Vitamin D: a novel therapeutic approach for keloid, an in vitro analysis

A double-blinded randomised control study to compare the effectiveness and safety of intralesional vitamin D3 with intralesional triamcinolone and its correlation with tissue expression of vitamin D receptors in patients with keloid

Intralesional steroids commonly used for keloid treatment have adverse effects like cutaneous atrophy and telangiectasias. Safer and more effective therapies are needed. Preliminary studies suggest intralesional vitamin D as a potential alternative treatment. The aim of this study was to compare efficacy and safety of intralesional vitamin D with triamcinolone for keloids, and correlate tissue expression of vitamin D receptors (VDRs) with treatment outcomes. Sixty patients were randomly assigned to two groups: Group A (intralesional vitamin D) and Group B (intralesional triamcinolone). Four injections were given at 4-week intervals, with an 8-week follow-up. Biopsies were taken pre- and post-treatment to examine VDR expression levels and treatment response correlation. The primary outcome of interest was the proportion of patients achieving a 50% reduction in Vancouver Scar Scale (VSS). Secondary outcomes included incidence of adverse effects, and changes in VDR expression before and after treatment. Baseline VSS scores were 9.73 ± 1.01 (vitamin D group) and 10.13 ± 1.07 (triamcinolone group). After treatment, mean VSS decreased to 5.17 ± 0.59 (vitamin D group, p < 0.001) and 4.77 ± 0.77 (triamcinolone group, p < 0.001), with significantly better response in latter (p = 0.03). More than 50% reduction in VSS score was higher in the triamcinolone group (76.7% vs. 50%, p = 0.032). No recurrences were noted during the 8-week follow-up. Hypopigmentation (80% vs. 36.7%, p < 0.001) and atrophy (73.3% vs. 40%, p = 0.009) were more common in the triamcinolone group. No significant difference in pre- and post-treatment VDR receptor expression was observed in either group. Both triamcinolone acetonide and vitamin D were effective for keloids. Triamcinolone was more efficacious, whereas vitamin D was safer, suggesting it as a viable alternative for keloid management.

Natural products - Dawn of keloid treatment

Keloids are prevalent pathological scars, often leading to cosmetic deformities and hindering joint mobility.They cause discomfort, including burning and itching, while gradually expanding and potentially posing a risk of cancer.Developing effective drugs and treatments for keloids has been a persistent challenge in the medical field. Natural products are an important source of innovative drugs and a breakthrough for many knotty disease.Herein, keywords of "natural, plant, compound, extract" were combined with "keloid" and searched in PubMed and Google Scholar, respectively. A total of 32 natural products as well as 9 extracts possessing the potential for treating keloids were ultimately identified.Current research in this field faces a significant challenge due to the lack of suitable animal models, resulting in a predominant reliance on in vitro studies.In vivo and clinical studies are notably scarce as a result.Moreover, there is a notable deficiency in research focusing on the role of nutrients in keloid formation and treatment.The appropriate dosage form (oral, topical, injectable) is crucial for the development of natural product drugs. Finally, the conclusion was hereby made that natural products, when used as adjuncts to other treatments, hold significant potential in the management of keloids.By summarizing the natural products and elucidating their mechanisms in keloid treatment, the present study aims to stimulate further discoveries and research in drug development for effectively addressing this challenging condition.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Metabolism, fibrosis, and apoptosis: The effect of lipids and their derivatives on keloid formation

Keloids, pathological scars resulting from skin trauma, have traditionally posed significant clinical management challenges due to their persistence and high recurrence rates. Our research elucidates the pivotal roles of lipids and their derivatives in keloid development, driven by underlying mechanisms of abnormal cell proliferation, apoptosis, and extracellular matrix deposition. Key findings suggest that abnormalities in arachidonic acid (AA) synthesis and non-essential fatty acid synthesis are integral to keloid formation. Further, a complex interplay exists between lipid derivatives, notably butyric acid (BA), prostaglandin E2 (PGE2), prostaglandin D2 (PGD2), and the regulation of hyperfibrosis. Additionally, combinations of docosahexaenoic acid (DHA) with BA and 15-deoxy-Δ12,14-Prostaglandin J2 have exhibited pronounced cytotoxic effects. Among sphingolipids, ceramide (Cer) displayed limited pro-apoptotic effects in keloid fibroblasts (KFBs), whereas sphingosine 1-phosphate (S1P) was found to promote keloid hyperfibrosis, with its analogue, FTY720, demonstrating contrasting benefits. Both Vitamin D and hexadecylphosphorylcholine (HePC) showed potential antifibrotic and antiproliferative properties, suggesting their utility in keloid management. While keloids remain a prevalent concern in clinical practice, this study underscores the promising potential of targeting specific lipid molecules for the advancement of keloid therapeutic strategies.

Comparison of Intralesional Vitamin D with Intralesional Triamcinolone Acetonide in the Treatment of Keloids

Background

Hypertrophic scars and keloids are disorders caused by the excessive growth of connective tissue, associated with the accumulation of collagen and cellular matrix components. These scars are caused by abnormal wound healing and can have a great impact on patients' lives. Therefore, we aimed to compare the effect of intralesional injection of vitamin D with triamcinolone acetonide in the treatment of keloid.

Methods

This study was a one-sided blind clinical trial, conducted on 22 patients (44 samples) with keloid. It was a randomized, blinded clinical trial, conducted in Imam Khomeini Hospital in Ahvaz, Iran in 2022. In each group, triamcinolone or vitamin D was injected at the lesion site with an interval of three weeks and an average of 6 sessions. The patients were re-evaluated 3 months after the end of the treatment in terms of recurrence.

Results

By examining the VSS scale in each of the groups, this scale decreased significantly in both groups after the intervention (P=0.001), which was greater in the group receiving triamcinolone (P=0.001).

Conclusion

It seems that the injection of vitamin D at the site of the lesion helps to treat it, but the effectiveness of the usual triamcinolone treatment was still higher, it is suggested to use vitamin D as an adjunctive treatment in these patients.

Possible benefits of food supplementation or diet in scar management: A scoping review

Aim

The evidence regarding a potential role of food supplementation as an adjunct therapy in scar aftercare is limited. In this scoping review we aim to provide an overview of the possible beneficial role of supplementations in aftercare settings.

Method

After formulating the research question and accompanying key words, a comprehensive search for relevant publications was performed using PubMed and Web of Science. Two authors independently identified and checked each study against the inclusion criteria. All data was collected and summarized for further discussion.

Results

After screening, 11 studies were included in the qualitative synthesis. Four studies including human subjects showed a promising connection between scar improvement and supplementation of vitamin D, omega-3 fatty-acids or a Solanaceae-free diet and lower omega-6 fatty-acid intake. Most of the studies were performed on in-vitro models. Preliminary evidence confirmed the beneficial role of vitamin D. Curcumin- and quercetin-supplementation were linked to decreased fibroblast proliferation. Vitamin C enhanced collagen production in healthy as well as keloidal dermal fibroblasts. Chitin stimulated cell-proliferation in human fibroblasts and keratinocytes.

Conclusion

The findings suggest early potential benefits of additional food supplementation in scar management for scars but provide no clear evidence. To establish guidelines or gather more evidence on food supplementation, studies involving human subjects (in vivo) are essential. The intricacies associated with nutritional studies in vivo present multifaceted challenges. It should be emphasized that substantial additional evidence is required before aspects such as timing and dosage of supplementation could be addressed for clinical application.

Lay Summary

Aim: This scoping review looks at whether taking food supplements might help with scar care alongside standard scar management following burn injury. Little information is thought to be available on this subject. An up-to-date review of the literature was undertaken to assimilate the body of evidence and determine if a consensus could be drawn.Method: A specific research question was designed and search conducted in scientific databases like PubMed and Web of Science. Two of our team members carefully selected and reviewed each study to determine which studies met the inclusion or exclusion criteria. All studies that met the inclusion criteria were then reviewed and the information collated to enable conclusions to be drawn.Results: Eleven studies met the inclusion criteria and were used to formulate the conclusions drawn. Four studies showed that taking vitamin D, omega-3 fatty acids, a diet without certain vegetables (Solanaceae), and eating less omega-6 fatty acids might help improve scars. It is important to note that most studies (seven out of 11) were carried out in a laboratory and not with real people. These lab studies showed that vitamin D might be helpful. Supplements like curcumin and quercetin seemed to slow down the growth of skin cells like fibroblasts and keratinocytes. Vitamin C aided collagen synthesis, which is important for healthy skin, in both normal and keloid scar cells. Another substance, chitin, was also found to help skin cells and keratinocytes grow better.Conclusion: Our findings point to some early possible benefits of taking extra nutrient supplements for managing scars but do not provide clear evidence. More research is required to enable the development of supplement recommendation and guidelines to be produced. Future research should focus on human trials but do keep in mind that carrying out supplement studies with people is more complicated. The evidence provided by this scoping review is insufficient to recommend the intake of any supplements or the imposition of dietary restrictions for the purpose of managing scars.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Increased Occurrence of Cutaneous Leiomyomas and Dermatofibromas in Patients with Uterine Leiomyomas without Fumarate Hydratase Gene Mutations

Leiomyomas are smooth muscle-derived benign neoplasms that can affect all organs, most frequently in the uterus. Fumarate hydratase gene (FH) mutation is characterised by an autosomal dominant disease with increased occurrence of renal tumours, but also by cutaneous (CLs) and uterine leiomyomas (ULs). So far, an increased occurrence of skin tumours in non-mutated patients with ULs has not been verified. To this aim, a case-group of women who were FH non-mutated patients surgically treated for ULs (n = 34) was compared with a control-group (n = 37) of consecutive age-matched healthy women. The occurrence of skin neoplasms, including CLs and dermatofibromas (DFs), was evaluated. Moreover, the microscopic features of FH non-mutated skin tumours were compared with those of an age-matched population group (n = 70) who presented, in their clinical history, only one type of skin tumour and no ULs. Immunohistochemical and in vitro studies analysed TGFβ and vitamin D receptor expression. FH non-mutated patients with ULs displayed a higher occurrence of CLs and DFs (p < 0.03 and p < 0.001), but not of other types of skin tumours. Immunohistochemistry revealed a lower vitamin D receptor (VDR) expression in CLs and DFs from the ULs group compared with those from the population group (p < 0.01), but a similar distribution of TGFβ-receptors and SMAD3. In vitro studies documented that TGFβ-1 treatment and vitamin D3 have opposite effects on α-SMA, TGFβR2 and VDR expression on dermal fibroblast and leiomyoma cell cultures. This unreported increased occurrence of CLs and DFs in FH non-mutated patients with symptomatic ULs with vitamin D deficiency suggests a potential pathogenetic role of vitamin D bioavailability also for CLs and DFs.

17,20S(OH)2pD Can Prevent the Development of Skin Fibrosis in the Bleomycin-Induced Scleroderma Mouse Model

Systemic sclerosis (SSc; scleroderma) is a chronic fibrotic disease involving TGF-β1. Low serum vitamin D (vit D) correlates with the degree of fibrosis and expression of TGF-β1. This study was designed to determine whether the noncalcemic vit D analog, 17,20S(OH)₂pD, suppresses fibrosis and mediators of the TGF-β1 pathway in the bleomycin (BLM) model of fibrosis. Fibrosis was induced into the skin of female C57BL/6 mice by repeated injections of BLM (50 μg/100 μL) subcutaneously. Mice received daily oral gavage with either vehicle (propylene glycol) or 17,20S(OH)₂pD using 5, 15, or 30 μg/kg for 21 days. The injected skin was biopsied; analyzed histologically; examined for total collagen by Sircol; and examined for mRNA expression of MMP-13, BMP-7, MCP-1, Gli1, and Gli2 by TR-PCR. Spleen was analyzed for lymphocytes using flow cytometry. Serum was analyzed for cytokines using a multiplexed ELISA. Results showed that all three doses of 17,20S(OH)₂pD suppressed net total collagen production, dermal thickness, and total collagen content in the BLM fibrosis model. 17,20S(OH)₂pD also increased MMP-13 expression, decreased MCP-1 and Gli-2 expression in vivo, and suppressed serum levels of IL-13, TNF-α, IL-6, IL-10, IL-17, and IL-12p70. In summary, 17,20S(OH)₂pD modulates the mediators of fibrosis in vivo and suppresses total collagen production and dermal thickness. This antifibrotic property of 17,20S(OH)₂pD offers new therapeutic approaches for fibrotic disorders.

Role of vitamin D in treatment of keloid

BACKGROUND

Keloid is a benign well-demarcated overgrowth of fibrotic tissue which extends beyond the original boundaries of a defect. The treatment of keloids is a particular challenge to dermatologists. Intralesional corticosteroid injection has been considered the first-line treatment for keloids. Vitamin D plays an important role in cell proliferation and differentiation as it slows the progression of tissue fibrosis by keloid fibroblasts and inhibits collagen synthesis in dermal fibrosis.

OBJECTIVES

To evaluate the efficacy of intralesional injection of vitamin D in the treatment of keloids, both clinically and ultrasonically.

METHODS

Forty Egyptian patients with keloid scars were injected weekly with intralesional vitamin D with dose of 0.2 ml (200,000 IU) per 1 cm lesion. The keloid scars were evaluated with Vancouver Scar Scale (VSS) and by a high-resolution ultrasound using B mode before and after treatment, the patients received 3 to 4 sessions.

RESULTS

There was statistically highly significant reduction in VSS after treatment with intralesional vitamin D injection (p value≤0.001). There was also statistically highly significant improvement in ultrasonic keloid scar thickness after treatment (P value ≤0.001).

CONCLUSIONS

Intralesional vitamin D is an effective and safe method in treatment of keloid scars. Ultrasound is a useful method in assessing the improvement of keloids after treatment.

Perioperative Optimization of Patients With Neuromuscular Disorders Undergoing Scoliosis Corrective Surgery: A Multidisciplinary Team Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

The high rate of complications associated with the surgical management of neuromuscular spinal deformities is well documented in the literature. This is attributed to attenuated protective physiological responses in multiple organ systems.

METHODS

Review and synthesis of the literature pertaining to optimization of patients with neuromuscular scoliosis undergoing surgery. Our institutional practice in the perioperative assessment and management of neuromuscular scoliosis is also described along with a clinical vignette.

RESULTS

Respiratory complications are the most common to occur following surgery for neuromuscular disorders. Other categories include gastrointestinal, cardiac, genitourinary, blood loss, and wound complications. A multidisciplinary approach is required for perioperative optimization of these patients and numerous strategies are described, including respiratory management.

CONCLUSION

Perioperative optimization for patients with neuromuscular disorders undergoing corrective surgery for spinal deformity is multifaceted and complex. It requires a multidisciplinary evidence-based approach. Preadmission of patients in advance of surgery for assessment and optimization may be required in certain instances to identify key concerns and formulate a tailored treatment plan.

Does vitamin D deficiency predispose to keloids via dysregulation of koebnerisin (S100A15)? A case-control study

Keloids result from uncontrolled inflammation and fibrosis during wound healing. Vitamin D can regulate skin proliferation and inflammation. Fibroblasts are vitamin D-responsive target cells and are source of koebnerisin (an antimicrobial peptide released during inflammation and wound healing). This study aimed to assess the levels and correlations between the serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin (S100A15) in patients with keloids. Nineteen patients with keloids and 20 matched controls were recruited. From each keloid patient, a serum sample and two biopsies were taken from the keloid (lesional) (Tissue A) and from normal skin (non-lesional) (Tissue B). From controls, a serum sample and a tissue biopsy from normal skin were taken. Serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin were measured in retrieved samples using ELISA. Results revealed a significantly lower serum 25-Hydroxyvitamin D, tissue vitamin D receptors, as well as, serum and tissue koebnerisin in keloid patients compared to controls. Tissue 25-Hydroxyvitamin D was significantly lower in keloidal skin biopsy (Tissue A) compared to non-lesional normal skin biopsy (Tissue B). Tissue koebnerisin showed a significant positive correlation with tissue vitamin D receptors, and a significant negative correlation with tissue 25-Hydroxyvitamin D. There was a significant negative correlation between serum 25-Hydroxyvitamin D and duration of keloid. Accordingly, low serum and tissue 25-Hydroxyvitamin D and deficient tissue vitamin D receptors contribute to the pathogenesis of keloids. This can be partly mediated by dysregulation of the antimicrobial peptide; koebnerisin. Artificial antimicrobial peptides and koebnerisin-modifying drugs, for example, vitamin D and TNF-α inhibitors can have a role in keloid prevention and treatment.

The association between keloid and osteoporosis: real-world evidence

Background

Keloids are characterized by disturbance of fibroblast proliferation and apoptosis, deposition of collagen, and upregulation of dermal inflammation cells. This benign dermal fibro-proliferative scarring condition is a recognized skin inflammation disorder. Chronic inflammation is a well-known contributor to bone loss and its sequelae, osteoporosis. They both shared a similar pathogenesis through chronic inflammation. We assessed whether keloids increase osteoporosis risk through using National Health Insurance Research Database.

Methods

The 42,985 enrolled patients included 8597 patients with keloids but no history of osteoporosis; 34,388 controls without keloids were identified from the general population and matched at a one-to-four ratio by age, gender. Kaplan-Meier method was applied to determine cumulative incidence of osteoporosis. Cox proportional hazard regression analysis was performed after adjustment of covariates to estimate the effect of keloids on osteoporosis risk.

Results

Of the 8597 patients with keloids, 178 (2.07%) patients were diagnosed with osteoporosis while in the 34,388 controls, 587 (1.71%) were diagnosed with osteoporosis. That is, the keloids patients had 2.64-fold higher risk of osteoporosis compared to controls after adjustment for age, gender, Charlson Comorbidity Index and related comorbidities. The association between keloids and osteoporosis was strongest in patients younger than 50 years (hazard ratio = 7.06%) and in patients without comorbidities (hazard ratio = 4.98%). In the keloids patients, a high incidence of osteoporosis was also associated with advanced age, high Charlson Comorbidity Index score, hyperlipidemia, chronic liver disease, stroke, and depression.

Conclusions

Osteoporosis risk was higher in patients with keloids compared to controls, especially in young subjects and subjects without comorbidities.

Associations of VDR gene polymorphisms with risk of coal workers' pneumoconiosis in Chinese Han population

Some studies showed that the polymorphisms of vitamin D receptor (VDR) gene were associated with pulmonary diseases. However, the relationship between the VDR variations and susceptibility to coal worker's pneumoconiosis (CWP) remains unclear. The study aimed to determine the associations between VDR polymorphisms and susceptibility to CWP in Chinese Han population. The study involved 340 CWP patients and 312 healthy controls. The VDR polymorphisms were determined by DNA sequencing, and serum 25(OH)2D levels were detected by Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry. The results showed that the VDR gene ApaI T allele increased the risk of CWP (OR = 1.486, 95% CI = 1.125-1.963, P = 0.006) and ApaI GT genotype as well as TT genotype increased the risk of CWP (GT vs. GG, OR = 1.461, 95% CI = 1.048-2.038, P = 0.025; TT vs. GG, OR = 2.673, 95% CI = 1.017-7.025, P = 0.039). Five haplotypes were identified and we found that the TGGT haplotype was associated with a lower risk of CWP (OR = 0.755, 95% CI = 0.603-0.946, P = 0.014). Meanwhile, multifactor dimensionality reduction analysis showed that the interaction between ApaI and exposure was the strongest, followed by TaqI and then BsmI. The study also found that the serum 25(OH)2D mean levels of the case group were significantly lower than that of the control group, and the serum 25(OH)2D mean levels of ApaI homozygous mutant and heterozygous mutant subjects were lower than that of the wild homozygosity, respectively (P < 0.001). The results suggested that ApaI T allele and GT or TT genotype and lower 25(OH)2D levels were increased the risk of CWP in Chinese Han population.

UV increases skin-derived 1α,25-dihydroxyvitamin D3 production, leading to MMP-1 expression by altering the balance of vitamin D and cholesterol synthesis from 7-dehydrocholesterol

The skin is a unique site in the human body that has the capacity to synthesize the active form of vitamin D, 1α,25-dihydroxyvitamin D₃ (1α,25(OH)₂D₃), from 7-dehydrocholesterol (7DHC) upon UV irradiation. Keratinocytes express both 25-hydroxylase (CYP27A1 and CYP2R1) and 1α-hydroxylase (CYP27B1), critical enzymes involved in active vitamin D synthesis. Here, we investigated the effect of skin-derived 1α,25(OH)₂D₃, synthesized purely within the keratinocytes, on MMP-1 expression. Treatment of human epidermal keratinocytes with 1α,25(OH)₂D_3, but not 7DHC or 25OHD₃, significantly increased MMP-1 expression. UV irradiation increases 1α,25(OH)₂D₃ levels, and ketoconazole inhibits UV-induced production of 1α,25(OH)₂D₃. Upregulation of MMP-1 by UV was reversed by inhibition of 1α,25(OH)₂D₃ synthesis using ketoconazole or CYP27B1 siRNA. In keratinocytes, 7DHC is a substrate for both cholesterol and 1α,25(OH)₂D₃ synthesis. We demonstrated that UV irradiation leads to decreased expression of DHCR7 (7-dehydrocholesterol reductase), the enzyme that converts 7DHC to cholesterol. Inhibition of DHCR7 with its inhibitor BM15766 decreased cholesterol synthesis and increased UV-induced MMP-1 expression, which was attenuated by ketoconazole. These findings suggest that UV-induced reduction of DHCR7 leads to a decrease in cholesterol synthesis, thereby increasing 7DHC availability for 1α,25(OH)₂D₃ production, which enhances MMP-1 expression. Finally, UV irradiation in human skin in vivo significantly increased CYP27B1 mRNA and decreased DHCR7 mRNA expression. Taken together, we demonstrate here that skin-derived 1α,25(OH)₂D₃ significantly increases MMP-1 expression in human keratinocytes, a previously unappreciated function of 1α,25(OH)₂D_3. Moreover, UV irradiation upregulates the enzyme CYP27B1, which leads to 1α,25(OH)₂D₃ synthesis, but downregulates the cholesterol-producing enzyme DHCR7, both of which collectively lead to increased MMP-1 expression in human keratinocytes. This pathway may be exploited to develop a novel cutaneous anti-aging agent that blocks local cutaneous 1α,25(OH)₂D₃ synthesis.

Calcimycin Suppresses S100A4 Expression and Inhibits the Stimulatory Effect of Transforming Growth Factor β1 on Keloid Fibroblasts

Recent researches have indicated that S100A4 participates in tissue fibrosis, whereas calcimycin inhibits this process as a novel S100A4 transcription inhibitor. However, the relationship and mechanisms between calcimycin and S100A4 in keloid fibroblasts (KFs) remain unknown. The present research was aimed to evaluate the effect of calcimycin on S100A4 expression and pathogenesis in KFs. Keloid fibroblasts were cultured and exposed to different concentrations of calcimycin in the absence or presence of transforming growth factor β1 (TGF-β1). The results showed that the expression of S100A4 was significantly increased in keloid derived fibroblasts compared with normal skin fibroblasts. Calcimycin depressed S100A4 in a concentration- and time-dependent manner. Moreover, calcimycin suppressed TGF-β1-induced collagen type I, fibronectin, and α-smooth muscle actin expression and cell viability in cultured KFs. Furthermore, calcimycin modulated expression of TGF-β/Smad target genes Smad7 and phosphorylation of TGF-β1-induced Smad2/3. This research for the first time confirmed the presence of S100A4 in KFs. Calcimycin inhibits the expression of S100A4, as well as KF proliferation and migration and extracellular matrix (ECM) synthesis. Taken together, these results indicate that calcimycin might be a therapeutic candidate to keloid or other related fibrotic disorders.

Vitamin D and Wnt3A have additive and partially overlapping modulatory effects on gene expression and phenotype in human colon fibroblasts

The Wnt/β-catenin signalling pathway is essential for intestinal epithelium homeostasis, but its aberrant activation is a hallmark of colorectal cancer (CRC). Several studies indicate that the bioactive vitamin D metabolite 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) inhibits proliferation and promotes epithelial differentiation of colon carcinoma cells in part through antagonism of the Wnt/β-catenin pathway. It is now accepted that stromal fibroblasts are crucial in healthy and pathologic intestine: pericryptal myofibroblasts are constituents of the stem cell niche and cancer-associated fibroblasts (CAFs) contribute to CRC progression. However, studies on the combined action of 1,25(OH)₂D₃ and Wnt factors in colon fibroblasts are lacking. Here we show by global transcriptomic studies that 1,25(OH)₂D₃ and Wnt3A have profound, additive, partially overlapping effects on the gene expression profile of CCD-18Co human colon myofibroblasts. Moreover, 1,25(OH)₂D₃ and Wnt3A inhibit CCD-18Co cell proliferation and migration, while 1,25(OH)₂D₃ reduces, but Wnt3A increases, their capacity to contract collagen gels (a marker of fibroblast activation). These data were largely confirmed in patient-derived primary colon normal fibroblasts and CAFs, and in fibroblasts from other origins. Our results indicate that 1,25(OH)₂D₃ and Wnt3A are strong regulators of colon fibroblast biology and contribute to a better knowledge of intestinal homeostasis and stromal fibroblast action in CRC.

Caveolin-1 as a target in prevention and treatment of hypertrophic scarring

Reduced expression of caveolin-1 (Cav-1) is an important pathogenic factor in hypertrophic scarring (HTS). Such a reduction can be found in connection with the main known risk factors for HTS, including dark skin, female gender, young age, burn site and severity of the injury. The degree of overexpression of Cav-1 associated with different therapeutic options for HTS correlates with clinical improvements in HTS. This makes endo- or exogenous induction of Cav-1 not only an important therapeutic target for HTS, but also highlights its use as a preventive target to reduce or avoid HTS formation.

Caveolin-1 as a pathophysiological factor and target in psoriasis

Low expression of caveolin-1 (Cav-1) is typical in psoriatic lesions and overexpression of Cav-1 leads to a reduction of inflammation and suppression of epidermal hyperproliferation, thus ameliorating these two well-known hallmarks of psoriasis. At the same time, the interfacial layers of the white adipose tissue (WAT) adjacent to psoriatic lesions demonstrate much higher stiffness, which also points to a modification of Cav-1 expression in this tissue. These processes are connected with each other and regulated via exosomal exchange. Here we discuss the role of Cav-1 expression in inflammatory and hyperproliferative processes and analyze the ways to provide spatially different modulation of Cav-1 expression in the skin and WAT. Such modulation can be induced by different pharmacological and physical factors. These include application of mechanical stress and supra-physiological temperatures. Cav-1 should therefore be considered as an important target in treatment of psoriasis.

Correlation between Serum 25-Hydroxyvitamin D Levels with Keloid Severity

BACKGROUND

Keloids are dermal fibroproliferative tumours characterised by excessive deposition of extra cellular matrix components. The active form of vitamin D is known to inhibit the proliferation of keloid fibroblasts by inhibiting extracellular matrix production induced by transforming growth factor ß (TGF-β) and increasing matrix metalloproteinase (MMP) activity. Vitamin D derivatives are thought to be an early preventive treatment strategy for keloid.

AIM

To determine the correlation between serum 25-hydroxyvitamin D level with keloid severity.

METHODS

This is a cross-sectional analytic study involving 32 keloid patients. Keloid patients were diagnosed by history and clinical examinations. Then an assessment of the severity was conducted using the Vancouver Scar Scale (VSS). We conducted blood sampling and measurement of serum 25-hydroxyvitamin D level to the patients. This study has been approved by the Health Research Ethics Commission of the Faculty of Medicine, Universitas Sumatera Utara, H. Adam Malik General Hospital Medan.

RESULTS

There is negative correlation between serum 25-hydroxyvitamin D level with severity in keloid patients (p = 0.0001; r = -0.737). There is no significant correlation between serum 25-hydroxyvitamin D level with gender (p = 0.271), age (p = 0.201; r = -0.232), duration of keloid (p = 0.505; r = -0.122) and family history (p = 0.262).

CONCLUSION

Lower level of plasma 25-hydroxyvitamin D, the severity of keloid became an increasingly heavy. There is no significant difference between serum 25-hydroxyvitamin D level with gender, age, duration of keloid and family history in keloid patients.

The Role of Vitamin D in the Pathogenesis of Adolescent Idiopathic Scoliosis

Several theories have been proposed to explain the etiology of adolescent idiopathic scoliosis (AIS) until present. However, limited data are available regarding the impact of vitamin D insufficiency or deficiency on scoliosis. Previous studies have shown that vitamin D deficiency and insufficiency are prevalent in adolescents, including AIS patients. A series of studies conducted in Hong Kong have shown that as many as 30% of these patients have osteopenia. The 25-hydroxyvitamin D3 level has been found to positively correlate with bone mineral density (BMD) in healthy adolescents and negatively with Cobb angle in AIS patients; therefore, vitamin D deficiency is believed to play a role in AIS pathogenesis. This study attempts to review the relevant literature on AIS etiology to examine the association of vitamin D and various current theories. Our review suggested that vitamin D deficiency is associated with several current etiological theories of AIS. We postulate that vitamin D deficiency and/or insufficiency affects AIS development by its effect on the regulation of fibrosis, postural control, and BMD. Subclinical deficiency of vitamin K2, a fat-soluble vitamin, is also prevalent in adolescents; therefore, it is possible that the high prevalence of vitamin D deficiency is related to decreased fat intake. Further studies are required to elucidate the possible role of vitamin D in the pathogenesis and clinical management of AIS.

Role of Homeodomain-Interacting Protein Kinase 2 in the Pathogenesis of Tissue Fibrosis in Keloid-Derived Keratinocytes

Epithelial-mesenchymal transition (EMT) plays a critical role in fibrotic keloid formation, which is characterized by excessive collagen and extracellular matrix synthesis and deposition. Growing evidence suggests that the serine/threonine kinase homeodomain-interacting protein kinase 2 (HIPK2) acts upstream of several major fibrosis signaling pathways; however, the role of HIPK2 in the keloid fibrogenesis remains unknown. In the current study, we investigated the roles of HIPK2 in the pathogenesis of keloids. Primary normal skin and keloid keratinocytes were cultured and pretreated with transforming growth factor (TGF)-β1. Next, keratinocytes were transfected with scrambled small interfering RNA (siRNA) and anti-HIPK2 siRNA. The TGF-β1-associated HIPK2 alterations were investigated by quantitative real-time polymerase chain reaction. Protein levels were analyzed by western blotting. The HIPK2 was markedly increased in the keloid-derived keratinocytes compared with normal skin keratinocytes. In addition, HIPK2 induced the expression of EMT markers in normal skin keratinocytes by TGF-β1-SMAD family member 3 (SMAD3). The effect of TGF-β1-related EMT markers and SMAD3 phosphorylation in response to added TGF-β1 was significantly abrogated when the cells were transfected with HIPK2 siRNA. We conclude that HIPK2 is a crucial factor in the pathogenesis of keloids, suggesting that HIPK2 might be a novel potential drug target for antikeloid therapy.

Abnormal expression of the vitamin D receptor in keloid scars

Keloids are abnormal fibroproliferative scars that pose a significant challenge to patients and clinicians. The molecular basis for keloid formation remains incompletely understood, and currently no universally effective treatments exist. It is well recognized that keloids are more prevalent in populations with darkly pigmented skin, such as African Americans, but the basis for the link between skin color and keloid risk is not known. Pigmentation reduces vitamin D production in the skin. Because most of the body's vitamin D is produced in the skin, rates of vitamin D deficiency are higher in populations with darker skin pigmentation. In addition to regulation of calcium homeostasis, vitamin D plays important roles in cell proliferation, differentiation, cancer progression, inflammation, and fibrosis. The activities of vitamin D are dependent on the vitamin D receptor (VDR), a member of the steroid nuclear receptor superfamily. The ligand-bound VDR acts as a transcription factor; thus, nuclear localization is required for ligand-dependent regulation of target gene expression. The current study investigated expression and nuclear localization of VDR in keloid scars (N=24) and biopsies of normal skin (N=24). Immunohistochemistry with two different antibodies demonstrated reduced VDR protein levels in a majority of keloid scars. Further, the percentage of epidermal cells displaying nuclear VDR localization was significantly lower in keloid scars compared with normal skin samples. Interestingly, analysis of VDR-positive nuclei among different normal skin samples showed a significant reduction in nuclear localization in epidermis of black donors compared with white donors. The results suggest that VDR may play a role in keloid pathology, and hint at a possible role for VDR in the increased susceptibility to keloid scarring in individuals with darkly pigmented skin.

Prevalence of Vitamin D Deficiency in Pediatric Patients With Scoliosis Preparing for Spinal Surgery

BACKGROUND

Establishing prevalence of vitamin D deficiency in elective scoliosis surgery may impact clinical outcomes. The objectives of this study were to document vitamin D status of patients with scoliosis preparing for surgical intervention in order to establish frequency of deficiency and determine characteristics influencing levels.

METHODS

Records were queried for patients with scoliosis diagnosis who underwent posterior spinal fusion or initial growing rod placement and had serum vitamin 25 hydroxyvitamin D (D25) recorded in the preoperative period. Demographic data (gender, age, body mass index [BMI], race, scoliosis type, spine surgery procedure, and season of the year) were extracted. Chi-square analysis and multivariate modeling were used to evaluate deficiency status among various demographic categories and determine the demographic factors impacting D25.

RESULTS

A total of 217 patients with a mean age of 13.6 ± 3.6 years had vitamin D levels drawn a mean of 38.7 ± 20.6 days prior to surgery. The majority of the sample presented with a diagnosis of idiopathic scoliosis (n = 126), and most patients were scheduled for spinal fusion surgery (n = 192). Nearly 75% of the study population (n = 162) demonstrated D25 values below normal. African Americans presented with greater risk of deficiency (p < .0002) compared to Caucasians, as did patients preparing for spinal fusion versus growing rod placement (p < .03). Severe hypovitaminosis D was more common in winter than any other season (p < .005). Patients with neuromuscular scoliosis demonstrated significantly higher D25 levels over the idiopathic diagnosis type (p < .0002). Gender, BMI, and age did not impact D25.

CONCLUSION

Low D25 levels are reported in pediatric patients with scoliosis preparing for corrective spinal surgery. Population subsets most at risk for deficiency in this limited study include African American children, those presenting for spinal fusion surgery, and patients admitted in winter season.

Epigenetic Regulation of Caveolin-1 Gene Expression in Lung Fibroblasts

Fibrotic disorders are associated with tissue accumulation of fibroblasts. We recently showed that caveolin (Cav)-1 gene suppression by a profibrotic cytokine, transforming growth factor (TGF)-β1, contributes to fibroblast proliferation and apoptosis resistance. Cav-1 has been shown to be constitutively suppressed in idiopathic pulmonary fibrosis (IPF), but mechanisms for this suppression are incompletely understood. We hypothesized that epigenetic processes contribute to Cav-1 down-regulation in IPF lung fibroblasts, and after fibrogenic stimuli. Cav-1 expression levels, DNA methylation status, and histone modifications associated with the Cav-1 promoter were examined by PCR, Western blots, pyrosequencing, or chromatin immunoprecipitation assays in IPF lung fibroblasts, normal fibroblasts after TGF-β1 stimulation, or in murine lung fibroblasts after bleomycin injury. Methylation-specific PCR demonstrated methylated and unmethylated Cav-1 DNA copies in all groups. Despite significant changes in Cav-1 expression, no changes in DNA methylation were observed in CpG islands or CpG island shores of the Cav-1 promoter by pyrosequencing of lung fibroblasts from IPF lungs, in response to TGF-β1, or after bleomycin-induced murine lung injury, when compared with respective controls. In contrast, the association of Cav-1 promoter with the active histone modification mark, H3 lysine 4 trimethylation, correlated with Cav-1 down-regulation in activated/fibrotic lung fibroblasts. Our data indicate that Cav-1 gene silencing in lung fibroblasts is actively regulated by epigenetic mechanisms that involve histone modifications, in particular H3 lysine 4 trimethylation, whereas DNA methylation does not appear to be a primary mechanism. These findings support therapeutic strategies that target histone modifications to restore Cav-1 expression in fibroblasts participating in pathogenic tissue remodeling.

Hypertrophic Scars: Are Vitamins and Inflammatory Biomarkers Related with the Pathophysiology of Wound Healing?

BACKGROUND

Hypertrophic scars are a consequence of wound healing.

OBJECTIVE

The objective of the present study is to evaluate vitamin D and inflammatory biomarker plasma levels during wound healing.

METHODS

A prospective study was performed in patients (n = 63) submitted to body contouring surgery. Blood samples were collected before (t ₀) and 5 days after surgery (t ₅). Blood cell count, protein inflammatory biomarkers, and circulating plasma levels of 25(OH)D, vitamin A and vitamin E were quantified. Six months after surgery, scars were evaluated and classified as normal or hypertrophic.

RESULTS

At the end of the study, 73% of the patients developed a normal scar (control group, n = 46) and 27% of the patients presented hypertrophic scars (HT group, n = 17). The patients in the HT group presented higher eosinophil (0.145 × 10⁹ /L vs. 0.104 × 10⁹ /L, p = 0.028) and basophil count (0.031 × 10⁹ /L vs. 0.22 × 10⁹ /L, p = 0.049) and C-reactive protein levels (6.12 mg/L vs. 2.30 mg/L, p = 0.015) in t ₀ than the patients in the control group. At t ₅, the patients in the HT group showed a decrease in neutrophil (3.144 × 10^9/L vs. 4.03 × 10⁹/L, p = 0.031) and an increase in basophil (0.024 × 10⁹/L vs. 0.015 × 10⁹/L, p = 0.005) and lymphocyte count (1.836 × 10⁹ /L vs. 1.557 × 10⁹/L; p = 0.028). Before surgery, vitamin D plasma levels were found to be decreased by almost 50% (23.52 ng/mL vs. 15.46 ng/mL, p = 0.031) in the patients who developed hypertrophic scars. Thirty-one percent of the patients submitted to bariatric surgery had more hypertrophic scars, versus 24% of the patients with no previous bariatric surgery.

CONCLUSION

There is a different systemic inflammatory profile response in the patients during the formation of hypertrophic scars. Vitamin D plasma levels are marked reduced in these patients. Considering the powerful anti-inflammatory effect of vitamin D, these findings could be related.

Association of plasminogen activator inhibitor-1 and vitamin D receptor expression with the risk of keloid disease in a Chinese population

Keloid disease (KD) is a benign fibroproliferative scarring condition of unknown etiopathogenesis. Plasminogen activator inhibitor-1 (PAI-1) and vitamin D receptor (VDR) have been shown to play important roles in the progression of tissue fibrosis; therefore, both these genes are potential susceptibility genes for KD. We aimed to determine whether the gene expression levels of PAI-1 and VDR are altered in Chinese KD patients. We measured the expression of PAI and VDR in human peripheral blood lymphocytes in 236 patients with keloid and 219 age- and sex-matched healthy controls by quantitative real-time polymerase chain reaction. We found that PAI-1 expression in peripheral blood lymphocytes was significantly higher in patients with KD than in control individuals (p < 0.0001), while VDR expression was significantly lower in KD patients than in control individuals (p < 0.0001). High levels of PAI-1 and low levels of VDR expression were significantly associated with an increased risk for KD. PAI-1 and VDR might play important roles in keloid development. Gene expression levels of PAI-1 and VDR may, therefore, be used as potential markers for the prediction of keloid development after scarring.

TGF-β1 Induces Polypyrimidine Tract-Binding Protein to Alter Fibroblasts Proliferation and Fibronectin Deposition in Keloid

Human dermal fibrotic disease keloid has been a clinical challenge because of its tumour-like growth and the lack of effective therapy. Dysregulated alternative splicing events have been demonstrated in tumours and fibrosis. In the current study, for the first time, it was demonstrated that the splicing regulator polypyrimidine tract-binding protein (PTB), which plays a pivotal role in tumour proliferation, invasion and metastasis, is overexpressed in keloid tissues and fibroblasts. Additionally, TGF-β1 upregulated the expressions of PTB and its upstream regulator, C-MYC, in keloid fibroblasts. Furthermore, we suppressed PTB using siRNA in keloid fibroblasts and in a keloid xenograft nude mouse model. PTB knockdown significantly slowed the proliferation of keloid fibroblasts and accelerated the regression of transplanted keloid tissues, which was accompanied by a shift in the alternative splicing of USP5 and RTN4. Moreover, when PTB was suppressed, there was a reduction in excessive deposition of FN1 and COL3A1 in transplanted keloid tissues. However, only FN1 was downregulated in keloid fibroblasts that were cultured in media supplemented with TGF-β1. Our study provides evidence for the role of PTB in keloid pathophysiology and offers a novel therapeutic target for keloids. Most importantly, the role TGF-β1 regulation of PTB may provide new insights into the mechanisms underlying inflammatory cytokine-induced fibrosis.

Clinical Trial of Vitamin D2 vs D3 Supplementation in Critically Ill Pediatric Burn Patients

BACKGROUND

Hypovitaminosis D exists postburn. However, evidence-based guidelines for vitamin D repletion are unknown. This investigation examined differences between D₂ and D₃ supplementation on outcome in children with burn injuries.

METHODS

Fifty patients with total body surface area burn of 55.7% ± 2.6% and full-thickness injury of 40.8% ± 3.8% were enrolled, ranging in age from 0.7-18.4 years. All participants received multivitamin supplementation per standardized clinical protocol. In addition, 100 IU/kg D₂, D₃, or placebo was administered daily during hospitalization using a randomized, double-blinded study design. Assay of total 25-hydroxyvitamin D (D25), 1,25-dihydroxyvitamin D (D1,25), 25-hydroxyvitamin D₂ (25-OH-D₂), 25-hydroxyvitamin D₃ (25-OH-D₃), and parathyroid hormone (PTH) was performed at 4 preplanned time intervals (baseline, midpoint, discharge, and 1 year postburn). Differences in vitamin D status were compared over time and at each specific study interval.

RESULTS

There were no significant differences in serum vitamin D levels between groups, but >10% of patients had low D25 at discharge, and percent deficiency worsened by the 1-year follow up for the placebo (75%), D₂ (56%), and D₃ (25%) groups. There were no statistical differences in PTH or clinical outcomes between treatment groups, although vitamin D supplementation demonstrated nonsignificant but clinically relevant decreases in exogenous insulin requirements, sepsis, and scar formation.

CONCLUSIONS

The high incidence of low serum D25 levels 1 year following serious thermal injury indicates prolonged compromise. Continued treatment with vitamin D₃ beyond the acute phase postburn is recommended to counteract the trajectory of abnormal serum levels and associated morbidity.

Synergistic effect of vitamin D and low concentration of transforming growth factor beta 1, a potential role in dermal wound healing

Dermal wound healing, in which transforming growth factor beta 1 (TGFβ1) plays an important role, is a complex process. Previous studies suggest that vitamin D has a potential regulatory role in TGFβ1 induced activation in bone formation, and there is cross-talk between their signaling pathways, but research on their effects in other types of wound healing is limited. The authors therefore wanted to explore the role of vitamin D and its interaction with low concentration of TGFβ1 in dermal fibroblast-mediated wound healing through an in vitro study. Human dermal fibroblasts were treated with vitamin D, TGFβ1, both, or vehicle, and then the wound healing functions of dermal fibroblasts were measured. To further explore possible mechanisms explaining the synergistic effect of vitamin D and TGFβ1, targeted gene silencing of the vitamin D receptor was performed. Compared to either factor alone, treatment of fibroblasts with both vitamin D and low concentration of TGFβ1 increased gene expression of TGFβ1, connective tissue growth factor, and fibronectin 1, and enhanced fibroblast migration, myofibroblast formation, and collagen production. Vitamin D receptor gene silencing blocked this synergistic effect of vitamin D and TGFβ1 on both collagen production and myofibroblast differentiation. Thus a synergistic effect of vitamin D and low TGFβ1 concentration was found in dermal fibroblast-mediated wound healing in vitro. This study suggests that supplementation of vitamin D may be an important step to improve wound healing and regeneration in patients with a vitamin D deficiency.

Vitamin D treatment for connective tissue diseases: hope beyond the hype?

The prevalence of vitamin D deficiency is increased among patients with CTDs. The active form of vitamin D (calcitriol) is a potent regulator of the immune system and may suppress inflammatory responses. This has led to claims that vitamin D may be a safe treatment, or a treatment adjunct, to reduce systemic inflammation in this patient population. It is important to note, however, that there is insufficient evidence from robust clinical trials to support these novel uses for vitamin D. In this review we examine the potential role of vitamin D as a treatment adjunct for CTDs. We will discuss how vitamin D may modulate the immune response and review the current evidence for using vitamin D to treat CTDs and their associated co-morbidities. We conclude that while there is much excitement about vitamin D in this context, further well-designed trials are needed to demonstrate its efficacy in the treatment of patients with CTDs.

NADPH oxidase-2 is a key regulator of human dermal fibroblasts: a potential therapeutic strategy for the treatment of skin fibrosis

The proliferation of human skin dermal fibroblasts (HDFs) is a critical step in skin fibrosis, and transforming growth factor-beta1 (TGF-β1) exerts pro-oxidant and fibrogenic effects on HDFs. In addition, the oxidative stress system has been implicated in the pathogenesis of skin disease. However, the role of NADPH oxidase as a mediator of TGF-β1-induced effects in HDFs remains unknown. Thus, our aim was to investigate the role of NADPH in human skin dermal fibroblasts. Primary fibroblasts were cultured and pretreated with various stimulants. Real-time Q-PCR and Western blotting analyses were used for mRNA and protein detection. In addition, siRNA technology was applied for gene knock-down analysis. Hydrogen peroxide production and 2',7'-dichlorofluorescein diacetate (DCFDA) measurement assay were performed. Here, our findings demonstrated that HDFs express key components of non-phagocytic NADPH oxidase mRNA. TGF-β1 induced NOX2 and reactive oxygen species formation via NADPH oxidase activity. In contrast, NOX3 was barely detectable, and other NOXs did not display significant changes. In addition, TGF-β1 phosphorylated MAPKs and increased activator protein-1 (AP-1) in a redox-sensitive manner, and NOX2 suppression inhibited baseline and TGF-β1-mediated stimulation of Smad2 phosphorylation. Moreover, TGF-β1 stimulated cell proliferation, migration, collagen I and fibronectin expression, and bFGF and PAI-1 secretion: these effects were attenuated by diphenylene iodonium (DPI), an NADPH oxidase inhibitor, and NOX2 siRNA. Importantly, NOX2 siRNA suppresses collagen production in primary keloid dermal fibroblasts. These findings provide the proof of concept for NADPH oxidase as a potential target for the treatment of skin fibrosis.

Preventive effects of vitamin D treatment on bleomycin-induced pulmonary fibrosis

Patients with pulmonary fibrosis often have low vitamin D levels, the effects of which are largely unknown. We here report that early vitamin D supplementation significantly reduced the severity of pulmonary fibrosis and inflammatory cell accumulationin in the bleomycin-induced pulmonary fibrosis mouse model on supplementary days 14, 21 and 28 (P < 0.001). Vitamin D supplementation also prevented some ultrastructural changes in response to bleomycin administration, including basement membrane thickening, interstitial fibrin deposition and microvilli flattening or disappearance on days 14, 21 and 28, and lamellar body swelling or vacuolation on days 21 and 28. The bleomycin group had rising hydroxyproline level on days 14, 21 and 28, whereas the vitamin D treatment group showed consistently lower hydroxyproline level but still higher than that of the control group (P < 0.001). Our immunohistochemistry and densitometry analyses showed less staining for α-smooth muscle actin, a myofibroblast marker, in the vitamin D group compared to the bleomycin group (P < 0.001). Thus, vitamin D treatment could prevent bleomycin-induced pulmonary fibrosis by delaying or suppressing ultrastructural changes, as well as attenuating hydroxyproline accumulation and inhibiting myofibroblastic proliferation. These data further our understanding of the roles of vitamin D in pulmonary fibrogenesis and in the treatment of pulmonary fibrosis.

High-mobility Group Box Protein-1, Matrix Metalloproteinases, and Vitamin D in Keloids and Hypertrophic Scars

Keloids and hypertrophic scars represent excessive wound healing involving high production of collagen by skin fibroblasts. This review focuses on the role of high-mobility group box protein-1 (HMGB-1), matrix metalloproteinases (MMPs), and vitamin D in these conditions. Although the role of HMGB-1 in keloids and hypertrophic scars is unclear, the effect of HMGB-1 on fibroblasts suggests a profibrotic role and a potential contribution to excessive scarring. MMPs contribute extensively to wound healing and characteristically degrade the extracellular matrix. MMP-1 is decreased in keloids and hypertrophic scars. However, other MMPs, including MMP-2, have been found to be increased and are thought to possibly contribute to keloid expansion through peripheral extracellular matrix catabolism. Many novel therapeutic approaches to keloids and hypertrophic scars target MMPs and aim to increase their levels and catabolic activity. The higher prevalence of keloids in darker skin types may partially be due to a tendency for lower vitamin D levels. The physiologically active form of vitamin D, 1,25(OH)2D3, inhibits the proliferation of keloid fibroblasts, and correlations between vitamin D receptor polymorphisms, such as the TaqI CC genotype, and keloid formation have been reported. Additionally, vitamin D may exert an antifibrotic effect partially mediated by MMPs. Here, we critically discuss whether keloid and hypertrophic scar formation could be predicted based on vitamin D status and vitamin D receptor polymorphisms. Specifically, the findings identified HMGB-1, MMPs, and vitamin D as potential avenues for further clinical investigation and potentially novel therapeutic approaches to prevent the development of keloids and hypertrophic scars.

In vivo early intervention and the therapeutic effects of 20(s)-ginsenoside rg3 on hypertrophic scar formation

BACKGROUND

Intra-lesional injections of corticosteroids, interferon, and chemotherapeutic drugs are currently the most popular treatments of hypertrophic scar formation. However, these drugs can only be used after HS is formed, and not during the inflammatory phase of wound healing, which regulates the HS forming process.

OBJECTIVE

To investigate a new, effective, combining therapeutic and safe drug for early intervention and treatment for hypertrophic scars.

METHODS

Cell viability assay and flow cytometric analysis were studied in vitro. Animal studies were done to investigate the combining therapeutic effects of 20(S)-ginsenoside Rg3 (Rg3) on the inflammatory phase of wound healing and HS formation.

RESULTS

In vitro studies showed that Rg3 can inhibit HS fibroblasts proliferation and induce HSF apoptosis in a concentration-dependent manner. In vivo studies demonstrated that Rg3 can limit the exaggerated inflammation, and do not delay the wound healing process, which indicates that Rg3 could be used as an early intervention to reduce HS formation. Topical injection of 4 mg/mL Rg3 can reduce HS formation by 34%. Histological and molecular studies revealed that Rg3 injection inhibits fibroblasts proliferation thus reduced the accumulation of collagen fibers, and down-regulates VEGF expression in the HS tissue.

CONCLUSION

Rg3 can be employed as an early intervention and a combining therapeutic drug to reduce inflammation and HS formation as well.

Interaction of vitamin D with membrane-based signaling pathways

Many studies in different biological systems have revealed that 1α,25-dihydroxyvitamin D₃ (1α,25(OH)₂D₃) modulates signaling pathways triggered at the plasma membrane by agents such as Wnt, transforming growth factor (TGF)-β, epidermal growth factor (EGF), and others. In addition, 1α,25(OH)₂D₃ may affect gene expression by paracrine mechanisms that involve the regulation of cytokine or growth factor secretion by neighboring cells. Moreover, post-transcriptional and post-translational effects of 1α,25(OH)₂D₃ add to or overlap with its classical modulation of gene transcription rate. Together, these findings show that vitamin D receptor (VDR) cannot be considered only as a nuclear-acting, ligand-modulated transcription factor that binds to and controls the transcription of target genes. Instead, available data support the view that much of the complex biological activity of 1α,25(OH)₂D₃ resides in its capacity to interact with membrane-based signaling pathways and to modulate the expression and secretion of paracrine factors. Therefore, we propose that future research in the vitamin D field should focus on the interplay between 1α,25(OH)₂D₃ and agents that act at the plasma membrane, and on the analysis of intercellular communication. Global analyses such as RNA-Seq, transcriptomic arrays, and genome-wide ChIP are expected to dissect the interactions at the gene and molecular levels.

New molecular medicine-based scar management strategies

Keloids and hypertrophic scars are prevalent disabling conditions with still suboptimal treatments. Basic science and molecular-based medicine research have contributed to unravel new bench-to-bedside scar therapies and to dissect the complex signalling pathways involved. Peptides such as the transforming growth factor beta (TGF-β) superfamily, with Smads, Ski, SnoN, Fussels, endoglin, DS-Sily, Cav-1p, AZX100, thymosin-β4 and other related molecules may emerge as targets to prevent and treat keloids and hypertrophic scars. The aim of this review is to describe the basic complexity of these new molecular scar management strategies and point out new fibrosis research lines.

Pharmacological treatment for keloids

INTRODUCTION

Keloids are fibroproliferative disorders that are characterized by histological accumulation of collagens and fibroblasts, refractory clinical symptoms such as itching, topical invasiveness, and frequent postsurgical recurrence. At present, to treat or prevent keloids, new drugs are currently being designed and the pharmaceutical indications of known drugs are being expanded.

AREAS COVERED

The current pharmacological interventions for keloids are mainly described on the basis of the various hypotheses on keloid etiology and the keloid ingredients that are targeted. These interventions include angiotension-converting enzyme inhibitors and calcium-channel blockers (based on hypertension hypothesis), selective estrogen receptor modulator (based on endocrinological hypothesis), vitamins and essential fatty acids (based on immunonutritional hypothesis), and transglutaminase inhibitor (based on metabolic hypothesis). Drugs that directly target the reduction or destruction of the major extracellular matrix or cellular constituents of keloids are also included. Besides, drugs that indirectly modulate the biochemical microenvironment are described. These include growth factors, immunomodulators, and anti-inflammation and anti-allergy drugs.

EXPERT OPINION

Due to the unclear etiology of keloids and the lack of animal models, efficient, reliable, and specific pharmaceutical interventions for keloids continue to be lacking. The reliability of current data and clinical observations must be strengthened by large-scale, randomized, controlled clinical trials.

Expression of Inflammatory Biomarkers from Cultured Sebocytes was Influenced by Treatment with Vitamin D

BACKGROUND

Inflammatory cytokines are the key factor in the pathophysiology of acne. It is well known that keratinocytes synthesize many kinds of inflammatory cytokines. In addition, it is reported that inflammatory cytokines are also expressed from sebocytes, which originate from the same stem cells with keratinocytes.

AIM

To clarify changes in the expression of inflammatory biomarkers from cultured sebocytes after treatment with vitamin D.

MATERIALS AND METHODS

Reverse transcription-polymerase chain reaction (RT-PCR) was done to measure changes in the expression of inflammatory biomarkers, including interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor-α (TNF-α), and several subtypes of matrix metalloproteinases (MMPs) after treatment of a group of cultured sebocytes with vitamin D. Vitamin D receptor (VDR) small interfering RNA (siRNA) was added in the other group of cultured sebocytes to assure the role of vitamin D on the expression of inflammatory biomarkers. Enzyme-linked immunosorbent assay (ELISA) was also performed in the vitamin D-treated sebocytes.

RESULTS

Cultured sebocytes showed non-significant changes in the gene expression of inflammatory biomarkers after treatment with vitamin D. In cultured sebocytes treated with a VDR siRNA, the expression of inflammatory biomarkers was not blocked after treatment with vitamin D. ELISA showed a significant decrease in the expression of IL-6, IL-8, and MMP-9, but a significant increase in the expression of MMP-1 and MMP-3, after treatment with vitamin D (10(-6) M).

CONCLUSION

Expression of inflammatory biomarkers is influenced by treatment with vitamin D in cultured sebocytes, but not through VDR.

Roles of lipid metabolism in keloid development

Keloids are common cutaneous pathological scars that are characterised by the histological accumulation of fibroblasts, collagen fibres, and clinically significant invasive growth. Although increasing lines of research on keloids have revealed genetic and environmental factors that contribute to their formation, the etiology of these scars remains unclear. Several studies have suggested the involvement of lipid metabolism, from a nutritional point of view. However, the role that lipid metabolism plays in the pathogenesis and progression of keloids has not previously been reviewed. The progress that has been made in understanding the roles of the pro- and anti-inflammatory lipid mediators in inflammation, and how they relate to the formation and progression of keloids, is also outlined. In particular, the possible relationships between mechanotransduction and lipid metabolites in keloids are explored. Mechanotransduction is the process by which physical forces are converted into biochemical signals that are then integrated into cellular responses. It is possible that lipid rafts and caveolae provide the location of lipid signaling and interactions between these signaling pathways and mechanotransduction. Moreover, interactions between lipid signaling pathway molecules and mechanotransduction molecules have been observed. A better understanding of the lipid profile changes and the functional roles lipid metabolism plays in keloids will help to identify target molecules for the development of novel interventions that can prevent, reduce, or even reverse pathological scar formation and/or progression.

Vitamin D increases cellular turnover and functionally restores the skeletal muscle after crush injury in rats

Insufficient skeletal muscle regeneration after injury often impedes the healing process and is accompanied by functional deficiencies or pain. The aim of our study was to provide evidence that vitamin D improves muscle healing after muscle injury. Therefore, we used male rats and induced an injury of the soleus muscle. After crush injury, animals received either 8.3 mg/kg (332,000 IU/kg) body weight vitamin D or vehicle solution, s.c. After assessment of muscle force at days 1, 4, 14, and 42 after injury, sampling of muscle tissue served for analysis of proliferation, apoptosis, satellite cells, and prolyl-4-hydroxylase-β expression. Vitamin D application caused a significant increase in cell proliferation and a significant inhibition of apoptosis at day 4 after injury compared to control animals. The numbers of satellite cells were not influenced by the vitamin D application, but there was an increase in prolyl-4-hydroxylase-β expression, indicative of increased extracellular matrix proteins. This cellular turnover resulted in a faster recovery of contraction forces at day 42 in the vitamin D group. Current data support the hypothesis that vitamin D promotes the regenerative process in injured muscle. Thus, vitamin D treatment may represent a promising therapy to optimize recovery after injury.

CARD-024, a vitamin D analog, attenuates the pro-fibrotic response to substrate stiffness in colonic myofibroblasts

Intestinal fibrosis is one of the major complications of Crohn's disease (CD) for which there are no effective pharmacological therapies. Vitamin D deficiency is common in CD, though it is not known whether this is a contributing factor to fibrosis, or simply a consequence of the disease itself. In CD, fibrosis is mediated mainly by activated intestinal myofibroblasts during remodeling of extracellular matrix in response to wound healing. We investigated the effects of CARD-024 (1-alpha-hydroxyvitamin D5), a vitamin D analog with minimal hypercalcemic effects, on the pro-fibrotic response of intestinal myofibroblasts to two fibrogenic stimuli: TGFβ stimulation and culture on a physiologically stiff matrix. TGFβ stimulated a fibrogenic phenotype in Ccd-18co colonic myofibroblasts, characterized by an increase in actin stress fibers and mature focal adhesions, and increased αSMA protein expression, while CARD-024 repressed αSMA protein expression in a dose-dependent manner. Culture of colonic myofibroblasts on physiological high stiffness substrates induced morphological changes with increased actin stress fibers and focal adhesion staining, induction of αSMA protein expression, FAK phosphorylation, induction of fibrogenic genes, and repression of COX-2 and IL-1β. CARD-024 treatment repressed the stiffness-induced morphological features including stellate cell morphology and the maturation of focal adhesions. CARD-024 repressed the stiffness-mediated induction of αSMA protein expression, FAK phosphorylation, and MLCK and ET-1 gene expression. In addition, CARD-024 partially stimulated members of the COX-2/IL-1β inflammatory pathway. In summary, CARD-024 attenuated the pro-fibrotic response of colonic myofibroblasts to high matrix stiffness, suggesting that vitamin D analogs such as CARD-024 may ameliorate intestinal fibrosis.