Administration Of Epidermal Growth Factor Research Articles

Importin subunit beta-1 mediates ERK5 nuclear translocation, and its inhibition synergizes with ERK5 kinase inhibitors in reducing cancer cell proliferation.

The mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 5 (ERK5) is emerging as a promising target in cancer. Indeed, alterations of the MEK5/ERK5 pathway are present in many types of cancer, including melanoma. One of the key events in MAPK signalling is MAPK nuclear translocation and its subsequent regulation of gene expression. Likewise, the effects of ERK5 in supporting cancer cell proliferation have been linked to its nuclear localization. Despite many processes regulating ERK5 nuclear translocation having been determined, the nuclear transporters involved have not yet been identified. Here, we investigated the role of importin subunit alpha (α importin) and importin subunit beta-1 (importin β1) in ERK5 nuclear shuttling to identify additional targets for cancer treatment. Either importin β1 knockdown or the α/β1 importin inhibitor ivermectin reduced the nuclear amount of overexpressed and endogenous ERK5 in HEK293T and A375 melanoma cells, respectively. These results were confirmed in single-molecule microscopy in HeLa cells. Moreover, immunofluorescence analysis showed that ivermectin impairs epidermal growth factor(EGF)-induced ERK5 nuclear shuttling in HeLa cells. Both co-immunoprecipitation experiments and proximity ligation assay provided evidence that ERK5 and importin β1 interact and that this interaction is further induced by EGF administration and prevented by ivermectin treatment. The combination of ivermectin and the ERK5 inhibitor AX15836 synergistically reduced cell viability and colony formation ability in A375 and HeLa cells and was more effective than single treatments in preventing the growth of A375 and HeLa spheroids. The increased reduction of cell viability upon the same combination was also observed in patient-derived metastatic melanoma cells. The combination of ivermectin and ERK5 inhibitors other than AX15836 provided similar effects on cell viability. The identification of importin β1 as the nuclear transporter of ERK5 may be exploited for additional ERK5-inhibiting strategies for cancer therapy.

IL-33 Induces Paneth Cell Production of EGF and Soluble ST2, Regulating Epithelial Regeneration after Intestinal Injury

Crypt base intestinal stem cells (ISCs) maintain the epithelial lining of the intestines, but their frequencies are reduced in experimental models of graft vs. host disease (GVHD). Paneth cells provide an epithelial contribution to the stem cell niche, but their frequencies are also reduced in GVHD mouse models and in patients with GVHD. Mechanisms regulating ISCs and their niche after damage remain poorly understood. Interleukin-33 (IL-33) is an immunomodulatory alarmin typically thought to target lymphocytes such as T cells and innate lymphoid cells. In experimental models of allogeneic bone marrow transplantation, IL-33 can promote or attenuate GVHD, depending on the cellular target and the timing of the exposure. A secreted isoform of the IL-33 receptor, termed soluble ST2 (sST2), acts as a negative regulator by blocking IL-33 from binding to the membrane-bound isoform that mediates intracellular signaling. sST2 also has diagnostic and prognostic utility, serving as a biomarker for GVHD severity. While IL-33 has well-described effects on lymphocytes populations, there is limited understanding of the role of IL-33 signaling within the intestinal mucosa after damage. Utilizing experimental radiation injury to model conditioning-related intestinal pathology, we investigated the role of the IL-33/ST2 axis in epithelial damage and regeneration. Wild-type (WT) mice increased IL-33 mRNA and protein expression in the small intestine within days after 10 Gy total body irradiation (TBI). Intestinal sST2 expression also increased quickly in WT mice after TBI, but not in IL-33 -/- mice, suggesting that IL-33 itself was a regulator of sST2. While the ileal mucosa appeared similar at baseline in wild-type and IL-33 -/- mice, the IL-33 -/- mice demonstrated more severe radiation injury 5 days after 10 Gy TBI, with more crypt loss, loss of ISCs and Paneth cells, and an attenuated regenerative response with smaller crypts post-TBI containing fewer Ki67 + cells. 3-D whole-mount confocal microscopy of ileal tissue from IL-33-GFP reporter mice indicated that the crypt epithelium did not express IL-33 at baseline, but Olfm4 + ISCs adjacent to Paneth cells began to express IL-33 following radiation injury (Fig 1). Anti-Thy1-mediated lymphocyte depletion prior to irradiation of WT and IL-33 -/- mice did not abrogate the increased radiation sensitivity of IL-33 -/- mice, indicating a role for IL-33 beyond immunomodulation and suggesting that IL-33 could have direct effects within the epithelium. Intestinal organoid cultures confirmed epithelial expression of IL-33, confirmed increased radiation sensitivity of IL-33 -/- epithelium, and identified impaired epidermal growth factor (EGF) expression in the absence of IL-33. Furthermore, treatment of intestinal organoids with IL-33 induced EGF mRNA and protein expression, both of which were abrogated by the p38 inhibitor SB202190. Treatment of purified Lysozyme-DsRed + Paneth cells indicated that IL-33 directly promoted their production of EGF. In vivo, TBI-induced EGF upregulation was absent in IL-33 -/- mice. To further investigate this newly identified epithelial IL-33/ST2/EGF pathway in the ISC compartment, RiboTag mice, which facilitate analysis of lineage-specific proteome-relevant gene expression with minimal tissue processing and artifact introduction, were crossed to Olfm4-Cre and Lysozyme-Cre transgenics. Lineage-specific ribosome targeting was confirmed by immunostains and qPCR, and this approach also confirmed ISC upregulation of IL-33 following radiation injury and Paneth cell upregulation of EGF and sST2. Finally, to investigate the importance of this radiation-induced EGF upregulation, WT mice were treated with the EGFR inhibitor gefitinib following irradiation, which resulted in more severe radiation-induced ISC loss, similar to IL-33 deficiency. Furthermore, epithelial regeneration and ISC recovery were augmented in IL-33 -/- mice after TBI by treatment with exogenous EGF (Fig 2). These findings reveal an unknown pathway of stem cell niche regulation and crypt regeneration whereby the Paneth cell niche responds dynamically upon injury by upregulating EGF and the stem cells orchestrate regeneration by regulating their niche with IL-33. This regenerative circuit also highlights the breadth of IL-33 activity beyond immunomodulation and the therapeutic potential of EGF administration for treatment of intestinal injury.

Differential Expression of MicroRNA (MiR-27, MiR-145) among Dental Pulp Stem Cells (DPSCs) Following Neurogenic Differentiation Stimuli.

This study sought to evaluate the expression of previously identified microRNAs known to regulate neuronal differentiation in mesenchymal stem cells (MSCs), including miR-27, miR-125, miR-128, miR-135, miR-140, miR-145, miR-218 and miR-410, among dental pulp stem cells (DPSCs) under conditions demonstrated to induce neuronal differentiation. Using an approved protocol, n = 12 DPSCs were identified from an existing biorepository and treated with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), which were previously demonstrated to induce neural differentiation markers including Sox1, Pax6 and NFM among these DPSCs. This study revealed that some microRNAs involved in the neuronal differentiation of MSCs were also differentially expressed among the DPSCs, including miR-27 and miR-145. In addition, this study also revealed that administration of bFGF and EGF was sufficient to modulate miR-27 and miR-145 expression in all of the stimulus-responsive DPSCs but not among all of the non-responsive DPSCs-suggesting that further investigation of the downstream targets of these microRNAs may be needed to fully evaluate and understand these observations.

A tissue-intrinsic IL-33/EGF circuit promotes epithelial regeneration after intestinal injury

Intestinal stem cells (ISCs) maintain the epithelial lining of the intestines, but mechanisms regulating ISCs and their niche after damage remain poorly understood. Utilizing radiation injury to model intestinal pathology, we report here that the Interleukin-33 (IL-33)/ST2 axis, an immunomodulatory pathway monitored clinically as an intestinal injury biomarker, regulates intrinsic epithelial regeneration by inducing production of epidermal growth factor (EGF). Three-dimensional imaging and lineage-specific RiboTag induction within the stem cell compartment indicated that ISCs expressed IL-33 in response to radiation injury. Neighboring Paneth cells responded to IL-33 by augmenting production of EGF, which promoted ISC recovery and epithelial regeneration. These findings reveal an unknown pathway of niche regulation and crypt regeneration whereby the niche responds dynamically upon injury and the stem cells orchestrate regeneration by regulating their niche. This regenerative circuit also highlights the breadth of IL-33 activity beyond immunomodulation and the therapeutic potential of EGF administration for treatment of intestinal injury.

Decreased Neonatal Neuroinflammation in the Experimental Model of Necrotizing Enterocolitis with Administration of Heparin-Binding Epidermal Growth Factor-like Growth Factor (HB-EGF)

Sacks, Marla MD; Mendez, Yomara S BS; Abdala, Jonathan BS; Wilson, Christopher G PhD; Radulescu, Andrei MD, PhD Author Information

Administration of Epidermal Growth Factor (EGF) and Basic Fibroblast Growth Factor (bFGF) to Induce Neural Differentiation of Dental Pulp Stem Cells (DPSC) Isolates

The aging populations in many countries have developed many chronic illnesses and diseases, including chronic neurologic conditions such as Parkinson's and Azheimer's diseases. Many new lines of research and treatment are focusing on the potential for neurologic regeneration using mesenchymal stem cells (MSCs) in the rapidly growing field of regenerative medicine. This may include dental pulp stem cells (DPSCs), which have recently been demonstrated to produce neuronal precursors. Based upon this evidence, the primary aim of this study was to determine if the growth factors used in MSC-based studies are sufficient to induce neuronal differentiation among DPSCs. Using an existing biorepository, n = 16 DPSC isolates were thawed and cultured for this study, which revealed several subpopulations of rapid-, intermediate-, and slowly dividing DPSCs. Administration of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) were sufficient to induce differential changes in growth and viability mainly among some of the rapidly growing DPSCs (n = 4). These phenotypic changes included expression of neural differentiation markers including Sox1, Pax6 and NF-M, which were observed only among those DPSC isolates not expressing early odontoblast-specific biomarkers such as ALP and DSPP. Future studies will be needed to confirm if these methods are sufficient to induce consistent and reliable induction of DPSCs towards neuronal specific differentiation.

The use of epidermal growth factor in dermatological practice.

Epidermal growth factor (EGF) is a growth factor that plays a pivotal role in wound healing and maintaining tissue homeostasis by regulating cell survival, proliferation, migration, and differentiation. Exogenous administration of bioidentical human recombinant epidermal growth factor (rhEGF) has been known to promote skin wound healing, although rhEGF is increasingly being used in drug delivery systems and nanotechnology. However, despite considerable attention being focused on the potential clinical applications of rhEGF in several dermatological conditions beyond wound healing, the number of studies still remains relatively low. Herein, we conducted a literature search of PubMed/Medline and Google Scholar databases to retrieve published literature related to rhEGF and summarised the effects of rhEGF in the treatment of various wound types, radiotherapy or chemotherapy-related skin reactions, atopic dermatitis, skin aging, and post-inflammatory hyperpigmentation.

The effect of human recombinant epidermal growth factor in the treatment of diabetic foot ulcers

Objectives. Diabetic foot ulcer (DFU) is one of the most important and common complication of type 2 diabetes mellitus (T2DM). A new therapy, consisting of intralesional administration of human recombinant epidermal growth factor (hrEGF), has been suggested to accelerate wound healing and prevent amputations. The effect of hrEGF on DFU treatment was investigated in this study. Materials and Methods. 20 patients with DFU were included in this study, all of whom were receiving insulin treatment for T2DM. In addition, they received intralesional therapy with a dose of 75 μgr of hrEGF, three times a week. Results. In 18 patients, complete granulation response was achieved in approximately 3,3 weeks. There were 2 cases of recurrence at 6 months after EGF treatment. Between 6 and 12 doses of epidermal growth factor were used for this study. The most common side effects were tremor, chills, pain and burning at the site of administration. Conclusions. Our study shows that intralesional administration of hrEGF in T2DM can prevent amputations in DFU and also accelerate wound healing. Thus, intralesional application of hrEGF should be an option for standard care, as a second line of treatment (given its cost-effectiveness) when appropriate.

Epidermal growth factor effect on lipopolysaccharide-induced inflammation in fibroblasts derived from diabetic foot ulcer.

BackgroundDiabetic foot ulcers (DFU) are characterised by high levels of inflammatory mediators, resulting from sustained hyperglycaemic insult and the local microbial biofilm. The intralesional administration of epidermal growth factor (EGF) has emerged as an effective treatment that stimulates granulation and closure of DFU, reducing the risk of amputation. Within the wound, fibroblasts play key roles during the healing process, promoting granulation and contraction. The aim of the present study was to examine the anti-inflammatory effect of EGF in DFU-derived fibroblasts, challenged with lipopolysaccharide (LPS), under hyperglycaemic conditions, recreating in vitro what happens in a clinical scenario.MethodsHealthy skin (HS) and DFU granulation tissue biopsies were used to isolate primary fibroblasts. The effect of LPS on cell proliferation was analysed. Transcriptional expression of toll-like receptor (TLR) pathway mediators (TLR4, TLR2, CD14, MYD88 and NFKB) and pro-inflammatory cytokines (TNF, IL-6 and IL-1B) were measured by semi-quantitative polymerase chain reaction (qPCR), in cells treated with appropriate concentrations of LPS, EGF and their combination. IL-6 protein concentration was quantified by ELISA.ResultsLPS stimulated proliferation of HS-derived fibroblasts, while inhibiting the proliferation of cells derived from DFU at the highest assayed concentration of 1 µg/mL. Regarding the TLR signalling pathway, LPS increased messenger RNA levels of mediators and pro-inflammatory genes, while EGF, alone or in the presence of LPS, downregulated them, except for IL-1B.ConclusionThe results suggest that EGF might elicit an anti-inflammatory response in LPS-challenged fibroblasts, even in a hyperglycaemic milieu. Collectively, our findings contribute to explain newly observed effects of EGF in the clinical arena.Lay SummaryIn this research article, we analyse the putative anti-inflammatory effect of epidermal growth factor (EGF) on fibroblast isolated from diabetic foot ulcer (DFU) granulation tissue. To induce the inflammatory response, the cells were treated with lipopolysaccharide (LPS), simulating the gram-negative bacterial infection that takes place in the wounds of diabetic patients. We studied the expression of genes involved in bacterial recognition receptors signalling pathway and those that code for different pro-inflammatory cytokines.We obtained primary fibroblasts from biopsies of a neuropathic diabetic ulcer and from healthy skin, the former was used as the control. Cells were isolated and grown in high glucose Dulbecco’s Modified Eagle Medium (DMEM) culture medium, to simulate the hyperglycaemic insult. The effect of increasing concentrations of LPS on cell proliferation was analysed. Relative transcriptional expression of genes in the study was quantified by quantitative polymerase chain reaction (qPCR) in cells treated with LPS, EGF or a combination. Untreated cells served to normalise the expression.In the present study, we demonstrated that EGF modulated the primary immune response by reducing the activation of pathogen-recognition receptors and common genes involved in these signalling pathways, even in hyperglycaemic conditions. This effect translated in a decreased expression of pro-inflammatory cytokines. These results contribute to explain our previous observations about the reduction of circulating levels of inflammatory cytokines after local administration of human recombinant EGF in DFU. Further molecular studies should be carried out to fully understand the biological mechanisms elicited by EGF in this clinical scenario.

Prenatal administration of heparin-binding epidermal growth factor-like growth factor in an experimental model of necrotizing enterocolitis decreased both incidence and severity of the disease.

Necrotizing enterocolitis (NEC) is the leading gastrointestinal cause of death in premature infants and causes long-term disabilities. Previously, enteral heparin-binding epidermal growth factor-like growth factor (HB-EGF) administered after birth demonstrated decreased incidence and severity of NEC in a neonatal animal model of NEC. We investigated the potential prophylactic strategy of preventing NEC using prenatally administered HB-EGF. An HB-EGF (800 µg/kg/dose) dose was injected into pregnant rats via tail vein or intraperitoneal route 2 hours prior to delivery. After cesarean section (C-section) at 21 days' gestation, the rat pups were subjected to the NEC protocol by inducing stressors: hypoxia, hypothermia, hypertonic feeds, and orogastric gavage of lipopolysaccharide (2 mg/kg). Postnatally, pups were monitored for 96 hours and assessed for the development of clinical and postmortem histological NEC. The experimental NEC incidence in untreated, stressed rat pups was 66%. Compared with untreated pups, the maternal administration of HB-EGF correlated with a significant NEC incidence and severity decrease in rat pups. The strongest decrease was seen when HB-EGF was administered via the intraperitoneal route 2 hours prior to C-section (66% vs 31%, *p<0.05). Prenatal HB-EGF administration significantly increased pups' survival after NEC protocol exposure, with the greatest benefit observed in the group that received HB-EGF intraperitoneally 2 hours before delivery. Prenatal administration of HB-EGF decreases the incidence and severity of NEC, preserves gut barrier function and increases survival. This may represent a novel prophylactic clinical strategy for NEC offered to mothers at risk of delivering a premature infant.

Effect of Epidermal Growth Factor Treatment and Polychlorinated Biphenyl Exposure in a Dietary-Exposure Mouse Model of Steatohepatitis.

Background:Polychlorinated biphenyls (PCBs) are signaling disrupting chemicals that exacerbate nonalcoholic steatohepatitis (NASH) in mice. They are epidermal growth factor receptor (EGFR) inhibitors that enhance hepatic inflammation and fibrosis in mice.Objectives:This study tested the hypothesis that epidermal growth factor (EGF) administration can attenuate PCB-related NASH by increasing hepatic EGFR signaling in a mouse model.Methods:C57BL/6 male mice were fed a 42% milk fat diet and exposed to Aroclor 1260 () or vehicle for 12 wk. EGF () or vehicle were administered daily for 10 d starting at study week 10. Liver and metabolic phenotyping were performed. The EGF dose was selected based on results of an acute dose–finding study (30 min treatment of EGF at 0.2, 0.02, of via intraperitoneal injection). Hepatic phosphoproteomic analysis was performed using liver tissue from this acute study to understand EGFR’s role in liver physiology.Results:Markers of EGFR signaling were higher in EGF-treated mice. –exposed mice had lower hepatic free fatty acids, inflammation, and fibrosis relative to PCB-only exposed mice. EGF-treated mice had higher plasma lipids, with no improvement in hepatic steatosis, and an association with higher LXR target gene expression and de novo lipogenesis. EGF-treated mice showed more severe hyperglycemia associated with lower adiponectin levels and insulin sensitivity. EGF-treated mice had higher hepatic , NRF2, and AhR target gene expression but lower constitutive androstane receptor and farnesoid X receptor target gene expression. The hepatic EGF-sensitive phosphoproteome demonstrated a role for EGFR signaling in liver homeostasis.Discussion:These results validated EGFR inhibition as a causal mode of action for PCB-related hepatic inflammation and fibrosis in a mouse model of NASH. However, observed adverse effects may limit the clinical translation of EGF therapy. More data are required to better understand EGFR’s underinvestigated roles in liver and environmental health. https://doi.org/10.1289/EHP8222

Reversal of autoimmunity by mixed chimerism enables reactivation of β cells and transdifferentiation of α cells in diabetic NOD mice

Type 1 diabetes (T1D) results from the autoimmune destruction of β cells, so cure of firmly established T1D requires both reversal of autoimmunity and restoration of β cells. It is known that β cell regeneration in nonautoimmune diabetic mice can come from differentiation of progenitors and/or transdifferentiation of α cells. However, the source of β cell regeneration in autoimmune nonobese diabetic (NOD) mice remains unclear. Here, we show that, after reversal of autoimmunity by induction of haploidentical mixed chimerism, administration of gastrin plus epidermal growth factor augments β cell regeneration and normalizes blood glucose in the firmly established diabetic NOD mice. Using transgenic NOD mice with inducible lineage-tracing markers for insulin-producing β cells, Sox9+ ductal progenitors, Nestin+ mesenchymal stem cells, and glucagon-producing α cells, we have found that both reactivation of dysfunctional low-level insulin expression (insulinlo) β cells and neogenesis contribute to the regeneration, with the latter predominantly coming from transdifferentiation of α cells. These results indicate that, after reversal of autoimmunity, reactivation of β cells and transdifferentiation of α cells can provide sufficient new functional β cells to reach euglycemia in firmly established T1D.

Epidermal growth factor receptor–dependent DNA repair promotes murine and human hematopoietic regeneration

AbstractChemotherapy and irradiation cause DNA damage to hematopoietic stem cells (HSCs), leading to HSC depletion and dysfunction and the risk of malignant transformation over time. Extrinsic regulation of HSC DNA repair is not well understood, and therapies to augment HSC DNA repair following myelosuppression remain undeveloped. We report that epidermal growth factor receptor (EGFR) regulates DNA repair in HSCs following irradiation via activation of the DNA-dependent protein kinase–catalytic subunit (DNA-PKcs) and nonhomologous end joining (NHEJ). We show that hematopoietic regeneration in vivo following total body irradiation is dependent upon EGFR-mediated repair of DNA damage via activation of DNA-PKcs. Conditional deletion of EGFR in hematopoietic stem and progenitor cells (HSPCs) significantly decreased DNA-PKcs activity following irradiation, causing increased HSC DNA damage and depressed HSC recovery over time. Systemic administration of epidermal growth factor (EGF) promoted HSC DNA repair and rapid hematologic recovery in chemotherapy-treated mice and had no effect on acute myeloid leukemia growth in vivo. Further, EGF treatment drove the recovery of human HSCs capable of multilineage in vivo repopulation following radiation injury. Whole-genome sequencing analysis revealed no increase in coding region mutations in HSPCs from EGF-treated mice, but increased intergenic copy number variant mutations were detected. These studies demonstrate that EGF promotes HSC DNA repair and hematopoietic regeneration in vivo via augmentation of NHEJ. EGF has therapeutic potential to promote human hematopoietic regeneration, and further studies are warranted to assess long-term hematopoietic effects.

260-OR: Transdifferentiation of a-Cells and Redifferentiation of InsulinLo ß-Cells Dominate ß-Cell Regeneration in Late-Stage Diabetic NOD Mice Cured with Induction of Mixed Chimerism and Administration of Gastrin and Epidermal Growth Factor

Type 1 diabetes (T1D) results from the autoimmune destruction of β cells. Cure of established T1D requires both reversal of autoimmunity and regeneration of β cells. Autoimmune NOD mice closely resemble human T1D. We have reported that administration of gastrin and epidermal growth factor (GE) allows β cell regeneration and cure of late-stage T1D in NOD mice after reversal of autoimmunity by induction of MHC-mismatched mixed chimerism. β cell regeneration in non-autoimmune diabetic mice can come from differentiation of Sox9+ pancreatic ductal progenitors, parenchymal progenitors, and transdifferentiation of α cells. However, the source of β cell regeneration in autoimmune NOD mice remains unclear. Using NOD mice with inducible Sox9-EGFP, we found that Sox9+ pancreatic ductal progenitors only accounted for a small fraction of total β cell regeneration. Using Nestin-EGFP mice, we did not see any β cells originating from Nestin+ parenchymal progenitor cells. Using NOD mice with inducible glucagon-RFP, we found that ∼50% of regenerated β cells were from α cell transdifferentiation in mice after induction of mixed chimerism and GE, although mixed chimerism alone induced few α to β cell transdifferentiation in mice. In addition, using NOD mice with inducible insulin-EGFP, we found that the majority of residual β cells in late-stage diabetic NOD mice were insulinlo, and they became insulinhi after induction of mixed chimerism and GE treatment. Taken together, transdifferentiation of α to β cells and re-differentiation of insulinlo cells are the major sources of β cell regeneration in late-stage diabetic NOD mice after induction of mixed chimerism and administration of GE. How hyperglycemia and GE differentially regulate α cell transdifferentiation and β cell re-differentiation is under investigation. This work is supported by the Wanek Family fund. Disclosure S. Tang: None. M. Zhang: None. P. Santamaria: Board Member; Self; Parvus Therapeutics. A.D. Riggs: None. L. Jin: None. D. Zeng: None. Funding Todd and Karen Wanek Family Foundation Ltd.

Preparation and Optimization of Chitosan-hEGF Nanoparticle Using Ionic Gelation Method Stabilized by Polyethylene Glycol (PEG) for Wound Healing Therapy

The administration of human Epidermal Growth Factor (hEGF) for diabetic ulcer treatment has been known to have high effectiveness because hEGF has mitogenic properties and has been proved to increase epithelial cell proliferation both in vitro and in vivo. However, hEGF in environmental conditions of diabetic ulcers is known to have low stability, so it is necessary to repeat the administration or protect the hEGF using suitable preparation. This study aims to produce a new drug delivery system in the form of chitosan nanoparticle as a therapy for diabetic ulcers. The nanoparticle formulation was carried out by varying hEGF concentrations using the ionic gelation method with sodium tripolyphosphate (Na-TPP) as a crosslinker and Polyethylene glycol (PEG) as a stabilizer. Chitosan-hEGF nanoparticle formed were characterized using particle size analysis, polydispersity index, zeta potential, SEM and TEM, pH, and FTIR to observe the functional groups. Chitosan-hEGF nanoparticle-containing 0.1% chitosan, 0.15% sodium tripolyphosphate (Na-TPP), 2% polyethylene glycol 400 (PEG 400), and 75 ng/mL hEGF has the smallest particle size with an average of 600.6 nm and D90 value of 135.7 nm. Nanoparticle formed were relatively stable with zeta potential reaching +41,29. The results of in vitro testing showed that hEGF 50 ng/mL had an optimal cell viability percentage with a value of 192%.

Epidermal Growth Factor in Healing Diabetic Foot Ulcers: From Gene Expression to Tissue Healing and Systemic Biomarker Circulation.

Lower-extremity diabetic ulcers are responsible for 80% of annual worldwide nontraumatic amputations. Epidermal growth factor (EGF) reduction is one of the molecular pillars of diabetic ulcer chronicity, thus EGF administration may be considered a type of replacement therapy. Topical EGF ad-ministration to improve and speed wound healing began in 1989 on burn patients as part of an acute-healing therapy. Further clinical studies based on topically administering EGF to different chronic wounds resulted in disappointing out-comes. An analysis of the literature on unsuccessful clinical trials identifi ed a lack of knowledge concerning: (I) molecular and cellular foundations of wound chronicity and (II) the phar-macodynamic requisites governing EGF interaction with its receptor to promote cell response. Yet, EGF intra- and perile-sional infi ltration were shown to circumvent the pharmacody-namic limitations of topical application. Since the fi rst studies, the following decades of basic and clinical research on EGF therapy for problem wounds have shed light on potential uses of growth factors in regenerative medicine. EGF's molecular and biochemical effects at both local and systemic levels are diverse: (1) downregulation of genes encoding infl ammation mediators and increased expression of genes involved in cell proliferation, angiogenesis and matrix secretion; (2) EGF in-tervention positively impacts both mesenchymal and epithelial cells, reducing infl ammation and stimulating the recruitment of precursor circulating cells that promote the formation of new blood vessels; (3) at the subcellular level, upregulation of the EGF receptor with subsequent intracellular traffi cking, includ-ing mitochondrial allocation along with restored morphology of multiple organelles; and (4) local EGF infi ltration resulting in a systemic, organismal repercussion, thus contributing to attenuation of circulating infl ammatory and catabolic reac-tants, restored reduction-oxidation balance, and decreased toxic glycation products and soluble apoptogenic effectors. It is likely that EGF treatment may rearrange critical epigenetic drivers of diabetic metabolic memory. KEYWORDS Epidermal Growth Factor, diabetes, diabetes complications, wound healing, diabetic foot, amputation, ulcer, Cuba.

Epidermal growth factor in sacran hydrogel film accelerates fibroblast migration.

Epidermal growth factor (EGF) accelerates epidermal regeneration, and it is widely studied as a wound-healing agent. However, the special carrier for the topical administration of EGF is urgently needed to deliver EGF on the wound site. In a preceding study, sacran hydrogel film (Sac-HF) showed a possible use as a dressing material for wound healing, as well as a good capability as a drug carrier. In the current study, we prepared Sac-HF containing EGF (Sac/EGF-HF) and then characterized their physicochemical properties, including thickness, swelling ratio, degradability, tensile strength, and morphology. In addition, we have also conducted thermal and crystallography studies using differential scanning calorimetry (DSC) and X-ray diffraction, respectively. Furthermore, we investigated the in vitro influence of Sac/EGF-HF on cell migration using a fibroblast cell line. Morphology study confirmed that the casting method used for the film preparation resulted in a homogeneous film of Sac/EGF-HF. Furthermore, EGF significantly increased the thickness, tensile strength, and degradability of Sac/EGF-HF compared to Sac-HF. Sac/EGF-HF had a lower swelling ability compared to Sac-HF; this result corroborated the tensile strength result. Interestingly, X-ray diffraction and DSC results showed that Sac/EGF-HF had an amorphous shape. The in vitro studies revealed that Sac/EGF-HF induced the fibroblast migration activity. These results conclude that Sac/EGF-HF has the potential properties of HF for biomedical applications.

Epidermal growth factor attenuates lingual papillae lesions in a rat model of sialoadenectomy

Salivary epidermal growth factor (EGF) plays an important role in the maintenance of the oral and gastro-esophageal mucosa. Sialoadenectomy delays healing of oral wounds and affects lingual papillae. In this work, we aimed to determine the effect of EGF deficiency induced by sialoadenectomy and evaluate the effect of exogenous EGF administration on the lingual papillae and taste buds in rats. Thirty male adult Wistar albino rats were equally divided into 3 groups; sham-operated control group, sialoadenectomy group and group of sialoadenectomy + EGF. EGF was given 8 weeks after sialoadenectomy in a dose of 1 μg /ml/day in drinking water for 2 weeks. The anterior two-thirds of the tongue was dissected and cut longitudinally into two halves; one half for light microscope and the other for electron microscope examinations. Saliva and blood were collected to determine salivary and plasma EGF. Our results revealed that sialoadenectomy significantly reduced plasma and saliva levels of EGF which resulted in severe disruption of the architecture of lingual papillae. These changes were effectively improved by the exogenous EGF administration. In conclusion, EGF supplementation reversed the effects of sialoadenectomy and restored almost normal architecture of lingual papillae and taste buds.

Neonatal exposure to an inflammatory cytokine, epidermal growth factor, results in the deficits of mismatch negativity in rats

Perinatal exposure to epidermal growth factor (EGF) induces various cognitive and behavioral abnormalities after maturation in non-human animals, and is used for animal models of schizophrenia. Patients with schizophrenia often display a reduction of mismatch negativity (MMN), which is a stimulus-change specific event-related brain potential. Do the EGF model animals also exhibit the MMN reduction as schizophrenic patients do? This study addressed this question to verify the pathophysiological validity of this model. Neonatal rats received repeated administration of EGF or saline and were grown until adulthood. Employing the odd-ball paradigm of distinct tone pitches, tone-evoked electroencephalogram (EEG) components were recorded from electrodes on the auditory and frontal cortices of awake rats, referencing an electrode on the frontal sinus. The amplitude of the MMN-like potential was significantly reduced in EGF-treated rats compared with saline-injected control rats. The wavelet analysis of the EEG during a near period of tone stimulation revealed that synchronization of EEG activity, especially with beta and gamma bands, was reduced in EGF-treated rats. Results suggest that animals exposed to EGF during a perinatal period serve as a promising neurodevelopmental model of schizophrenia.

Epidermal growth factor protects against myocardial ischaemia reperfusion injury through activating Nrf2 signalling pathway

Alleviating the oxidant stress associated with myocardial ischaemia reperfusion has been demonstrated as a potential therapeutic approach to limit ischaemia reperfusion (I/R)-induced cardiac damage. It is reported that EGFR/erbB2 signalling is an important cardiac survival pathway in cardiac function and activation of EGFR has a cardiovascular effect in global ischaemia. Epidermal growth factor (EGF), a typical EGFR ligand, was considered to have a significant role in activating EGFR. However, no evidence has been published whether exogenous EGF has protective effects on myocardial ischaemia reperfusion. This study aims to investigate the effects of EGF in I/R-induced heart injury and to demonstrate its mechanisms. H9c2 cells challenged with H2O2 were used for in vitro biological activity and mechanistic studies. The malondialdehyde (MDA) and Superoxide Dismutase (SOD) levels in H9c2 cells were determined, and the cell viability was assessed by MTT assay. Myocardial I/R mouse administrated with or without EGF were used for in vivo studies. Pretreatment of H9c2 cells with EGF activated Nrf2 signalling pathway, attenuated H2O2-increased MDA and H2O2-reduced SOD level, followed by the inhibition of H2O2-induced cell death. In in vivo animal models of myocardial I/R, administration of EGF reduced infarct size and myocardial apoptosis. These data support that EGF decreases oxidative stress and attenuates myocardial ischaemia reperfusion injury via activating Nrf2.