Sellar region related to the transsphenoidal endoscopic approach of pituitary surgery.

INTRODUCTION: Transsphenoidal endoscopic approach gives significant advantages in the surgery of pituitary adenomas. A sound knowledge of the anatomy is essential for the surgeons to perform the procedure in a safe and efficient way. This study aims to provide a better understanding of the complex anatomical structures involved in the transsphenoidal approach and to increase familiarity with the endoscopic views and associated skills. PATIENTS AND METHODS: Computed tomographic angiography images from 122 individuals were used for measurements between landmark structures that are relevant to these surgeries. The parameters including the size, shape, and available angles were measured. RESULTS: The angle between 2 lines that are from the sphenoidal rostrum to the middle point of tuberculum sellae and to the tangential point of a tangent which is through the center of sphenoidal rostrum to the pituitary fossa (AR) was 30.62 ± 4.70 degrees; the angle between 2 lines that are from the unilateral sphenoidal rostrum to the bilateral nearest point of the 2 internal carotid arteries within the area of sellar region (AI) was 39.06 ± 9.82 degrees; the anteroposterior diameter of the pituitary fossa (SP) was 11.07 ± 1.36 mm; the vertical diameter of the pituitary fossa (BH) was 7.20 ± 1.46 mm; the distance from the middle point of tuberculum sellae to the lowest point of the pituitary (SB) was 9.59 ± 1.37 mm; the angle between line SB and the horizontal plane (ASB) was 49.29 ± 7.51 mm; the width of tuberculum sellae was (SD) 10.16 ± 1.47 mm; the width of the intermediate part of the pituitary fossa was (BD) 12.09 ± 2.01 mm; the width of the posterior wall of the pituitary fossa (PD) was 12.84 ± 1.57 mm; and the ply of the bone of the front (PB) and bottom (PA) of pituitary fossa were 0.75 ± 0.22 mm and 0.91 ± 0.26 mm, respectively. CONCLUSIONS: These measurements can help to understand the complicated anatomical structures around the pituitary fossae and can contribute to ensure the efficiency and success of the surgery as well.

Anatomical study of cavernous segment of the internal carotid artery and its relationship to the structures in sella region.

INTRODUCTION: The shape and position of the cavernous segment of the internal carotid artery (CSICA) are complicated, which makes the surgeries around it difficult. There were many reports about the primary event of internal carotid artery injury resulting in hemorrhage during transsphenoidal resection of pituitary tumors. The anatomical relationship between CSICA and the structures in the sella region around can explain its mechanism. PURPOSE: We study the CSICA and its positional relationship to some stationary structures in the sellar region to locate CSICA and prevent it from injuring in the process of transsphenoidal surgery. MATERIAL AND METHODS: Computed topographic angiography images of 144 internal carotid arteries in individuals were reviewed. The distance from CSICA to midpoint of sella bottom (SB) and the angle between line BA and line BM were measured in the coronal plane, which is across the middle point of SB. The vertical distance from the anterior curve segment of CSICA to the top edge of the sphenoid sinus was measured in people with sphenoid sinus of types III and IV. The horizontal distance between the midpoint of the posterior curve segment and the coronal middle line of SB was measured in the sagittal plane after multiplanar reformation. RESULTS: The mean (SD) distances from the CSICA to the midpoint of SB were 11.25 (3.35) mm in the right and 11.06 (2.98) mm in the left, and the mean (SD) angles between line BA and line BM were 74.2 (2.16) degrees in the right and 73.5 (2.33) degrees in the left. The mean (SD) vertical distance between the anterior curve segment of the CSICA and the top edge of the sphenoid sinus was -0.62 (0.96) mm, the mean (SD) of the right side was -0.68 (1.24) mm, and the mean (SD) of the left was -0.54 (1.15) mm. The mean (SD) horizontal distance between the midpoint of PS segment and the coronal middle line of SB was 6.41 (1.94) mm in the right and 6.31 (1.33) mm in the left. CONCLUSIONS: The data in our study are valuable for surgeons in real clinical practice to achieve the best possible surgical outcome and maximize safety, and they also contribute to the understanding of the anatomy of CSICA and the structures around.

A new method of locating the optic canal based on structures in sella region: computed tomography study.

BACKGROUND: The location of optic canal and the intracranial segment of optic nerve is difficult because of the high possibility of the deficiency of optic protuberance as well as its complex relationship to sphenoid and ethmoidal sinus. A new method of locating the optic canal and a comprehensive analysis of it and the structures around is of great importance. PURPOSE: Our study aimed to provide a new method to locate the optic canal and analyze the relationship between optic canal and other structures in the sella region, which can be a guidance for endoscopic sinus surgery such as the optic nerve decompression and transsphenoidal approach to the pituitary adenoma and reduced complications caused by the injury of optic nerve. METHODS: Computed tomography images of 120 sphenoid sinuses in adults were reviewed, and multiplanar reconstruction was used to make it possible to make the measurement in coronal, sagittal, and axial plane at the same time. The positional relationship between optic canal and the stationary structures in sella region was analyzed. RESULTS: The horizontal distance between the lowest point of sella bottom (SB) and sulcus prechiasmaticus in the sagittal plane was 8.08 (SD, 0.79) mm. The distance between the medial wall of optic canal and the midline of SB were 7.01 (SD, 1.43) mm in plane 1, 7.78 (SD, 0.86) mm in plane 2, 11.08 (SD, 0.82) mm in plane 3, and 13.81 (SD, 0.66) mm in plane 4; the angles between line BO and line BC were 87.99 (SD, 5.04) degrees in plane 1, 87.71 (SD, 4.98) degrees in plane 2, 82.54 (SD, 5.78) degrees in plane 3, and 82.57 (SD, 6.99) degrees in plane 4. As for the relationship between optic canal and the sphenoid sinus, there were 2.08% of sphenoid sinus of type A, 19.17% of type B, 45.00% of type C, 17.50% of type D, and 16.25% of type E. CONCLUSIONS: Optic canal can be located by the structures or markers in sella region such as the midline of SB, the lowest point of SB, the midpoint in the top edge of sphenoid sinus, and tubercular recess. The analysis of the relationship between optic canal and the sphenoid sinus as well as the data measured in our study is helpful to make an accurate location of the optic canal when the bony landmarks of optic canal are not available.

Probiotics: Can it modulate fracture healing?

OBJECTIVE: Fractures remain a huge burden and their management adversely affects individuals' function and productivity during the lengthy healing period. Gut microbiota exerts a systemic influence on diverse aspects of host physiology, including bone. The primary objective of this study was to evaluate if oral probiotic treatment before or after a fracture in a mouse model could increase cytokines and biomarkers essential for bone healing with subsequent improvement in the biomechanical properties of the healed callus. METHODS: Femoral osteotomy and intramedullary pinning were performed on C57BL/6 mice. Group 1 received either control PBS or probiotic via oral gavage for 5 weeks before fracture (pre-fracture). Group 2 received equivalent treatments for 4 weeks only after fracture (post-fracture). Fracture calluses were harvested on day 3 and 7 for RT-qPCR to quantify osteogenic-related inflammatory cytokines and bone biomarkers. Fractured femurs were evaluated day 28 post-osteotomy via microstructural analysis (µCT) and biomechanical testing (torsion). RESULTS: Mice treated with probiotics pre-fracture (group 1) showed significantly increased gene expression on day 3 of cytokines TGF-ß, IL-6 and IL-17F and a corresponding increase in gene expression on day 7 for Col1 and Runx2. Significant improvement was also seen in bone volume fraction, bone mineral density, tissue mineral density, maximum yield torque, stiffness and strain energy. Mice treated with probiotics post-fracture (group 2), demonstrated no changes in cytokine or bone marker gene expression with no significant changes on microstructural analysis. However, significant increases were seen in twist angle at failure and strain energy, with a corresponding reduction in torsional stiffness. CONCLUSION: Our results suggest that oral probiotic administration, before or after a fracture, may sufficiently alter the gut flora microenvironment leading to improved bone healing biomechanical properties. The use of probiotics may provide a cost-effective and low-risk adjunctive therapy to improve fracture healing.

Morphological structure of the infraorbital canal using three-dimensional reconstruction.

Our study aim was to evaluate the initial position accurately and the direction of infraorbital canal approximately by analyzing the parameters of infraorbital canal. This study was based on 64-slice computed tomographic multiple planar reconstruction technique and can improve the success rate of infraorbital nerve blockade. The following observations and measurements were carried out in 224 normal infraorbital canals (112 people): the length, angle, and adjoined relations of initial infraorbital canal, to reveal the anatomic characteristics of the canals and to compare the difference between left and right or male and female. Six indicators were measured: (1) the length of initial infraorbital canal; (2) the distance between skin and the first obvious turn of infraorbital canal along the direction of initial infraorbital canal (the depth of puncture); (3) the vertical distance between infraorbital canal and nasal septum; (4) the vertical distance between infraorbital canal and infraorbital rim; (5) the angle between the infraorbital canal and the Frankfort plane; and (6) the angle between the infraorbital canal and the sagittal plane. The difference was statistically significant between 2 sides on the depth of puncture. For other values, the differences between left and right and between women and men were of no statistical significance.

Trained immunity induced by in vivo peptide-based STAT6 inhibition prevents ragweed allergy in mice.

BACKGROUND: Trained immunity is the ability of the innate immune system to form immune memory responses to provide support the formation of appropriate adaptive responses. Allergic airways disease (AAD) is a maladapted immune response to allergens, initiated and maintained by the type 2 (T2) inflammatory pathway. It is predicated by the elaboration of cytokines IL-4 and IL-13 and follows activation of the STAT6 transcription factor. OBJECTIVE: To investigate the role of trained immunity in mucosal immune responses following neonatal vaccination with the STAT6 inhibitory peptide (STAT6-IP), in preventing the development of ragweed-induced AAD. METHODS: We demonstrate that transfer of CD4+ T cells or dendritic cells (DC) from STAT6-IP vaccinated wild-type BALB/c mice to naïve mice, that were subsequently chronically exposed to sensitizing doses of ragweed allergen, is sufficient to prevent development of T2 responses in recipients. RESULTS: Our results demonstrate significant reductions in; airways hyperresponsiveness (AHR); ragweed-specific IgE; pulmonary inflammation; T2 cytokines; and inflammatory gene expressions in recipient mice. Expression of IDO, TGFß and T regulatory cells were all significantly increased. Anti-TGFß treatment during the ragweed sensitization phase re-constituted the pro-inflammatory T2 immune response. We show that tolerance can be attained via DC trained in the STAT6-IP-mediated tolerant milieu. This effect is not restricted to a particular allergen and does not require antigen-mediated T cell activation prior to transfer. CONCLUSION: Adoptive transfer experiments suggest that STAT6-IP treatment trains dendritic and cells to mediate tolerant immunity to chronic ragweed exposure in the airways. This indicates that early transient STAT6-inhibition constitutes an effective immunomodulatory airways allergy preventative strategy.

Estrogen aggravates inflammation in Pseudomonas aeruginosa pneumonia in cystic fibrosis mice.

BACKGROUND: Among patients with cystic fibrosis (CF), females have worse pulmonary function and survival than males, primarily due to chronic lung inflammation and infection with Pseudomonas aeruginosa (P. aeruginosa). A role for gender hormones in the causation of the CF "gender gap" has been proposed. The female gender hormone 17ß-estradiol (E2) plays a complex immunomodulatory role in humans and in animal models of disease, suppressing inflammation in some situations while enhancing it in others. Helper T-cells were long thought to belong exclusively to either T helper type 1 (Th1) or type 2 (Th2) lineages. However, a distinct lineage named Th17 is now recognized that is induced by interleukin (IL)-23 to produce IL-17 and other pro-inflammatory Th17 effector molecules. Recent evidence suggests a central role for the IL-23/IL-17 pathway in the pathogenesis of CF lung inflammation. We used a mouse model to test the hypothesis that E2 aggravates the CF lung inflammation that occurs in response to airway infection with P. aeruginosa by a Th17-mediated mechanism. RESULTS: Exogenous E2 caused adult male CF mice with pneumonia due to a mucoid CF clinical isolate, the P. aeruginosa strain PA508 (PA508), to develop more severe manifestations of inflammation in both lung tissue and in bronchial alveolar lavage (BAL) fluid, with increased total white blood cell counts and differential and absolute cell counts of polymorphonuclear leukocytes (neutrophils). Inflammatory infiltrates and mucin production were increased on histology. Increased lung tissue mRNA levels for IL-23 and IL-17 were accompanied by elevated protein levels of Th17-associated pro-inflammatory mediators in BAL fluid. The burden of PA508 bacteria was increased in lung tissue homogenate and in BAL fluid, and there was a virtual elimination in lung tissue of mRNA for lactoferrin, an antimicrobial peptide active against P. aeruginosa in vitro. CONCLUSIONS: Our data show that E2 increases the severity of PA508 pneumonia in adult CF male mice, and suggest two potential mechanisms: enhancement of Th17-regulated inflammation and suppression of innate antibacterial defences. Although this animal model does not recapitulate all aspects of human CF lung disease, our present findings argue for further investigation of the effects of E2 on inflammation and infection with P. aeruginosa in the CF lung.

Screening of the candidate inhibitory peptides of subtilisin by in vitro RNA display technique.

The application of inhibitors facilitates the stable preservation of enzyme in liquid detergent by mitigating the proteolytic activity of subtilisin. The conventionally used subtilisin inhibitors such as boric acid pose a threat to the environment and human health. Thus, the formulation of novel subtilisin inhibitors demands immediate attention. In the current study, we have screened the peptide inhibitors for subtilisin by employing the in vitro mRNA display technique. It is a sensitive screening technique with a high library capacity. The affinity screening was performed between the biotin-modified subtilisin immobilized on the streptavidin magnetic beads and the cDNA-mRNA-peptide fusion molecular library acquired from the in vitro translation and reverse transcription. The candidate peptides with high affinity were obtained after multiple rounds of screening. Furthermore, the inhibitory effect was evaluated, showing that some candidate peptides had inhibitory effects, but the isothermal titration calorimetry and time dependent experiments ultimately proved that these candidate peptides were not stable inhibitors. However, the in vitro mRNA display method explored in this study can be used as a preliminary screening method to provide candidate peptides for the screening of subtilisin inhibitors.

Author Correction: Mutations in COMP cause familial carpal tunnel syndrome.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Mutations in COMP cause familial carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, affecting a large proportion of the general population. Genetic susceptibility has been implicated in CTS, but the causative genes remain elusive. Here, we report the identification of two mutations in cartilage oligomeric matrix protein (COMP) that segregate with CTS in two large families with or without multiple epiphyseal dysplasia (MED). Both mutations impair the secretion of COMP by tenocytes, but the mutation associated with MED also perturbs its secretion in chondrocytes. Further functional characterization of the CTS-specific mutation reveals similar histological and molecular changes of tendons/ligaments in patients' biopsies and the mouse models. The mutant COMP fails to oligomerize properly and is trapped in the ER, resulting in ER stress-induced unfolded protein response and cell death, leading to inflammation, progressive fibrosis and cell composition change in tendons/ligaments. The extracellular matrix (ECM) organization is also altered. Our studies uncover a previously unrecognized mechanism in CTS pathogenesis.

A two phase regulation of bone regeneration: IL-17F mediates osteoblastogenesis via C/EBP-ß in vitro.

T lymphocytes and pro-inflammatory cytokines, specifically interleukin-17F (IL-17F) have been identified as important regulators in bone regeneration during fracture repair. To better understand the molecular mechanisms of IL-17F-mediated osteoblastogenesis, a mouse pre-osteoblast cell line (MC3T3-E1) was utilized to characterize the intracellular signal transduction of IL-17F. Comparisons to the established canonical Wnt signaling pathway were made using Wnt3a ligand. Our results demonstrated greater bone marker gene expression in IL-17F-treated cells, compared to cells treated with Wnt3a. Western blot analysis confirmed degradation of ß-catenin and up-regulation of two key proteins in osteoblast differentiation, Runx2 and C/EBP-ß, in response to IL-17F treatment. RNA silencing of IL-17F receptors, IL-17Ra and IL-17Rc via siRNA transfection resulted in decreased expression of Act2, Runx2, and C/EBP-ß, demonstrating the direct ligand-receptor interaction between IL-17F and IL-17Ra/c as an activator of osteoblastogenesis. Our findings suggest that IL-17F promotes osteoblast differentiation independent of the canonical Wnt pathway and ß-catenin signaling, presenting new insights on modulating the adaptive immune response in the inflammatory phase, temporally distinct from the reparative and remodeling phases of fracture healing.

Design of experiments confirms optimization of lithium administration parameters for enhanced fracture healing.

Fracture healing is a lengthy process which fails in 5-10% of cases. Lithium, a low-cost therapeutic used in psychiatric medicine, up-regulates the canonical Wingless pathway crucial for osteoblastic mineralization in fracture healing. A design-of-experiments (DOE) methodology was used to optimize lithium administration parameters (dose, onset time and treatment duration) to enhance healing in a rat femoral fracture model. In the previously completed first stage (screening), onset time was found to significantly impact healing, with later (day 7 vs. day 3 post-fracture) treatment yielding improved maximum yield torque. The greatest strength was found in healing femurs treated at day 7 post fracture, with a low lithium dose (20 mg/kg) for 2 weeks duration. This paper describes the findings of the second (optimization) and third (verification) stages of the DOE investigation. Closed traumatic diaphyseal femur fractures were induced in 3-month old rats. Healing was evaluated on day 28 post fracture by CT-based morphometry and torsional loading. In optimization, later onset times of day 10 and 14 did not perform as well as day 7 onset. As such, efficacy of the best regimen (20 mg/kg dose given at day 7 onset for 2 weeks duration) was reassessed in a distinct cohort of animals to complete the DOE verification. A significant 44% higher maximum yield torque (primary outcome) was seen with optimized lithium treatment vs. controls, which paralleled the 46% improvement seen in the screening stage. Successful completion of this robustly designed preclinical DOE study delineates the optimal lithium regimen for enhancing preclinical long-bone fracture healing.

Low-dose lithium regimen enhances endochondral fracture healing in osteoporotic rodent bone.

Osteoporotic bone fractures are highly prevalent and involve lengthy recovery. Lithium, commonly used in psychiatric medicine, inhibits glycogen synthase kinase-3ß in the Wnt/ß-catenin pathway, leading to up-regulation of osteogenesis. Our recent preclinical work demonstrated that a 20 mg/kg lithium dose administered beginning 7 days post-fracture for 14 days optimally improved femoral fracture healing in healthy rats at 4 weeks post fracture (46% higher torsional strength). In this study, lithium treatment was evaluated for healing of osteoporotic bone fractures. Six-month-old ovariectomized rats were subjected to closed, load-drop induced femoral diaphyseal fracture. Two regimens involving treatment initiation on day 7 and day 10, respectively, 20 mg/kg/day oral dose and 14 days duration were evaluated. Femurs of lithium- vs. saline- treated rats were analyzed at 4 weeks (for day 7 onset regimen) or 6 weeks (for day 10 onset regimen) post-fracture by stereology and torsional mechanical testing. Initiation on day 10 led to a significant 50% higher maximum yield torque (primary outcome measure) at 6 weeks (309 vs. 206 N-mm, p = 0.005; n = 7, 7). Initiation on day 7 suggested a trend toward a more modest improvement in maximum yield torque (13%) evaluated at 4 weeks post-fracture (234 vs. 206 N-mm, p = 0.10; n = 10, 13). Qualitatively, lithium-treated femurs demonstrated better periosteal and mineralized callus bridging in the day 10 initiation group. Lithium is a widely-available, orally administered, low-cost drug, which represents a feasible pharmacological intervention for both healthy and osteoporotic fracture healing. This study provides important guidelines for future clinical evaluation of lithium in osteoporotic fracture patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1783-1789, 2018.

Anatomic and Ultrasonic Study Based on Selective Tibial Neurotomy.

BACKGROUND: Selective tibial neurotomy (STN) was considered as an effective procedure for the treatment of spastic feet. It is also widely used for treating obese calves in some Asian countries. This study aimed to provide morphologic measurement data and theoretical support for the operation and intraoperative localization. METHODS: Fifty lower legs from 20 embalmed cadavers and 5 fresh corpses were dissected to observe and record the relationship of 4 branches of the tibial nerve, as well as the length, width, and thickness of the triceps surae. An ultrasonic transducer was also used to measure the thickness of muscles of 50 volunteers and acquire the ultrasonic image of muscles and nerve branches. RESULTS: Anatomic results showed that the tibial nerve gave off 4 branches in a proximal to distal direction: the medial sural cutaneous nerve, the motor branches innervating the medial and lateral gastrocnemius, and the motor branch innervating the soleus. These nerve branches had 8 patterns of origin. A significant finding was that the nerve innervating the soleus consisted of 2 branches. Ultrasonic measurement results showed that the thickness of the gastrocnemius and the soleus were positively related to the circumference of the calf. CONCLUSIONS: The calf circumference was positively related to the thickness of the soleus and the gastrocnemius. Diverging patterns of tibial nerve branches were multiple, and caution should be used to prevent damaging other branches. Tibial nerve, branches, and diverging sites could be seen clearly in the ultrasonic image. A preoperational ultrasonic examination is recommended.

[Experimental study on the viscoelastic properties of cancellous bone of the os calcaneus, os lunatum and os capitalum].

We have researched the viscoelastic properties of the cancellous bones of the os calcaneus, os lunatum and os capitalum. The compressing stress relaxation experiment and the creep experiment in the vertical, horizontal and 45 degree directions on the os calcaneus were performed. The data and curve of the compressing stress relaxation and creep were obtained. By masing regression analysis we worked out the compressing reduced stress relaxation and creep functions and curves. The results show that the quantities of compressing stress relaxation and creep of the calcaneus in the vertical direction are larger than those in the other two directions. The initial quantities of creep of the os capitalum are larger than those of the os lunatum, and there are no significant different between the quantities of stress relaxation of the cancellous bones of the os lunatum and os capitalum.

Parameters for lithium treatment are critical in its enhancement of fracture-healing in rodents.

BACKGROUND: Lithium, a treatment for bipolar disorder, is not clinically indicated for use in fracture management but has been reported to positively influence bone biology. It is hypothesized that lithium dosing for beneficial effects on bone health may be much lower than the dosing required for psychotropic benefits in patients with bipolar disorder. A preclinical study with a rodent fracture model was utilized to best define the lowest effective dose, best timing of treatment onset, and optimal treatment duration for the use of lithium as a new treatment in fracture care. METHODS: A design-of-experiments approach was used to assess the parameters of dose, timing of treatment onset, and treatment duration. Closed femoral shaft fractures were generated and analyzed with use of destructive torsional mechanical testing and microcomputed tomography-based image analysis. Eleven different outcome measures were quantified, with maximum yield torque as the primary study outcome, to assess the quality of long-bone fracture-healing. RESULTS: Fracture-healing was maximized with a lithium treatment combination of a low dose (twenty milligrams per kilogram of body weight per day), later onset of lithium treatment (seven days after fracture), and longer treatment duration (two weeks), with maximum yield torque displaying a 46% increase compared with nontreated and sham-treated controls (481.1 ± 104.0 N-mm compared with 329.9 ± 135.8 N-mm; p = 0.04). Design-of-experiments analysis determined the timing of treatment onset to be the most influential parameter for improving fracture-healing, with femora treated at a later onset (seven days after fracture) showing a significant (21%) increase in maximum yield torque compared with those treated at an earlier onset (three days after fracture) (p = 0.01). CONCLUSIONS: A later onset of lithium administration significantly improved femoral fracture-healing. Trends indicated that a lower dose and longer treatment duration also had a positive effect on fracture repair. CLINICAL RELEVANCE: Orally administered low-dose lithium therapy with a large postfracture administration window has the potential to yield a safe, reliable, and cost-effective treatment to enhance bone-healing and restore earlier function and mobility pending appropriate large-animal proof-of-concept models, safety data, and U.S. Food and Drug Administration clinical trials approval.

T-lymphocytes enable osteoblast maturation via IL-17F during the early phase of fracture repair.

While it is well known that the presence of lymphocytes and cytokines are important for fracture healing, the exact role of the various cytokines expressed by cells of the immune system on osteoblast biology remains unclear. To study the role of inflammatory cytokines in fracture repair, we studied tibial bone healing in wild-type and Rag1(-/-) mice. Histological analysis, µCT stereology, biomechanical testing, calcein staining and quantitative RNA gene expression studies were performed on healing tibial fractures. These data provide support for Rag1(-/-) mice as a model of impaired fracture healing compared to wild-type. Moreover, the pro-inflammatory cytokine, IL-17F, was found to be a key mediator in the cellular response of the immune system in osteogenesis. In vitro studies showed that IL-17F alone stimulated osteoblast maturation. We propose a model in which the Th17 subset of T-lymphocytes produces IL-17F to stimulate bone healing. This is a pivotal link in advancing our current understanding of the molecular and cellular basis of fracture healing, which in turn may aid in optimizing fracture management and in the treatment of impaired bone healing.

Inhibition of experimental allergic airways disease by local application of a cell-penetrating dominant-negative STAT-6 peptide.

Allergic airways disease is initiated and perpetuated by an aberrant Th2 inflammatory response regulated in part by the cytokines IL-4 and IL-13, each of which induces activation of the STAT-6 transcription factor. Data from murine models indicate that the clinical manifestations of acute asthma are STAT-6 dependent, and thus, STAT-6 is a target for drug development in allergic airways disease. We designed a novel chimeric peptide (STAT-6 inhibitory peptide (STAT-6-IP)) comprised of a sequence predicted to bind to and inhibit STAT-6, fused to a protein transduction domain, to facilitate cellular uptake of the STAT-6-binding peptide. Our data demonstrate that the STAT-6-IP inhibited OVA-induced production of Th2 cytokines IL-4 and IL-13 in vitro. In contrast, the STAT-6-IP did not affect production of IFN-gamma, demonstrating specificity for Th2 cytokine inhibition. Following intranasal administration, the STAT-6-IP was localized to epithelial cells in the airways. Finally, in in vivo murine models of allergic rhinitis and asthma, intranasal delivery of the STAT-6-IP inhibited OVA-induced lung inflammation and mucus production as well as accumulation of eosinophils and IL-13 in bronchoalveolar lavage fluid and OVA-dependent airway hyperresponsiveness. Together these data show that local application of cell-penetrating peptide inhibitors of STAT-6 has significant potential for the treatment of allergic rhinitis and asthma.

Neonatal exposure with LPS and/or allergen prevents experimental allergic airways disease: development of tolerance using environmental antigens.

BACKGROUND: Studies show that children in rural environments develop less asthma and allergic rhinitis than their urban counterparts. This may be a result, in part, of neonatal exposure to environmental antigens such as LPS and/or early exposure to allergens. OBJECTIVE: This study examined the effects of neonatal allergen and/or LPS exposure on subsequent immune responses to allergen. METHODS: Newborn mice were exposed to LPS and/or ovalbumin. At age 6 weeks, these animals were sensitized and challenged with ovalbumin, and airway inflammation, hyperresponsiveness, and cytokine expression were assessed. RESULTS: Animals exposed to LPS in the neonatal period developed T cells expressing CD25 and IL-10 on sensitization and challenge. They demonstrated abrogation of airway hyperresponsiveness and significant decreases in IL-13 from bronchoalveolar lavage fluid and in specific IgE. IL-4-expressing spleen cells were also significantly decreased. Mice exposed in the neonatal period to ovalbumin demonstrated airway hyporesponsiveness after subsequent ovalbumin sensitization and challenge and did not produce specific IgE. In contrast, these animals showed increases in IFN-gamma. Animals exposed to both LPS and ovalbumin developed a response characterized by IL-10 and IFN-gamma-expressing T cells. CONCLUSION: This suggests that mucosal antigen exposure in the neonatal period results in inhibition of allergic responses to environmental allergens. Early LPS exposure directs mucosal responses toward tolerance, whereas ovalbumin exposure follows the T(H)1-type response on subsequent sensitization. CLINICAL IMPLICATIONS: This study suggests that prevention of airways allergy may be best achieved by appropriate exposure of the airway mucosa early in life to environmental antigens.

The N-terminal region of the CCAAT displacement protein (CDP)/Cux transcription factor functions as an autoinhibitory domain that modulates DNA binding.

The CCAAT displacement protein/Cut homeobox (CDP/Cux) transcription factor is expressed as multiple isoforms that may contain up to four DNA-binding domains: Cut repeats 1, 2, and 3 (CR1, CR2, CR3) and the Cut homeodomain (HD). The full-length protein, which contains all four DNA-binding domains, is surprisingly less efficient than the shorter isoforms in DNA binding. Using a panel of recombinant proteins expressed in mammalian or bacterial cells, we have identified a domain at the extreme N terminus of the protein that can inhibit DNA binding. This domain was able to inhibit the activity of full-length CDP/Cux and of proteins containing various combinations of DNA-binding domains: CR1CR2, CR3HD, or CR2CR3HD. Since inhibition of DNA binding was also observed with purified proteins obtained from bacteria, we conclude that autoinhibition does not require post-translational modification or interaction with an interacting protein but instead functions through an intramolecular mechanism. Antibodies directed against the N-terminal region were able to partially relieve inhibition. In vivo, the transition between the inactive and active states for DNA binding is likely to be governed by posttranslational modifications and/or interaction with one or more protein partners. In addition, we show that the relief of autoinhibition can be accomplished via the proteolytic processing of CDP/Cux. Altogether, these results reveal a novel mode of regulation that serves to modulate the DNA binding activity of CDP/Cux.