Substance P Inhibitor Promotes Tendon Healing in a Collagenase-Induced Rat Model of Tendinopathy.

BACKGROUND: The substance P-neurokinin 1 receptor pathway has been proposed as a therapeutic target for tendinopathy. However, there is a lack of evidence regarding its practical applications. PURPOSE: To investigate the therapeutic effects of substance P inhibitor (SPI) on inflamed tenocytes in vitro and in a collagenase-induced rat model of tendinopathy in vivo. STUDY DESIGN: Controlled laboratory study. METHODS: We analyzed the mRNA levels of inflammatory (cyclooxygenase [COX]-2 and interleukin [IL]-6) and tenogenic (Mohawk and scleraxis [SCX]) markers using reverse transcription quantitative polymerase chain reaction to demonstrate the effects of SPI on lipopolysaccharide-treated (inflamed) tenocytes. A collagenase-induced rat model of tendinopathy was created by injecting 20 µL of collagenase into the Achilles tendon. A behavior test using an incapacitance apparatus was performed to detect changes in postural equilibrium. The tendon specimens were obtained, and their gross findings were examined. The tensile strength was measured, and histopathological evaluation was performed (hematoxylin and eosin, alcian blue, and immunohistochemical staining). RESULTS: The mRNA levels of COX-2, IL-6, Mohawk, and SCX differed significantly between inflamed tenocytes and those treated with SPI. SPI improved the weight burden in a rat model of tendinopathy in a behavioral test. The specimens of the SPI group showed a normal tendon-like appearance. In the biomechanical test, the tensile strength of the SPI group was significantly greater than that of the tendinopathy group. In the histopathological evaluation, the degree of collagen matrix breakdown was mild in the SPI group. In alcian blue staining, only small focal depositions of proteoglycans and glycosaminoglycans were observed in the SPI group. The SPI group showed decreased expression of IL-6 and neurokinin 1 receptor. CONCLUSION: This study suggests that SPI has therapeutic effects on tendon healing and restoration in a collagenase-induced rat model of tendinopathy. CLINICAL RELEVANCE: SPI is a promising agent for tendinopathy in humans.

Pro-Angiogenic and Osteogenic Effects of Adipose Tissue-Derived Pericytes Synergistically Enhanced by Nel-like Protein-1.

An important objective of vascularized tissue regeneration is to develop agents for osteonecrosis. We aimed to identify the pro-angiogenic and osteogenic efficacy of adipose tissue-derived (AD) pericytes combined with Nel-like protein-1 (NELL-1) to investigate the therapeutic effects on osteonecrosis. Tube formation and cell migration were assessed to determine the pro-angiogenic efficacy. Vessel formation was evaluated in vivo using the chorioallantoic membrane assay. A mouse model with a 2.5 mm necrotic bone fragment in the femoral shaft was used as a substitute for osteonecrosis in humans. Bone formation was assessed radiographically (plain radiographs, three-dimensional images, and quantitative analyses), and histomorphometric analyses were performed. To identify factors related to the effects of NELL-1, analysis using microarrays, qRT-PCR, and Western blotting was performed. The results for pro-angiogenic efficacy evaluation identified synergistic effects of pericytes and NELL-1 on tube formation, cell migration, and vessel formation. For osteogenic efficacy analysis, the mouse model for osteonecrosis was treated in combination with pericytes and NELL-1, and the results showed maximum bone formation using radiographic images and quantitative analyses, compared with other treatment groups and showed robust bone and vessel formation using histomorphometric analysis. We identified an association between FGF2 and the effects of NELL-1 using array-based analysis. Thus, combinatorial therapy using AD pericytes and NELL-1 may have potential as a novel treatment for osteonecrosis.

Paradoxical Pro-angiogenic Effect of Low-Dose Ellipticine Identified by In Silico Drug Repurposing.

Inadequate vessel maintenance or growth causes ischemia in diseases such as myocardial infarction, stroke, and neurodegenerative disorders. Therefore, developing an effective strategy to salvage ischemic tissues using a novel compound is urgent. Drug repurposing has become a widely used method that can make drug discovery more efficient and less expensive. Additionally, computational virtual screening tools make drug discovery faster and more accurate. This study found a novel drug candidate for pro-angiogenesis by in silico virtual screening. Using Gene Expression Omnibus (GEO) microarray datasets related to angiogenesis studies, differentially expressed genes were identified and characteristic direction signatures extracted from GEO2EnrichR were used as input data on L1000CDS2 to screen pro-angiogenic molecules. After a thorough review of the candidates, a list of compounds structurally similar to TWS-119 was generated using ChemMine Tools and its clustering toolbox. ChemMine Tools and ChemminR structural similarity search tools for small-molecule analysis and clustering were used for second screening. A molecular docking simulation was conducted using AutoDock v.4 to evaluate the physicochemical effect of secondary-screened chemicals. A cell viability or toxicity test was performed to determine the proper dose of the final candidate, ellipticine. As a result, we found ellipticine, which has pro-angiogenic effects, using virtual computational methods. The noncytotoxic concentration of ellipticine was 156.25 nM. The phosphorylation of glycogen synthase kinase-3ß was decreased, whereas the ß-catenin expression was increased in human endothelial cells treated with ellipticine. We concluded that ellipticine at sublethal dosage could be successfully repositioned as a pro-angiogenic substance by in silico virtual screening.

Sustained Exposure of Substance P Causes Tendinopathy.

Recently, neuromediators such as substance P (SP) have been found to be important factors in tendon homeostasis. Some studies have found SP to be the cause of inflammation and tendinopathy, whereas others have determined it to be a critical component of tendon healing. As demonstrated by these conflicting findings, the effects of SP on tendinopathy remain unclear. In this study, we hypothesized that the duration of SP exposure determines its effect on the tendons, with repetitive long-term exposure leading to the development of tendinopathy. First, we verified the changes in gene and protein expression using in vitro tenocytes with 10-day exposure to SP. SP and SP + Run groups were injected with SP in their Achilles tendon every other day for 14 days. Achilles tendons were then harvested for biomechanical testing and histological processing. Notably, tendinopathic changes with decreased tensile strength, as observed in the Positive Control, were observed in the Achilles in the SP group compared to the Negative Control. Subsequent histological analysis, including Alcian blue staining, also revealed alterations in the Achilles tendon, which were generally consistent with the findings of tendinopathy in SP and SP + Run groups. Immunohistochemical analysis revealed increased expression of SP in the SP group, similar to the Positive Control. In general, the SP + Run group showed worse tendinopathic changes. These results suggest that sustained exposure to SP may be involved in the development of tendinopathy. Future research on inhibiting SP is warranted to target SP in the treatment of tendinopathy and may be beneficial to patients with tendinopathy.

Water strider females use individual experience to adjust jumping behaviour to their weight within physical constraints of water surface tension.

Different species of water striders match leg speeds to their body sizes to maximize their jump take off velocity without breaking the water surface, which might have aided evolution of leg structures optimized for exploitation of the water surface tension. It is not understood how water striders achieve this match. Can individuals modify their leg movements based on their body mass and locomotor experience? Here we tested if water striders, Gerris latiabdominis, adjust jumping behaviour based on their personal experience and how an experimentally added body weight affects this process. Females, but not males, modified their jumping behaviour in weight-dependent manner, but only when they experienced frequent jumping. They did so within the environmental constraint set by the physics of water surface tension. Females' ability to adjust jumping may represent their adaptation to frequent increases or decreases of the weight that they support as mating bouts, during which males ride on top of females, start or end, respectively. This suggests that natural selection for optimized biomechanics combined with sexual selection for mating adaptations shapes this ability to optimally exploit water surface tension, which might have aided adaptive radiation of Gerromorpha into a diversity of semiaquatic niches.

A Protocol to Acquire the Degenerative Tenocyte from Humans.

Tendinopathy, a painful condition that develops in response to tendon degeneration, is on the rise in the developed world due to increasing physical activity and longer life expectancy. Despite its increasing prevalence, the underlying pathogenesis still remains unclear, and treatment is generally symptomatic. Recently, numerous therapeutic options, including growth factors, stem cells, and gene therapy, were investigated in hopes of enhancing the healing potency of the degenerative tendon. However, the majority of these research studies were conducted only on animal models or healthy human tenocytes. Despite some studies using pathological tenocytes, to the best of our knowledge there is currently no protocol describing how to obtain human degenerative tenocytes. The aim of this study is to describe a standard protocol for acquiring human degenerative tenocytes. Initially, the tendon tissue was harvested from a patient with lateral epicondylitis during surgery. Then biopsy samples were taken from the extensor carpi radialis brevis tendon corresponding to structural changes observed at the time of surgery. All of the harvested tendons appeared to be dull, gray, friable, and edematous, which made them visually distinct from the healthy ones. Tenocytes were cultured and used for experiments. Meanwhile, half of the harvested tissues were analyzed histologically, and it was shown that they shared the same key features of tendinopathy (angiofibroblastic dysplasia or hyperplasia). A secondary analysis by immunocytochemistry confirmed that the cultured cells were tenocytes with the majority of the cells having positive stains for mohawk and tenomodulin proteins. The qualities of the degenerative nature of tenocytes were then determined by comparing the cells with the healthy control using a proliferation assay or qRT-PCR. The degenerative tenocyte displayed a higher proliferation rate and similar gene expression patterns of tendinopathy that matched previous reports. Overall, this new protocol might provide a useful tool for future studies of tendinopathy.

Psychometric Properties of a Short Korean Version of the Revised Obsessive Intrusion Inventory.

OBJECTIVE: The Revised Obsessive Intrusion Inventory (ROII) is a 52-item scale that evaluates obsessional intrusive thoughts. The aim of the present study was to validate a short, 20-item Korean version of the ROII (ROII-20). METHODS: Of the 1125 participants who completed the ROII-20, 895 participants completed the scale to examine the factor structure of the scale. A subgroup of these participants (n=53) completed the scale twice to determine test-retest reliability. To establish external validity, 230 participants completed the scale and other questionnaires. RESULTS: Exploratory factor analyses suggested a hierarchical model comprising two higher order factors of autogenous obsessions (resulting from aggressive thoughts and sexual thoughts) and reactive obsessions (resulting from thoughts about contamination, thoughts about accidents, and thoughts about dirt). Confirmatory factor analyses supported this model. The results indicated good internal consistency and test-retest reliability. External validity was supported by relationships with obsessive-compulsive symptoms and general distress. CONCLUSION: The ROII-20 presents good psychometric properties and may be considered as a promising instrument for measuring obsessional intrusions.

Interleukin-1ß induces angiogenesis and innervation in human intervertebral disc degeneration.

Degenerative disorders of the intervertebral discs (IVDs) are generally characterized by enhanced matrix degradation, angiogenesis, innervation, and increased expression of catabolic cytokines. In this study, we investigated the effects of inflammatory cytokines, IL-1ß, and TNF-α, on the expression of an angiogenic factor, vascular endothelial growth factor (VEGF), and neurotrophic factors, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), in human IVD degeneration. IL-1ß and TNF-α stimulated the gene expression of VEGF, NGF, and BDNF in nucleus pulposus (NP) cells isolated from patient tissues. Immunohistochemical results demonstrated a positive correlation between IL-1ß and VEGF/NGF/BDNF expression in human IVD tissues. RNA expression analysis of patient tissues also identified positive correlations between VEGF and platelet endothelial cell adhesion molecule-1 (PECAM-1) and between NGF/BDNF and protein gene product 9.5 (PGP9.5). Our findings suggest that IL-1ß is generated during IVD degeneration, which stimulates the expression of VEGF, NGF, and BDNF, resulting in angiogenesis and innervation.

Heterotopic quadruplet pregnancy: conservative management with ultrasonographically-guided KCl injection of cornual pregnancy and laparoscopic operation of tubal pregnancy.

OBJECTIVE: To discuss a case of heterotopic cornual and tubal pregnancy managed with transvaginal potassium chloride (KCl) injection of cornual pregnancy and laparoscopic operation of tubal pregnancy. METHODS: The subject was a 30-year-old woman with twin pregnancy with a left cornual and a tubal pregnancy. The heterotopic cornual pregnancy was treated with ultrasonographically-guided transvaginal injection of KCl into the thorax of ectopic fetus, and the tubal pregnancy was treated with laparoscopic left salpingectomy. RESULTS: The woman was discharged on the 6th postoperative day. After complete ablation of the cornual and tubal pregnancy, the subject had no complications or side effects for the duration of her pregnancy up to the 37th week. Elective cesarean section was performed at 37 weeks and allowed the birth of 2 boys weighing 2,500 and 2,000 g and of normal development. CONCLUSIONS: A minimally invasive approach should be considered in a hemodynamically stable patient to treat a first-trimester heterotopic pregnancy to maintain the intrauterine pregnancy with a satisfactory outcome.