sirolimus and Cicatrix

Several good-quality randomised trials brought useful information on how to manage severe skin infections and develop anti-staphylococcus strategies. Trials on common warts did not bring any valuable solution. Rituximab and omalizumab have seen their indications becoming more precise or broadened. Meta-analyses have been particularly numerous, but most of the time with no decisive conclusion, since this methodology presents strong limitations for studying safety data. Most important work has been rather directed toward analysing safety data rather than efficacy. Among the most important results, are those from a retrospective cohort of patients taking isotretinoin: suicidal risk has to be linked to severe acne itself, rather than to the drug.

Topics: Abscess; Adalimumab; Anti-Bacterial Agents; Antibodies, Anti-Idiotypic; Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal, Murine-Derived; Cicatrix; Dermatologic Agents; Dermatology; Humans; Immunologic Factors; Immunosuppressive Agents; Isotretinoin; Methicillin-Resistant Staphylococcus aureus; Methotrexate; Omalizumab; Papillomavirus Vaccines; Rituximab; Sirolimus; Skin Diseases; Transforming Growth Factor beta3

Vocal fold scar formation due to vocal fold injury (VFI) is a common cause of surgery or trauma-induced voice disorders. Severe scar formation can lead to reduced voice quality or even be life-threatening. Here, we investigated the role of autophagy in VFI, focusing on fibrosis as a consequence of autophagy in inducing VFI. A VFI model was constructed in rats by dissecting the lamina propria tissue from the thyroarytenoid muscle. Real-time PCR and Western blot were used to analyze expressions of autophagy markers, including Beclin1 and Atg7, in VFI. Tgfb1 and Col1a1 were assessed to determine the correlation of fibrosis with VFI progression and autophagy levels. Rat vocal fold fibroblasts were also treated with TGF-β1 or rapamycin, which activates and suppresses autophagy respectively, to explore how autophagy regulates fibrosis in VFI. Initially, we observed that autophagy was downregulated in vocal fold mucosa after VFI in rats. This was particularly evident by the time-dependent downregulation of Beclin1 and Atg7 following VFI. Concurrently, levels of Tgfb1 and Col1a1 also surged, hinting at elevated fibrosis levels. Furthermore, our experiments with TGF-β1 stimulation revealed that it inhibited autophagy in rat vocal fold fibroblasts. Interestingly, when we introduced rapamycin, this effect was reversed. Our data suggest that autophagy is a suppressor of VFI by alleviating fibrosis, making targeting autophagy a potential therapeutic route in VFI.

Topics: Animals; Beclin-1; Cicatrix; Fibrosis; Rats; Sirolimus; Transforming Growth Factor beta1; Vocal Cords

Wound healing is a multicellular process that involves the coordinated efforts of several cell types, including keratinocytes, fibroblasts, and endothelial cells. This process is also regulated by an equally complex signaling network involving numerous growth factors, cytokines, and chemokines. The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth, proliferation, and differentiation. A recent study showed that mTORC1 activation in epithelial cells dramatically enhanced epithelial cell proliferation, migration, and cutaneous wound healing; however, the roles of mTORC1 in fibroblasts during wound healing remain unknown. Here, we generated genetically mutated mice with activated mTORC1 in fibroblasts by conditionally deleting the mTORC1 inhibitor, TSC1. Activation of mTORC1 in fibroblasts significantly increased fibroblastic cell proliferation and contractile α-smooth muscle actin expression, thus promoting wound closure. Elevated mTORC1 activity also adversely induced excessive collagen production, leading to excessive scaring and fibrosis. Importantly, both accelerated wound healing and fibrotic phenotypes were largely reversed by the mTORC1 inhibitor, rapamycin. These observations were also replicated in primary human dermal fibroblasts. These results collectively demonstrated that mTORC1 activity in skin fibroblasts was a critical orchestrator in cutaneous wound healing and scarring.

Topics: Actins; Animals; Apoptosis; Cell Proliferation; Cicatrix; Collagen; Fibroblasts; Fibrosis; Humans; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Primary Cell Culture; Protein Kinase Inhibitors; Sirolimus; Tuberous Sclerosis Complex 1 Protein; Wound Healing

To study the effect of rapamycin on scar formation in rabbit eyes following filtering operation and explore the possible mechanism.. Rapamycin can inhibit hyperplasia of the filtering passage tissue, helps to preserve the functional filtering blebs and prolong their life span, and induces apoptosis of RTFS.

Topics: Animals; Cicatrix; Eye; Glaucoma; Ophthalmologic Surgical Procedures; Rabbits; Sirolimus

Topics: Administration, Topical; Cicatrix; Humans; Sirolimus; TOR Serine-Threonine Kinases

The functional outcome after peripheral nerve repair is often unpredictable for many reasons, e.g., the severity of neuronal death and scarring. Axonal degeneration significantly affects outcomes. Post-injury axonal degeneration in peripheral nerves is accompanied by myelin degradation initiated by Schwann cells (SCs), which activate autophagy, a ubiquitous cytoprotective process essential for degrading and recycling cellular constituents. Scar formation occurs concomitantly with nerve insult and axonal degeneration. The association between SC autophagy and the mechanisms of nerve scar formation is still unknown. A rat model of peripheral nerve lesions induced by sciatic nerve transection injuries was used to examine the function of autophagy in fibrosis reduction during the early phase of nerve repair. Rats were treated with rapamycin (autophagy inducer) or 3-methyladenine (autophagy inhibitor). One week after the nerve damage, fibrosis was potently inhibited in rapamycin-treated rats and, based on gait analysis, yielded a better functional outcome. Immunohistochemistry showed that the autophagic activity of SCs and the accumulation of neurofilaments were upregulated in rapamycin-treated rats. A deficiency of SC autophagic activity might be an early event in nerve scar formation, and modulating autophagy might be a powerful pharmacological approach for improving functional outcomes.

Topics: Adenine; Animals; Autophagy; Cicatrix; Male; Nerve Regeneration; Peripheral Nerve Injuries; Rats; Rats, Sprague-Dawley; Schwann Cells; Sciatic Nerve; Sirolimus

Glial scar impedes axon regeneration and functional recovery following traumatic brain injury (TBI). Although it has been shown that rapamycin (a specific inhibitor of mammalian target of rapamycin) can reduce astrocyte reactivation in the early stage of TBI, its effect on glial scar formation has not been characterized in TBI and other acute brain injury models. To test this, ICR mice received daily administration of rapamycin (0.5 or 1.5 mg/kg, i.p.) beginning at 1 h after cryogenic TBI (cTBI). The results showed that at 3 d post-injury, 1.5 mg/kg rapamycin increased cTBI-induced motor functional deficits and infarct size, and attenuated astrocyte reactivation in the ipsilateral cortex, while 0.5 mg/kg rapamycin did not worsen brain damage and only slightly attenuated astrocyte reactivation. Furthermore, at 7 and 14 d after cTBI, 0.5 mg/kg rapamycin group showed a better motor functional performance than cTBI group. At 14 d post-injury, 0.5 mg/kg rapamycin significantly reduced the area and thickness of glial scar and chondroitin sulfate proteoglycan expression, accompanied by decreased expression of p-S6 and enhanced expression of growth associated protein 43 (an axon regeneration marker) in the region of glial scar. Our data suggest that long-term treatment with rapamycin can inhibit glial scar formation after cTBI, which may be involved in the mechanisms of increased axon regeneration and improved neurological functional recovery, and low-dose rapamycin may be more beneficial for such a therapy.

Topics: Animals; Astrocytes; Axons; Behavior, Animal; Brain; Brain Injuries, Traumatic; Chondroitin Sulfate Proteoglycans; Cicatrix; Cold Temperature; Male; Mice, Inbred ICR; Nerve Regeneration; Recovery of Function; Rotarod Performance Test; Sirolimus; TOR Serine-Threonine Kinases

TGFβ1 and mTOR are considered to play important roles in fibrotic diseases. Rapamycin has been reported to inhibit urethral stricture formation in a rabbit model of urethral fibrosis.. To evaluate if dual mTOR inhibitor has a superior efficacy compared with rapamycin on inhibiting cell proliferation and collagen expression in human urethral scar fibroblasts (HUSFs).. We established HUSF cultures from fresh surgical specimen. The HUSFs were identified with typical fibroblast markers using immunofluorescence. Then we examined the effect of TGFβ1 on HUSFs using Cell Counting Kit-8 and Western blot. The inhibiting effects of OSI-027 (a dual mTOR inhibitor) on cell proliferation and collagen expression in TGFβ1-induced HUSFs were compared with rapamycin using Cell Counting Kit-8, Western blot, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).. HUSFs were stained positive for vimentin, collagen I, and collagen III. TGFβ1 had no effect on cell proliferation but increased collagen I and collagen III expressions in HUSFs. OSI-027 was more effective inhibiting cell proliferation and collagen expression compared with rapamycin in TGFβ1-induced HUSFs. OSI-027 played a more important role in inhibiting TGFβ1-induced mTOR pathway and phosphorylation of Smad2 compared with rapamycin in HUSFs.. OSI-027 can inhibit the pro-fibrotic effects of TGFβ1 significantly compared with rapamycin in HUSFs. These findings may provide a new therapy in the adjunctive treatment of urethral stricture disease.

Topics: Cell Proliferation; Cells, Cultured; Cicatrix; Collagen Type I; Collagen Type I, alpha 1 Chain; Collagen Type III; Dose-Response Relationship, Drug; Fibroblasts; Fibrosis; Humans; Imidazoles; Phosphorylation; Primary Cell Culture; Protein Kinase Inhibitors; Signal Transduction; Sirolimus; Smad2 Protein; Time Factors; TOR Serine-Threonine Kinases; Transforming Growth Factor beta1; Triazines; Urethra; Vimentin

To study the anti- scarring effect of rapamycin in rabbits receiving glaucoma filtering surgery.. Ninety-six Chinchilla rabbits were randomized equally into 3 rapamycin treatment groups and one control group. All the rabbits underwent trabeculectomy, after which the rabbits in the 3 rapamycin groups were treated with eye drops containing 1%, 3%, or 5% rapamycin in the operated eyes, and those in the control groups were given castor oil 4 times a day. The intraocular pressure (IOP) and inflammatory reaction in the treated eyes were observed, and the PCNA-positive cells in the filtering bleb were detected using immunohistochemistry. RTFs isolated from the Tenon's capsule of the rabbits were cultured. The IOP was significantly lower in rapamycin-treated group than in the control group after the surgery (. Rapamycin can inhibit excessive proliferation of the fibroblasts in the filtering bleb to reduce scar formation after glaucoma filtration surgery in rabbits. Rapamycin also increases the expressions of caspase-3 and caspase-9 to induce apoptosis of the RTFs.

Topics: Animals; Caspase 3; Caspase 9; Cell Proliferation; Cicatrix; Filtering Surgery; Glaucoma; Intraocular Pressure; Postoperative Complications; Proliferating Cell Nuclear Antigen; Rabbits; Random Allocation; Sirolimus; Trabeculectomy

Several studies suggest that glial scars pose as physical and chemical barriers that limit neurite regeneration after spinal cord injury (SCI). Evidences suggest that the activation of the PI3K/Akt/mTOR signaling pathway is involved in glial scar formation. Therefore, inhibition of the PI3K/Akt/mTOR pathway may beneficially attenuate glial scar formation after SCI. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates the PI3K/Akt/mTOR pathway. Therefore, we hypothesized that the overexpression of PTEN in the spinal cord will have beneficial effects after SCI. In the present study, we intrathecally injected a recombinant adenovirus carrying the pten gene (Ad-PTEN) to cause overexpression of PTEN in rats with contusion injured spinal cords. The results suggest overexpression of PTEN in spinal cord attenuated glial scar formation and led to improved locomotor function after SCI. Overexpression of PTEN following SCI attenuated gliosis, affected chondroitin sulfate proteoglycan expression, and improved axon regeneration into the lesion site. Furthermore, we suggest that the activation of the PI3K/Akt/mTOR pathway in astrocytes at 3 days after SCI may be involved in glial scar formation. Because delayed treatment with Ad-PTEN enhanced motor function recovery more significantly than immediate treatment with Ad-PTEN after SCI, the results suggest that the best strategy to attenuate glial scar formation could be to introduce 3 days after SCI. This study's findings thus have positive implications for patients who are unable to receive immediate medical attention after SCI.

Topics: Animals; Cicatrix; Disease Models, Animal; Female; Gliosis; Green Fluorescent Proteins; Humans; Immunosuppressive Agents; Locomotion; Nerve Tissue Proteins; Neuroglia; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; PTEN Phosphohydrolase; Rats; Rats, Wistar; Signal Transduction; Sirolimus; Spinal Cord Injuries; Time Factors

Epidural fibrosis is a common complication after laminectomy. It is associated with intractable lower back pain and additional complications. To date, no study has evaluated whether the local application of rapamycin (RAPA) can inhibit fibroblast proliferation and reduce epidural scar adhesion after laminectomy. The results of the present study showed that the local application of RAPA reduces epidural fibrosis after laminectomy in rats.. In this study, 32 male Sprague-Dawley rats were randomly divided into four groups (0.2 mg/ml RAPA-treated group, 0.1 mg/ml RAPA-treated group, 0.05 mg/ml RAPA-treated group and physiological saline group). Laminectomy was performed at the level of lumbar segment 1 to 2, and different concentrations of RAPA or saline were applied to the laminectomy sites for 10 min. Four weeks after laminectomy, the rats were sacrificed, and the degrees of epidural adhesion in each group were evaluated. Macroscopic assessment, analysis of hydroxyproline content, and histological analysis were used to determine the therapeutic effect of the local application of RAPA on the inhibition of fibroblast proliferation and the reduction of epidural fibrosis after laminectomy. Next, we cultured fibroblasts from epidural scar tissues of rats that had undergone laminectomy. Fibroblasts were exposed to the indicated concentrations of RAPA, and western blotting and TUNEL assays were used to assess the effects of RAPA on inhibiting fibroblasts proliferation and promoting fibroblast apoptosis.. The results of macroscopic assessments, analysis of hydroxyproline content, and histological analyses indicated that RAPA significantly inhibited fibroblast proliferation and reduced epidural fibrosis in the treated groups in the rat model. The western blotting results indicated that the expression levels of the pro-apoptotic proteins cleaved-PARP and Bax were up-regulated, whereas those of Bcl-2 were reduced. TUNEL assay indicated that the apoptosis rates of fibroblasts were significantly increased after exposure to the indicated concentrations of RAPA.. The local application of RAPA reduced epidural fibrosis after laminectomy by inhibiting the proliferation of fibroblasts, stimulating their apoptosis, and decreasing collagen synthesis. This protocol may be used in new clinical treatment strategies to reduce epidural fibrosis after laminectomy.

Topics: Animals; Apoptosis; Cell Proliferation; Cells, Cultured; Cicatrix; Epidural Space; Fibroblasts; Fibrosis; Hydroxyproline; Immunosuppressive Agents; In Situ Nick-End Labeling; Laminectomy; Male; Random Allocation; Rats, Sprague-Dawley; Sirolimus

To investigate whether temporary placement of a paclitaxel or rapamycin eluting stent is more effective to reduce stenting induced inflammatory reaction and scaring than a bared stent in benign cardia stricture models.. Eighty dog models of stricture were randomly divided into a control group (CG, n=20, no stent insertion), a bare stent group (BSG, n=20), a paclitaxel eluting (Pacl-ESG, n=20) and a rapamycin eluting stent group (Rapa-ESG, n=20), with one-week stent retention. Lower-oesophageal-sphincter pressure (LOSP), 5-minute barium height (5-mBH) and cardia diameter were assessed before, immediately after the procedure, and regularly for 6 months. Five dogs in each group were euthanized for histological examination at each follow-up assessment.. Stent insertion was well tolerated, with similar migration rates in three groups. At 6 months, LOSP and 5-mBH improved in Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with no difference between Pacl-ESG and Rapa-ESG (p>0.05). Cardia kept more patency in the Pacl-ESG and Rapa-ESG than in BSG (p<0.05). Reduced peak inflammatory reactions and scarring occurred in the Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with a similar outcome in the Pacl-ESG and Rapa-ESG (p>0.05).. Paclitaxel or rapamycin-eluting stents insertion led to better outcomes than bare stents in benign cardia stricture models.

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents, Phytogenic; Cardia; Cicatrix; Constriction, Pathologic; Disease Models, Animal; Dogs; Drug-Eluting Stents; Esophageal Sphincter, Lower; Esophageal Stenosis; Female; Humans; Inflammation; Male; Manometry; Paclitaxel; Random Allocation; Sirolimus; Time Factors

Corneal stromal scarring partly involves the production of corneal myofibroblasts. The purpose of this study was to examine the effects of rapamycin (an inhibitor of the mammalian target of rapamycin [mTOR] pathway) on myofibroblast formation in vitro and in-vivo.. Human corneal fibroblasts were grown in culture and transformed into myofibroblasts using TGF-β (2 ng/mL). The phosphorylation (activation) of the mTOR pathway was examined by immunoblotting. Cell proliferation with and without rapamycin was examined by thiazolyl blue tetrazolium bromide (MTT) assay and Ki67 staining. The expression of the myofibroblast differentiation marker smooth muscle actin (SMA) was examined by immunostaining and immunoblotting. The functional effects of rapamycin were measured using a gel contraction assay. For in vivo studies, 140 μm laser ablation was performed on rabbit corneas followed by subconjunctival rapamycin or vehicle. Corneal haze development was graded at 4 weeks, while the expression of myofibroblast markers was examined by immunostaining and immunoblotting.. The TGF-β activated the mTOR pathway with peak phosphorylation at 2 to 4 hours. Treatment of corneal fibroblasts with rapamycin reduced their proliferation by 46% compared to control. Rapamycin significantly inhibited TGF-β-induced expression of myofibroblast markers (17.2% SMA positive cells with rapamycin compared to 69.0% in control). Rapamycin also significantly inhibited TGF-β-induced collagen gel contraction. In the rabbit eyes treated with rapamycin, corneal haze development was significantly less compared to controls (0.75 ± 0.4 vs. 2.17 ± 0.7).. Rapamycin appears to inhibit proliferation and differentiation of corneal myofibroblasts and, thus, may provide an effective therapeutic measure for preventing corneal scarring.

Topics: Animals; Blotting, Western; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cicatrix; Corneal Opacity; Corneal Stroma; Disease Models, Animal; Female; Humans; Immunosuppressive Agents; Myofibroblasts; Photorefractive Keratectomy; Rabbits; Sirolimus; Transforming Growth Factor beta

To investigate the efficacy, safety, and mechanisms of Sirolimus sustained delivery film on prevention of scar formation in a rabbit model of glaucoma filtration surgery.. Sixty-four New Zealand white rabbits who underwent trabeculectomy in the right eye were randomly allocated to one of the four treatment regimens: Sirolimus sustained delivery film treatment group (Group A), or drug-free film treatment group (Group B), or 30 ng/ml Sirolimus-soaked sponge treatment group (Group C), or no adjunctive treatment group (Group D), and each group consists of 16 rabbits. Intraocular pressure (IOP), morphologic changes of bleb, anterior chamber flare, and corneal endothelial cell count and complications were evaluated over a 28-day period follow-up time. Aqueous humor samples were gathered from Group A, and the concentration of Sirolimus was measured regularly post-operation. Rabbits were sacrificed on the 7th, 14th, and 28th day post-operation separately, and the fibroblast hypertrophy, infiltration of inflammatory, and proliferation of new collagen fiber formation in each group were evaluated with HE and Masson staining. Proliferative cell nuclear antigen (PCNA) and fibroblast apoptosis were evaluated by immunohistochemistry and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) assay at the 28th day post-operation.. Both Sirolimus sustained delivery film (Group A) and Sirolimus alone (Group C) were well tolerated in this model, and significantly prolonged bleb survival compared with no drug treatment group (Group B and D; p<0.001). Group A had the longest bleb survival time in comparison with other groups (p<0.001). There were significant differences in IOP readings between Group A and other groups at the last follow-up (p<0.05). The concentration of Group A maintained stable for over 2 weeks, drops from (10.56 ±0.05) ng/ml at day 3 to (7.74 ±0.05) ng/ml at day 14. The number of corneal endothelial cells of Group A was not statistically significant between pre and post-operation. Histologic examination demonstrated that eyes treated with Sirolimus, especially the Sirolimus sustained delivery film, showed an obvious reduction in subconjunctival fibroblast scar tissue formation compared with no drug treatment groups, and had minimal evidence of inflammatory cell infiltration and new collagen deposition in the subconjunctiva. Immunohistochemistry assay showed that PCNA-expression was lower in the Group A (16.25±3.24%) compared to other groups (p<0.01). TUNEL assay showed a significant increase in the number of apoptotic fibroblasts around the surgical area in Group A and Group C (9.75±1.71% and 8.50±1.92%) compared to the Group B and D (p<0.01).. Sirolimus drug sustained delivery film can inhibit inflammatory cell activity, impede fibroblast proliferation activity, and induce fibroblast apoptosis in the filtration surgery sites in rabbit. The results indicate a safe and effective treatment strategy in anti-scaring treatment in glaucoma surgery.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Aqueous Humor; Blister; Cell Proliferation; Cicatrix; Drug Administration Routes; Drug Administration Schedule; Drug Delivery Systems; Endothelial Cells; Eye; Female; Fibroblasts; Filtering Surgery; Glaucoma; Intraocular Pressure; Proliferating Cell Nuclear Antigen; Rabbits; Sirolimus; Tonometry, Ocular; Trabeculectomy

Rapamycin represents a recognized drug-based therapeutic approach to treat cardiovascular disease. However, at least in the female heart, rapamycin may suppress the recruitment of putative signalling events conferring cardioprotection. The present study tested the hypothesis that rapamycin-sensitive signalling events contributed to the cardioprotective phenotype of the female rat heart after an ischemic insult. Rapamycin (1.5 mg/kg) was administered to adult female Sprague-Dawley rats 24 h after complete coronary artery ligation and continued for 6 days. Rapamycin abrogated p70S6K phosphorylation in the left ventricle of sham rats and the noninfarcted left ventricle (NILV) of 1-week postmyocardial-infarcted (MI) rats. Scar weight (MI 0.028 +/- 0.006, MI+rapamycin 0.064 +/- 0.004 g) and surface area (MI 0.37 +/- 0.08, MI+rapamycin 0.74 +/- 0.03 cm2) were significantly larger in rapamycin-treated post-MI rats. In the NILV of post-MI female rats, rapamycin inhibited the upregulation of eNOS. Furthermore, the increased expression of collagen and TGF-beta3 mRNAs in the NILV were attenuated in rapamycin-treated post-MI rats, whereas scar healing was unaffected. The present study has demonstrated that rapamycin-sensitive signalling events were implicated in scar formation and reactive fibrosis. Rapamycin-mediated suppression of eNOS and TGF-beta3 mRNA in post-MI female rats may have directly contributed to the larger infarct and attenuation of the reactive fibrotic response, respectively.

Topics: Animals; Blotting, Western; Cicatrix; Collagen; Disease Models, Animal; Female; Fibrosis; Heart Ventricles; Myocardial Infarction; Myocardium; Nitric Oxide Synthase Type III; Phosphorylation; Rats; Rats, Sprague-Dawley; Ribosomal Protein S6 Kinases, 70-kDa; Sirolimus; Transforming Growth Factor beta3; Ventricular Remodeling

Proliferation signal inhibitors (PSI) could help to lower the calcineurine inhibitors level to minimize their toxicity and improve long-term graft survival. Side effects of this drugs are specific and must been known. Hyperlipidemia and cutaneous side-effects are the most frequent, angioedema and interstital pneumonitis the most serious. In majority of cases, early and adapted management could limit the impact of these side effects.

Topics: Angioedema; Calcineurin Inhibitors; Cicatrix; Cyclosporine; Graft Rejection; Graft Survival; Hematologic Diseases; Humans; Hyperlipidemias; Immunosuppressive Agents; Intracellular Signaling Peptides and Proteins; Kidney Diseases; Lymphocele; Pneumonia; Protein Serine-Threonine Kinases; Sirolimus; Skin Diseases; TOR Serine-Threonine Kinases