TDP-43 regulates cholesterol biosynthesis by inhibiting sterol regulatory element-binding protein 2.

Dyslipidemia is considered an essential component of the pathological process of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disease. Although TAR DNA Binding Protein 43 kDa (TDP-43) links both familial and sporadic forms of ALS and cytoplasmic aggregates are a hallmark of most cases of ALS, the molecular mechanism and the in vivo relation of ALS dyslipidemia with TDP-43 have been unclear. To analyze the dyslipidemia-related gene expression by TDP-43, we performed expression microarray and RNA deep sequencing (RNA-Seq) using cell lines expressing high levels of TDP-43 and identified 434 significantly altered genes including sterol regulatory element-binding protein 2 (SREBP2), a master regulator of cholesterol homeostasis and its downstream genes. Elevated TDP-43 impaired SREBP2 transcriptional activity, leading to inhibition of cholesterol biosynthesis. The amount of cholesterol was significantly decreased in the spinal cords of TDP-43-overexpressed ALS model mice and in the cerebrospinal fluids of ALS patients. These results suggested that TDP-43 could play an essential role in cholesterol biosynthesis in relation to ALS dyslipidemia.

Chondroitin Sulfate Promotes the Proliferation of Keloid Fibroblasts Through Activation of the Integrin and Protein Kinase B Pathways.

Keloids are dermal fibroproliferative tumors that arise beyond the boundary of the original wound edges and invades adjacent tissue. Keloids are characterized by the extensive production of extracellular matrix (ECM) and abnormal fibroblast proliferation. Chondroitin sulfate (CS) is one of the major structural components of cartilage and ECM. Recently, we reported the over-accumulation of CS in keloid lesions. Keloid-derived fibroblasts (KFs) and normal dermal fibroblasts (NFs) were incubated with CS. The fibroblast proliferation rate was analyzed using a tetrazolium salt colorimetric assay. The activation of the intracellular signaling pathway was analyzed by Western blotting. Wortmannin, a PI3K inhibitor, and anti-integrin antibodies were tested to investigate the mechanism of the CS-induced cell proliferation. CS strongly stimulated the proliferation of KFs, but not NFs. The analysis of the intracellular signal transduction pathway revealed that the stimulation effect of CS on KF proliferation was due to the activation of the protein kinase B (AKT) pathway and that integrin α1 was responsible for this phenomenon. We revealed that CS probably activates the AKT pathway through integrin to induce KF proliferation. CS may be a novel clinical therapeutic target in keloids.

MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons.

Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3'-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4.

HtrA1 Is Specifically Up-Regulated in Active Keloid Lesions and Stimulates Keloid Development.

Keloids occur after failure of the wound healing process; inflammation persists, and various treatments are ineffective. Keloid pathogenesis is still unclear. We have previously analysed the gene expression profiles in keloid tissue and found that HtrA1 was markedly up-regulated in the keloid lesions. HtrA1 is a serine protease suggested to play a role in the pathogenesis of various diseases, including age-related macular degeneration and osteoarthritis, by modulating extracellular matrix or cell surface proteins. We analysed HtrA1 localization and its role in keloid pathogenesis. Thirty keloid patients and twelve unrelated patients were enrolled for in situ hybridization, immunohistochemical, western blot, and cell proliferation analyses. Fibroblast-like cells expressed more HtrA1 in active keloid lesions than in surrounding lesions. The proportion of HtrA1-positive cells in keloids was significantly higher than that in normal skin, and HtrA1 protein was up-regulated relative to normal skin. Silencing HtrA1 gene expression significantly suppressed cell proliferation. HtrA1 was highly expressed in keloid tissues, and the suppression of the HtrA1 gene inhibited the proliferation of keloid-derived fibroblasts. HtrA1 may promote keloid development by accelerating cell proliferation and remodelling keloid-specific extracellular matrix or cell surface molecules. HtrA1 is suggested to have an important role in keloid pathogenesis.

ß-Adrenergic Receptor Blockers Reduce the Occurrence of Keloids and Hypertrophic Scars after Cardiac Device Implantation: A Single-Institution Case-Control Study.

BACKGROUND: Keloids and hypertrophic scars are characterized by excessive proliferation of fibroblasts; abnormal accumulation of extracellular matrix; and clinical findings of raised, red, itchy, and painful lesions. There are few sufficient interventions for keloids, and the development of new therapeutic agents is urgently needed. Several studies suggest that a therapeutic possibility is ß-adrenergic receptor blocker treatment. METHODS: In this single-center case-control study, patients who had undergone cardiac device implantation 7 to 23 months earlier were identified. The implantation incision scars of the patients were deemed to be normal or abnormal depending on their redness. The cases (abnormal scars) and controls (normal scars) were compared in terms of their ß-blocker use rates. RESULTS: Of the 45 eligible patients, 12 and 33 patients were cases and controls, respectively. The cases tended to be less likely to have taken blockers than the controls (25 percent versus 45.5 percent). This difference became significant when the patients whose scars were diagnosed 7 or 8 months after implantation were excluded from the analysis: the age-adjusted odds ratios of the patients who were diagnosed 8 to 23 and 9 to 23 months after implantation were 0.10 (95 percent CI, 0.00 to 0.83; p = 0.0309) and 0.11 (95 percent CI, 0.00 to 0.98; p = 0.047), respectively. CONCLUSIONS: ß-Blockers may be an effective alternative modality for preventing and treating keloids and hypertrophic scars. Large-scale multicenter prospective studies that use histology to diagnose scars and diagnose the postoperative scars at the most suitable period are needed to confirm the effectiveness of blockers for abnormal scars. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Regeneration of elastic fibers by three-dimensional culture on a collagen scaffold and the addition of latent TGF-ß binding protein 4 to improve elastic matrix deposition.

The objective of this study was to investigate the effects of latent TGF-ß binding protein 4 (LTBP-4) on elastic fiber regeneration in three-dimensional cultures of human dermal fibroblasts (HDFs). Appropriate collagen scaffold for elastic fiber regeneration was also examined. Collagen sponges cross-linked at 120 °C and composed of small pores (25 µm on average) was favorable for elastic fiber regeneration by HDFs. Addition of LTBP-4, followed by culture for 21 days, accelerated elastic fiber accumulation within the scaffolds. Conditioned scaffolds containing either HDFs or LTBP-4-built mature elastic fibers were implanted between the dermis and the cutaneous muscle of mice. The combined use of HDFs and LTBP-4 resulted in thicker tissues containing elastic fibers. These results indicate that weakly cross-linked collagen sponges can be used as scaffolds for regenerating elastic fibers both in vitro and in vivo, and that the addition of LTBP-4 accelerates the deposition of both elastin and fibrillin-1, and increases cell proliferation. These techniques may be useful for generating cutaneous or cardiovascular tissue equivalents; furthermore, they may serve as a useful method for the three-dimensional analyses of drugs used to treat skin diseases or to examine the microstructure of elastin networks.

The Shear Wave Velocity on Elastography Correlates with the Clinical Symptoms and Histopathological Features of Keloids.

BACKGROUND: Keloids present as red, painful lesions causing serious functional and cosmetic problems; however, there is no consensus regarding tools for objectively evaluating keloids. To demonstrate the utility of shear wave elastography in keloids, we investigated the correlations between clinical symptoms, ultrasound shear wave velocity, and histopathological findings. METHODS: Three patients with keloids containing both red hypertrophic and mature areas were evaluated using the shear wave velocity and histopathological findings. RESULTS: The results indicate that the shear wave velocity is high in active hypertrophic areas and low in mature areas. The areas with high elastography values exhibited numerous fibrillar collagenous matrices forming a whorled pattern with hyalinized tissue on hematoxylin-eosin staining corresponding with metachromasia on toluidine blue staining. In the mature area, the collagen fibers were oriented parallel to each other without metachromasia. CONCLUSIONS: Shear wave elastography provides quantitative estimates of tissue stiffness that correlate with the clinical symptoms and histopathological findings of the keloid lesions and can be used to assess the activity of keloids.

A toe keloid after syndactyly release treated with surgical excision and intralesional steroid injection.

SUMMARY: A keloid is a benign fibroproliferative disease of unknown etiology. Although it is common among Asians, the development of keloid on the foot is rare. We experienced a case of a keloid which arose on the foot of a 4-year-old boy after the surgical release of syndactyly. He had congenital cutaneous syndactyly of the third and fourth toes. After the reconstructive operation was performed when the patient was 2 years old, the wound became hypertrophic and grew to 37 × 37 × 8 mm. After the diagnosis of keloid based on a pathological examination, the keloid was resected completely. The web was reconstructed with a planter rectangular flap, and the skin defects were covered with a full-thickness skin graft. After the operation, we administered 5 intralesional steroid injections. Finally, the keloid was diminished 2 years after the operation.

Treatment for infection of artificial dura mater using free fascia lata.

Synthetic artificial dura mater materials, such as expanded polytetrafluoroethylene sheets, are widely used in dura mater reconstruction in cases involving brain tumors or trauma surgery. In patients with postoperative infection related to the use of artificial dura mater, surgical debridement of the infected wound and removal of the artificial dura mater materials are necessary to control infection. In cases involving cerebrospinal fluid leakage, dura mater reconstruction must be performed immediately. Many useful techniques for performing dura mater reconstruction to treat postoperative infection have been reported; however, some have drawbacks with respect to the need for microvascular anastomosis or difficulties in obtaining watertight closure. We successfully treated 6 patients with postoperative artificial dura mater infection using free thigh fascia lata. Some surgeons believe that the use of free fascia in infected wounds is dangerous because free fascia is a non-vascularized tissue. However, performing complete debridement and covering such free fascia with well-vascularized tissue allow the fascia to become vascularized and tolerant of infection. Therefore, if the blood flow in the scalp is acceptable after a sufficient debridement, free fascia lata can be used for reconstruction in patients with postoperative infection of artificial dura mater. Furthermore, skull reconstruction can be performed safely and easily with solid-type artificial bone, sometimes combined with tissue expansion, thus resulting in good aesthetic outcomes.