Corticosteroids impair intestinal epithelial wound repair mechanisms in vitro

Oral Budesonide and low serum albumin levels at surgery are associated with a higher risk of postoperative intra-abdominal septic complications after primary ileocaecal resection for Crohn's disease: A retrospective analysis of 853 consecutive patients

BACKGROUND AND AIMS

The terminal ileum is the most frequent site of Crohn's Disease (CD) that necessitates surgery. Of the postoperative complications (POCs) associated with ileocaecal resection for CD, intra-abdominal septic complications (IASCs) include anastomotic leak, abscesses, and entero-cutaneous fistula. We aimed to identify predictors of IASCs and severe POCs (Clavien-Dindo ≥3) after primary ileocaecal resection for CD.

METHODS

This is a retrospective single-centre cohort study including all consecutive primary ileocaecal resection for CD in a tertiary IBD centre between 2004 and 2021.

RESULTS

A total of 853 patients underwent primary ileocaecal resection for CD. 307 (36.6 %) patients were receiving antibiotics, 253 (29.8 %), systemic steroids, and 178 (21.0 %) oral budesonide at surgery. At 90 days, 260 (30.8 %) patients developed POCs, 62 (7.3 %) severe POCs, and 56 (6.6 %) IASCs. At multivariate analysis, severe POCs were associated with lower preoperative albumin levels (OR1.58, 95 %CI 1.02-2.50, p = 0.040) and a history of cardiovascular diseases (OR2.36, 95 %CI 1.08-7.84, p = 0.030). IASCs were associated with lower preoperative albumin levels (OR1.81, 95 %CI 1.15-2.94, p = 0.011) and oral budesonide (OR2.07, 95 %CI 1.12-3.83, p = 0.021) with a dose-dependent effect.

CONCLUSIONS

The independent association, dose-dependent effect, and biological plausibility of budesonide and IASCs suggest a robust causal effect. Oral budesonide should be carefully assessed before primary ileocaecal resection for CD.

Decreasing the steroid rapidly may help to improve the clinical outcomes of patients with intestinal steroid-refractory acute graft-versus-host disease receiving basiliximab treatment

Intestinal steroid refractory acute graft-versus-host disease (SR-aGVHD) is the major cause of mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT). This retrospective cohort study aimed to identify the relationship between different steroid decreasing velocity and therapeutic response in patients with intestinal SR-aGVHD receiving basiliximab treatment, and also aimed to propose a reasonable steroid decreasing regimen for these patients. The median time for steroid dose decreasing to the 50% of initial dose and decreasing to the low-dose steroid for patients achieving ORR was 5 days and 12 days, respectively, which was both shorter than patients without achieving ORR. The ORR, NRM and survival in rapid and medium steroid decreasing group were all better than slow group. The cumulative incidence of ORR at any time was 90.4%, 78.1% and 62.3%, respectively, in rapid, medium, and slow group. The cumulative incidence of NRM at 1 year after basiliximab treatment was 18.7% (95% CI 11.3%-26.1%), 22.8% (95% CI 14.2%-31.4%) and 32.8% (95% CI 24.1%-41.5%), respectively, in rapid, medium, and slow group. The probability of OS at 1 year after basiliximab treatment was 76.9% (95% CI 68.9%-84.9%), 72.7% (95% CI 63.7%-81.7%), and 62.3% (95% CI 53.5%-71.1%), respectively, in rapid, medium, and slow group. Hence, it was helpful to decrease steroid to the 50% of initial dose ≤ 5 days and to the low-dose steroid ≤ 12 days after basiliximab treatment for intestinal SR-aGVHD patients, which may also be the reasonable steroid decrease protocol for these patients.

Risk Factors for Dehiscence of Operative Incisions in Newborns after Laparotomy

BACKGROUND

 Surgical wound dehiscence (SWD) in neonates is a life-threatening complication. The aim was to define risk factors of postoperative incision dehiscence in this population.

METHODS

 Data of 144 patients from 2010 to 2020 were analyzed retrospectively. All full-term newborns or preterm newborns up to 42 weeks of amenorrhea (adjusted) who had a laparotomy within 30 days were included. Descriptive patient information and perioperative data were collected. SWD was defined as any separation of cutaneous edges of postoperative wounds.

RESULTS

 Overall, SWD occurred in 16/144 (11%) patients, with a significantly increased incidence in preterm newborns (13/59, 22%) compared with full-term newborns (3/85, 4%; p < 0.001). SWD was significantly associated with exposure to postnatal steroids (60% vs. 4%, p < 0.001) and nonsteroidal anti-inflammatory drugs (25% vs. 4%, p < 0.01), invasive ventilation duration before surgery (median at 10 vs. 0 days, p < 0.001), preoperative low hemoglobin concentration (115 vs. 147 g/L, p < 0.001) and platelet counts (127 vs. 295 G/L, p < 0.001), nonabsorbable suture material (43% vs. 8%, p < 0.001), the presence of ostomies (69% vs. 18%, p < 0.001), positive bacteriological wound cultures (50% vs. 6%, p < 0.001), and relaparotomy (25% vs. 3%, p < 0.01). Thirteen of 16 patients with SWD presented necrotizing enterocolitis/intestinal perforations (81%, p < 0.001).

CONCLUSION

 This study identified prematurity and a number of other factors linked to the child's general condition as risk factors for SWD. Some of these can help physicians recognize and respond to at-risk patients and provide better counseling for parents.

Pneumatosis intestinalis in the pediatric oncology population: An 11-year retrospective review at Memorial Sloan Kettering Cancer Center

BACKGROUND

Pneumatosis intestinalis (PI) is characterized by the presence of intramural gas in the gastrointestinal (GI) tract. The overall aim of this study was to review risk factors and outcome of pediatric oncology patients at our institution who developed PI.

PROCEDURE

Patients diagnosed with PI between 2007 and 2018 were identified from ICD-10 coding of radiology reports at Memorial Sloan Kettering Kids, a tertiary pediatric oncology center. Outcomes of interest were (a) resolution and time to resolution of PI, (b) surgical intervention within 2 weeks of diagnosis of PI, or (c) death secondary to PI. To capture the resolution of PI, we defined the "time to recovery (TTR)" as the time elapsed between date of PI diagnosis and the date of recovery.

RESULTS

Forty-two patients were identified. Within 30 days of diagnosis of PI, three patients had surgical intervention for PI (7%) and two patients died (5%) due to non-PI causes. Median TTR of PI was 4.5 days (95% CI: 3-7 days). In univariable and multivariable analyses, only steroid use in the prior 30 days was significantly associated with a faster TTR of PI (HR = 2.27 [95% CI: 1.17-4.41], p = .02).

CONCLUSIONS

This is the largest case series of patients with PI in the pediatric oncology population, which reveals significantly lower surgical and mortality rates than other published PI series. For the majority of patients, conservative medical management is indicated. A prospective study is warranted to define diagnosis and management guidelines for PI in the pediatric oncology population in a cooperative group setting.

MODULATION OF INTESTINAL BARRIER FUNCTION BY GLUCOCORTICOIDS: LESSONS FROM PRECLINICAL MODELS

Glucocorticoids (GCs) are widely used drugs for their anti-inflammatory and immunosuppressant effects, but they are associated with multiple adverse effects. Despite their frequent oral administration, relatively little attention has been paid to the effects of GCs on intestinal barrier function. In this review, we present a summary of the published studies on this matter carried out in animal models and cultured cells. In cultured intestinal epithelial cells, GCs have variable effects in basal conditions and generally enhance barrier function in the presence of inflammatory cytokines such as tumor necrosis factor (TNF). In turn, in rodents and other animals, GCs have been shown to weaken barrier function, with increased permeability and lower production of IgA, which may account for some features observed in stress models. When given to animals with experimental colitis, barrier function may be debilitated or strengthened, despite a positive anti-inflammatory activity. In sepsis models, GCs have a barrier-enhancing effect. These effects are probably related to the inhibition of epithelial cell proliferation and wound healing, modulation of the microbiota and mucus production, and interference with the mucosal immune system. The available information on underlying mechanisms is described and discussed.

Graft-versus-host disease: a disorder of tissue regeneration and repair

Regenerative failure at barrier surfaces and maladaptive repair leading to fibrosis are hallmarks of graft-versus-host disease (GVHD). Although immunosuppressive treatment can control inflammation, impaired tissue homeostasis leads to prolonged organ damage and impaired quality of life. In this Spotlight article, we review recent research that addresses the critical failures in tissue regeneration and repair that underpin treatment-resistant GVHD. We highlight current interventions designed to overcome these defects and provide our assessment of the future therapeutic landscape.

Curative effects of sophorolipid on physical wounds: In vitro and in vivo studies

Early‐weaning syndrome is harmful to animals because an effect on growth in the early‐stage of life generally determines the overall growth rate. Sophorolipid (SPL), a surface‐active glycolipid compound, has been shown to exhibit antimicrobial activity and stimulate cell proliferation. Thus, in vitro and in vivo studies were conducted to evaluate the potential of SPL on the gut turnover after the wound. The in vitro experiment with HT‐29 cells showed the increased proliferation with increasing gene levels of collagenase‐1 and matrilysin‐1. Next, the 16‐day in vivo experiment was conducted with thirty rats (14‐day‐old), and the allocation was performed according to their body weight (BW) into three treatments: control diet (CON), 48 ppm of oxytetracycline‐supplemented diet (OTC) and 10 ppm of SPL‐supplemented diet (SPL). Dietary SPL accelerates the growth of rats in overall periods, and intestinal permeability was lower in SPL at day 16. Villus:crypt ratio and the goblet cell count were also higher in SPL than in CON at day 8. Caecal Streptococcus spp. were significantly reduced with dietary SPL and OTC at day 8 and 16, and total short‐chain fatty acid, acetate and butyrate levels were increased in the SPL at day 8. In conclusion, these data demonstrated that SPL could improve gut remodelling potential and modulate the gut environments, resulted in acceleration of post‐weaning growth. Therefore, SPL could have a potential as a feed additive aimed at promoting repair system after wound in animal's gut.

[Perioperative handling of immunosuppressive therapy]

Every year 16 million operations are performed in Germany. Many patients have an autoimmune disorder, for example rheumatoid arthritis, psoriasis or chronic inflammatory bowel disease, which requires treatment. Immunosuppressants are widely applied. Physicians must make a risk-adapted decision whether the immunosuppressant medication can be continued perioperatively or if certain drugs must be paused and if so, with what risks. The handling of immunosuppressants during the perioperative period is very relevant as many patients, for example with rheumatoid arthritis are in need of a hip or knee replacement or patients with inflammatory bowel disease need an operation due to the chronic illness. The interruption of an immunosuppressant therapy should be discussed in an interdisciplinary board according to the underlying disease, because the continuation of immunosuppressants perioperatively can lead to an increased rate of complications, especially wound healing disorders. If a patient is on a glucocorticoid therapy the following must be considered: during the perioperative period the body has an increased demand for glucocorticoids due to the stress reaction. If glucocorticoids are administered in a dosage of more than 7.5 mg/day equivalent of prednisolone this stress reaction is inhibited. Thus, in these cases a perioperative substitution with hydrocortisone is recommended.

Pharmacological activation of epidermal growth factor receptor signaling inhibits colitis-associated cancer in mice

Current treatments for inflammatory bowel disease (IBD) target the overactive immune response of the intestinal mucosa. However, epidermal growth factor (EGF), an activating ligand of the EGF receptor (EGFR), has been shown to induce disease remission through direct targeting of intestinal mucosal healing. Despite promising preclinical and clinical results, this EGFR-activating therapy has not progressed, in part due to the potential for carcinogenesis associated with long-term use and the increased risk of colitis-associated cancer (CAC) in IBD. Here we tested whether pharmacological modulation of EGFR altered outcomes of CAC in the murine azoxymethane/dextran sulfate sodium model. We found that administering EGF during the period of maximum colitis severity ("early"), coincident with the initiation and early promotion of tumors, improved outcomes of colitis and reduced tumor size. In contrast, daily EGF administration beginning ~2 months after tumor initiation ("late") increased tumor size. Administration of the EGFR kinase inhibitor gefitinib increased the tumor size when the drug was given early and decreased the tumor size when the drug was administered late. EGF administration not only reduced colonic cytokine and chemokine expression during injury, but also baseline chemokine expression in homeostasis. These results suggest that EGFR activation during acute bouts of colitis may reduce the long-term burden of CAC.

Implementation of the hyaluronic acid fat graft myringoplasty technique, pitfalls and lessons learned

BACKGROUND

Myringoplasty is a common procedure in otorhinolaryngology. Many techniques with different complications and outcomes have been described, one of which is hyaluronic acid fat graft myringoplasty (HAFGM). This technique, as proposed by Saliba, uses fat tissue and hyaluronic acid discs. The technique is relatively fast with a high success rate and low complications. However, what outcomes can be expected when performed by other surgeons? In this paper, we report on the technique's success in our own hands.

MATERIALS AND METHODS

Based on Saliba's protocol, we performed 86 HAFGMs by a transcanal approach between 2012 and August 2014. However, our 70% success rate was significantly different from Saliba's 92% (p value 2.8e - 05). We visited Saliba's clinic in order to identify critical differences between our approaches. We adapted the differences we found in our protocol and analysed another 50 HAFGMs performed afterwards, between October 2014 and December 2015.

RESULTS

The success rate increased to 86-89%, this percentage is not different compared to Saliba's results (p value .25 and .54).

CONCLUSION

HAFGM is a reproducible technique in the hands of other surgeons, but critical following of the surgical protocol is important.

Regulation of antiapoptotic and cytoprotective pathways in colonic epithelial cells in ulcerative colitis

Ulcerative colitis is an inflammatory bowel disease involving the colon resulting in bloody diarrhea and increased risk of colorectal cancer in certain patient subgroups. Increased apoptosis in the epithelial cell layer causes increased permeability, especially during flares; this leads to translocation of luminal pathogens resulting in a continued inflammatory drive. The present work investigates how epithelial apoptosis is regulated in ulcerative colitis. The main results are that Fas mediated apoptosis is inhibited during flares of ulcerative colitis, probably by an upregulation of cellular inhibitor of apoptosis protein 2 (cIAP2) and cellular FLICE-like inhibitory protein. cIAP2 is upregulated in regenerative epithelial cells both in ulcerative colitis and in experimental intestinal wounds. Inhibition of cIAP2 decreases wound healing in vitro possibly through inhibition of migration. Altogether, it is shown that epithelial cells in ulcerative colitis responds to the hostile microenvironment by activation of cytoprotective pathways that tend to counteract the cytotoxic effects of inflammation. However, the present studies also show that epithelial cells produce increased amounts of reactive oxygen species during stimulation with tumor necrosis factor-α and interferon-γ resulting in DNA instability. The combined effect of increased DNA-instability and decreased apoptosis responses could lead to neoplasia.

Abdominal Wound Dehiscence in Patients Receiving Long-term Steroid Treatment

Steroids inhibit primary wound healing and delay the formation of granulation tissue, but it has been controversial whether long-term steroid treatment by itself increases the risk of abdominal wound dehiscence. The aim of this study was to determine whether the pre-operative dose and post-operative total dose of steroids influence abdominal wound dehiscence. Of 28 patients who had surgery while receiving long-term steroid treatment, seven had abdominal wound dehiscence and 21 did not have dehiscence. The two groups differed significantly in the post-operative dose of steroids (404.3 ± 147.1 and 135.6 ± 118.7 mg, respectively) and the duration of wound healing (57.3 ± 18.0 and 12.4 ± 3.8 days), but no other differences were found. Abdominal wound dehiscence may be influenced by the post-operative rather than the pre-operative steroid dose.

Postoperative irrigation therapy after sinonasal tumor surgery

BACKGROUND

Sinonasal care after endoscopic tumor resection aims to manage crusting, edema, mucus, and a healing cavity. High-volume irrigations have proved beneficial in this setting. The addition of corticosteroid to the irrigation is used for chronic rhinosinusitis (CRS) in modifying the postsurgical inflammatory response; however, its effect in endoscopic sinonasal tumor resection is unknown. Saline alone versus combination saline and corticosteroid irrigations in postoperative nasal care of sinonasal tumor patients was assessed.

METHODS

A retrospective cohort of patients postendoscopic endonasal tumor resection was assessed. Patients used 240 mL of saline or 240 mL of saline with 1 mg of betamethasone daily. Nasal symptom scores (NSSs) and the 22-item Sino-Nasal Outcome test (SNOT-22) was recorded 3 months postoperatively. An endoscopic score was made of the area undergoing secondary healing at 3 months by two blinded assessors.

RESULTS

Fifty-nine patients were assessed (aged 50.1 ± 18.26 years; 36% female subjects). The groups were similar in number (saline n = 31), treatment, and surgical characteristics. The endoscopic scores did not differ between the groups at 3 months. NSS was lower in the saline group (1.0 [interquartile range {IQR}, 3] versus 7.0 [IQR, 9]; p = 0.03) and, similarly, for SNOT-22 (0.24 [IQR, 1] versus 1.09 [IQR, 1]; p = 0.01) compared with the saline with steroid group.

CONCLUSION

Although corticosteroid irrigations have become routine for managing inflammatory sinus disease at our center, their use after tumor surgery does not appear to be warranted. The inflammatory healing process after tumor surgery differs from CRS inflammation and may explain the observed findings.

Cellular inhibitor of apoptosis protein 2 controls human colonic epithelial restitution, migration, and Rac1 activation

Identification of pathways involved in wound healing is important for understanding the pathogenesis of various intestinal diseases. Cellular inhibitor of apoptosis protein 2 (cIAP2) regulates proliferation and migration in nonepithelial cells and is expressed in human colonocytes. The aim of the study was to investigate the role of cIAP2 for wound healing in the normal human colon. Wound tissue was generated by taking rectosigmoidal biopsies across an experimental ulcer in healthy subjects after 5, 24, and 48 h. In experimental ulcers, the expression of cIAP2 in regenerating intestinal epithelial cells (IECs) was increased at the wound edge after 24 h (P < 0.05), returned to normal after reepithelialization, and correlated with the inflammatory reaction in the experimental wounds (P < 0.001). cIAP2 was induced in vitro in regenerating Caco2 IECs after wound infliction (P < 0.01). Knockdown of cIAP2 caused a substantial impairment of the IEC regeneration through inhibition of migration (P < 0.005). cIAP2 overexpression lead to formation of migrating IECs and upregulation of expression of RhoA and Rac1 as well as GTP-activation of Rac1. Transforming growth factor-β1 enhanced the expression of cIAP2 but was not upregulated in wounds in vivo and in vitro. NF-κB and MAPK pathways did not affect cIAP2 expression. cIAP2 is in conclusion a regulator of human intestinal wound healing through enhanced migration along with activation of Rac1, and the findings suggest that cIAP2 could be a future therapeutic target to improve intestinal wound healing.

Intestinal barrier function and the brain-gut axis

The luminal-mucosal interface of the intestinal tract is the first relevant location where microorganism-derived antigens and all other potentially immunogenic particles face the scrutiny of the powerful mammalian immune system. Upon regular functioning conditions, the intestinal barrier is able to effectively prevent most environmental and external antigens to interact openly with the numerous and versatile elements that compose the mucosal-associated immune system. This evolutionary super system is capable of processing an astonishing amount of antigens and non-immunogenic particles, approximately 100 tons in one individual lifetime, only considering food-derived components. Most important, to develop oral tolerance and proper active immune responses needed to prevent disease and inflammation, this giant immunogenic load has to be managed in a way that physiological inflammatory balance is constantly preserved. Adequate functioning of the intestinal barrier involves local and distant regulatory networks integrating the so-called brain-gut axis. Along this complex axis both brain and gut structures participate in the processing and execution of response signals to external and internal changes coming from the digestive tract, using multidirectional pathways to communicate. Dysfunction of brain-gut axis facilitates malfunctioning of the intestinal barrier, and vice versa, increasing the risk of uncontrolled immunological reactions that may trigger mucosal and brain low-grade inflammation, a putative first step to the initiation of more permanent gut disorders. In this chapter, we describe the structure, function and interactions of intestinal barrier, microbiota and brain-gut axis in both healthy and pathological conditions.

Endoscopic resection of gastric neoplasm in solid-organ transplant recipients

BACKGROUND

The aim of this study was to investigate the feasibility and safety of endoscopic resection of gastric neoplasm in solid-organ transplant (SOT) recipients.

METHODS

Between January 1994 and December 2011, the results of endoscopic resection of 17 lesions in 15 consecutive patients who had previously undergone SOT at Asan Medical Center were retrospectively evaluated. We compared clinical outcomes of this group with 1:5 matched non-SOT patients treated by endoscopic resection.

RESULTS

Of the 6,491 patients who underwent SOT during the study periods, 30 patients (0.46%) with 31 lesions were diagnosed with gastric cancer, and eight patients (0.12%) with nine lesions were diagnosed with gastric adenoma. Among them, 15 patients with 17 lesions were treated by endoscopic resection, and 19 patients with 20 lesions have undergone gastrectomy. In endoscopically resected SOT group, the median duration between transplantation and endoscopic treatment was 41 months (range, 5-196 months). En bloc and complete resection were achieved in 13 (76.5%) and 15 (88.2%) lesions. Four lesions (23.5%) experienced bleeding, which was successfully managed endoscopically. When compared with post-endoscopic resection bleeding rate of non-SOT group (5.9%, [5/85]), there was no significant difference in multivariable analysis (P=0.083).

CONCLUSIONS

In endoscopic resection for gastric neoplasm of SOT recipients, only manageable complications were noted in some patients, and graft dysfunctions or perforations did not occur. To avoid surgical resection with its associated perioperative mortality and morbidity, endoscopic resection for gastric neoplasm in SOT recipients is recommended as a feasible treatment with high efficacy and safety.

Pre- and posttherapy assessment of intestinal soluble mediators in IBD: where we stand and future perspectives

Inflammatory bowel disease (IBD) is a chronic inflammatory condition characterized by an abnormal immune response against food or bacterial antigens in genetically predisposed individuals. Several factors of innate and adaptive immune system take part in the inflammatory process, probably actively contributing in endoscopic and histological healing at molecular level. Although it is difficult to discriminate whether they are primary factors in determining these events or they are secondarily involved, it would be interesting to have a clear map of those factors in order to have a restricted number of potentially "good candidates" for mucosal healing. The present review will present a class of these factors and their modulation in course of therapy, starting from pathogenic studies involving several treatments associated with good clinical outcomes. This approach is meant to help in the difficult task of identifying "good candidates" for healing signatures, which could also be possible new therapeutic targets for clinical management of IBD patients.

Mucosal healing in ulcerative colitis: pathophysiology and pharmacology

Ulcerative colitis (UC) is a colonic inflammatory condition with a substantial impact on the quality of life of affected persons. The disease carries a cumulative risk of need of colectomy of 20-30% and an estimated cumulative risk of colorectal cancer of 18% after 30 years of disease duration. With the introduction of the tumor necrosis factor-alpha inhibitors for the treatment of UC, it has become increasingly evident that the disease course is influenced by whether or not the patient achieves mucosal healing. Thus, patients with mucosal healing have fewer flare-ups, a decreased risk of colectomy, and a lower probability of developing colorectal cancer. Understanding the mechanisms of mucosal wound formation and wound healing in UC, and how they are affected therapeutically is therefore of importance for obtaining efficient treatment strategies holding the potential of changing the disease course of UC. This review is focused on the pathophysiological mechanism of mucosal wound formation in UC as well as the known mechanisms of intestinal wound healing. Regarding the latter topic, pathways of both wound healing intrinsic to epithelial cells and the wound-healing mechanisms involving interaction between epithelial cells and other cells of the mucosa are discussed. The biochemistry of wound healing in UC provides the basis for the subsequent description of how these pathways are affected by the current medications, and what can be learnt on how to design future treatment regimens for UC based on targeting mucosal healing.

Results of the 2nd scientific workshop of the ECCO (III): basic mechanisms of intestinal healing

The second scientific workshop of the European Crohn's and Colitis Organization (ECCO) focused on the relevance of intestinal healing for the disease course of inflammatory bowel disease (IBD). The objective was to better understand basic mechanisms, markers for disease prediction, detection and monitoring of intestinal healing, impact of intestinal healing on the disease course of IBD as well as therapeutic strategies. The results of this workshop are presented in four separate manuscripts. This section describes basic mechanisms of intestinal healing, identifies open questions in the field and provides a framework for future studies.

Selective non-steroidal glucocorticoid receptor agonists attenuate inflammation but do not impair intestinal epithelial cell restitution in vitro

Introduction

Despite the excellent anti-inflammatory and immunosuppressive action of glucocorticoids (GCs), their use for the treatment of inflammatory bowel disease (IBD) still carries significant risks in terms of frequently occurring severe side effects, such as the impairment of intestinal tissue repair. The recently-introduced selective glucocorticoid receptor (GR) agonists (SEGRAs) offer anti-inflammatory action comparable to that of common GCs, but with a reduced side effect profile.

Methods

The in vitro effects of the non-steroidal SEGRAs Compound A (CpdA) and ZK216348, were investigated in intestinal epithelial cells and compared to those of Dexamethasone (Dex). GR translocation was shown by immunfluorescence and Western blot analysis. Trans-repressive effects were studied by means of NF-κB/p65 activity and IL-8 levels, trans-activation potency by reporter gene assay. Flow cytometry was used to assess apoptosis of cells exposed to SEGRAs. The effects on IEC-6 and HaCaT cell restitution were determined using an in vitro wound healing model, cell proliferation by BrdU assay. In addition, influences on the TGF-β- or EGF/ERK1/2/MAPK-pathway were evaluated by reporter gene assay, Western blot and qPCR analysis.

Results

Dex, CpdA and ZK216348 were found to be functional GR agonists. In terms of trans-repression, CpdA and ZK216348 effectively inhibited NF-κB activity and IL-8 secretion, but showed less trans-activation potency. Furthermore, unlike SEGRAs, Dex caused a dose-dependent inhibition of cell restitution with no effect on cell proliferation. These differences in epithelial restitution were TGF-β-independent but Dex inhibited the EGF/ERK1/2/MAPK-pathway important for intestinal epithelial wound healing by induction of MKP-1 and Annexin-1 which was not affected by CpdA or ZK216348.

Conclusion

Collectively, our results indicate that, while their anti-inflammatory activity is comparable to Dex, SEGRAs show fewer side effects with respect to wound healing. The fact that SEGRAs did not have a similar effect on cell restitution might be due to a different modulation of EGF/ERK1/2 MAPK signalling.

Ganoderma lucidum polysaccharides reduce methotrexate-induced small intestinal damage in mice via induction of epithelial cell proliferation and migration

AIM

To study the effects of Ganoderma lucidum polysaccharides (Gl-PS) on methotrexate (MTX)-induced small intestinal damage in mice and the underlying mechanisms.

METHODS

BALB/c mice were used for in vivo study. The mice were administered with Gl-PS (50, 100, or 200 mg/kg, ig) for 10 d, and injected with MTX (50 mg/kg, ip) on d 7 and 8 to induce intestinal damage, and then sacrificed on d 11 for morphological study and tissue malondialdehyde (MDA) and superoxide dismutase (SOD) measurements. Before sacrificing, blood samples were collected to analyze immunoglobulin A (IgA). Rat intestinal IEC-6 cells were used for in vitro study. Cell proliferation and migration were assessed using MTT method and an in vitro wounding model, respectively. Transforming growth factor β (TGFβ) protein expression was determined using ELISA assay. Ornithine decarboxylase (ODC) and c-Myc mRNA expression profiles were determined using RT-PCR.

RESULTS

MTX treatment caused severe mucosal damage, significantly increased small intestine MDA levels, and decreased SOD and serum IgA levels in BALB/c mice. Gl-PS (100 and 200 mg/kg) markedly reversed the MTX effects. In IEC-6 cells, Gl-PS (0.1, 1, and 10 μg/mL) significantly stimulated the cell proliferation. Furthermore, Gl-PS (10 μg/mL) significantly stimulated the cell migration. In addition, Gl-PS (10 and 20 μg/mL) significantly increased the expression of ODC and c-Myc mRNAs. However, Gl-PS (up to 20 μg/mL) had no effect on the expression of TGFβ protein.

CONCLUSION

The results suggest that Gl-PS protects small intestine against MTX-induced injury via induction of epithelial cell proliferation and migration.

Effects of Ganoderma lucidum polysaccharides on IEC-6 cell proliferation, migration and morphology of differentiation benefiting intestinal epithelium healing in vitro

OBJECTIVES

Restoration of epithelial continuity in the intestinal surface after extensive destruction is important since intestinal epithelial cells stand as a boundary between the body's internal and external environment. Polysaccharides from Ganoderma lucidum (Gl-PS) may benefit intestinal epithelial wound healing in different aspects, which awaits clarification. To identify potential effects, a non-transformed small-intestinal epithelial cell line, IEC-6 cells, was used.

METHODS

Effects on epithelial cell proliferation, migration, morphology of differentiation and transforming growth factor beta (TGF-β) protein expression, as well as the cellular ornithine decarboxylase (ODC) mRNA and c-Myc mRNA expression, were assessed, respectively, by MTT assay, wound model in vitro, observation under a microscope after hematoxylin and eosin staining, enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction assays.

KEY FINDINGS

It was shown that Gl-PS stimulated IEC-6 cell proliferation and migration significantly in a dose-dependent manner; 10 µg/ml Gl-PS improved the morphology of differentiation in IEC-6 cells. Inefficacy in expression of TGF-β in IEC-6 cells indicated a possible TGF-β independent action of Gl-PS. However, Gl-PS increased ODC mRNA and c-Myc mRNA expression in a dose-dependent manner, indicating, at least partially possible involvement of ODC and c-Myc gene expression in improvement of intestinal wound healing.

CONCLUSIONS

These results suggest the potential usefulness of Gl-PS to cure intestinal disorders characterized by injury and ineffective repair of the intestinal mucosa.

Effect of corticosteroid dose and duration of administration on colonic anastomosis

BACKGROUND

Surgical intervention under concomitant steroid therapy can be complicated by impaired anastomotic healing. The aim of this experimental study was to investigate the effects of a corticosteroid (methylprednisolone) on healing colonic anastomoses in relation to the dose and duration of administration.

METHODS

Fifty male Spraque-Dawley rats weighing 200-220 g were divided into five groups each containing 10 rats. No treatment was given in the control group. Group HDST: high-dose methylprednisolone (1 mg/kg/day, intramuscular) treatment for a short term of 2 days; group HDLT: high-dose methylprednisolone treatment for a long term of 60 days; group LDST: low-dose methylprednisolone (0.28 mg/kg/day) treatment for a short term of 2 days; and group LDLT: low-dose methylprednisolone treatment for a long term of 60 days. Standard left colonic anastomosis was performed in all rats. Anastomotic bursting pressure, hydroxyproline measurement, and histopathological data were evaluated in all groups on postoperative day 4.

RESULTS

The mean anastomotic bursting pressure value was significantly lower in the HDLT group (P < 0.05). The mean hydroxyproline levels were significantly lower in all groups (P < 0.05). Histopathological results demonstrated significant changes according to neutrophil infiltration, granulation tissue formation, presence of vascularization, and peritonitis in the HDLT, LDST, and LDLT groups (P < 0.05).

CONCLUSIONS

High and low doses of the corticosteroid produced adverse effects on the healing of colon anastomosis in rats regardless of whether it was administered over a long or short preoperative period. However, the most prominent negative effect was associated with high-dose, long-term corticosteroid administration.

Granulocyte-macrophage colony-stimulating factor elicits bone marrow-derived cells that promote efficient colonic mucosal healing

BACKGROUND

Granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy is effective in treating some Crohn's disease (CD) patients and protects mice from colitis induced by dextran sulfate sodium (DSS) administration. However, its mechanisms of action remain elusive. We hypothesized that GM-CSF affects intestinal mucosal repair.

METHODS

DSS colitic mice were treated with daily pegylated GM-CSF or saline and clinical, histological, and inflammatory parameters were kinetically evaluated. Further, the role of bone marrow-derived cells in the impact of GM-CSF therapy on DSS colitis was addressed using cell transfers.

RESULTS

GM-CSF therapy reduced clinical signs of colitis and the release of inflammatory mediators. GM-CSF therapy improved mucosal repair, with faster ulcer reepithelialization, accelerated hyperproliferative response of epithelial cells in ulcer-adjacent crypts, and lower colonoscopic ulceration scores in GM-CSF-administered mice relative to untreated mice. We observed that GM-CSF-induced promotion of mucosal repair is timely associated with a reduction in neutrophil numbers and increased accumulation of CD11b(+) monocytic cells in colon tissues. Importantly, transfer of splenic GM-CSF-induced CD11b(+) myeloid cells into DSS-exposed mice improved colitis, and lethally irradiated GM-CSF receptor-deficient mice reconstituted with wildtype bone marrow cells were protected from DSS-induced colitis upon GM-CSF therapy. Lastly, GM-CSF-induced CD11b(+) myeloid cells were shown to promote in vitro wound repair.

CONCLUSIONS

Our study shows that GM-CSF-dependent stimulation of bone marrow-derived cells during DSS-induced colitis accelerates colonic tissue repair. These data provide a putative mechanism for the observed beneficial effects of GM-CSF therapy in Crohn's disease.

Is pseudo-Cushing's syndrome in a critically ill patient "pseudo"? Hypothesis and supportive case report

OBJECTIVE

To propose a new hypothesis regarding the possible role of glucocorticoid excess in patients with an extended acute illness, based on a patient's presentation and therapy in a critical care situation.

METHODS

We present a detailed case report, review the related literature, and suggest the need for prospective studies to determine the appropriate intervention in critically ill patients with pseudo-Cushing's syndrome.

RESULTS

A 50-year-old woman with diabetes and obesity who underwent vertical banded gastroplasty had postoperative complications, including refractory gastrostomy leakage, peritoneal and abdominal wall infections, and multiorganism sepsis despite intensive antibiotic therapy and surgical drainage procedures. Her physical appearance, elevated and relatively nonsuppressible plasma cortisol levels, and radiologic study supported a tentative diagnosis of Cushing's syndrome in a critically ill patient. Intravenously administered itraconazole and rectally administered aminoglutethimide were used to suppress endogenous glucocorticoid synthesis. Glucocorticoids were administered at dosages that provided 1/3 to 1/2 of her expected maximal daily cortisol secretion during her complicated hospital course. Insulin resistance declined with adrenal suppression and infection control, and wound healing improved dramatically. Adrenal suppression was discontinued, and she was reevaluated for hypercortisolism. Results of all studies for Cushing's syndrome were normal and remained so 1 year later.

CONCLUSION

In our patient, substantially increased glucocorticoid levels were associated with severe insulin resistance, retarded wound healing, and persistent infections. Suppression of endogenous cortisol production and replacement with more physiologic concentrations of glucocorticoid were associated with clinical improvement and appeared to contribute to her recovery. Review of the literature leads us to propose the following hypotheses: (1) that considerably increased stress-induced cortisol concentrations in critically ill patients may contribute to adverse outcomes and (2) that therapeutic suppression of the persistent and substantially elevated glucocorticoid levels in selected cases may be a beneficial therapeutic option.

Cytokine expression in rat colon during postnatal development: regulation by glucocorticoids

OBJECTIVES

Cytokine expression and regulation by glucocorticoids and retinoic acid were investigated in the colon during postnatal development.

MATERIALS AND METHODS

Gene expression of the transforming growth factors (TGFs) TGF-beta1, TGF-beta2 and TGF-alpha and the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) in rat colon mucosa during weaning and in adult rats. Protein expression and distribution of TGF-betas was analysed in the colon from 14- and 60-day-old animals. The effect of hydrocortisone administration on mucosal cytokine transcripts (RT-PCR) and of dexamethasone on the expression of cytokines by the epithelial cell line IEC-18 and 2 subepithelial myofibroblasts (MIC 307-1 and 316) was examined.

RESULTS

TGF-beta1 and TGF-beta2 messenger RNAs and proteins decreased in the entire colon from weaning to adult stages, whereas the amount of TGF-alpha messenger RNA increased in the proximal colon and decreased in the distal part of the colon in adult rats in comparison with weanlings. However, proinflammatory cytokines showed no postnatal changes in the proximal colon but decreased in the distal part in comparison with weaning rats. Hydrocortisone treatment did not affect growth factor expression but decreased proinflammatory cytokines. Likewise, dexamethasone decreased TNF-alpha and IL-1beta gene expression but did not affect TGF-betas in either epithelial or myofibroblast cells.

CONCLUSIONS

During postnatal maturation, the expression of growth factors and proinflammatory cytokines decreased in the distal colon, whereas in the proximal colon, a differential maturation occurs with no changes in proinflammatory cytokines, an increase in TGF-alpha and a decrease in TGF-beta. Glucocorticoids may control the developmental profile of proinflammatory cytokines.

Corticosteroids induce the differential expression of TGFbeta isoforms, receptors and signaling in the gastric mucosa of suckling rats

Glucocorticoids inhibit the cell proliferation in the gastric epithelium, and induce differentiation, migration and death. The mechanism by which these effects are triggered and controlled is still discussed and can involve the transcription and activation of transforming growth factor beta (TGFbeta). The present study was conducted to evaluate the effect of hydrocortisone short-term treatment on tissue level and distribution of TGFbeta isoforms, receptors and signaling through Smad2/3. To achieve that, 18-day-old rats were injected with hydrocortisone (50 mg/Kg b.wt.) for 0, 1 and 3 h. The stomachs were collected and processed for immunohistochemistry and western blotting. We observed that the treatment for 3 h increased the number of labeled epithelial cells for TGFbeta1 (p < 0.05), decreased the distribution of TGFbeta2 (p < 0.05) and did not alter TGFbeta3, TbetaRI and TbetaRII status. The levels of TGFbeta1 and receptors were checked by western blotting and results corroborate the immunodetection. We also found that phosphorylation of Smad2/3 into Smad2P increased after 3 h (p < 0.05), indicating that the high level TGFbeta1 was active on the cells. We suggest that glucocorticoids differentially regulate the expression of TGFbeta isoforms, receptors and signaling, and so TGFbeta1 might be involved in the inhibitory pathway triggered by the hormone.

Intestinal damage in strongyloidiasis: the imbalance between cell death and proliferation

Strongyloidiasis is an endemic tropical parasitosis caused by Strongyloides stercoralis that also affects immigrants in nontropical countries. The nematode colonizes the duodenum and upper jejunum, inducing mucosal alterations. Because integrity is essential for a functional barrier, we aimed to study apoptosis and proliferation in the small bowel epithelium infected with S. stercoralis. We evaluated 23 patients and 17 controls. Apoptotic cells were detected by TUNEL and M30 immunolabelling, whereas proliferation was scored by Ki67 immunostaining and mitotic counting. Infection increased apoptotic indices in duodenum and jejunum (P < 0.001). Conversely, it decreased cell proliferation in both segments (P < 0.001). Our results showed that intestinal strongyloidiasis promotes an imbalance between cell death and proliferation. This is the first evidence of disruption of the epithelial kinetics with S. stercoralis infection, though the mechanisms remain unclear. Furthermore, our results support the idea that strongyloidiasis disturbs the mucosal integrity and can compromise the intestinal barrier.

Characterization of tumour-infiltrating lymphocytes and apoptosis in colitis-associated neoplasia: comparison with sporadic colorectal cancer

The development of colorectal cancer is a major complication for patients with chronic idiopathic colitis. Colitis-associated tumours tend to occur at a younger age and be more aggressive than sporadic colorectal cancers. While we have previously associated the presence of tumour-infiltrating lymphocytes (TILs) and increased apoptosis in sporadic colorectal cancer with high-level microsatellite instability and improved prognosis, little is known of the relationship between these variables in colitis-associated colorectal cancer. The aim of this study was to correlate TILs and tumour cell apoptosis in colitis-associated neoplasms stratified according to microsatellite instability. Twenty tumour and 11 dysplastic samples resected from 21 patients with long-standing colitis were analysed for microsatellite instability at 10 microsatellite markers. TIL distribution (CD3, CD8) and function (granzyme B) were quantified by immunohistochemistry. Neoplastic cell apoptosis was assessed using the M30 CytoDEATH antibody. These findings were compared with 40 microsatellite stable (MSS) sporadic colorectal cancers previously evaluated for TILs and neoplastic apoptosis. Low-level microsatellite instability was found in 1/20 colitis-associated tumours. All other colitis-associated lesions were designated MSS. CD3(+) and CD8(+) TIL counts were significantly higher in colitis-associated lesions compared with MSS sporadic colorectal cancer (p < 0.0001, p = 0.001 respectively). Despite their higher TIL density, colitis-associated tumours were more likely to present late (Dukes' stage C or D) (p = 0.02). Functionally, colitis-associated TILs demonstrated significantly less granzyme B expression compared to sporadic cancers (p = 0.002). The level of tumour cell apoptosis was similar between the two groups (sporadic, 1.53%; colitis cancers, 1.45%). In conclusion, MSS colitis-associated tumours have a higher prevalence of CD3(+)/CD8(+) TILs but no associated increase in tumour cell killing by apoptosis. Unlike cytotoxic T cells in sporadic colorectal cancer, TILs do not appear to enhance the prognosis of colitis-associated colorectal cancer. This may be related to an impairment of granzyme B expression within these lesions.

Review article: the aetiopathogenesis of inflammatory bowel disease--immunology and repair mechanisms

Although the aetiopathogenesis of Crohn's disease and ulcerative colitis, remains unsolved, current evidence indicates that defective T-cell apoptosis and impairment of intestinal epithelial barrier function play important roles in the pathogenesis of both conditions. Without appropriate control of T-cell proliferation and death during an immune response, an inappropriate accumulation of T cells and subsequent intestinal inflammation may occur. Differences in T-cell responses between Crohn's disease and ulcerative colitis have been identified, with mucosal T-cell apoptosis being defective in Crohn's disease, but not in ulcerative colitis. Furthermore, cell cycling is considerably faster, with a vigorous clonal expansion, in Crohn's disease, whereas, in ulcerative colitis, T cells cycle normally, but have a remarkably reduced capacity to divide and expand. The elimination of excessive T cells therefore seems to be a reasonable approach to restore the gut to a physiological state or, at least, a controlled state of inflammation. The tumour necrosis factor-alpha blocker, infliximab, exerts its beneficial effects, at least in part, by the induction of apoptosis in lamina propria T cells and monocytes. In addition, repeated damage and injury of the intestinal surface is a hallmark of inflammatory bowel disease and may facilitate the entry of luminal antigens into the mammalian organism and the initiation and perpetuation of both nonspecific and specific immune responses. A better understanding of and enhancement of intestinal repair mechanisms may thus provide future approaches for the treatment of inflammatory bowel disease.

Early postoperative complications are not increased in patients with Crohn's disease treated perioperatively with infliximab or immunosuppressive therapy

AIM

The aim was to determine whether the use of steroids, immunosuppressive agents, or infliximab prior to abdominal surgery for Crohn's disease is associated with an increased rate of early postoperative complications.

METHODS

All patients who underwent abdominal surgery for Crohn's disease between October 1998 and December 2001 were identified. Medical records were abstracted for demographics, location and duration of disease, use of infliximab within 8 wk before and 4 wk after surgery, and dose and duration of corticosteroids, azathioprine/6-mercaptopurine, and methotrexate. Steroid use was defined as: high (intravenous or oral >/=40 mg/day), moderate (oral >/=20 mg/day for at least 2 months), low (oral <20 mg/day or oral >20 mg/day for <2 months), or none. Early (within 30 days postinfliximab) septic and nonseptic complications were identified. Septic complications included wound sepsis, intraabdominal, and extraabdominal infections. Nonseptic complications included Crohn's disease recurrence, small bowel obstruction, gastrointestinal bleeding, and thromboembolism. A logistic regression analysis assessed the association between perioperative therapy with infliximab, corticosteroids, or immunosuppressive therapy and subsequent occurrence of septic complications and separately overall complications.

RESULTS

Two hundred and seventy patients were operated upon including 107 patients who received steroids (34 low dose, 34 moderate dose, 43 high dose), 105 patients who received immunosuppressives (64 azathioprine, 38 6-mercaptopurine, 4 methotrexate), and 52 who received infliximab. Forty-eight patients underwent urgent or emergent surgery and 222 underwent elective surgery. Septic complications occurred in 52 of 270 (19%) patients including wound sepsis in 28 (10%), anastomotic leak in 9 (3%), intraabdominal abscess in 5 (2%), and extraabdominal infections in 19 (7%). Nonseptic complications occurred in 18 of 270 (7%) patients. Preoperative use of high- or moderate-dose steroids, immunosuppressives, or infliximab was not associated with greater complication rates. No deaths occurred.

CONCLUSION

Early complications after elective abdominal surgery for CD are not associated with steroid dose, immunosuppressive therapy, or infliximab use.

Cellular, biochemical, and clinical aspects of wound healing

BACKGROUND

The response to tissue injury requires the symphonious interaction of immune cells, keratinocytes, fibroblasts, and endothelial cells, which unite to regenerate the damaged epithelium. Recent insights have elucidated the cellular and molecular mechanisms required for wound healing and have raised the prospect of novel therapeutic targets.

METHODS

Review of the pertinent literature.

RESULTS

The initial inflammatory response leads to the influx of macrophages and neutrophils, which release cytokines, growth factors, and nitric oxide, and induce nearby keratinocytes to migrate across the wounded epithelium. This process, known as re-epithelialization, requires integrin-mediated activation of Rho-GTPases. The subsequent influx of fibroblasts and endothelial cells results in the production of tissue stroma and formation of new blood vessels, which lead to the generation of functional tissue. Importantly, disease states associated with impaired or excessive wound healing can be attributed to defects in these responses, providing a rationale for the use of evidence-based biological therapies.

CONCLUSION

The elucidation of the cellular and biochemical response to wound healing is essential for an understanding to the treatment of clinical conditions during which impaired healing is encountered.

Intestinal barrier function

Intestinal barrier function regulates transport and host defense mechanisms at the mucosal interface with the outside world. Transcellular and paracellular fluxes are tightly controlled by membrane pumps, ion channels and tight junctions, adapting permeability to physiological needs. Food and microbial antigens are under constant surveillance of the mucosal immune system. Tolerance against commensals and immunity against pathogens require intact antigen uptake, recognition, processing and response mechanisms. Disturbance at any level, but particularly bacterial translocation due to increased permeability and breakdown of oral tolerance due to compromised epithelial and T cell interaction, can result in inflammation and tissue damage. New therapeutic approaches including probiotics and peptides to restore disrupted barrier function are evolving.

Perioperative anticoagulation management in patients who are receiving oral anticoagulant therapy: a practical guide for clinicians

The management of patients who require temporary interruption of oral anticoagulant therapy because of surgery or other invasive procedures is a clinically important topic because of the increasing prevalence of patients who are receiving oral anticoagulants and the availability of low-molecular-weight heparins (LMWHs), which allow out-of-hospital perioperative anticoagulation. The optimal management of such patients has been hampered by the lack of well-designed prospective studies investigating the efficacy and safety of different perioperative management strategies. The two main issues that need to be considered in perioperative anticoagulant management is the patient's risk of thromboembolic event when anticoagulant therapy is interrupted and the risk of bleeding that is associated with the surgery or procedure. An assessment of these factors will determine the perioperative management approach. The objectives of this review are to focus on practical issues relating to perioperative anticoagulation and the implementation of a perioperative anticoagulation management approach that can be used in everyday clinical practice.

Differential glucocorticoid effects on repair mechanisms and NF-kappaB activity in the intestinal epithelium

Glucocorticoids are effective agents in the management of inflammatory bowel diseases. However, information about their effects on repair mechanisms of the intestinal epithelium is incomplete.Therefore, the aim was to analyse in vitro effects of glucocorticoids on proliferation, restitution, and apoptosis as well as their effects on activity and expression of nuclear factor (NF)-kappaB, a known regulator of apoptosis and inflammation, in intestinal epithelial cells.Non-transformed rat jejunum epithelial cells (IEC-6) were cultured in the presence and absence of various concentrations of prednisolone and budesonide. IEC-6 cell proliferation was assessed by [3H]-thymidine incorporation. Restitution was analysed by an IEC-6 in vitro assay. Apoptosis was evaluated by ELISA and fluorescence microscopy. DNA binding activity and nuclear expression of NF-kappaB was determined by electrophoretic mobility shift assays and Western blotting, respectively. Prednisolone and budesonide stimulated IEC-6 cell proliferation at low to medium pharmacologic concentrations (prednisolone: 10(-9) to 10(-6) M; budesonide: 10(-11) to 10(-8) M). In contrast, high concentrations (>5 x 10(-5) M) had inhibitory effects on proliferation. 10(-7) M prednisolone and 10(-8) M budesonide increased restitution of IEC-6 cells, whereas high concentrations (10(-4) M) of prednisolone and budesonide decreased restitution. Apoptosis of IEC-6 cells was substantially enhanced by 10(-4) M budesonide; apoptosis was slightly increased by the highest prednisolone concentration used (5 x 10(-4) M). Furthermore, both glucocorticoids inhibited DNA binding activity and nuclear NF-kappaB expression in IEC-6 cells in a dose- and time-dependent fashion. In conclusion, prednisolone and budesonide modulate repair mechanisms of intestinal epithelial cells in vitro in a dose-dependent manner and profoundly modulate the inflammatory regulator NF-kappaB.

Detection of apoptosis in keloids and a comparative study on apoptosis between keloids, hypertrophic scars, normal healed flat scars, and dermatofibroma

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and the development of pathological scarring. In this study, we demonstrate that keloid fibroblasts can be identified as apoptotic cells because of their highly condensed chromatin and discrete nuclear fragments. To further reveal the phenomenon of apoptosis, we quantified the number of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in surgically resected tissues of keloids (N = 10), hypertrophic scars (N = 10), normal healed flat scars (N = 10), and dermatofibroma (N = 10). The number of TUNEL-positive cells was relatively low, but was significantly higher for the keloid group compared with the normally healed flat scar group (p = 0.004), suggesting reduced cell survival and increased apoptotic cell death in a subpopulation of keloid fibroblasts. Furthermore, the number of TUNEL-positive cells was significantly higher for the keloid group compared with the dermatofibroma group (p = 0.044), suggesting that a subpopulation of keloid fibroblasts may suppress tumorgenicity at a greater rate than dermatofibroma by undergoing cell death. Hypertrophic scars had significantly higher levels of apoptosis than normally healed flat scars (p = 0.033). Therefore, these results suggest that selected fibroblasts in keloids and hypertrophic scars undergo apoptosis, which may play a role in the process of pathological scarring.