG-E8 in GC tissues and clinical outcomes in GC patients. In this study, 3 independent cohorts (GSE15460, n = 192; TCGA, n = 380 and ACRG, n = 300) were used to assess MFG-E8 as a biomarker, Kaplan-Meier survival analysis showed that its overexpression was associated with poor prognosis of GC with good discriminative ability in 3 independent cohorts (GSE15460, P &amp;lt;0.001; TCGA, P &amp;lt;0.001 and ACRG, P &amp;lt;0.001). Multivariate analysis further confirmed its prognostic significance (GSE15460, P =0.028; TCGA, P &amp;lt;0.001 and ACRG, P =0.012). These results suggest MFG-E8 may become a potential prognostic factor for GC. Note: This abstract was not presented at the meeting. Citation Format: Sai Ge, Jing Gao, Lin Shen. MFG-E8: A novel prognostic marker for gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3146.

Immunological and Clinicopathological Significance of MFG-E8 Expression in Patients with Oral Squamous Cell Carcinoma.

Milk fat globule-epidermal growth factor 8 (MFG-E8) is a glycoprotein secreted by the activated macrophages and acts as a bridge between apoptotic cells and phagocytes. Aside from macrophages, a variety of malignant cells also express MFG-E8. The objective of this study is to elucidate the clinical relevance and significance of MFG-E8 in the tumor microenvironment (TME) of patients with oral squamous cell carcinoma (OSCC). We investigated MFG-E8 expression in 74 patients with OSCC by immunohistochemistry and evaluated the relationship between MFG-E8 expression and various clinicopathological factors including immune cell infiltration. MFG-E8 expression was detected in 34 of 74 (45.9%) patients with OSCC and a significant correlation was observed with levels of infiltrating T cells, macrophages, and immunosuppressive M2 macrophages. Furthermore, MFG-E8 expression was also associated with clinical stage, lymphatic/vascular invasion, and Ki-67+ tumor cells but not with survival. Our results suggest that MFG-E8 may play an important role in shaping the immune suppressive network in TME as well as tumor progression.

Macrophage Smad3 Protects the Infarcted Heart, Stimulating Phagocytosis and Regulating Inflammation.

TGF (transforming growth factor)-β is critically involved in myocardial injury, repair, and fibrosis, activating both Smad (small mothers against decapentaplegic)-dependent and non-Smad pathways. The in vivo role of TGF-β signaling in regulation of macrophage function is poorly understood. We hypothesized that in the infarcted myocardium, activation of TGF-β/Smad signaling in macrophages may regulate repair and remodeling. To investigate the role of macrophage-specific TGF-β Smad3 signaling in a mouse model of myocardial infarction and to dissect the mechanisms mediating Smad-dependent modulation of macrophage function. TGF-βs markedly activated Smad3 in macrophages, without affecting Smad-independent pathways. Phagocytosis rapidly and directly activated macrophage Smad3, in the absence of active TGF-β release. MyS3KO (myeloid cell-specific Smad3 knockout) mice had no baseline defects but exhibited increased late mortality and accentuated dilative postmyocardial infarction remodeling. Adverse outcome in infarcted MyS3KO mice was associated with perturbations in phagocytic activity, defective transition of macrophages to an anti-inflammatory phenotype, scar expansion, and accentuated apoptosis of border zone cardiomyocytes. In vitro, Smad3 null macrophages exhibited reduced expression of genes associated with eat-me signals, such as Mfge8 (milk fat globule-epidermal growth factor factor 8), and reduced capacity to produce the anti-inflammatory mediators IL (interleukin)-10 and TGF-β1, and the angiogenic growth factor VEGF (vascular endothelial growth factor). Mfge8 partly rescued the phagocytic defect of Smad3 null macrophages, without affecting inflammatory activity. Impaired anti-inflammatory actions of Smad3 null macrophages were associated with marked attenuation of phagocytosis-induced PPAR (peroxisome proliferator-activated receptor) expression. MyS3KO mice had no significant alterations in microvascular density and interstitial fibrosis in remodeling myocardial segments. We demonstrate that Smad3 critically regulates function of infarct macrophages, by mediating acquisition of a phagocytic phenotype and by contributing to anti-inflammatory transition. Smad3-dependent actions in macrophages protect the infarcted heart from adverse remodeling.

Construction of short hairpin RNA interfering milk fat globule-epidermal growth factor 8 gene lentiviral vector and its effect on inhibition of breast cancer cells

Objective To construct the lentiviral vector of milk fat globule-epidermal growth factor 8 (MFG-E8) short hairpin RNA (shRNA), and stably transfected the HCC1973 cell line to detect its interference efficiency and influence in breast cancer cell HCC1973. Methods The knockout gene fragment was synthesized and inserted into the shRNA lentiviral vector PLKO.1 with a cherry protein reporter. The constructed recombinant plasmids were transfected into 293T cells respectively. The lentiviruses were transfected into HCC1973 cells and stably transfected PLKO.1-MFG-E8 shRNA recombinant lentiviruses were obtained. The expression of MFG-E8 was detected by real-time PCR and Western blotting. The cell proliferation was measured by methyl thiazol tetrazolium (MTT) assay and Flow cytometry was used to detect the cell cycle and apoptosis, Transwell was used to detect the invasion and migration of cells. Statisticalanalysis of data using the statistical product and service solutions 17.0 software. Results The constructed vector of PLKO.1-MFG-E8 shRNA significantly reduced the expression of MFG-E8 gene and protein in breast cancer cell HCC1973, the lentivirus titer was 3×108 PFU/ml. The proliferation of breast cancer cells was significantly suppressed (t=4.426, P<0.05), G0/G1 phase cells increased significantly with a decrease of cells in S phase (t=2.264, P<0.05), the ability of cell invasion and migration was significantly reduced (t=4.802, P<0.05), after the lentiviral infection. Conclusion The expression of MFG-E8 gene and protein by shRNA interference can inhibit the malignant biological behavior of breast cancer cells effectively, which indicates that MFG-E8 is involved in the invasion, metastasis and apoptosis of breast cancer during the process of breast carcinogenesis. Key words: Milk fat globule-epidermal growth factor 8 short hairpin RNA; Cell cycle; Cell proliferation; Cell poptosis; Invasion and metastasis

Unaltered prion disease in mice lacking developmental endothelial locus–1

Progression of prion diseases is driven by the accumulation of prions in the brain. Ablation of microglia or deletion of the eat-me-signal, milk-fat globule epidermal growth factor VIII (Mfge8), accelerates prion pathogenesis, suggesting that microglia defend the brain by phagocytosing prions. Similar to Mfge8, developmental endothelial locus–1 (Del-1) is a secreted protein that acts as an opsonin bridging phagocytes and apoptotic cells to facilitate phagocytosis. We therefore asked whether Del-1 might play a role in controlling prion pathogenesis. We assessed the anti-inflammatory and phagocytosis-promoting functions of Del-1 in prion disease and determined whether Del-1 complements Mfge8 in prion clearance in mice with a C57BL/6J genetic background. We found that Del-1 deficiency did not change prion disease progression or lesion patterns. In addition, prion clearance and scrapie prion protein deposition were unaltered in Del-1–deficient mice. In addition, prion-induced neuroinflammation was not affected by Del-1 deficiency. We conclude that Del-1 is not a major determinant of prion pathogenesis in this context.

Milk fat globule-epidermal growth factor 8 (MFG-E8) attenuates sepsis-induced acute kidney injury by inhibiting NF-κB signaling pathway1.

Purpose To explore the effect of milk fat globule-epidermal growth factor 8 (MFG-E8) on sepsis-induced acute kidney injury (SAKI). MethodsMale C57BL/6 mice were randomized to control, sham, CLP, CLP+PBS, and CLP+rmMFG-E8 groups. SAKI was induced by cecal ligation and puncture (CLP). Recombinant mouse MFG-E8 (rmMFG-E8) (20 μg/kg) or PBS (vehicle) was administered intraperitoneally. Blood, urine and renal tissue were collected at 24 h after CLP. Blood samples were tested for serum kidney injury biomarker and cytokines. Urine samples were collected to detect KIM-1, and NGAL. Real-time PCR was tested for Bax and Bcl-2. TUNEL staining was used to determine renal apoptosis. Western blot was used to detect the expression of Bax, Bcl-2, and proteins in the NF-κB pathway. Results MFG-E8 alleviated SAKI by decreasing serum Cre, BUN, urine KIM-1 and NGAL and by mitigating renal pathological changes significant (p < 0.05). IL-1β, IL-6, TNF-α were significantly inhibited by MFG-E8 (p < 0.05). Apoptosis induced by SAKI was markedly suppressed by MFG-E8. Finally, MFG-E8 attenuated the activation of the NF-𝜅B signaling pathway in SAKI. ConclusionMFG-E8 has beneficial effects on SAKI, which may be achieved by inhibiting the NF-κB pathway.

Efficient method for isolation of exosomes from raw bovine milk

Objective: This study aimed to establish a rapid and simple method for isolating exosomes from raw bovine milk and to compare the quality of the isolated exosomes with those isolated by a standard method involving ultracentrifugation (UC).Methods: To remove caseins, which are major milk proteins consisting more than 80% of milk protein (35% in human breast milk) and hamper isolation and purification of exosomes, hydrochloride (HCl) was added to milk for isoelectric precipitation (IP). The effects of acidification on morphological features, particle size distribution, surface charge, and exosome surface proteins were analyzed by electron microscopy, tunable resistive pulse sensing (TRPS), and Western blot (WB) analysis, respectively.Results: Electron microscopy showed that some of the exosomes isolated using IP had rough surfaces; most exosomes were successfully isolated without breakage, and their morphological features were similar to those of exosomes isolated by UC. TRPS showed that their surface charge and peaks (mode) for particle size distribution did not significantly differ between both methods. WB analysis using antibodies against the exosome surface marker proteins – milk fat globule-epidermal growth factor 8 (MFG-E8) and CD63 – revealed that the structures of exosome surface proteins were not affected by adding HCl.Conclusions: IP can be used to remove caseins to reduce operation time. This method will be useful for efficient isolation and purification of bovine milk exosomes and contribute to progression of research on health management of dairy cattle and drug delivery systems in human medicine, which require large amounts of milk exosomes.

Autocrine Mfge8 Signaling Prevents Developmental Exhaustion of the Adult Neural Stem Cell Pool.

Adult neurogenesis, arising from quiescent radial-glia-like neural stem cells (RGLs), occurs throughout life in the dentate gyrus. How neural stem cells are maintained throughout development to sustain adult mammalian neurogenesis is not well understood. Here, we show that milk fat globule-epidermal growth factor (EGF) 8 (Mfge8), a known phagocytosis factor, is highly enriched in quiescent RGLs in the dentate gyrus. Mfge8-null mice exhibit decreased adult dentate neurogenesis, and furthermore, adult RGL-specific deletion of Mfge8 leads to RGL overactivation and depletion. Similarly, loss of Mfge8 promotes RGL activation in the early postnatal dentate gyrus, resulting in a decreased number of label-retainingRGLs in adulthood. Mechanistically, loss of Mfge8 elevates mTOR1 signaling in RGLs, inhibition of which by rapamycin returns RGLs to quiescence. Together, our study identifies a neural-stem-cell-enriched niche factor that maintains quiescence and prevents developmental exhaustion of neural stem cells to sustain continuous neurogenesis in the adult mammalian brain.

MFGE8 polymorphisms are significantly associated with metabolism-related indicators rather than metabolic syndrome in Chinese people: A nested case–control study

BackgroundThe correlation between single nucleotide polymorphisms (SNPs) of milk fat globule-epidermal growth factor 8 (MFGE8) and metabolic syndrome (MetS) and metabolism-related indicators are limited. The present study explored the relation in Chinese adults. MethodsWe conducted a nested case–control study based on the Rural Chinese Cohort Study including 408 people with MetS and 408 controls matched by baseline sex, age (±2 years), marital status, and residence village. Four polymorphisms were selected and genotyped by using the SNPscan Genotyping system. Conditional logistic regression was used to estimate the association of MFGE8 polymorphisms with MetS incidence, and linear regression was used to assess the association with metabolism-related indicators in controls. ResultsWe found no significant association of MFGE8 SNPs with MetS incidence or systolic blood pressure, or triglycerides level, or fasting plasma glucose (P > 0.05). However, MFGE8 rs4932450 was negatively associated with high-density lipoprotein cholesterol (HDL-C) level under the dominant model (β = −0.0218, P = 0.007) and the additive model (β = −0.0175, P = 0.012) and positively associated with diastolic blood pressure (DBP) under the recessive model (β = 4.8848, P = 0.011). The rs3784751 SNP was associated with increased waist circumference (WC) in controls (β = 0.0307, P = 0.028). ConclusionsMFGE8 polymorphisms were not associated with MetS but were related to DBP, HDL-C level, and WC in Chinese adults.

MFG-E8 inhibits Aβ-induced microglial production of cathelicidin-related antimicrobial peptide: A suitable target against Alzheimer’s disease

Neuroinflammation plays a pivotal role in the incidence and progression of Alzheimer’s disease (AD). Cathelicidin-related antimicrobial peptide (CRAMP) is critically involved in the innate neuronal responses of chronic neuroinflammation in AD and thus plays a key role in the disease. Here, we show that Aβ42 induced microglial production of CRAMP, which was effectively inhibited by milk-fat globule-epidermal growth factor 8 (MFG-E8). Production of CRAMP was associated with activation of ERK1/2, p38 and phospho-P65-NF-kB upregulation. Additionally, the phosphorylation of these signaling proteins was also reversed by MFG-E8. Pre-incubation with signaling inhibitors confirmed that MFG-E8 has a regulatory role on CRAMP through MAPK and NF-kB signaling pathways. MFG-E8 treatment may thus be a potential pharmacotherapy for chronic inflammation in AD.