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Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that controls vascular responses to hypoxia and ischemia. In this study, mice that were heterozygous (HET) for a null allele at the locus encoding the HIF-1[alpha] subunit (HET mice) and their wild-type (WT) littermates were subjected to a thermal injury involving 10% of the body surface area. HIF-1[alpha] protein levels were increased in burn wounds of WT but not of HET mice on day 2. The serum levels of stromal-derived factor 1[alpha], which binds to CXCR4, were increased on day 2 in WT but not in HET mice. Circulating angiogenic cells were also increased on day 2 in WT but not in HET mice and included CXCR4+Sca1+ cells. Laser Doppler perfusion imaging demonstrated increased blood flow in burn wounds of WT but not HET mice on day 7. Immunohistochemistry on day 7 revealed a reduced number of CD31+ vessels at the healing margin of burn wounds in HET as compared with WT mice. Vessel maturation was also impaired in wounds of HET mice as determined by the number of [alpha]-smooth muscle actin-positive vessels on day 21. The remaining wound area on day 14 was significantly increased in HET mice compared with WT littermates. The percentage of healed wounds on day 14 was significantly decreased in HET mice. These data delineate a signaling pathway by which HIF-1 promotes angiogenesis during burn wound healing. [ABSTRACT FROM AUTHOR]

Critical limb ischemia is an important clinical entity due to its association with increased morbidity and mortality. The mortality and amputation-free survival remains poor especially in those where revascularization is not an option. Recently, the role of cellular therapy has emerged as a promising therapeutic measure that may aid in wound healing and revascularization and improve functional outcomes., Competing Interests: Disclosure Dr J.W. Harmon is a founding member of MedRegen Baltimore, Maryland, which was established to develop a therapeutic to mobilize endogenous stem cells for wound healing., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Hypoxia-Inducible Factor-1α (HIF-1α) has presented a new direction for ischemic preconditioning of surgical flaps to promote their survival. In a previous study, we demonstrated the effectiveness of HIF-1a DNA plasmids in this application. In this study, to avoid complications associated with plasmid use, we sought to express HIF-1α through mRNA transfection and determine its biological activity by measuring the upregulation of downstream angiogenic genes. We transfected six different HIF-1a mRNAs-one predominant, three variant, and two novel mutant isoforms-into primary human dermal fibroblasts using Lipofectamine, and assessed mRNA levels using RT-qPCR. At all time points examined after transfection (3, 6, and 10 h), the levels of HIF-1α transcript were significantly higher in all HIF-1α transfected cells relative to the control (all p < 0.05, unpaired Student's T-test). Importantly, the expression of HIF-1α transcription response genes (VEGF, ANG-1, PGF, FLT1, and EDN1) was significantly higher in the cells transfected with all isoforms than with the control at six and/or ten hours post-transfection. All isoforms were transfected successfully into human fibroblast cells, resulting in the rapid upregulation of all five downstream angiogenic targets tested. These findings support the potential use of HIF-1α mRNA for protecting ischemic dermal flaps., (© 2024. The Author(s).)

Extracellular vesicles (EVs) derived from mesenchymal stem/stromal cells (MSCs) have recently been explored in clinical trials for treatment of diseases with complex pathophysiologies. However, production of MSC EVs is currently hampered by donor-specific characteristics and limited ex vivo expansion capabilities before decreased potency, thus restricting their potential as a scalable and reproducible therapeutic. Induced pluripotent stem cells (iPSCs) represent a self-renewing source for obtaining differentiated iPSC-derived MSCs (iMSCs), circumventing both scalability and donor variability concerns for therapeutic EV production. Thus, it is initially sought to evaluate the therapeutic potential of iMSC EVs. Interestingly, while utilizing undifferentiated iPSC EVs as a control, it is found that their vascularization bioactivity is similar and their anti-inflammatory bioactivity is superior to donor-matched iMSC EVs in cell-based assays. To supplement this initial in vitro bioactivity screen, a diabetic wound healing mouse model where both the pro-vascularization and anti-inflammatory activity of these EVs would be beneficial is employed. In this in vivo model, iPSC EVs more effectively mediate inflammation resolution within the wound bed. Combined with the lack of additional differentiation steps required for iMSC generation, these results support the use of undifferentiated iPSCs as a source for therapeutic EV production with respect to both scalability and efficacy., (© 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.)

Wound therapies involving gene delivery to the skin have significant potential due to the advantage and ease of local treatment. However, choosing the appropriate vector to enable successful gene expression while also ensuring that the treatment's immediate material components are conducive to healing itself is critical. In this study, we utilized a particulate formulation of the polymer chitosan (chitosan particles, CPs) as a non-viral vector for the delivery of a plasmid encoding human CA5-HIF-1α, a degradation resistant form of HIF-1α, to enhance wound healing. We also compared the angiogenic potential of our treatment (HIF/CPs) to that of chitosan particles containing only the plasmid backbone (bb/CPs) and the chitosan particle vector alone (CPs). Our results indicate that chitosan particles exert angiogenic effects that are enhanced with the human CA5-HIF-1α-encoded plasmid. Moreover, HIF/CPs enhanced wound healing in diabetic db/db mice ( p < 0.01), and healed tissue was found to contain a significantly increased number of blood vessels compared to bb/CPs ( p < 0.01), CPs ( p < 0.05) and no-treatment groups ( p < 0.01). Thus, this study represents a method of gene delivery to the skin that utilizes an inherently pro-wound-healing polymer as a vector for plasmid DNA that has broad application for the expression of other therapeutic genes.

Worldwide, gastric cancer results in significant morbidity and mortality. Ten per cent of patients with gastric cancer have a strong family history of the disease. CDH1 (E-cadherin) has been identified as a key gene whose mutation leads to hereditary diffuse gastric cancer. We overviewed 33 articles with prophylactic total gastrectomy and assessed the outcomes and benefits. Families with mutations in CDH1 may benefit from early prophylactic total gastrectomy. Dr Mark Duncan has applied his experience as a high-volume gastric cancer surgeon to treat not only individual patients, but several generations of patients within a family. This use of prophylactic total gastrectomy is well tolerated by patients and prevents the future development of gastric cancer., Competing Interests: Competing interests JWH is the Editor-in-Chief for eGastroenterology.

The History Maker paper focuses on the extraordinary revolution that dramatically improved the surgical results for the Whipple procedure (pancreaticoduodenectomy) in the 1980s and identifies Dr. Cameron as the leader of this revolution, who reported a mortality rate of approximately 1%. The revolutionary reduction of postoperative mortality for the Whipple procedure was achieved by adherence to gentle and precise Halstedian surgical techniques with adequate drainage of pancreatico-jejunal anastomosis with closed-suction silastic drains, along with the development of high-volume surgeons and hospitals. Excellent teamwork in patient care, including but not limited to preoperative evaluation by multidisciplinary teams, intraoperative communication between surgeons and anaesthesiologists, and postoperative management, contributed to a successful Whipple procedure., Competing Interests: Competing interests JWH is the Editor-in-Chief of eGastroenterology.

Extracellular vesicles (EVs) are implicated as promising therapeutics and drug delivery vehicles in various diseases. However, successful clinical translation will depend on the development of scalable biomanufacturing approaches, especially due to the documented low levels of intrinsic EV-associated cargo that may necessitate repeated doses to achieve clinical benefit in certain applications. Thus, here the effects of a 3D-printed scaffold-perfusion bioreactor system are assessed on the production and bioactivity of EVs secreted from bone marrow-derived mesenchymal stem cells (MSCs), a cell type widely implicated in generating EVs with therapeutic potential. The results indicate that perfusion bioreactor culture induces an ≈40-80-fold increase (depending on measurement method) in MSC EV production compared to conventional cell culture. Additionally, MSC EVs generated using the perfusion bioreactor system significantly improve wound healing in a diabetic mouse model, with increased CD31 + staining in wound bed tissue compared to animals treated with flask cell culture-generated MSC EVs. Overall, this study establishes a promising solution to a major EV translational bottleneck, with the capacity for tunability for specific applications and general improvement alongside advancements in 3D-printing technologies., (© 2023 Wiley-VCH GmbH.)

Background Aims: As evidenced by ongoing clinical trials and increased activity in the commercial sector, extracellular vesicle (EV)-based therapies have begun the transition from bench to bedside. As this progression continues, one critical aspect of EV clinical translation is understanding the effects of storage and transport conditions. Several studies have assessed the impact of storage on EV characteristics such as morphology, uptake and component content, but effects of storage duration and temperature on EV functional bioactivity and, especially, loaded cargo are rarely reported., Methods: The authors assessed EV outcomes following storage at different temperatures (room temperature, 4°C, -20°C, -80°C) for various durations as well as after lyophilization., Results: Mesenchymal stromal cell (MSC) EVs were observed to retain key aspects of their bioactivity (pro-vascularization, anti-inflammation) for up to 4-6 weeks at -20°C and -80°C and after lyophilization. Furthermore, via in vitro assays and an in vivo wound healing model, these same storage conditions were also demonstrated to enable preservation of the functionality of loaded microRNA and long non-coding RNA cargo in MSC EVs., Conclusions: These findings extend the current understanding of how EV therapeutic potential is impacted by storage conditions and may inform best practices for handling and storing MSC EVs for both basic research and translational purposes., Competing Interests: Declaration of Competing Interest The authors have no commercial, proprietary or financial interest in the products or companies described in this article., (Copyright © 2022 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Introduction: Esophageal cancer is an aggressive malignancy with high mortality. Optimal treatment of esophageal cancer remains an elusive goal. Ribonucleic acid (RNA) interference is a novel potential targeted approach to treat esophageal cancer. Targeting oncogenes that can alter critical cellular functions with silencing RNA molecules is a promising approach. The silencing of specific oncogenes in esophageal cancer cells in the experimental setting has been shown to decrease the expression of oncogenic proteins. This has resulted in cell apoptosis, reduction in cell proliferation, reduced invasion, migration, epithelial-mesenchymal transition, decrease in tumor angiogenesis and metastasis, and overcoming drug resistance. The Hedgehog (Hh) signaling pathway has been shown to be involved in esophageal adenocarcinoma formation in a reflux animal model. In addition to Hh, we will focus on other targets with clinical potential in the treatment of esophageal cancer., Materials and Methods: We searched for articles published from 2005 to August 2020 that studied the siRNA effects on inhibiting esophageal cancer formation in experimental settings. We used combinations of the following terms for searching: "esophageal cancer," "RNA interference," "small interfering RNA," "siRNA," "silencing RNA," "Smoothened (Smo)," "Gli," "Bcl-2," "Bcl-XL," "Bcl-W,″ "Mcl-1," "Bfl-1," "STAT3,"and "Hypoxia inducible factor (HIF)". A total of 21 relevant articles were found., Results and Conclusions: Several proto-oncogenes/oncogenes including Hh pathway mediators, glioma-associated oncogene homolog 1 (Gli-1), Smoothened (Smo), and antiapoptotic Bcl-2 have potential as targets for silencing RNA in the treatment of esophageal cancer., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Chronic wounds remain a substantial source of morbidity worldwide. An emergent approach that may be well-suited to induce the complex, multicellular processes such as angiogenesis that are required for wound repair is the use of extracellular vesicles (EVs). EVs contain a wide variety of proteins and nucleic acids that enable multifactorial signaling. Here, the capability of EVs is leveraged to be engineered via producer cell modification to investigate the therapeutic potential of EVs from mesenchymal stem/stromal cells (MSCs) transfected to overexpress long non-coding RNA HOX transcript antisense RNA (HOTAIR). HOTAIR is previously shown by the authors' group to be critical in mediating angiogenic effects of endothelial cell EVs, and MSCs are chosen as EV producer cells for this study due to their widely reported intrinsic angiogenic properties. The results indicate that MSCs overexpressing HOTAIR (HOTAIR-MSCs) produce EVs with increased HOTAIR content that promote angiogenesis and wound healing in diabetic (db/db) mice. Further, endothelial cells exposed to HOTAIR-MSC EVs exhibit increased HOTAIR content correlated with upregulation of the angiogenic protein vascular endothelial growth factor. Thus, this study supports EV-mediated HOTAIR delivery as a strategy for further exploration toward healing of chronic wounds., (© 2021 Wiley-VCH GmbH.)

Ischemic necrosis of surgical flaps after reconstruction is a major clinical problem. Hypoxia-inducible factor-1α (HIF-1α) is considered the master regulator of the adaptive response to hypoxia. Among its many properties, it regulates the expression of genes encoding angiogenic growth factors, which have a short half-life in vivo. To achieve a continuous application of the therapeutic, we utilized DNA plasmid delivery. Transcription of the DNA plasmid confirmed by qRT-PCR showed significantly increased mRNA for HIF-1α in the transfected tissue compared to saline control tissue. Rats were preconditioned by injecting with either HIF-1α DNA plasmid or saline intradermally in the designated flap region on each flank. Seven days after preconditioning, each rat had two isolated pedicle flaps raised with a sterile silicone sheet implanted between the skin flap and muscle layer. The flaps preconditioned with HIF-1α DNA plasmid had significantly less necrotic area. Angiogenesis measured by CD31 staining showed a significant increase in the number of vessels per high powered field in the HIF-1α group (p < 0.05). Our findings offer a potential therapeutic strategy for significantly promoting the viability of surgical pedicle flaps by ischemic preconditioning with HIF-1α DNA plasmid.

Objective: The aim of the study was to investigate whether inhibition of Sonic Hedgehog (SHH) pathway would prevent progression of Barrett's Esophagus (BE) to esophageal adenocarcinoma., Background: The hedgehog signaling pathway is a leading candidate as a molecular mediator of BE and esophageal adenocarcinoma (EAC). Repurposed use of existing off-patent, safe and tolerable drugs that can inhibit hedgehog, such as itraconazole, could prevent progression of BE to EAC., Methods: The efficacy of itraconazole was investigated using a surgical rat reflux model of Barrett's Metaplasia (BM). Weekly intraperitoneal injections of saline (control group) or itraconazole (treatment group; 200 mg/kg) were started at 24 weeks postsurgery. Esophageal tissue was harvested at 40 weeks. The role of the Hh pathway was also evaluated clinically. Esophageal tissue was harvested after 40 weeks for pathological examination and evaluation of the SHH pathway by immunohistochemistry., Results: BM was present in control animals 29 of 31 (93%) versus itraconazole 22 of 24 (91%). EAC was significantly lower in itraconazole 2 of 24 (8%) versus control 10 of 31 (32%), respectively (P = 0.033). Esophageal SHH levels were lower in itraconazole vs control (P = 0.12). In esophageal tissue from humans with recurrent or persistent dysplastic BE within 24 months of ablative treatment, strong SHH and Indian Hedgehog expression occurred in distal BE versus proximal squamous epithelium, odds ratio = 6.1 (95% confidence interval: 1.6, 23.4) and odds ratio = 6.4 (95% confidence interval: 1.2, 32.8), respectively., Conclusion: Itraconazole significantly decreases EAC development and SHH expression in a preclinical animal model of BM. In humans, BE tissue expresses higher SHH, Indian Hedgehog, and bone morphogenic protein levels than normal squamous esophageal epithelium., Competing Interests: The authors report no conflicts of interest., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Both extracellular vesicles (EVs) and long noncoding RNAs (lncRNAs) have been increasingly investigated as biomarkers, pathophysiological mediators, and potential therapeutics. While these two entities have often been studied separately, there are increasing reports of EV-associated lncRNA activity in processes such as oncogenesis as well as tissue repair and regeneration. Given the powerful nature and emerging translational impact of other noncoding RNAs such as microRNA (miRNA) and small interfering RNA, lncRNA therapeutics may represent a new frontier. While EVs are natural vehicles that transport and protect lncRNAs physiologically, they can also be engineered for enhanced cargo loading and therapeutic properties. In this review, we will summarize the activity of lncRNAs relevant to both tissue repair and cancer treatment and discuss the role of EVs in enabling the potential of lncRNA therapeutics., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Bioengineering & Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.)

Background: Gastric cancer is a leading cause of cancer-related death across the world. A subset of gastric cancers demonstrates an inherited genetic predisposition. Individuals with germline mutations in the CDH1 gene incur a lifetime risk for diffuse gastric cancer and benefit from prophylactic gastrectomy. The results for this operative intervention remain relatively undescribed in the literature, despite guidelines supporting its use., Methods: We present a single-institution series of patients with confirmed CDH1 mutations who underwent gastrectomy. We describe their presenting symptoms, preoperative screening, clinicopathologic features, and outcomes. Focal outcomes of interest are weight loss and postoperative morbidity., Results: Between 2010 and 2018, ten patients with a confirmed CDH1 mutation underwent total gastrectomy with intestinal pouch reconstruction at our institution. Two patients had clinical gastric cancer at the time of their operation at 21 and 60 y of age. Eight patients had prophylactic gastrectomy. All prophylactic patients had undergone prior endoscopic screening without detection of cancer; however, three had occult gastric cancer on pathological examination. Median weight loss after gastrectomy was 10 kg at 6 mo and 11 kg at 1 y. Postoperative morbidity was limited to one anastomotic leak, one hematoma, and one case of pneumonia. All patients remain disease-free with median follow-up of 19 mo., Conclusions: Total gastrectomy for patients with a CDH1 mutation is a cancer-preventing operation for a high-risk population. For this series, jejunal pouch reconstruction was performed with encouragingly low postoperative morbidity, weight loss, and good subjective function., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Krüppel-like Factor 5 (KLF5) is a zinc-finger transcription factor associated with cell cycle progression and cell survival. KLF5 plays a key role in mammalian intestinal epithelium development and maintenance, expressed at high levels in basal proliferating cells and low levels in terminally differentiated cells. Considering Barrett's esophagus (BE) and esophageal adenocarcinoma's (EAC) histopathological similarities to intestinal epithelium, we sought to determine KLF5's role in BE and EAC, as well as KLF5's possible connection to the sonic hedgehog (SHH) pathway which is highly active in BE and EAC development. Low levels of KLF5 mRNA were found in BE cell lines and tissue- similar to what has been reported in differentiated intestinal epithelium. In contrast, higher KLF5 levels were observed in EAC cells and tissues. KLF5 knockdown in EAC cells caused significant decreases in cell migration, proliferation, and EAC-associated gene expression. Moreover, KLF5 knockdown led to decreased SHH signaling. These results suggest that KLF5 is connected to the SHH pathway in BE and EAC and may represent a potential drug target in EAC; further studies are now indicated to verify these findings and elucidate underlying mechanisms involved., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background/aim: The aim of the study was to evaluate the status of extravasated platelet activation (EPA) surrounding podoplanin (PDPN)-positive cancer-associated fibroblasts (CAFs) in pancreatic cancer stroma by neoadjuvant chemotherapy., Patients and Methods: A total of 74 patients were enrolled in this study. We investigated CD42b and PDPN expression in the groups of untreated, gemcitabine (GEM) alone, GEM plus S-1 (GS) and GEM plus nab-paclitaxel (GnP)., Results: CD42b expression in surrounding CAFs was observed in 58% patients. CD42b expression was significantly correlated with PDPN expression. CD42b-positive cases were significantly lower in the group treated with GnP than in the untreated group and groups treated with GEM alone or GS. PDPN expression was reduced in the GnP group, as revealed by markedly disorganized collagen and a low density of PDPN-positive fibroblasts. There was a significantly lower CD42b expression and fewer PDPN-positive fibroblasts in the GnP group than in untreated, GEM alone, and GS groups, but there was no significant difference between the latter three groups., Conclusion: There is a significant association between EPA and PDPN-positive CAFs in pancreatic cancer stroma. Our data suggest that the GnP regimen decreases EPA through PDPN-positive CAF depletion., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Skin and skin appendages protect the body from harmful environment and prevent internal organs from dehydration. Superficial epidermal wounds usually heal without scarring, however, deep dermal wound healing commonly ends up with nonfunctioning scar formation with substantial loss of skin appendage. Wound healing is one of the most complex dynamic biological processes, during which a cascade of biomolecules combine with stem cell influx and matrix synthesis and synergistically contribute to wound healing at all levels. Although many approaches have been investigated to restore complete skin, the clinically effective therapy is still unavailable and the regeneration of perfect skin still remains a significant challenge. The complete mechanism behind scarless skin regeneration still requires further investigation. Fortunately, recent advancement in regenerative medicine empowers us more than ever to restore tissue in a regenerative manner. Many studies have elucidated and reviewed the contribution of stem cells and growth factors to scarless wound healing. This article focuses on recent advances in scarless wound healing, especially strategies to engineer pro-regenerative scaffolds to restore damaged skin in a regenerative manner., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Prostaglandin E2 is one of the potential products that promotes development of tumors and also is a strong inducer of M2 phenotype macrophages, which contribute to tumor development in the immunosuppressed microenvironment. Hangeshashinto (TJ-14), a Japanese traditional medicine (Kampo medicine), has been reported to be effective in preventing chemotherapy-induced oral mucositis through the reduction of prostaglandin E2. We previously developed a surgical rat reflux model of esophageal cancer and used this well-established animal model to investigate the action of TJ-14 in preventing esophageal cancer. We also assessed the effect of TJ-14 on the downregulation of prostaglandin E2 production, utilizing esophageal squamous cell carcinoma cell line exposed to bile acid., Methods: An end-to-side esophagojejunostomy was performed for the reflux model. A daily oral diet was subsequently administered, consisting of either diet-incorporated TJ-14 or standard diet as a control group. The rats were killed at 40 weeks after surgery. The incidence of esophageal cancer, Barrett's metaplasia, and proliferative hyperplasia were assessed histologically. CD163, a M2 phenotype macrophage marker, was assessed with immunohistochemistry. Prostaglandin E2 enzyme immunoassay and lactate dehydrogenase assay were performed on chenodeoxycholic acid or gastroesophageal reflux contents exposed to esophageal squamous cell carcinoma cell line., Results: Sixty-seven percent of the controls (n = 12) developed esophageal cancer, but animals that received TJ-14 (n = 10) had a cancer incidence of 10% (P=.007). Barrett's metaplasia was found in 83% of the rats in the control group and 50% of the rats in the TJ-14 indicating a protective tendency of TJ-14 (P=.095). All of the rats developed proliferative hyperplasia. The number of M2 phenotype macrophage were significantly decreased in the TJ-14 group compared to the control group in both Barrett's metaplasia and esophageal cancer lesions. TJ-14 inhibited chenodeoxycholic acid or gastroesophageal reflux content-induced prostaglandin E2 production in esophageal squamous cell carcinoma cell., Conclusion: TJ-14 reduced the incidence of reflux-induced esophageal cancer and the infiltration of M2 macrophages in a surgical rat model or suppressed prostaglandin E2 production in esophageal squamous cell carcinoma cell. Further investigation is required regarding the potential clinical use of TJ-14 as an esophageal cancer chemopreventive agent., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Excessive bleeding is a complication of wound debridement in patients receiving anticoagulation treatment. Chitosan is a linear, positively charged polysaccharide that has potential as a hemostatic topical dressing. This study examined the hemostatic efficacy of the chitosan based Opticell dressing (Medline Industries, Chicago, Ill) in heparinized rats with excisional wounds mimicking debridement. Methods: Three paired 12-mm excisional wounds were created on the dorsum of 600-g Sprague-Dawley rats 2 hours after intraperitoneal injection of heparin 800 IU/kg. Opticell or gauze dressings were applied with 3 seconds of gentle pressure. Results: Total Bleeding : The dressings were left in place until cessation of bleeding. Ten minutes was enough time for complete bleeding cessation in both groups. Gauze and Opticell were weighed before and after bleeding cessation, with the difference representing blood loss. Total blood loss was 627 ± 47 mg/10 min with the standard gauze, but 247 ± 47 mg/10 min with Opticell ( P = .002 Mann-Whitney). N = 6 wounds per group. Rate of Bleeding: Gauze and Opticell dressings were removed and instantly replaced with 3 seconds of gentle pressure every minute until bleeding cessation. The removed dressings were weighed before and after application. There was less bleeding in the Opticell group at minutes 1, 2, and 3. Gauze: 183 ± 40, 140 ± 30, and 109 ± 15 mg/min vs Opticell: 91 ± 17, 54 ± 8, and 57 ± 11 mg/min). Analysis of variance, Tukey's test, P < .05. N = 12 wounds per group. Conclusion: Topical application of Opticell dressing with chitosan has hemostatic effects that could be a useful tool to control bleeding associated with wound debridement.

Background: In this study, the effects of neoadjuvant chemotherapy (NAC) on cancer-associated fibroblasts (CAFs) in pancreatic cancer stroma were investigated., Materials and Methods: Density of α-smooth muscle actin (αSMA)-positive fibroblasts in resected surgical specimens from untreated patients, patients receiving conventional gemcitabine plus S-1 (GS), and patients receiving gemcitabine plus nab-paclitaxel (GnP) was determined by hybrid cell counting. 18F-Fluorodeoxyglucose positron-emission tomography (FDG-PET) scans and carbohydrate antigen 19-9 (CA19-9) concentrations were used to assess tumor activity before and after chemotherapy in the GnP group., Results: In this retrospective study of 65 patients, αSMA expression was reduced in the GnP group, as revealed by markedly disorganized collagen and a low density of αSMA-positive fibroblasts. There were significantly fewer αSMA-positive fibroblasts in the GnP than in the untreated and GS groups, but there was no significant difference between the latter two groups. αSMA density reflected a decrease in standardized uptake value on FDG-PET, but not CA19-9 concentration, after GnP chemotherapy., Conclusion: These data suggest that the GnP regimen induces stromal depletion, resulting in fewer CAFs., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

To improve natural killer group 2 member D (NKG2D)-dependent cytotoxicity, the inhibition of cleavage and release of major histocompatibility complex class 1-related chain (MIC) molecules from the tumor surface are required. Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is able to induce cell-surface MICA/B on tumor cells. In the present study, the ability of VPA and gemcitabine (GEM) to upregulate MICA/B in pancreatic cancer cells was investigated, resulting in the inhibition of cleavage and release of MIC molecules from the tumor surface. Flow cytometry was used to quantify MICA/B expression in six human pancreatic cancer lines. Functional cytotoxic activity of γδT cells against pancreatic cancer cells treated with VPA and GEM was determined using cytotoxicity assays. At low doses of VPA (0.7 mM) and GEM (0.001 µM), which did not induce tumor growth alterations, the agents individually increased cell-surface MICA/B expression in MICA/B-positive cell lines, but not in the MICA/B-negative cell line. Furthermore, the combination of VPA and GEM synergistically induced cell-surface MICA/B expression. In MICA/B-positive cell lines, the increase in MICA/B expression was dependent on VPA concentration. The combination of low-dose VPA and GEM enhanced the susceptibility of the PANC-1 cell line to γδT cell-mediated tumor cell lysis. It was observed that soluble MIC was released from PANC-1 in the culture supernatant following treatment with GEM. However, the combination of low-dose VPA with low-dose GEM increased MICA/B expression without inducing soluble MIC, resulting in enhanced tumor cell lysis. The results of the present study suggest that the combined administration of low-dose VPA with low-dose GEM has the potential to enhance the therapeutic effects of immunotherapy in pancreatic cancer. Furthermore, it is proposed that the combination acts, in part, by upregulating MICA/B and prevents soluble MIC from being released.

Background/aim: Severe sepsis is associated with high morbidity and mortality rates. Inflammation and coagulation play pivotal roles in the pathogenesis of sepsis leading to multiple organ failure, especially in the liver. The aim of the present study was to assess the mechanism from sepsis to liver damage in a mouse model., Materials and Methods: We created a sepsis model by injecting lipopolysaccharide (LPS) intraperitoneally in mice. At 0, 6, 12, and 24 h following intraperitoneal injection of LPS, mice were euthanised and analyzed. Primary antibodies against myeloperoxidase (MPO), hepatic sinusoidal endothelial cells (SE-1), and P-selectin (CD62p) were used. Expression and localization in neutrophil, sinusoidal endothelial, and platelet cells were assessed by immunohistochemistry., Results: Immunohistochemical analyses revealed a positive staining for MPO, most abundantly in neutrophil granulocytes, within the hepatic sinusoids immediately after injection. Neutrophil extracellular trap (NET)-like structures stained for MPO, indicating the presence of neutrophils undergoing NETosis, were confirmed at 6 h after LPS administration. SE-1 staining for liver sinusoidal endothelial cells was significantly reduced at 12 h post-LPS administration through sinusoidal endothelial injury or detachment. Furthermore, the presence of extravasated platelets was confirmed in the space of Disse at 24 h after LPS administration. Blood sample analyses showed that white blood cell counts and platelet counts decreased gradually, while MPO amounts increased until 12 h after LPS administration., Conclusion: We conclude that NET formation and intravasated platelet aggregation are the first steps from sepsis to liver damage, and that extravasated platelet aggregation promoted by NET-facilitated detachment of sinusoidal endothelial cells is the origin of sepsis-induced liver dysfunction., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

We investigated the effect of gemcitabine (GEM), a key drug for pancreatic cancer treatment, on the expression of cell surface MICA/B in pancreatic cancer cells and resulting cytotoxicity of γδ T cells. We assessed the effect of GEM on the upregulation of cell surface MICA/B expression by flow cytometry, utilizing six pancreatic cancer cell lines. MICA and CD16 expressions from resected pancreatic cancer patient specimens, which received neoadjuvant chemotherapy (NAC) with GEM, were analyzed by immunohistochemistry. GEM could increase MICA/B expression on cell surface in pancreatic cancer cell lines (in 2 of 6 cell lines). This effect was most effectively at concentration not affecting cell growth of GEM (0.001 μM), because MICA/B negative population was appeared at concentration at cytostatic and cytotoxic effect to cell growth (0.1 and 10 μM). The cytotoxic activity of γδ T cells against PANC-1 was detected and functions through interactions between NKG2D and MICA/B. However, the enhancement of NKG2D-dependent cytotoxicity with increased MICA/B expression, by GEM treatment, was not observed. In addition, soluble MIC molecules were released from pancreatic cancer cell lines in culture supernatant with GEM treatment. Immunohistochemical staining demonstrated that MICA expression in tumor cells and CD16 positive cells surrounding tumors were significantly higher in the NAC group compared to that of the control group. There was a significant correlation between NAC and MICA expression, as well as NAC and CD16 positive cell expression. The present results indicate that low-dose GEM-induced MICA/B expression enhances innate immune function rather than cytotoxicity in pancreatic cancer. In addition, our result suggests that the inhibition of cleavage and release of MIC molecules from the tumor surface could potentially improve NKG2D-dependent cytotoxicity.

Study Design: Experimental study., Objectives: The objective of this study was to establish a non-invasive model to produce pressure ulcers of varying severity in animals with spinal cord injury (SCI)., Setting: The study was conducted at the Johns Hopkins Hospital in Baltimore, Maryland, USA., Methods: A mid-thoracic (T7-T9) left hemisection was performed on Sprague-Dawley rats. At 7 days post SCI, rats received varying degrees of pressure on the left posterior thigh region. Laser Doppler Flowmetry was used to record blood flow. Animals were killed 12 days after SCI. A cardiac puncture was performed for blood chemistry, and full-thickness tissue was harvested for histology., Results: Doppler blood flow after SCI prior to pressure application was 237.808±16.175 PFUs at day 7. Following pressure application, there was a statistically significant decrease in blood flow in all pressure-applied groups in comparison with controls with a mean perfusion of 118.361±18.223 (P<0.001). White blood cell counts and creatine kinase for each group were statistically significant from the control group (P=0.0107 and P=0.0028, respectively)., Conclusions: We have created a novel animal model of pressure ulcer formation in the setting of a SCI. Histological analysis revealed different stages of injury corresponding to the amount of pressure the animals were exposed to with decreased blood flow immediately after the insult along with a subsequent marked increase in blood flow the next day, conducive to an ischemia-reperfusion injury (IRI) and a possible inflammatory response following tissue injury. Following ischemia and hypoxia secondary to microcirculation impairment, free radicals generate lipid peroxidation, leading to ischemic tissue damage. Future studies should be aimed at measuring free radicals during this period of increased blood flow, following tissue ischemia.

Green Fluorescent protein (GFP), used as a cellular tag, provides researchers with a valuable method of measuring gene expression and cell tracking. However, there is evidence to suggest that the immunogenicity and cytotoxicity of GFP potentially confounds the interpretation of in vivo experimental data. Studies have shown that GFP expression can deteriorate over time as GFP tagged cells are prone to death. Therefore, the cells that were originally marked with GFP do not survive and cannot be accurately traced over time. This review will present current evidence for the immunogenicity and cytotoxicity of GFP in in vivo studies by characterizing these responses., Competing Interests: The authors of this manuscript do not indicate any conflict of interest.

A number of studies have reported that acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are independent risk factors for organ dysfunction and mortality in patients with sepsis. Although ALI/ARDS might be an essential therapeutic target during the management of sepsis, severe sepsis should be treated effectively and as soon as identified. We have classified three phases, ranging from sepsis to organ dysfunction, characterizing the interaction between neutrophils and platelets. The first phase is neutrophil extracellular trap (NET) formation and intravasated platelet aggregation. The next phase is extravasated platelet aggregation (EPA), promoted by NET-facilitated detachment of endothelial cells. The final phase is organ dysfunction, caused by pulmonary veno-occlusive disease (VOD), fibrosis, and immunoparalysis induced by EPA. Severe sepsis is characterized by a continuum of coagulopathy, with coagulation abnormalities often developing before the onset of clinical symptoms. The initial medical treatment for ALI/ARDS is inhibition of NET formation and intravasated platelet aggregation to prevent endothelial cell damage (Phase 1). Beraprost and silvestat, phosphodiesterase 3 (PDE3) inhibitors, are often administered in clinical practice. To determine hypercoagulopathy, plasma levels of thrombin-antithrombin complex and plasmin-plasmin inhibitor complex are continuously monitored in patients with suspected sepsis. Furthermore, the implementation of quality indicators for the early management of severe sepsis and septic shock is strongly associated with a reduced mortality. We conclude that pathophysiology of organ dysfunction from severe sepsis is caused by pulmonary VOD, fibrosis, and EPA-facilitated immunoparalysis. In order to prevent ALI/ARDS in patients with sepsis, countermeasures for NET and platelet aggregation should be pre-emptively employed and confirmed by several trials., (Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Background: The exact sequence of events leading to ultimate hepatocellular damage following ischemia/reperfusion (I/R) is incompletely understood. In this article, we review a mechanism of organ dysfunction after hepatic I/R or immunosuppressive treatment, in addition to the potential of liver sinusoidal endothelial cell (LSEC) protection and antiplatelet treatment for the suppression of hepatocellular damage., Methods: A review of the literature, utilizing PubMed-NCBI, was used to provide information on the components necessary for the development of hepatocellular damage following I/R., Results: It is well-established that LSECs damage following hepatic I/R or immunosuppressive treatment followed by extravasated platelet aggregation (EPA) is the root cause of organ dysfunction in liver transplantation. We have classified three phases, from LSECs damage to organ dysfunction, utilizing the predicted pathogenic mechanism of sinusoidal obstruction syndrome. The first phase is detachment of LSECs and sinusoidal wall destruction after LSECs injury by hepatic I/R or immunosuppressive treatment. The second phase is EPA, accomplished by sinusoidal wall destruction. The various growth factors, including thromboxane A2, serotonin, transforming growth factor-beta and plasminogen activator inhibitor-1, released by EPA in the Disse's space of zone three, induce portal hypertension and the progression of hepatic fibrosis. The third phase is organ dysfunction following portal hypertension, hepatic fibrosis, and suppressed liver regeneration through various growth factors secreted by EPA., Conclusion: We suggest that EPA in the space of Disse, initiated by LSECs damage due to hepatic I/R or immunosuppressive treatment, and activated platelets may primarily contribute to liver damage in liver transplantation. Endothelial protective therapy or antiplatelet treatment may be useful in the treatment of hepatic I/R following EPA.

Wounds are among the most common, painful, debilitating and costly conditions in older adults. Disruption of the angiotensin type 1 receptors (AT1R), has been associated with impaired wound healing, suggesting a critical role for AT1R in this repair process. Biological functions of angiotensin type 2 receptors (AT2R) are less studied. We investigated effects of genetically disrupting AT2R on rate and quality of wound healing. Our results suggest that AT2R effects on rate of wound closure depends on the phase of wound healing. We observed delayed healing during early phase of wound healing (inflammation). An accelerated healing rate was seen during later stages (proliferation and remodeling). By day 12, fifty percent of AT2R(-/-) mice had complete wound closure as compared to none in either C57/BL6 or AT1R(-/-) mice. There was a significant increase in AT1R, TGFβ1 and TGFβ2 expression during the proliferative and remodeling phases in AT2R(-/-) mice. Despite the accelerated closure rate, AT2R(-/-) mice had more fragile healed skin. Our results suggest that in the absence of AT2R, wound healing rate is accelerated, but yielded worse skin quality. Elucidating the contribution of both of the angiotensin receptors may help fine tune future intervention aimed at wound repair in older individuals.

Background: The last decade has focused attention on the central role of platelets interacting with the tumor cells and the immune system in promoting tumor progression and distant spread through release of growth factors, such as transforming growth factor beta, vascular endothelial growth factor A, and plasminogen activator inhibitor 1, into the tumor microenvironment. We focused on the potential metastasis-promoting role of extravasated platelet aggregation in pancreatic cancer and stroma., Materials and Methods: Resected pancreatic cancer specimens from 40 patients were used in this study. To examine the expression and localization of platelet aggregation in the epithelial-mesenchymal transition (EMT) region in cancer and stroma, CD42b, Snail1, and E-cadherin were assessed using immunohistochemistry. We determined the correlation of these expressed proteins with clinical features., Results: CD42b expression was detected at the invasive front of the tumor, which was in 73% of the EMT portion, but not in the region of tubular formation. Increased Snail1 and reduction and/or loss of E-cadherin expressions were noted in 85% and 75% of the EMT portion, respectively. There was a significant correlation between CD42b and Snail1 expressions (P = 0.02) and CD42b and reduction and/or loss of E-cadherin expressions (P = 0.008)., Conclusions: We demonstrate that extravasated platelet aggregation is associated with the first step in the formation of the EMT. These data suggest a potential role for antiplatelet agents to suppress EMT and metastasis by changing the tumor microenvironment., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Animal models are important for the development of novel therapies for esophageal cancer. Histone deacetylase 1 ( HDAC1 )/metastasis-associated gene ( MTA1 ) complexes inhibit p53 acetylation and thus, inhibit p53-induced apoptosis. The aim of the present study was to evaluate HDAC1 and MTA1 expression in esophageal carcinogenesis in rats. The rats underwent a total gastrectomy followed by esophagojejunostomy to induce chronic duodenal content reflux esophagitis. The rats were sacrificed sequentially at 20, 30, 40 and 50 weeks post-surgery and the esophagi were examined. Immunohistochemical analysis was conducted to assess the expression and localization of HDAC1 and MTA1. At 20 weeks post-surgery, squamous proliferative hyperplasia and Barrett's metaplasia (BM) were observed. While, adenocarcinoma-associated BM and squamous cell carcinoma were observed at 30-50 weeks post-surgery. The nuclear expression of HDAC1 and MTA1 was observed in all of the stages of squamous carcinogenesis and adenocarcinogenesis, although not in the normal esophageal epithelium. The expression of HDAC1 and MTA1 may be involved in duodenoesophageal reflux-induced neoplastic transformation of the esophageal mucosa into cancer cells with squamous and adeno differentiation.

Background and Aims: Chronic inflammation has been demonstrated to correlate with tumor onset and progression. Tumor-associated macrophages (TAMs) play an important role in inflammatory tumor microenvironment. We hypothesized that an inflammatory microenvironment around TAMs may promote the development of esophageal carcinomas when induced by duodenal content reflux without carcinogens., Animals and Methods: A total gastrectomy followed by esophagojejunostomy was performed on rats in order to induce chronic duodenal content reflux esophagitis. The animals were sacrificed sequentially, at the 20th, 30th, 40th and 50th week after surgery, and their esophagi were examined. The primary antibodies against CD68, CD163, pStat3 and Foxp3 were used. Expression and localization of infiltrated cells was assessed by immunohistochemical analysis., Results: At 20-weeks' post-surgery, squamous proliferative hyperplasia (PHP) and Barrett's metaplasia (BM) were observed. Adenocarcinoma (ADC) associated with BM, and squamous cell carcinoma (SCC) were observed 30-50 weeks' post-surgery. Numerous CD68 and pStat3-positive cells were identified surrounding PHP and BM after 20 weeks, and around ADC and SCC after 30 weeks. Moderate infiltration of CD163-positive macrophages was seen with BM, ADC, and SCC after 30 weeks. However, very few Foxp3-positive cells were observed around ADC and SCC., Conclusion: Macrophages infiltrate the esophagus and activate the pStat3 pathway in stromal cells and epithelium. M2 phenotype macrophages infiltrate following infiltration of M1 macrophage and contribute to tumor development through regulatory T cells (Tregs). The involvement of immune cells such as TAMs and Tregs in the inflammatory microenvironment promotes esophageal carcinogenesis.

Fragile skin, susceptible to decubitus ulcers and incidental trauma, is a problem particularly for the elderly and for those with spinal cord injury. Here, we present a simple approach to strengthen the skin by the topical delivery of keratinocyte growth factor-1 (KGF-1) DNA. In initial feasibility studies with the novel minimalized, antibiotic-free DNA expression vector, NTC8385-VA1, the reporter genes luciferase and enhanced green fluorescent protein were delivered. Transfection was documented when luciferase expression significantly increased after transfection. Microscopic imaging of enhanced green fluorescent protein-transfected skin showed green fluorescence in hair follicles, hair shafts, and dermal and superficial epithelial cells. With KGF-1 transfection, KGF-1 mRNA level and protein production were documented with quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. Epithelial thickness of the transfected skin in the KGF group was significantly increased compared with the control vector group (26 ± 2 versus 16 ± 4 µm) at 48 hours (P = 0.045). Dermal thickness tended to be increased in the KGF group (255 ± 36 versus 162 ± 16 µm) at 120 hours (P = 0.057). Biomechanical assessment showed that the KGF-1-treated skin was significantly stronger than control vector-transfected skin. These findings indicate that topically delivered KGF-1 DNA plasmid can increase epithelial thickness and strength, demonstrating the potential of this approach to restore compromised skin.

Impaired burn wound healing in the elderly represents a major clinical problem. Hypoxia-inducible factor-1 (HIF-1) is a transcriptional activator that orchestrates the cellular response to hypoxia. Its actions in dermal wounds promote angiogenesis and improve healing. In a murine burn wound model, aged mice had impaired wound healing associated with reduced levels of HIF-1. When gene therapy with HIF-1 alone did not correct these deficits, we explored the potential benefit of HIF-1 gene therapy combined with the intravenous infusion of bone marrow-derived angiogenic cells (BMDACs) cultured with dimethyloxalylglycine (DMOG). DMOG is known to reduce oxidative degradation of HIF-1. The mice treated with a plasmid DNA construct expressing a stabilized mutant form of HIF-1α (CA5-HIF-1α)+BMDACs had more rapid wound closure. By day 17, there were more mice with completely closed wounds in the treated group (χ(2), P=0.05). The dermal blood flow measured by laser Doppler showed significantly increased wound perfusion on day 11. Homing of BMDACs to the burn wound was dramatically enhanced by CA5-HIF-1α gene therapy. HIF-1α mRNA expression in the burn wound was increased after transfection with CA5-HIF-1α plasmid. Our findings offer insight into the pathophysiology of burns in the elderly and point to potential targets for developing new therapeutic strategies.

Gastro-duodenal content reflux from gastro-esophageal reflux disease (GERD) induces the inflammation-metaplasia-dysplasia-adenocarcinoma sequence. Proton pump inhibitors (PPIs) are potent blockers of gastric acid secretion, which are widely used for treating GERD and peptic ulcer-associated acid-secreting diseases. The effect of PPI therapy on esophageal carcinogenesis remains unclear. While some studies suggest PPIs result in a significant reduction in the risk of developing dysplasia and adenocarcinoma in patients with Barrett's esophagus, others suggest that PPIs have no effect. Recent studies have revealed that PPIs can exert anti-inflammatory effects such as anti-oxidant properties and immunomodulatory effects through their interactions with neutrophils, monocytes, endothelial and epithelial cells. In addition, PPIs have the ability to prevent adhesion molecule binding in malignant cells and suppress metastasis. This article reviews the role of PPIs in esophageal carcinogenesis and their use as antitumor agents.

The mechanism through which each histological type of carcinoma arises from the esophageal mucosa remains unknown. This study was designed to investigate whether there is an association between the severity of duodeno-esophageal reflux and the histological type of esophageal cancer. A series of 120 male Fischer rats, weighing ∼180 g, were randomized to receive one of the following procedures: duodeno-forestomach reflux (DFR) with reduced exposure to duodenal contents, duodeno-esophageal reflux (DER) with increased exposure to duodenal contents and three control operations (DFR, DER control and sham). The reflux of bile was estimated with (99m)Tc-PMT scintigraphy. All animals were fed a standard diet without carcinogen. The esophageal mucosa was assessed 50 weeks after surgery for carcinoma. The median scanned fraction rate of duodeno-esophageal reflux was significantly lower for the rodents in the DFR group than those in the DER group. Five of 28 rodents in the DFR group and 17 of the 22 rodents in the DER group developed esophageal carcinoma. None of the controls developed carcinoma. The five rodents in the DFR group developed SCC. Of 22 esophageal carcinomas for the DER group, nine were SCC, 12 ADC and one was adenosquamous carcinoma. The fraction of esophageal SCC for the DFR group was significantly higher than that for the DER group, while the fraction of esophageal ADC for the DFR group was significantly lower than that for the DER group. These observations suggest that the severity of duodeno-esophageal reflux in rodents is related to the development of different histological types of esophageal carcinoma., (Copyright © 2012 UICC.)

The incidence of esophageal cancer continues to rise in the Western world. Prior studies have suggested that gastroduodenal content reflux from gastroesophageal reflux disease induces the inflammation-mediated progression from hyperplasia to metaplasia, and to adenocarcinoma. We further investigated the sequential development of esophageal adenocarcinoma (EADC) with the use of an established surgical rat model. The present paper will describe the impact of the inflammation-metaplasia-adenocarcinoma sequence and chemoprevention in surgical rat models. A clinically relevant rat reflux model was used to investigate the cause of carcinogenesis, the sequential development of adenocarcinoma and chemoprevention with the use of a proton pump inhibitor. We found that duodenal reflux plays an important role in the inflammation-induced transformation of esophageal mucosa to adenocarcinoma. We were able to inhibit this transformation with rabeprazole, a proton pump inhibitor. Duodenal reflux promotes inflammation in the esophagus. The inflammation-metaplasia-adenocarcinoma sequence is important in the progression and development of EADC. Carcinogenesis can be prevented with chemoprevention agents such as rabeprazole. These results will need to be validated in clinical trials., (Copyright © 2013 S. Karger AG, Basel.)

Chronic systemic hypertension causes cardiac pressure overload leading to increased myocardial O(2) consumption. Hypoxia-inducible factor 1 (HIF-1) is a master regulator of O(2) homeostasis. Mouse embryos lacking expression of the O(2)-regulated HIF-1α subunit die at midgestation with severe cardiac malformations and vascular regression. Here we report that Hif1a(f/f);Tie2-Cre conditional knockout mice, which lack HIF-1α expression only in Tie2(+) lineage cells, develop normally, but when subjected to pressure overload induced by transaortic constriction (TAC), they manifest rapid cardiac decompensation, which is accompanied by excess cardiac fibrosis and myocardial hypertrophy, decreased myocardial capillary density, increased myocardial hypoxia and apoptosis, and increased TGF-β signaling through both canonical and noncanonical pathways that activate SMAD2/3 and ERK1/2, respectively, within endothelial cells of cardiac blood vessels. TAC also induces dilatation of the proximal aorta through enhanced TGF-β signaling in Hif1a(f/f);Tie2-Cre mice. Inhibition of TGF-β signaling by treatment with neutralizing antibody or pharmacologic inhibition of MEK-ERK signaling prevented TAC-induced contractile dysfunction and pathological remodeling. Thus, HIF-1 plays a critical protective role in the adaptation of the heart and aorta to pressure overload by negatively regulating TGF-β signaling in endothelial cells. Treatment of wild-type mice with digoxin, which inhibits HIF-1α synthesis, resulted in rapid cardiac failure after TAC. Although digoxin has been used for decades as an inotropic agent to treat heart failure, it does not improve survival, suggesting that the countertherapeutic effects of digoxin observed in the TAC mouse model may have clinical relevance.

Aims: Hypoxia-inducible factor 1 (HIF-1) is a heterodimer composed of HIF-1α and HIF-1β subunits. HIF-1 is known to promote tissue vascularization by activating the transcription of genes encoding angiogenic factors, which bind to receptors on endothelial cells (ECs) and bone marrow-derived angiogenic cells (BMDACs). In this study, we analysed whether HIF-1 activity in the responding ECs and BMDACs is also required for cutaneous vascularization during burn wound healing., Methods and Results: We generated mice with floxed alleles at the Hif1a or Arnt locus encoding HIF-1α and HIF-1β, respectively. Expression of Cre recombinase was driven by the Tie2 gene promoter, which is expressed in ECs and bone marrow cells. Tie2Cre(+) and Tie2Cre(-) mice were subjected to burn wounds of reproducible diameter and depth. Deficiency of HIF-1α or HIF-1β in Tie2-lineage cells resulted in delayed wound closure, reduced vascularization, decreased cutaneous blood flow, impaired BMDAC mobilization, and decreased BMDAC homing to burn wounds., Conclusion: HIF-1 activity in Tie2-lineage cells is required for the mobilization and homing of BMDACs to cutaneous burn wounds and for the vascularization of burn wound tissue.

Neovascularization is a critical determinant of wound-healing outcomes for deep burn injuries. We hypothesize that dextran-based hydrogels can serve as instructive scaffolds to promote neovascularization and skin regeneration in third-degree burn wounds. Dextran hydrogels are soft and pliable, offering opportunities to improve the management of burn wound treatment. We first developed a procedure to treat burn wounds on mice with dextran hydrogels. In this procedure, we followed clinical practice of wound excision to remove full-thickness burned skin, and then covered the wound with the dextran hydrogel and a dressing layer. Our procedure allows the hydrogel to remain intact and securely in place during the entire healing period, thus offering opportunities to simplify the management of burn wound treatment. A 3-week comparative study indicated that dextran hydrogel promoted dermal regeneration with complete skin appendages. The hydrogel scaffold facilitated early inflammatory cell infiltration that led to its rapid degradation, promoting the infiltration of angiogenic cells into the healing wounds. Endothelial cells homed into the hydrogel scaffolds to enable neovascularization by day 7, resulting in an increased blood flow significantly greater than treated and untreated controls. By day 21, burn wounds treated with hydrogel developed a mature epithelial structure with hair follicles and sebaceous glands. After 5 weeks of treatment, the hydrogel scaffolds promoted new hair growth and epidermal morphology and thickness similar to normal mouse skin. Collectively, our evidence shows that customized dextran-based hydrogel alone, with no additional growth factors, cytokines, or cells, promoted remarkable neovascularization and skin regeneration and may lead to novel treatments for dermal wounds.

Impaired wound healing in the elderly represents a major clinical problem. Delineating the cellular and molecular mechanisms by which aging impairs wound healing may lead to the development of improved treatment strategies for elderly patients with non-healing wounds. Neovascularization is an essential step in wound healing, and bone marrow-derived angiogenic cells (BMDACs) play an important role in vascularization. Using a mouse full-thickness burn wound model, we demonstrate that perfusion and vascularization of burn wounds were impaired by aging and were associated with dramatically reduced mobilization of BMDACs bearing the cell surface molecules CXCR4 and Sca1. Expression of stromal-derived factor 1 (SDF-1), the cytokine ligand for CXCR4, was significantly decreased in peripheral blood and burn wounds of old mice. Expression of hypoxia-inducible factor (HIF)-1α was detected in burn wounds from young (2-month-old), but not old (2-year-old), mice. When BMDACs from young donor mice were injected intravenously, homing to burn wound tissue was impaired in old recipient mice, whereas the age of the BMDAC donor mice had no effect on homing. Our results indicate that aging impairs burn wound vascularization by impairing the mobilization of BMDACs and their homing to burn wound tissue as a result of impaired HIF-1 induction and SDF-1 signaling.

Background: The role of proton pump inhibitors in Barrett's metaplasia and esophageal adenocarcinoma has been an area of controversy., Aims: We evaluated the effectiveness of the proton pump inhibitor rabeprazole as a chemoprevention agent in a surgical rat reflux model of esophageal cancer., Methods: The rat reflux model was created by performing a jejuno-esophagostomy on Sprague-Dawley rats. The surgery promoted the reflux of gastro-duodenal contents into the esophagus. Rabeprazole sodium (Eisai, Tokyo, Japan) was dissolved in 0.9% physiological saline to a desired concentration of 1.5% (W/V). Beginning 4 weeks post-surgery, all animals were administered either 0.2 ml per 100 g body weight injections of rabeprazole or equivalent injections of saline 3 days per week into the subcutaneous tissue of the back. Forty animals were killed 40 weeks after surgery and their esophagi were examined. Of these, 23 were included in the control group, while the remaining 17 were subjected to rabeprazole., Results: While 74% (17/23) of the controls developed esophageal cancer, animals administered rabeprazole had an incidence of cancer of 29% (5/17) (p < 0.05, Fisher's exact test). Barrett's metaplasia was found on 100% (23/23) of the rats in the placebo group, but there was a protective effect in the rabeprazole group with 65% (11/17) of the rats displaying signs of Barrett's metaplasia (p < 0.05, Fisher's exact test). All of the rats developed proliferative hyperplasia., Conclusions: Rabeprazole protected against the development of esophageal cancer in a clinically relevant surgical reflux model. Rabeprazole warrants further investigation for potential clinical use as a chemoprevention agent.

Hypoxia Inducible Factor-1 (HIF-1) is considered the major coordinator of the cellular adaptive response to hypoxia. Over recent years, its activity in the context of wound healing has been the object of increasing investigation. On the molecular level, HIF-1 transcriptional target products have been shown to regulate the process of endothelial cell survival, migration and proliferation (VEGF, ANGPT-1, ANGPT-2, ANGPT-4, FGF-2, PlGF, PDGF-B, RGC-32), vascular smooth muscle cell migration and proliferation (FGF-2, EGF, PDGF, thrombospondin) and mobilization of Circulating Angiogenic Cells to the periphery (SFD-1/CXCR4). Studies on the effect of HIF-1 on the expression and activity of extracellular cell matrix modifying enzymes, such as MMPs and prolidase, have been conducted in the context of tumor angiogenesis and metastasis, and have resulted in controversial findings. A growing body of evidence suggests that HIF-1 also affects reepithelialization of the wound bed, through increasing keratinocyte migration, but decreasing their proliferation. Diminished HIF-1 levels and activity have been documented in conditions of impaired wound healing, such as wound healing in aged and in diabetic mice. The increasing number of studies on the role of HIF-1 in wound healing, apart from answering certain questions, has also raised an equal number, if not more. Clarifying the topics that still remain unclear could introduce a new era of HIF-1 targeted management of a wide range of problematic wounds.

The importance of hypoxia-inducible factor (HIF) in promoting angiogenesis and vasculogenesis during wound healing has been demonstrated. It is widely accepted that HIF activity can be promoted by many factors, including hypoxia in the wound or cytokines from inflammatory cells infiltrating the wound. However, there has not been a systematic exploration of the relationship between HIF activity and hypoxia in the burn wound. The location of the hypoxic tissue has not been clearly delineated. The time course of the appearance of hypoxia and the increased activity of HIF and appearance of HIF's downstream transcription products has not been described. The aim of this study was to utilize pimonidazole, a specific tissue hypoxia marker, to characterize the spatial and temporal course of hypoxia in a murine burn model and correlate this with the appearance of HIF-1α and its important angiogenic and vasculogenic transcription products vascular endothelial growth factor and SDF-1. Hypoxia was found in the healing margin of burn wounds beginning at 48 hours after burn and peaking at day 3 after burn. On sequential sections of the same tissue block, positive staining of HIF-1α, SDF-1, and vascular endothelial growth factor all occurred at the leading margin of the healing area and peaked at day 3, as did hypoxia. Immunohistochemical analysis was used to explore the characteristics of the hypoxic region of the wound. The localization of hypoxia was found to be related to cell growth and migration, but not to proliferation or inflammatory infiltration., (© 2011 by the Wound Healing Society.)