The dinucleotide (CA) repeat polymorphism of estrogen receptor beta but not the dinucleotide (TA) repeat polymorphism of estrogen receptor alpha is associated with venous ulceration

Laryngotracheal stenosis: Mechanistic review

Background

The purpose of this review article is to summarize the existing literature surrounding wound healing mechanisms in laryngotracheal stenosis.

Methods

A review of general wound healing pathophysiology, followed by a focused review of iatrogenic laryngotracheal stenosis (iLTS) and idiopathic subglottic stenosis (iSGS) as conditions of aberrant wound healing.

Results

iLTS is the scarring of the laryngotracheal complex, coming secondary to injury from prolonged intubation. iSGS is a chronic fibroinflammatory scarring and narrowing of the subglottic airway in the absence of any obvious preceding injury or trauma. They are both thought to result from a prolonged and dysregulated wound healing response that promotes the deposition of pathologic scar in the airway.

Conclusions

Understanding the mechanisms that underlie wound healing will help identify and intervene on the process early in its development and discover future therapies that target individual wound healing mechanisms limiting the incidence of this recalcitrant disease process.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

The role of nuclear hormone receptors in cutaneous wound repair

The cutaneous wound repair process involves balancing a dynamic series of events ranging from inflammation, oxidative stress, cell migration, proliferation, survival and differentiation. A complex series of secreted trophic factors, cytokines, surface and intracellular proteins are expressed in a temporospatial manner to restore skin integrity after wounding. Impaired initiation, maintenance or termination of the tissue repair processes can lead to perturbed healing, necrosis, fibrosis or even cancer. Nuclear hormone receptors (NHRs) in the cutaneous environment regulate tissue repair processes such as fibroplasia and angiogenesis. Defects in functional NHRs and their ligands are associated with the clinical phenotypes of chronic non-healing wounds and skin endocrine disorders. The functional relationship between NHRs and skin niche cells such as epidermal keratinocytes and dermal fibroblasts is pivotal for successful wound closure and permanent repair. The aim of this review is to delineate the cutaneous effects and cross-talk of various nuclear receptors upon injury towards functional tissue restoration.

Proteomic approach to skin regeneration in a marine teleost: modulation by oestradiol-17β

Skin and scale formation and regeneration in teleosts have mainly been described from a morphological perspective, and few studies of the underlying molecular events exist. The present study evaluates (1) the change in the skin proteome during its regeneration in a marine teleost fish (gilthead sea bream, Sparus aurata) and (2) the impact of oestradiol-17β (Ε2) on regeneration and the involvement of oestrogen receptor (ER) isoforms. Thirty-five candidate proteins were differentially expressed (p < 0.05) between intact and regenerated skin proteome 5 days after scale removal, and 27 proteins were differentially expressed after E2 treatment. Agglomerative hierarchical clustering of the skin proteome revealed that the skin treated with E2 clustered most closely to intact skin, while regenerating untreated skin formed an independent cluster. Gene Ontology classification associated the differentially expressed proteins in E2-treated skin with developmental processes and cellular morphogenesis. The proteins modified during skin regeneration suggest a balance exists between immune response and anatomical repair. Overall, the results indicate that, even after 5 days regeneration, the composition of mature skin is not attained, and endocrine factors, in particular E2, can accelerate wound repair acting possibly via ERβs expressed in the skin-scales. Several candidate proteins probably involved in scale development, osteoglycin, lipocalin2 and lamin A and the transcription factors PHD and grainyhead were identified. Future studies of fish skin regeneration will be required to provide further insight into this multistage process, and the present study indicates it will be useful to explore immune adaptations of epithelia permanently exposed to an aqueous environment.

A retrospective analysis of amputation rates in diabetic patients: can lower extremity amputations be further prevented?

Background

Lower extremity amputations are costly and debilitating complications in patients with diabetes mellitus (DM). Our aim was to investigate changes in the amputation rate in patients with DM at the Karolinska University Hospital in Solna (KS) following the introduction of consensus guidelines for treatment and prevention of diabetic foot complications, and to identify risk groups of lower extremity amputations that should be targeted for preventive treatment.

Methods

150 diabetic and 191 nondiabetic patients were amputated at KS between 2000 and 2006; of these 102 diabetic and 99 nondiabetic patients belonged to the catchment area of KS. 21 diabetic patients who belonged to KS catchment area were amputated at Danderyd University Hospital. All patients' case reports were searched for diagnoses of diabetes, vascular disorders, kidney disorders, and ulcer infections of the foot.

Results

There was a 60% reduction in the rate of amputations performed above the ankle in patients with DM during the study period. Patients with DM who underwent amputations were more commonly affected by foot infections and kidney disorders compared to the nondiabetic control group. Women with DM were 10 years older than the men when amputated, whereas men with DM underwent more multiple amputations and had more foot infections compared to the women. 88% of all diabetes-related amputations were preceded by foot ulcers. Only 30% of the patients had been referred to the multidisciplinary foot team prior to the decision of amputation.

Conclusions

These findings indicate a reduced rate of major amputations in diabetic patients, which suggests an implementation of the consensus guidelines of foot care. We also propose further reduced amputation rates if patients with an increased risk of future amputation (i.e. male sex, kidney disease) are identified and offered preventive treatment early.

The role of estrogen deficiency in skin ageing and wound healing

The links between hormonal signalling and lifespan have been well documented in a range of model organisms. For example, in C. elegans or D. melanogaster, lifespan can be modulated by ablating germline cells, or manipulating reproductive history or pregnenolone signalling. In mammalian systems, however, hormonal contribution to longevity is less well understood. With increasing age human steroid hormone profiles change substantially, particularly following menopause in women. This article reviews recent links between steroid sex hormones and ageing, with special emphasis on the skin and wound repair. Estrogen, which substantially decreases with advancing age in both males and females, protects against multiple aspects of cellular ageing in rodent models, including oxidative damage, telomere shortening and cellular senescence. Estrogen's effects are particularly pronounced in the skin where cutaneous changes post-menopause are well documented, and can be partially reversed by classical Hormone Replacement Therapy (HRT). Our research shows that while chronological ageing has clear effects on skin wound healing, falling estrogen levels are the principle mediator of these effects. Thus, both HRT and topical estrogen replacement substantially accelerate healing in elderly humans, but are associated with unwanted deleterious effects, particularly cancer promotion. In fact, much current research effort is being invested in exploring the therapeutic potential of estrogen signalling manipulation to reverse age-associated pathology in peripheral tissues. In the case of the skin the differential targeting of estrogen receptors to promote healing in aged subjects is a real therapeutic possibility.

Does inflammation have a role in the pathogenesis of venous ulcers? A critical review of the evidence

Chronic venous disease, a disorder involving venous return from the legs, is a growing epidemic in the developed world. Numerous studies have been conducted in the past two decades in an attempt to elucidate its underlying pathophysiology. Many theories have been proposed to address the profound inflammatory dysregulation, with the majority focusing on fibrin trap, inflammatory trap, cytokines, growth factors, and matrix metalloproteinases. Although many of these theories have obtained great momentum, much of the data are contradictory. Moreover, many treatments built on these theories have claimed overwhelming success despite insufficient evidence. At the same time, there are few reviews that critically analyze and evaluate these data. Therefore, in this paper, we will provide summaries of the background data and evolution of these theories and examine their supporting evidence.

The phytoestrogen genistein promotes wound healing by multiple independent mechanisms

Genistein has been implicated in the beneficial effects of soy on human health, particularly in the context of ageing. In post-menopausal women reduced systemic estrogen leads to a range of age-associated pathologies, including delayed cutaneous wound healing. We have previously shown that this can be reversed by estrogen replacement. However, the effect of genistein on the skin is poorly understood and crucially the influence of genistein on wound healing has not been assessed. 10-week-old ovariectomised mice were systemically treated with 17beta-estradiol or genistein. Genistein substantially accelerated wound repair, associated with a dampened inflammatory response. Unexpectedly, co-treatment with the ER antagonist ICI had little impact on the anti-inflammatory, healing promoting effects of genistein. Thus genistein's actions are only partially mediated via classical estrogen receptor-dependent signalling pathways. Indeed, we report that alternative (cell-type specific) signalling mechanisms are activated in the skin in response to genistein treatment.

Sex steroids as inflammatory regulators

It is becoming increasingly clear that endogenous sex steroids are key players in a range of inflammatory contexts. Androgens and estrogens have been shown to have a profound influence on the function of inflammatory cells including macrophages and on the secretion and activation of a range of plasma-borne inflammatory mediators. The menopause and polymorphisms in estrogen receptor genes have separately been shown to affect the incidence of a range of inflammatory disorders. Sex steroids themselves have been shown to be protective in certain conditions; harmful in others. This review will summarize their documented effects on inflammatory processes, with particular focus on two areas that have received much recent attention: the antiatherosclerotic properties of estrogens in females and the wound healing effects of sex steroids.

Unique and synergistic roles for 17beta-estradiol and macrophage migration inhibitory factor during cutaneous wound closure are cell type specific

The cutaneous wound healing response is complex, comprising numerous overlapping events including inflammation, fibroblast migration, reepithelialization, and wound contraction. With increased age and resultant reduced systemic estrogens, these processes are disrupted and delayed healing ensues. We have demonstrated previously that the proinflammatory cytokine macrophage migration inhibitory factor (MIF) acts as a global regulator of wound healing mediating the majority of estrogen's healing promoting activity. MIF is expressed by numerous wound cell types yet the interaction between estrogens and MIF at the cellular level is still poorly understood. In this study we demonstrate novel accelerated healing in MIF null mice using an excisional wound model. Moreover, we show cell-type-specific differences in the effects of 17beta-estradiol and/or MIF on the cellular function of a range of wound cell types in vitro. Intriguingly, 17beta-estradiol is able to promote the migration of all cell types studied indicating a clear role for cell migration in accelerated wound healing.

Risks of nontraumatic lower-extremity amputations in patients with type 1 diabetes: a population-based cohort study in Sweden

OBJECTIVE

The purpose of this study was to estimate the risks of nontraumatic lower-extremity amputations (LEAs) in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We identified 31,354 patients with type 1 diabetes (15,001 women and 16,353 men) in the Swedish Inpatient Register between 1975 and 2004. The incidence of nontraumatic LEAs was followed up until 31 December 2004 by cross-linkage in the Inpatient Register and linkage to the Death and Migration registers. Poisson regression modeling was used to compare the risks of nontraumatic LEAs during different calendar periods of follow-up, with adjustment for both sex and attained age at follow-up. Standardized incidence ratios (SIRs) were used to estimate the relative risks (RRs) with the age-, sex-, and calendar period-matched general Swedish population as reference. The cumulative probability of nontraumatic LEAs was calculated by the Kaplan-Meier method.

RESULTS

In total, 465 patients with type 1 diabetes underwent nontraumatic LEAs. The risk was lower during the most recent calendar period (2000-2004) than during the period before 2000 (RR 0.6 [95% CI 0.5-0.8]). However, even in this most recent period, the risk for nontraumatic LEAs among these relatively young patients was 86-fold higher than that in the matched general population (SIR 85.8 [72.9-100.3]). By age 65 years, the cumulative probability of having a nontraumatic LEA was 11.0% for women with type 1 diabetes and 20.7% for men with type 1 diabetes.

CONCLUSIONS

Although the risks appeared to have declined in recent years, patients with type 1 diabetes still have a very high risk for nontraumatic LEAs.

Estrogen, not intrinsic aging, is the major regulator of delayed human wound healing in the elderly

Analysis of gene expression in male elderly and young human wounds suggests that estrogen has a more profound influence on aging than previously thought.

Background

Multiple processes have been implicated in age-related delayed healing, including altered gene expression, intrinsic cellular changes, and changes in extracellular milieu (including hormones). To date, little attempt has been made to assess the relative contribution of each of these processes to a human aging phenomenon. The objective of this study is to determine the contribution of estrogen versus aging in age-associated delayed human wound healing.

Results

Using an Affymetrix microarray-based approach we show that the differences in gene expression between male elderly and young human wounds are almost exclusively estrogen regulated. Expression of 78 probe sets was significantly decreased and 10 probe sets increased in wounds from elderly subjects (with a fold change greater than 7). A total of 83% of down-regulated probe sets and 80% of up-regulated probe sets were estrogen-regulated. Differentially regulated genes were validated at the level of gene and protein expression, with genes identified as estrogen-regulated in human confirmed as estrogen-dependent in young estrogen depleted mice in vivo. Moreover, direct estrogen regulation is demonstrated for three array-identified genes, Sele, Lypd3 and Arg1, in mouse cells in vitro.

Conclusion

These findings have clear implications for our understanding of age-associated cellular changes in the context of wound healing, the latter acting as a paradigm for other age-related repair and maintenance processes, and suggest estrogen has a more profound influence on aging than previously thought.

Selective estrogen receptor modulators accelerate cutaneous wound healing in ovariectomized female mice

A lack of systemic hormones in elderly postmenopausal women leads to delayed cutaneous wound healing. This effect can be reversed by systemic or topical estrogen replacement in both humans and rodent models. Over recent years selective estrogen receptor modulators have been developed in an attempt to achieve the beneficial effects of estrogen clinically, while minimizing the detrimental side effects. The effects of selective estrogen receptor modulators on the skin are poorly understood, and the effects on wound healing have not been assessed. In this study we treated 10-wk-old ovariectomized mice with estradiol, tamoxifen (TAM), raloxifene (RAL), or vehicle and examined the effect on healing of full-thickness incisional wounds. Both TAM and RAL substantially accelerate healing, associated with a dampened inflammatory response and altered inflammatory cytokine profile. In vitro TAM and RAL demonstrate antiinflammatory activity comparable to estrogen. These results have significant implications for the clinical modulation of wound healing.

Polymorphisms spanning the 0N exon and promoter of the estrogen receptor-beta (ERbeta) gene ESR2 are associated with venous ulceration

Venous ulcers are characterized by excessive inflammation and raised levels of proinflammatory cytokines. Estrogen has been shown to accelerate the rate of wound healing in elderly subjects by dampening the inflammatory response. The estrogen receptor (ER) proteins, ER-alpha (ERalpha) and ER-beta (ERbeta) mediate the actions of estrogen during wound repair through the activation or repression of target gene transcription. Recent evidence implicates the chromosomal region harboring the ERbeta gene with venous ulceration in a British Caucasian population, highlighting the need to conduct further genetic interrogation. To address this, we conducted a case-control study to investigate whether single nucleotide polymorphisms in the ERbeta gene are associated with venous ulceration in elderly (age >50 years) subjects. We recruited a case group (n = 124, 56 males and 68 females) consisting of patients with an active venous ulcer and a control group consisting of individuals from the general population with no evidence of venous disease or history of venous ulceration (n = 380, 189 males and 191 females). Polymorphisms in close proximity to upstream regulatory regions of the ERbeta gene, including the 0N exon and promoter transcribed in inflammatory cells, were significantly (p < 0.05) associated with venous ulceration. A major susceptibility haplotype carried by 23% (26/112) of cases compared with only 10% (27/276) of controls (odds ratio = 2.8, 95% confidence interval = 1.6-5.0) was significantly (p < 0.01) associated with elevated serum levels of tumor necrosis factor-alpha. In conclusion, common variation in the regulatory regions of the ERbeta gene may pre-dispose to venous ulceration in a British Caucasian population.

Sex steroids and cutaneous wound healing: the contrasting influences of estrogens and androgens

The increased prevalence in the elderly of chronic wound-healing conditions, such as venous and diabetic ulceration, is firmly established. This same population additionally suffers from impaired healing of acute wounds, which are characterized by delayed closure, increased local inflammation, and excessive proteolytic activity. In females, this decline in the effectiveness of skin repair mechanisms follows the menopause, and a series of clinical studies has identified estrogens as being endogenous enhancers of healing processes. The administration of 17beta-estradiol, either systemically or topically, has been shown to reverse the fundamental repair defects observed in postmenopausal women. By contrast, androgenic species retard repair and interfere with the accumulation of the structural proteins that reconstitute the damaged dermis. Since estrogen-based hormone replacement therapy produces wide-ranging effects, not all of which are considered to be desirable, more recent studies have sought to identify downstream mediators of estrogenic effects in order to formulate better targeted strategies for improving skin repair in the elderly.

The hormonal regulation of cutaneous wound healing

Conditions of impaired wound healing in the elderly are associated with substantial morbidity and mortality and impose a significant financial burden upon the world's health services. The findings of a series of recent studies have served to highlight the contrasting contributions made by sex steroid hormones to the regulation of cutaneous repair processes. Although estrogens accelerate healing, the actions of the "male" sex hormones 5alpha-dihydrotestosterone and testosterone are primarily deleterious. The shift that occurs in the balance between serum estrogen and androgen levels as a normal feature of human aging may therefore have important consequences for fundamental tissue repair processes.

Steroid hormones polymorphisms and cholelithiasis in Greek population

BACKGROUND

Genetic variation in genes involved in steroid biosynthesis, metabolism and signal transduction have been suggested to play a role in gallstone disease.

METHODS

To elucidate the possible role of genetic variation in the estrogen receptors alpha and beta (ER-alpha, ER-beta) and androgen receptor (AR) genes in breast cancer risk, the -1174(TA)n, c.1092+3607(CA)(n) and c.172(CAG)n repeat polymorphisms of the three genes were studied. A case-control cohort of 99 patients with cholelithiasis and 179 controls were used.

RESULTS

No significant difference was observed in the frequency distribution of -1174(TA)(0-26) in the ER-alpha gene between patients and controls, while a significant difference was observed in the frequency distribution of repeat polymorphism c.1092+3607(CA)5-27 and c.172(CAG)5-32 in the ER-beta gene and AR gene, respectively (P< or =0.001 and P=0.05, respectively). A significant difference was observed in the repeat genotype distribution (SS, SL, LL) in the (CA)n of the ER-beta gene (P<0.0001) and in the (CAG)n of the AR gene (P< or =0.0001). A significantly decreased odds ratio for cholelithiasis risk was observed in individuals having the SL and LL genotype for ER-beta gene compared with SS genotype (OR=0.212; 95% CI 0.105-0.426; P<0.0001 and OR=0.042; 95% CI 0.018-0.097, respectively) and LL genotype for AR gene (OR=0.622; 95% CI 0.345-1.121; P=0.114 and OR=0.287; 95% CI 0.151-0.543, P<0.0001, respectively). This protective effect of SL and LL genotypes for ER-beta and LL for AR gene remained evident (P<0.0001 for all of them) even after adjustment for various risk factors.

CONCLUSIONS

In conclusion an association for cholelithiasis risk between short alleles for both c.1092+3607(CA)5-27 and c.172(CAG)5-32 repeat polymorphisms of the ER-beta and AR was found in individuals of Greek descent.

Influence of gene polymorphisms in ulcer healing process after superficial venous surgery

OBJECTIVE

Role of superficial venous surgery in reducing the time it takes for ulcers to heal is still controversial, although all studies confirm a significant reduction in ulcer recurrences. Recently, the HFE-C282Y and FXIII-V34L gene variants demonstrated a role in the risk of venous ulceration in primary chronic venous disorder (CVD) and in modulating lesion size in chronic venous ulcer (CVU), respectively. This study was conducted to investigate the role of HFE-C282Y and FXIII (V34L and P564L) gene variants in ulcer healing time after superficial venous surgery, by assessing the outcome of a cohort of homogeneous CVU patients.

METHODS

The study selected 91 patients affected by primary CVU (CEAP C6, Ep, Asp, Pr), with the exclusion of any other comorbidity factor involved in delayed healing process, who underwent surgery. We assessed the ulcer area and the healing time. Patients were genotyped by polymerase chain reaction for FXIII (V34L and P564L) and for HFE-C282Y substitutions.

RESULTS

Globally, CVU cases had a postoperative mean healing time of 8.5 +/- 5.7 weeks. For the subset of cases above and below the median value (M = 8.0 weeks), FXIII-V34L genotype distribution significantly differed (P < .0001). In addition, Kaplan-Meier analysis yielded specific healing time profiles for the different FXIII-V34L classes of genotype (P = .00001), with an increased risk of delayed healing for the FXIII-VV genotype (hazard ratio, 4.14; 95% confidence interval, 2.1 to 8.2; P = .00005). Although FXIII-P54L genotype distributions did not differ, homozygous 564LL cases (P = .005) and double carriers for both FXIII variants (P < .0001), had a significantly reduced healing time vs wild types. No differences in healing time were observed between carriers and noncarriers of the HFE-C282Y variant, whereas when these cases were stratified by FXIII-V34L genotypes, the L34 carriers had a significantly shorter healing time, irrespective of the HFE genotype.

CONCLUSION

The FXIII-34L variant was significantly associated with shorter healing time after superficial venous surgery, suggesting a role in the healing and tissue regeneration phases. Conversely, HFE-C282Y, despite its role in ulcer establishment, did not affect the postoperative healing time. In perspective, the identification of patients with a poor prognosis may give clinicians the opportunity to modify management and to target tailored therapies in the view of a new and alternative concept of treatment based on pharmacogenomics.