Thyroid hormone and wound healing

Efficacy of the Novel Formulation of Topical Liothyronine and Liothyronine-insulin in Mild to Moderate Diabetic Foot Ulcer: A Randomized, Triple-blind Clinical Trial

BACKGROUND

Diabetic foot ulcer (DFU) is one of the challenging complications of chronic diabetes.

OBJECTIVE

The study aimed to investigate whether liothyronine (T3) and liothyronineinsulin (T3/Ins) topical preparations could significantly reduce the healing time of DFU.

METHODS

A prospective, randomized, placebo-controlled, patient-blinded clinical trial was conducted on patients with mild to moderate DFU, over a lesion area of no greater than 100 cm2. The patients were randomized to receive T3, T3/Ins, or honey cream 10% as the routine of care twice a day. Patients were examined for tissue healing weekly for 4 weeks, or until the total lesion clearance was observed, whichever was earlier.

RESULTS

Of 147 patients with DFUs, 78 patients (26 per group) completed the study and were included in the final evaluation. At the time of study termination, all participants in each of the T3 or T3/Ins groups were free of symptoms based on the REEDA score, while about 40% of participants in the control group were detected with each of grades 1, 2, or 3. A significant difference was observed on days 7, 14, and 21 of consumption of topical preparations (p-value < 0.001). The mean time to complete wound closure in the routine care group was about 60.6 days, while it was 15.9 and 16.4 days in T3 and T3/Ins groups, respectively. Within the T3 and T3/Ins groups, significant earlier wound closure was detected at day 28 (p-value < 0.001).

CONCLUSION

T3 or T3/Ins topical preparations are effective for wound healing and acceleration of wound closure in mild to moderate DFUs.

Hypothyroidism as an Independent Predictor of 30-day Readmission in Head and Neck Cancer Patients

OBJECTIVES

To define the role of hypothyroidism and other risk factors for unplanned readmissions after surgery for head and neck cancer.

STUDY DESIGN

Retrospective cohort study.

METHODS

The Nationwide Readmission Database (NRD) was used to identify patients who underwent surgery for mucosal head and neck cancer (oral cavity, oropharynx, larynx, and hypopharynx) between 2010 and 2017. Univariate and multivariate logistic regression were performed to determine patient, tumor, and hospital related risk factors for 30-day readmission. Readmitted patients were stratified by preoperative diagnosis of hypothyroidism to compare readmission characteristics.

RESULTS

For the 131,013 patients who met inclusion criteria, the readmission rate was 15.9%. Overall, 11.91% of patients had a preoperative diagnosis of hypothyroidism. After controlling for other variables, patients with a preoperative diagnosis of hypothyroidism had 12.2% higher odds of readmission compared to those without hypothyroidism (OR: 1.12, 1.03-1.22, p = 0.008). Patients with hypothyroidism had different reasons for readmission, including higher rates of wound dehiscence, fistula, infection, and electrolyte imbalance. Among readmitted patients, the length of stay for index admission (mean 10.5 days vs. 9.2 days, p < 0.001), readmission (mean 7.0 vs. 6.6 days, p = 0.05), and total hospital charge were higher for hypothyroid patients ($137,742 vs. $119,831, p < 0.001).

CONCLUSION

Hypothyroidism is an independent risk factor for 30-day readmission following head and neck cancer resection. Furthermore, hypothyroid patients are more likely to be readmitted for wound complications, infection, and electrolyte imbalance. Targeted interventions should be considered for hypothyroid patients to decrease readmission rates and associated patient morbidity, potentially leading to earlier initiation of adjuvant treatment.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2988-2998, 2023.

A short review on the role of thyroxine in fast wound healing and tissue regeneration

Wound healing is a multiplex interaction process that involves extracellular matrix, blood vessels, proteases, cytokines, and chemokine. So far, a number of studies have been performed to understand the basis of the wound-healing process and multiple wound-healing products have been designed. However, significant morbidity and mortality incidents still occurred due to poor wound healing. Thus, there is a dire need to understand the effects of topical applications of various therapeutic options that lead to fast wound healing. Thyroxine is one great panacea for wound healing that has been vigorously mooted throughout the years but a conclusive result regarding its effectiveness is still not achieved. This review is intended to find a rational basis for its positive role in wound healing. To accomplish the objective, this review highlights the different aspects of thyroxine's role in wound healing like keratin synthesis, skin thickening, and pro-angiogenesis, the basis of controversy on its wound healing ability and its potential to be used as a wound healing agent. This study will be helpful for researchers and surgeons to assess the importance of thyroxine as a candidate to comprehensively research to develop a potent, effective, and affordable wound healing drug.

MicroRNAs expressed during normal wound healing and their associated pathways: A systematic review and bioinformatics analysis

MicroRNAs (miRNAs) are responsible for regulating gene expression post-transcriptionally. Are involved in several biological processes, such as wound healing. Understanding the miRNAs involved in this process is fundamental for the development of new therapies. So, due to the need to understand the role of these molecules, we aimed systematically review the literature in order to identify which miRNAs are involved in the wound healing and determine, through bioinformatics analysis, which signaling pathways are associated with these miRNAs. An electronic search was performed in the following databases: National Library of Medicine National Institutes of Health (PubMed), Science Direct, Scifinder, Scopus and Web of Science, using the descriptors: "(microRNA [MeSH])" and "(skin [MeSH])" and "(wound healing [MeSH])". After the search, two independent and previously calibrated reviewers selected the articles that analyzed the expression pattern of miRNAs in wound healing in in vivo studies, using the software Zotero bibliography manager. Following, bioinformatic analysis was performed using the software DIANA Tools, mirPath v.3 and the data was interpreted. The bioinformatics analysis revealed that on the day 1 there were 13 union pathways, eight of which were statistically significant. Still on the day 1, among the miRNAs that had a decrease in their expression, 12 of 17 union pathways found were statistically significant. On the day 5, among the miRNAs with an increase in expression, 16 union pathways were found, 12 of which were statistically significant. Finally, among the miRNAs with decreased expression, 11 of 15 union pathways found were statistically significant. Although it has been found substantial heterogeneity in the studies, with this systematic review, it was possible to study the panorama of miRNAs that may be altered in the wound healing. The present review summarizes existing evidence of miRNAs associated to wound healing, and these findings can contribute to new therapeutic approaches.

Thyroid Hormone Signalling in Human Evolution and Disease: A Novel Hypothesis

Thyroid hormone (TH) signalling is a universally conserved pathway with pleiotropic actions that is able to control the development, metabolism, and homeostasis of organisms. Using evidence from paleoecology/palaeoanthropology and data from the physiology of modern humans, we try to assess the natural history of TH signalling and its role in human evolution. Our net thesis is that TH signalling has likely played a critical role in human evolution by facilitating the adaptive responses of early hominids to unprecedently challenging and continuously changing environments. These ancient roles have been conserved in modern humans, in whom TH signalling still responds to and regulates adaptations to present-day environmental and pathophysiological stresses, thus making it a promising therapeutic target.

Continuous Diffusion of Oxygen Adjunct Therapy to Improve Scar Reduction after Cervicotomy - A Proof of Concept Randomized Controlled Trial

BACKGROUND

Dressing materials are known to influence post-operative surgical wound healing and scar formation (SF). A particular dressing that could promote wound hydration is essential to ensure quick epithelialization and reduce SF. This study examined the effectiveness of a novel Continuous Diffusion of Oxygen (CDO) dressing to reduce scar length post cervicotomy.

METHODS

A randomized controlled trial was performed in patients undergoing cervicotomy, either for thyroid or parathyroid disease. Patients were randomized to either control (CG) or intervention (IG) groups. The IG received a portable CDO system (TransCu O2, EO2 Concepts Inc., TX, USA), whereas the CG received a standard dressing for a 4-week period. The primary outcome was >10% of scar length reduction and %change in scar length.

RESULTS

21 patients were recruited (Age: 53 ± 16 years; 90% female; CG = 9, IG = 12). 5 patients were lost to follow-up. At 4 weeks, 88.8% of the IG significantly achieved >10% of scar reduction (versus CG = 28.5%, d = 0.48, P = 0.049), showing a 40.4% smaller scar (15.7% versus 11.2%, d = 0.13, P = 0.72) compared to the CG. However, the difference was not significant. A sub-sample of patients undergoing thyroidectomy showed a significant scar reduction using CDO (IG = 11.6% versus CG = 5.1%, d = 2.96, P = 0.009).

CONCLUSIONS

This is the first study to assess scar reduction using CDO adjunct therapy after cervicotomy. Advanced CDO dressings may assist wound healing showing improved outcomes for scar visualization in patients undergoing thyroidectomy. A larger sample is required to validate this observation.

Update of hypothyroidism and its management in Unani medicine

Hypothyroidism is a clinical syndrome caused by thyroid hormone deficiency due to reduced production, deranged distribution, or lack of effects of thyroid hormone. The prevalence of hypothyroidism in developed countries is around 4-5%, whereas it is about 11% in India, only 2% in the UK, and 4·6% in the USA. It is more common in women than in men. Hypothyroidism has multiple etiologies and manifestations. The most common clinical manifestations are weight gain, loss of hair, cold intolerance, lethargy, constipation, dry skin, and change in voice. The signs and symptoms of hypothyroidism differ with age, gender, severity of condition, and some other factors. The diagnosis is based on clinical history, physical examination and serum level of FT3, FT4, and thyroid-stimulating hormone, imaging studies, procedures, and histological findings. The treatment of choice for hypothyroidism is levothyroxine, however; in this review article, we have discussed the epidemiology, etiology, clinical sign and symptoms, diagnosis, complications, and management of hypothyroidism in modern medicine and a comparative treatment by the Unani system of medicine (USM). In the USM, the main emphasis of the principle of treatment (Usool-e-Ilaj) is to correct the abnormal constitution (Su-e-Mizaj) and alter the six prerequisites for existence (Asbab-e-Sitta Zarooriya) to restore normal health. It is a packaged treatment, that is, different components of treatment are given as a package form which includes different drugs, dosages form, and regimens.

The Thyroid Hormone Inactivator Enzyme, Type 3 Deiodinase, Is Essential for Coordination of Keratinocyte Growth and Differentiation

Background: Thyroid hormones (THs) are key regulators of development, tissue differentiation, and maintenance of metabolic balance in virtually every cell of the body. Accordingly, severe alteration of TH action during fetal life leads to permanent deficits in humans. The skin is among the few adult tissues expressing the oncofetal protein type 3 deiodinase (D3), the TH inactivating enzyme. Here, we demonstrate that D3 is dynamically regulated during epidermal ontogenesis. Methods: To investigate the function of D3 in a postdevelopmental context, we used a mouse model of conditional epidermal-specific D3 depletion. Loss of D3 resulted in tissue hypoplasia and enhanced epidermal differentiation in a cell-autonomous manner. Results: Accordingly, wound healing repair and hair follicle cycle were altered in the D3-depleted epidermis. Further, in vitro ablation of D3 in primary culture of keratinocytes indicated that various markers of stratified epithelial layers were upregulated, thereby confirming the pro-differentiative action of D3 depletion and the consequent increased intracellular triiodothyronine levels. Notably, loss of D3 reduced the clearance of systemic TH in vivo, thereby demonstrating the critical requirement for epidermal D3 in the maintenance of TH homeostasis. Conclusion: In conclusion, our results show that the D3 enzyme is a key TH-signaling component in the skin, thereby providing a striking example of a physiological context for deiodinase-mediated TH metabolism, as well as a rationale for therapeutic manipulation of deiodinases in pathophysiological contexts.

Thyroxine restores severely impaired cutaneous re-epithelialisation and angiogenesis in a novel preclinical assay for studying human skin wound healing under "pathological" conditions ex vivo

Impaired cutaneous wound healing remains a major healthcare challenge. The enormity of this challenge is compounded by the lack of preclinical human skin wound healing models that recapitulate selected key factors underlying impaired healing, namely hypoxia/poor tissue perfusion, oxidative damage, defective innervation, and hyperglycaemia. Since organ-cultured human skin already represents a denervated and impaired perfusion state, we sought to further mimic “pathological” wound healing conditions by culturing experimentally wounded, healthy full-thickness frontotemporal skin from three healthy female subjects for three days in either serum-free supplemented Williams’ E medium or in unsupplemented medium under “pathological” conditions (i.e. hypoxia [5% O₂], oxidative damage [10 mM H₂O₂], absence of insulin, excess glucose). Under these “pathological” conditions, dermal–epidermal split formation and dyskeratosis were prominent in organ-cultured human skin, and epidermal reepithelialisation was significantly impaired (p < 0.001), associated with reduced keratinocyte proliferation (p < 0.001), cytokeratin 6 expression (p < 0.001) and increased apoptosis (p < 0.001). Moreover, markers of intracutaneous angiogenesis (CD31 immunoreactivity and the number of of CD31 positive cells and CD31 positive vessel lumina) were significantly reduced. Since we had previously shown that thyroxine promotes wound healing in healthy human skin ex vivo, we tested whether this in principle also occurs under “pathological” wound healing conditions. Indeed, thyroxine administration sufficed to rescue re-epithelialisation (p < 0.001) and promoted both epidermal keratinocyte proliferation (p < 0.01) and angiogenesis in terms of CD31 immunoreactivity and CD31 positive cells under “pathological” conditions (p < 0.001) ex vivo. This demonstrates the utility of this pragmatic short-term ex vivo model, which recapitulates some key parameters of impaired human skin wound healing, for the preclinical identification of promising wound healing promoters.

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14-8.23; P<0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19-3.77; P=0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08-3.47; P=0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10-5.50; P=0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30-0.72; P=0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01-1.04; P<0.001) and age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54-0.69) and a specificity of 0.63 (95% CI, 0.59-0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study.

Nanofiber-Mediated Sustained Delivery of Triiodothyronine: Role in Angiogenesis

Angiogenesis is a vital component of the orchestrated wound healing cascade and tissue regeneration process, which has a therapeutic prominence in treatment of ischemic vascular diseases and certain cardiac conditions. Based on its eminence, several strategies using growth factors have been studied to initiate angiogenesis. However, growth factors are expensive and have short half-life. In this work, sustained release of triiodothyronine, which plays a crucial role in stimulating growth factors and other signaling pathways that are instrumental in initiating angiogenesis, has been attempted through electrospun polycaprolactone nanofibers. This delivery system enabled the slow and sustained delivery of triiodothyronine into the micro-environment, reducing seepage of excess into systemic circulation and eliminating the necessity of repeated dosage forms. It was observed that triiodothyronine-incorporated nanofibers exhibited favorable interaction with cells (phalloidin staining of actin filaments) and also enhanced the rate of endothelial proliferation, migration, and adhesion. The angiogenic potential of these nanofibers was further corroborated through chorioallantoic membrane and rat aortic ring assay (demonstrating cell sprouting area of 3.3 ± 0.71 mm² compared to 1.2 ± 0.01 mm² in control). The nanofiber matrix thus fabricated demonstrated a vibrant therapeutic potential to induce angiogenesis. Triiodothyronine also plays a significant role in wound healing independent of initiating angiogenesis. This further substantiates the positive impact of this delivery system as a dressing material for chronic wound therapeutics, ischemic vascular diseases, and certain cardiac conditions.

TDP-43 proteinopathy in aging: Associations with risk-associated gene variants and with brain parenchymal thyroid hormone levels

TDP-43 proteinopathy is very prevalent among the elderly (affecting at least 25% of individuals over 85 years of age) and is associated with substantial cognitive impairment. Risk factors implicated in age-related TDP-43 proteinopathy include commonly inherited gene variants, comorbid Alzheimer's disease pathology, and thyroid hormone dysfunction. To test parameters that are associated with aging-related TDP-43 pathology, we performed exploratory analyses of pathologic, genetic, and biochemical data derived from research volunteers in the University of Kentucky Alzheimer's Disease Center autopsy cohort (n = 136 subjects). Digital pathologic methods were used to discriminate and quantify both neuritic and intracytoplasmic TDP-43 pathology in the hippocampal formation. Overall, 46.4% of the cases were positive for TDP-43 intracellular inclusions, which is consistent with results in other prior community-based cohorts. The pathologies were correlated with hippocampal sclerosis of aging (HS-Aging) linked genotypes. We also assayed brain parenchymal thyroid hormone (triiodothyronine [T3] and thyroxine [T4]) levels. In cases with SLCO1A2/IAPP or ABCC9 risk associated genotypes, the T3/T4 ratio tended to be reduced (p = .051 using 2-tailed statistical test), and in cases with low T3/T4 ratios (bottom quintile), there was a higher likelihood of HS-Aging pathology (p = .025 using 2-tailed statistical test). This is intriguing because the SLCO1A2/IAPP and ABCC9 risk associated genotypes have been associated with altered expression of the astrocytic thyroid hormone receptor (protein product of the nearby gene SLCO1C1). These data indicate that dysregulation of thyroid hormone signaling may play a role in age-related TDP-43 proteinopathy.

Hypothyroidism increases 90-day postoperative complications in patients undergoing primary single level anterior cervical disectomy and fusion: a matched control analysis

Background

Anterior cervical discectomy and fusion (ACDF) is indicated for patients suffering from cervical radiculopathy, myelopathy, and degenerative disc disease, among other diseases. There is paucity in the literature regarding postoperative complications in patients undergoing primary ACDF with a diagnosis of hypothyroidism. The purpose of this study is to compare 90-day postoperative complications in patients with and without hypothyroidism undergoing primary ACDF.

Methods

A retrospective analysis was completed using a national administrative database known as Pearl Diver (Pearl Diver Technologies, Fort Wayne, Indiana) using the International Classification of Disease, ninth revision (ICD-9) codes. The study group consisted of patients having undergone ACDF with an active diagnosis of hypothyroidism 90 days prior to and on the day of surgery. Patients undergoing primary ACDF without hypothyroidism served as the control group. Patients in both groups were randomly matched according to age, gender, and Charlson-Comorbidity Index (CCI). The 90-day postoperative medical complications were assessed along with readmission rates and total cost of care.

Results

There were a total of 107,066 patients equally divided between the 2 cohorts. Patients with hypothyroidism had greater odds of developing complications such as non-healing surgical wound (OR: 2.27; P<0.001), pulmonary embolus (OR: 2.16; P<0.001), myocardial infarction (OR: 2.10; P<0.001), compared to patients in the control group after undergoing primary ACDF. Readmission rates were also higher in patients with hypothyroidism (OR: 1.45; P<0.001). Total cost of care was also greater in patients with hypothyroidism compared to patients without hypothyroidism undergoing primary ACDF.

Conclusions

Hypothyroidism is a risk factor for worse postoperative outcomes in patients undergoing primary ACDF. Appropriate preoperative optimization with thyroid hormone supplementation could potentially minimize the incidence of developing numerous medical complications, in addition to potentially lowering readmission rates and the total cost of care.

Thyroid Hormone Receptors Regulate the Expression of microRNAs with Key Roles in Skin Homeostasis

BACKGROUND

MicroRNAs (miRNAs) play a unique role in posttranscriptional regulation of gene expression and control different aspects of skin development, homeostasis, and disease. Although it is generally accepted that thyroid hormone signaling is important in skin pathophysiology, the role of their nuclear receptors (TRs) in cutaneous miRNA expression has yet to be explored.

METHODS

RNAseq was used to compare the skin miRnome of wild-type mice and genetically modified mice lacking both TRα1 and TRβ, the main thyroid hormone binding isoforms. Changes in miRNAs with a crucial role in skin physiopathology were confirmed by stem-loop quantitative polymerase chain reaction in both total skin and isolated keratinocytes, and the levels of their target mRNAs were evaluated by real-time polymerase chain reaction.

RESULTS

The skin of TRα1/TRβ knockout mice displays altered levels of >50 miRNAs. Among the downregulated species are several miRNAs, including miR-21, miR-31, miR-34, and miR-203, with crucial roles in skin homeostasis. TRα1 appears to be the main isoform responsible for their regulation. Increased levels of gene transcripts previously shown to be bona fide targets of these miRNAs are also found in the skin and keratinocytes of TR-deficient mice. This suggests that multiple miRNAs that are downregulated in the absence of TRs cooperate to regulate gene expression in the skin.

CONCLUSIONS

The miRNAs reduced in TRα1/TRβ knockout mice are known to play crucial roles in epidermal proliferation, hair cycling, wound healing, stem-cell function, and tumor development, all processes altered in the absence of TRs. These results suggest that their regulation could contribute to the skin defects found in these mice and to the skin disorders associated with altered thyroid status in humans.

A bioengineered living cell construct activates an acute wound healing response in venous leg ulcers

Chronic nonhealing venous leg ulcers (VLUs) are widespread and debilitating, with high morbidity and associated costs; about $15 billion is spent annually on the care of VLUs in the United States. Despite this, there is a paucity of treatments for VLUs because of the lack of pathophysiologic insight into ulcer development as well as the lack of knowledge regarding biologic actions of existing VLU-targeted therapies. The bioengineered bilayered living cellular construct (BLCC) skin substitute is a U.S. Food and Drug Administration-approved biologic treatment for healing VLUs. To elucidate the mechanisms through which the BLCC promotes healing of chronic VLUs, we conducted a clinical trial (NCT01327937) in which patients with nonhealing VLUs were treated with either standard of care (compression therapy) or the BLCC together with standard of care. Tissue was collected from the VLU edge before and 1 week after treatment, and the samples underwent comprehensive microarray mRNA and protein analyses. Ulcers treated with the BLCC skin substitute displayed three distinct transcriptomic patterns, suggesting that BLCC induced a shift from a nonhealing to a healing tissue response, involving modulation of inflammatory and growth factor signaling, keratinocyte activation, and attenuation of Wnt/β-catenin signaling. In these ways, BLCC application orchestrated a shift from the chronic nonhealing ulcer microenvironment to a distinctive healing milieu resembling that of an acute, healing wound. Our findings provide in vivo evidence in VLU patients of pathways that can be targeted in the design of new therapies to promote healing of chronic VLUs.

Effects of Thyroid Hormone Therapy on Cut-Surface Healing of the Remnant Stomach with Short-Term Weight Loss Alterations after Sleeve Gastrectomy

BACKGROUND

The hypothalamic-pituitary-tyhroid axis is directly affected by drastic changes in energy stores. The aim of the present study was to determine the effects of triiodothyronine (T3) treatment on cut-surface healing of remnant stomach with weight loss alterations after sleeve gastrectomy (SG).

METHODS

Thirty male Wistar Albino rats were divided into three groups: sham (n = 6), control (n = 12), and experimental (n = 12). Control and experimental group rats underwent sleeve gastrectomy. Experimental group rats received a single dose of T3 (400 mg/100 g) on the first postoperative day whereas control group rats received 0.9% NaCl. All rats were sacrificed on the seventh postoperative day.

RESULTS

In the group of rats receiving T3, levels of FT3 were significantly higher and that of FT4 were significantly lower compared with both the control and sham group rats (p <.05). No significant difference was found between control and T3 group rats in terms of weight loss (p >.05). Microscopic examination of the cut surface of remnant stomach in the control group rats revealed significantly more severe tissue necrosis, edema, and disruption of mucosal epithelium than in the T3 group rats (p <.05). On the other hand, bridging of the submucosal and muscular layers, tissue granulation, fibroblast accumulation, neoangiogenesis, and collagen deposition in the T3 group rats were significantly higher than in the control group rats (p <.05).

CONCLUSIONS

Sleeve gastrectomy did not significantly alter thyroid hormone levels in short term. T3 hormone therapy seems to deliver constructive therapeutic effects for wound healing while causing no adverse effect on weight reduction.

Fabrication of a triiodothyronine incorporated nanofibrous biomaterial: its implications on wound healing

Triiodothyronine incorporated nanofibers and its impact on wound healing.

Impaired hair growth and wound healing in mice lacking thyroid hormone receptors

Both clinical and experimental observations show that the skin is affected by the thyroidal status. In hypothyroid patients the epidermis is thin and alopecia is common, indicating that thyroidal status might influence not only skin proliferation but also hair growth. We demonstrate here that the thyroid hormone receptors (TRs) mediate these effects of the thyroid hormones on the skin. Mice lacking TRα1 and TRβ (the main thyroid hormone binding isoforms) display impaired hair cycling associated to a decrease in follicular hair cell proliferation. This was also observed in hypothyroid mice, indicating the important role of the hormone-bound receptors in hair growth. In contrast, the individual deletion of either TRα1 or TRβ did not impair hair cycling, revealing an overlapping or compensatory role of the receptors in follicular cell proliferation. In support of the role of the receptors in hair growth, TRα1/TRβ-deficient mice developed alopecia after serial depilation. These mice also presented a wound-healing defect, with retarded re-epithelialization and wound gaping, associated to impaired keratinocyte proliferation. These results reinforce the idea that the thyroid hormone nuclear receptors play an important role on skin homeostasis and suggest that they could be targets for the treatment of cutaneous pathologies.