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.

Severe Acute Radiodermatitis in a Keloid Patient with Takayasu's Arteritis.

SUMMARY: Although combination therapy for keloid including postoperative radiation therapy (RT) is common, the radiation toxicity of RT in a patient with a history of collagen vascular disease has not been fully recognized. We experienced a case of an acute radiodermatitis in a patient with keloid. This patient had a chest keloid because of the bypass surgery for Takayasu's arteritis. After we performed an excision and postoperative RT, severe radiodermatitis occurred. We speculate that the higher single dose and the use of electron beams may be related to the onset of severe acute radiodermatitis in this case. It should be kept in mind that there is a risk of exacerbation of radiation toxicity in patients with collagen vascular disease.

Response to comment on "Drug screening for ALS using patient-specific induced pluripotent stem cells".

Our work and the study of Bilican et al. highlight the need for complementary assays to detect subtle phenotypic differences between control and mutant induced pluripotent stem cell lines.

Chondroitinase injection improves keloid pathology by reorganizing the extracellular matrix with regenerated elastic fibers.

Keloids are a proliferative fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. Keloid lesions lack skin plasticity due to deficiencies in elastic fiber formation in the extracellular matrix. The loss of elastic fiber is caused by excessive accumulation of chondroitin sulfate (CS), a sulfated glycosaminoglycan. However, there is no radical cure for keloids. Using a model system, we show herein that treatment of keloid tissues with chondroitinase ABC, an enzyme that specifically digests CS, improves clinical features of keloids. Keloid tissues obtained from patients were grafted on nude mice, and chondroitinase ABC was injected into the grafted keloid tissues. Chondroitinase ABC treatment significantly reduced the volume of keloid implants concomitant with recovery of elastic fiber formation. These results suggest that chondroitinase ABC injection is an effective therapy for keloid.

Modeling Alzheimer's disease with iPSCs reveals stress phenotypes associated with intracellular Aß and differential drug responsiveness.

Oligomeric forms of amyloid-ß peptide (Aß) are thought to play a pivotal role in the pathogenesis of Alzheimer's disease (AD), but the mechanism involved is still unclear. Here, we generated induced pluripotent stem cells (iPSCs) from familial and sporadic AD patients and differentiated them into neural cells. Aß oligomers accumulated in iPSC-derived neurons and astrocytes in cells from patients with a familial amyloid precursor protein (APP)-E693Δ mutation and sporadic AD, leading to endoplasmic reticulum (ER) and oxidative stress. The accumulated Aß oligomers were not proteolytically resistant, and docosahexaenoic acid (DHA) treatment alleviated the stress responses in the AD neural cells. Differential manifestation of ER stress and DHA responsiveness may help explain variable clinical results obtained with the use of DHA treatment and suggests that DHA may in fact be effective for a subset of patients. It also illustrates how patient-specific iPSCs can be useful for analyzing AD pathogenesis and evaluating drugs.

Latent TGF-ß binding protein 4 promotes elastic fiber assembly by interacting with fibulin-5.

Elastic fiber assembly requires deposition of elastin monomers onto microfibrils, the mechanism of which is incompletely understood. Here we show that latent TGF-ß binding protein 4 (LTBP-4) potentiates formation of elastic fibers through interacting with fibulin-5, a tropoelastin-binding protein necessary for elastogenesis. Decreased expression of LTBP-4 in human dermal fibroblast cells by siRNA treatment abolished the linear deposition of fibulin-5 and tropoelastin on microfibrils. It is notable that the addition of recombinant LTBP-4 to cell culture medium promoted elastin deposition on microfibrils without changing the expression of elastic fiber components. This elastogenic property of LTBP-4 is independent of bound TGF-ß because TGF-ß-free recombinant LTBP-4 was as potent an elastogenic inducer as TGF-ß-bound recombinant LTBP-4. Without LTBP-4, fibulin-5 and tropoelastin deposition was discontinuous and punctate in vitro and in vivo. These data suggest a unique function for LTBP-4 during elastic fibrogenesis, making it a potential therapeutic target for elastic fiber regeneration.

Multipotent stem cells are effectively collected from adult human cheek skin.

Skin-derived precursor (SKP) cells are a valuable resource for tissue engineering and regenerative medicine, because they represent multipotent stem cells that differentiate into neural and mesodermal progenies. Previous studies suggest that the stem cell pool decreases with age. Here, we show that human multipotent SKP cells can be efficiently collected from adult cheek/chin skin, even in aged individuals of 70-78years. SKP cells were isolated from 38 skin samples by serum-free sphere culture and examined for the ability to differentiate into neural and mesodermal lineages. The number of spheres obtained from adult facial skin was significantly higher than that of trunk or extremity skin. SKP cells derived from cheek/chin skin exhibited a high ability to differentiate into neural and mesodermal cells relative to those derived from eyelid, trunk, or extremity skin. Furthermore, cheek/chin skin SKP cells were shown to express markers for undifferentiated stem cells, including a high expression level of the Sox9 gene. These results indicate that cheek/chin skin is useful for the recovery of multipotent stem cells for tissue engineering and regenerative therapy.

An ex vivo model employing keloid-derived cell-seeded collagen sponges for therapy development.

The most distinctive feature of keloid is the extreme deposition of extracellular matrix, including collagens and proteoglycans (PGs). The focus of this study was the PG versican, which presumably defines keloid volume because of its ability to retain large amounts of water through its component glycosaminoglycans (GAGs). The excessive deposition of versican in keloids was examined by immunohistochemical analysis and by upregulation of the versican gene in these lesions by real-time PCR. The latter showed that mesenchymal cells derived from keloid lesion (KL) cells continue to exhibit above-normal versican production in culture. To establish a model of GAG deposition in keloids, collagen sponges seeded with KL cells (KL-SPos) were implanted in the subcutaneous space of nude mice. After 1 month, the KL-SPos were significantly heavier than the fibroblast (Fb)-seeded sponges (Fb-SPos). This ex vivo model was subsequently used to examine an inhibitory ability of IL-1ß that was identified to reduce versican in vitro. IL-1ß or chondroitinase ABC, when injected directly, successfully reduced the weight of the KL-SPos. Thus, on the basis of the change in weight of the seeded sponges, this ex vivo model can be used to test therapies aimed at reducing or inhibiting keloid formation and to study the pathogenesis of this aberrant response.

Drug screening for ALS using patient-specific induced pluripotent stem cells.

Amyotrophic lateral sclerosis (ALS) is a late-onset, fatal disorder in which the motor neurons degenerate. The discovery of new drugs for treating ALS has been hampered by a lack of access to motor neurons from ALS patients and appropriate disease models. We generate motor neurons from induced pluripotent stem cells (iPSCs) from familial ALS patients, who carry mutations in Tar DNA binding protein-43 (TDP-43). ALS patient-specific iPSC-derived motor neurons formed cytosolic aggregates similar to those seen in postmortem tissue from ALS patients and exhibited shorter neurites as seen in a zebrafish model of ALS. The ALS motor neurons were characterized by increased mutant TDP-43 protein in a detergent-insoluble form bound to a spliceosomal factor SNRPB2. Expression array analyses detected small increases in the expression of genes involved in RNA metabolism and decreases in the expression of genes encoding cytoskeletal proteins. We examined four chemical compounds and found that a histone acetyltransferase inhibitor called anacardic acid rescued the abnormal ALS motor neuron phenotype. These findings suggest that motor neurons generated from ALS patient-derived iPSCs may provide a useful tool for elucidating ALS disease pathogenesis and for screening drug candidates.

Keloids can be forced into remission with surgical excision and radiation, followed by adjuvant therapy.

We have treated keloids using a combination of surgical excision and postoperative irradiation. The objective of this study was to evaluate the results of our treatment over 12 years. From 1995 until 2006, we treated keloids using the aforementioned treatment. If we identified a sign of recurrence during the follow-up period, we started an intralesional injection of triamcinolone acetonide immediately. We selected 91 keloids for which we had more than 2 years of follow-up data for this study and assessed the results according to our original scale (Kyoto scar scale) based on objective and subjective symptoms. In all, 51 keloids (56.0%) were cured completely by a combination of surgical excision and postoperative irradiation without additional treatment, and finally 81 keloids (89.0%) showed good results with additional treatment. Keloids are a controllable condition when treated with combination therapy, involving surgical excision with postoperative irradiation and early conservative treatment after the detection of recurrence.

Adipose tissue-specific regulation of angiotensinogen in obese humans and mice: impact of nutritional status and adipocyte hypertrophy.

BACKGROUND: The adipose tissue renin-angiotensin system (RAS) has been implicated in the pathophysiology of obesity and dysfunction of adipose tissue. However, neither regulation of angiotensinogen (AGT) expression in adipose tissue nor secretion of adipose tissue-derived AGT has been fully elucidated in humans. METHODS: Human subcutaneous abdominal adipose tissue (SAT) biopsies were performed for 46 subjects with a wide range of body mass index (BMI). Considering the mRNA level of AGT and indices of body fat mass, the amount of adipose tissue-derived AGT secretion (A-AGT-S) was estimated. Using a mouse model of obesity and weight reduction, plasma AGT levels were measured with a newly developed enzyme-linked immunosorbent assay (ELISA), and the contribution of A-AGT-S to plasma AGT levels was assessed. RESULTS: A-AGT-S was substantially increased in obese humans and the value was correlated with the plasma AGT level in mice. A-AGT-S and plasma AGT were higher in obese mice, whereas lower in mice with weight reduction. However, the AGT mRNA levels in the liver, kidney, and aorta were not altered in the mouse models. In both humans and mice, the AGT mRNA levels in mature adipocytes (MAs) were comparable to those in stromal-vascular cells. Coulter Multisizer analyses revealed that AGT mRNA levels in the MAs were inversely correlated with the average size of mature adipocytes. CONCLUSIONS: This study demonstrates that adipose tissue-derived AGT is substantially augmented in obese humans, which may contribute considerably to elevated levels of circulating AGT. Adipose tissue-specific regulation of AGT provides a novel insight into the clinical implications of adipose tissue RAS in human obesity.