Remodeling Process Research Articles

Cracking the Pericellular Matrix Code: Exploring how MMP-2, -3, and -7 influence matrix breakdown and biomechanical properties

IntroductionThe intricate process of articular cartilage remodeling, pivotal for both physiological functions and osteoarthritis (OA) progression, is orchestrated through a balance of matrix synthesis and breakdown, which is mediated by matrix metalloproteinase enzymes (MMPs). At the heart of this remodeling lies the pericellular matrix (PCM), a specialized microenvironment encapsulating each chondrocyte and composed mainly of collagen type VI and perlecan. The aim of this study was to assess the impact of MMP-2, -3, and -7 on the structural integrity and biomechanical attributes of the PCM. MethodsHuman articular cartilage explants (N=10 patients) were incubated with activated MMP-2, -3, or -7, individually or in combination. Structural alterations in the PCM were evaluated by immunolabeling. The biomechanical properties of the PCM were measured using atomic force microscopy (AFM). ResultsCollagen type VI structural integrity and fluorescence intensity uniformly decreased across all enzyme groups, while perlecan was selectively affected by MMP-3 and -7. AFM measurements demonstrated decreased PCM stiffness after incubation with individual MMPs, leading to an overall ~31 % reduction in elastic modulus for each enzyme. Combinations of enzymes induced comparable significant biomechanical alterations (~35 %), except for MMP-2+MMP-7. DiscussionThis study highlights the significant influence of MMP-induced alterations in PCM composition on biomechanical properties, mirroring characteristics observed in early OA. Each MMP showed specificity in breaking down PCM, and an intriguing interplay, especially between MMP-2 and -7, indicated reduced efficacy in lowering PCM stiffness. Overall, MMP-2, -3, and -7 directly induce functional and structural PCM modifications.

In situ boro-mullite phase formation in Glass–Ceramic glazes: Anatase–rutile phase transformations and microstructure properties

‘‘Boro-mullite’’ is the name for mullites produced through the synthesis of boron-rich material and playing a critical role in producing high-performance materials. Also, the stability of the anatase phase in the glaze and against temperature has been addressed and improved by many studies. In situ boro-mullite crystals generated using various glass-ceramic glaze compositions that contain TiO2 and their impact on the transformation of anatase into a rutile phase were examined in this study. Additionally, the samples' water absorption, bulk density, apparent porosity and shrinkage, Vickers hardness, and optical properties were evaluated at various Al2O3 and B2O3 amounts at 700 °C, 800 °C, 900 °C, 1000 °C and 1100 °C. X-ray diffraction analysis revealed that as the temperature and Al2O3 ratio rose, it triggered the boro-mullite phase formation. On the other hand, increasing the Al2O3 ratio led to a rise in the samples' sintering temperature and delayed the anatase to rutile phase transformation. Furthermore, the presence of corundum crystals retarded the anatase crystal size growth during the remodelling process of the conversion of anatase to rutile. While the increase in the B2O3 ratio sharpened the peaks of albite crystals, the formation of rutile crystals accelerated with the increase in temperature and caused inhibition of albite formation. The albite phase's presence facilitated the creation of the liquid phase and achieved the 0.010 % water absorption and 0 % apparent porosity values as well the highest bulk density and microhardness with 2.476 g/cm3 and 550 H V. The yellowness (+b∗) values were found to be the highest at 1100 °C where the rutile crystals reached their maximum size. The anatase-rutile conversion is postponed and the increase in the yellowness value is prevented by the glaze's formation of boro-mullite. FESEM-EDS analysis showed that the temperature was the driving force in the transformation of acicular boro-mullite crystal into highly acicular prismatic needle crystal and spherical anatase crystals into the rod shape rutile.

A novel non-invasive method for measuring the spatial kinematic behavior of cardiomyocytes regulated by mechanical cues

The intact heart undergoes complex and multiscale mechanical remodeling processes. Measuring rhythmic spatial contraction of the myocardium is crucial for assessing mechanical durability and the ability to mount coordinated responses to pressure, electrical, and hemodynamic signals. However, current cardiomyocyte measurement platforms typically focus on action potentials and XY-plane contractions. Therefore, effective evaluation methods for studying the influence of mechanical cues on the spatial dynamic contraction of cardiomyocytes are still lacking. In this study, we developed a topographic guiding combined with an optical spatial motion tracking method to provide controllable mechanical stimulation for inducing directed contraction of cardiomyocytes and obtaining spatial motion information in vitro. We first performed a detailed investigation of cell connections and cytoskeleton orientations by combining the proposed method with immunofluorescence. Next, spatial constrictive modes, features, and key parameters of microgroove-guided cardiomyocytes were studied. Finally, the three-dimensional (3D) motions of the cardiomyocytes at different positions on the structure were compared. We found that the XY-plane contraction of cardiomyocytes typically has only one direction and shows a significant phase delay compared to the axial motion. In addition, cardiomyocytes located near the edges of the microgrooves were restricted by stronger mechanical forces, resulting in a significant height change reduction. These results provide new perspectives for structural and functional research on cardiomyocytes under long-term mechanical regulation. Overall, this study provides a highly precise and convenient method for evaluating the 3D cardiomyocyte motion under mechanical induction. This method is expected to enhance understanding of cardiomyocyte development and be useful for research on cardiac mechanics and functions.

Facile engineering of interactive double network hydrogels for heart valve regeneration

Regenerative heart valve prostheses are essential for treating valvular heart disease, which requested interactive materials that can adapt to the tissue remodeling process. Such materials typically involves intricate designs with multiple active components, limiting their translational potential. This study introduces a facile method to engineer interactive materials for heart valve regeneration using 1,1’-thiocarbonyldiimidazole (TCDI) chemistry. TCDI crosslinking forms cleavable thiourea and thiocarbamate linkages which could gradually release H2S during degradation, therefore regulates the immune microenvironment and accelerates tissue remodeling. By employing this approach, a double network hydrogel was formed on decellularized heart valves (DHVs), showcasing robust anti-calcification and anti-thrombosis properties post fatigue testing. Post-implantation, the DHVs could adaptively degrade during recellularization, releasing H2S to further support tissue regeneration. Therefore, the comprehensive endothelial cell coverage and notable extracellular matrix remodeling could be clearly observed. This accessible and integrated strategy effectively overcomes various limitations of bioprosthetic valves, showing promise as an attractive approach for immune modulation of biomaterials.

The post-viral GPNMB+ immune niche persists in long-term Covid, asthma, and COPD.

Epithelial injury calls for a regenerative response from a coordinated network of epithelial stem cells and immune cells. Defining this network is key to preserving the repair process for acute resolution, but also for preventing a remodeling process with chronic dysfunction. We recently identified an immune niche for basal-epithelial stem cells using mouse models of injury after respiratory viral infection. Niche function depended on an early sentinel population of monocyte-derived dendritic cells (moDCs) that provided ligand GPNMB to basal-ESC receptor CD44 for reprogramming towards chronic lung disease. These same cell and molecular control points worked directly in mouse and human basal-ESC organoids, but the findings were not yet validated in vivo in human disease. Further, persistence of GPNMB expression in moDCs and M2-macrophages in mouse models suggested utility as a long-term disease biomarker in humans. Here we show increased expression of GPNMB localized to moDC-macrophage populations in lung tissue samples from long-term Covid, asthma, and COPD. The findings thereby provide initial evidence of a persistent and correctable pathway from acute injury to chronic disease with implications for cellular reprogramming and inflammatory memory.

Topology Optimization Driven Bone-Remodeling Simulation for Lumbar Interbody Fusion.

This study proposes a numerical approach for simulating bone remodeling in lumbar interbody fusion (LIF). It employs a topology optimization method to drive the remodeling process and uses a pixel function to describe the structural topology and bone density distribution. Unlike traditional approaches based on strain energy density or compliance, this study adopts von Mises stress to guide the remodeling of LIF. A novel pixel interpolation scheme associated with stress criteria is applied to the physical properties of the bone, directly addressing the stress shielding effect caused by the implanted cage, which significantly influences the bone remodeling outcome in LIF. Additionally, a boundary inverse approach is utilized to reconstruct a simplified analysis model. To reduce computational cost while maintaining high structural resolution and accuracy, the Scaled Boundary Finite Element Method (SBFEM) is introduced. The proposed numerical approach successfully generates results that closely resemble human lumbar interbody fusion.

The role of deubiquitinase USP2 in driving bladder cancer progression by stabilizing EZH2 to epigenetically silence SOX1 expression

BackgroundThe Ubiquitin-proteasome system (UPS) is known to participate in multiple cellular events. The deubiquitinating enzyme USP2 (ubiquitin-specific protease 2) is involved in the vasculature remodeling process associated with bladder cancer (BLCA). However, the role of USP2 in BLCA progression has not been clearly defined and whether its regulatory mechanism involving EZH2 (Enhancer of Zeste Homolog 2) remains elusive yet. MethodsDifferential expression patterns of USP2 and EZH2 were examined in 46 pairs of BLCA and adjacent normal tissues. USP2 knockdown plasmids were transfected into 5637 and J82 cells to detect its impact on cell proliferation, migration and invasion using CCK-8, EdU, wound healing and transwell assays. The USP2-EZH2-SOX1 cascade was confirmed through Co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP) assays. An in vivo verification was conducted using a xenograft model of nude mice. ResultsUSP2 was significantly upregulated in BLCA tissues and cells, which was associated with poor clinical prognosis in BLCA patients. USP2 depletion resulted in decreased cell proliferation, migration and invasion in BLCA cells. USP2 stabilized the EZH2 protein by directly binding to it, thereby reducing its ubiquitination. Ectopic introduction of EZH2 restored cell growth and invasion of BLCA cells, which had been inhibited by USP2 silencing. USP2-mediated stabilization of EZH2 promoted the enrichment of histone H3K27me3 and repression of SOX1. Involvement of the USP2-EZH2-SOX1 axis in tumor formation was ultimately verified in vivo. ConclusionOur findings reveal that a USP2-EZH2-SOX1 axis orchestrates the interplay between dysregulated USP2 and EZH2-mediated gene epigenetic silencing in BLCA progression.

Mid-term Outcomes of Thoracic Endovascular Aortic Repair (TEVAR) in Acute Complicated Type B Aortic Dissection: A Comprehensive Analysis of Aortic Remodeling Patterns.

This study provides a comprehensive analysis of the clinical outcomes associated with endovascular treatment for acute complicated type B aortic dissection, with a focus on the complex process of aortic remodeling. We conducted a retrospective investigation using data extracted from the Songklanagarind Hospital database between January 2010 and January 2022. Electronic medical records of patients who underwent thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissections were reviewed. The analysis focused on in-hospital outcomes, overall survival, aorta-related survival, reintervention-free survival, and changes in aortic lumen diameter to assess aortic remodeling. Over the study period, 32 patients with acute complicated type B aortic dissections underwent TEVAR. The in-hospital mortality rate was 9.4%, with complications occurring in 21.9% of patients. Temporary acute kidney injury was observed in 9.4% of the cases, wound bleeding in 6.3%, pneumonia in 6.3%, and permanent spinal cord ischemia in 3.1%. Re-intervention was necessary in 6.3% of cases. The overall survival rates at 6 months, 1 year, 3 years, and 6 years were 78%, 75%, 65%, and 44%, respectively. Aorta-related survival rates were 87%, 87%, 83%, and 75% at the corresponding time intervals. The reintervention-free survival rates were 96%, 96%, 71%, and 71%, respectively. Survival analysis revealed that patients with ideal aortic remodeling experienced the most favorable outcomes, whereas those with undesirable aortic remodeling exhibited the least favorable survival. Notably, undesirable pattern of aortic remodeling emerged as a singular factor with a statistically significant influence on predicting survival (hazard ratio 4.37, P-value=0.021). TEVAR resulted in favorable aorta-related survival outcomes. Notably, the identification of changes in aortic lumen diameter alongside false lumen thrombosis, encapsulated within the framework of aortic remodeling patterns, has emerged as a robust predictor of post-TEVAR survival outcomes.

Inhibition of Macrophage Recruitment to Heart Valves Mediated by the C-C Chemokine Receptor Type 2 Attenuates Valvular Inflammation Induced by Group A Streptococcus in Lewis Rats.

Rheumatic heart disease (RHD) is an autoimmune disease caused by recurrent infections of Group A streptococcus (GAS), ultimately leading to inflammation and the fibrosis of heart valves. Recent studies have highlighted the crucial role of C-C chemokine receptor type 2-positive (CCR2+) macrophages in autoimmune diseases and tissue fibrosis. However, the specific involvement of CCR2+ macrophages in RHD remains unclear. This study established an RHD rat model using inactivated GAS and complete Freund's adjuvant, demonstrating a correlation between CCR2+ macrophages and fibrosis in the mitral valves of these rats. Intraperitoneal injection of the CCR2 antagonist Rs-504393 significantly reduced macrophage infiltration, inflammation, and fibrosis in valve tissues of RHD rats compared to the solvent-treated group . Existing evidence suggests that C-C motif chemokine ligand 2 (CCL2) acts as the primary recruiting factor for CCR2+ cells. To validate this, human monocytic leukemia cells (THP-1) were cultured in vitro to assess the impact of recombinant CCL2 protein on macrophages. CCL2 exhibited pro-inflammatory effects similar to lipopolysaccharide (LPS), promoting M1 polarization in macrophages. Moreover, the combined effect of LPS and CCL2 was more potent than either alone. Knocking down CCR2 expression in THP-1 cells using small interfering RNA suppressed the pro-inflammatory response and M1 polarization induced by CCL2. The findings from this study indicate that CCR2+ macrophages are pivotal in the valvular remodeling process of RHD. Targeting the CCL2/CCR2 signaling pathway may therefore represent a promising therapeutic strategy to alleviate valve fibrosis in RHD.

Trans-resveratrol mitigates miR-204-3p mediated progression of allergic rhinitis by regulating the EGLN3/HIF-1α/IL33/ST2 signalling pathway

BackgroundAllergic rhinitis (AR) is a multifactorial disease triggered by interactions between genes and the environment. Clinical evidence has shown that trans-resveratrol, a widely used drug, significantly ameliorates AR pathology. However, the precise mechanisms underlying this effect remain unclear. PurposeThis study aimed to elucidate the pharmacological mechanisms of action of trans-resveratrol in patients with AR who exhibit hypoxic symptoms. This will be achieved through microRNA sequencing and signaling pathway screening combined with basic experiments to determine the effects of Trans-resveratrol intervention in this patient population. MethodsNetwork pharmacology was used to determine the therapeutic value of trans-resveratrol in AR. The micro-RNA miR-204-3p was pinpointed by sequencing. Quantitative reverse transcription polymerase chain reaction was used to quantify the expression levels. Haematoxylin and eosin, alcian blue-periodic acid–Schiff, and Masson's trichrome staining were used to assess the effects of hypoxia on nasal mucosa immunohistochemistry and immunofluorescence-localised target proteins. Egl nine homolog 3 (EGLN3) was screened using bioinformatics software. Protein expression was detected by western blotting. Cell growth and death were gauged via Cell Counting Kit-8 and terminal deoxynucleotidyl transferase dUTP nick end labelling staining, respectively. Cell migration was observed using a transwell assay. Enzyme-linked immunosorbent assay was used to measure interleukin (IL)33 levels in the cell supernatants. Flow cytometry was used to verify cell cycle and antigen levels. Electron microscopy was used to visualise the status of the nasal mucosa prior to in vivo expression analysis. ResultsPatients with hypoxic AR demonstrated more pronounced nasal mucosal remodelling than that in patients with common AR. Sequencing results indicated that these patients had a reduced expression of miR-204-3p. Through a combination utilizing of bioinformatics analysis and experimental validation, EGLN3 has been identified as a direct target of HIF-1α. The low expression level of miR-204-3p represses EGLN3, resulting in the accumulation of HIF-1α and the activation of the IL33/ST2 signaling pathway. These stimulate the proliferation, survival, and migration of HNEpCs, ultimately contributing to mucosa remodeling and AR progression. Trans-resveratrol notably downregulated the levels of HIF-1α and IL33/ST2, while simultaneously increasing the expression of EGLN3. ConclusionsDownregulation of miR-204-3p initiated a vicious cycle of hypoxic AR via EGLN3/HIF-1α/IL33/ST2. Trans-resveratrol reversed the pathological process of nasal mucosa remodeling of hypoxic AR by exhibiting anti-inflammatory and anti-angiogenic functions via the above signaling pathway. Our study uncovers the underlying mechanism by which hypoxia drives the progression of AR. It presents innovative strategies for addressing inflammatory and hypoxia-related diseases, bridging traditional and modern medicine, and highlighting the potential of natural compounds in clinical practice.

A Mathematical Model for Postimplant Collagen Remodeling in an Autologous Engineered Pulmonary Arterial Conduit.

This study was undertaken to develop a mathematical model of the long-term in vivo remodeling processes in postimplanted pulmonary artery (PA) conduits. Experimental results from two extant ovine in vivo studies, wherein polyglycolic-acid (PGA)/poly-L-lactic acid tubular conduits were constructed, cell seeded, incubated for 4 weeks, and then implanted in mature sheep to obtain the remodeling data for up to two years. Explanted conduit analysis included detailed novel structural and mechanical studies. Results in both studies indicated that the in vivo conduits remained dimensionally stable up to 80 weeks, so that the conduits maintained a constant in vivo stress and deformation state. In contrast, continued remodeling of the constituent collagen fiber network as evidenced by an increase in effective tissue uniaxial tangent modulus, which then stabilized by one year postimplant. A mesostructural constitute model was then applied to extant planar biaxial mechanical data and revealed several interesting features, including an initial pronounced increase in effective collagen fiber modulus, paralleled by a simultaneous shift toward longer, more uniformly length-distributed collagen fibers. Thus, while the conduit remained dimensionally stable, its internal collagen fibrous structure and resultant mechanical behaviors underwent continued remodeling that stabilized by one year. A time-evolving structural mixture-based mathematical model specialized for this unique form of tissue remodeling was developed, with a focus on time-evolving collagen fiber stiffness as the driver for tissue-level remodeling. The remodeling model was able to fully reproduce (1) the observed tissue-level increases in stiffness by time-evolving simultaneous increases in collagen fiber modulus and lengths, (2) maintenance of the constant collagen fiber angular dispersion, and (3) stabilization of the remodeling processes at one year. Collagen fiber remodeling geometry was directly verified experimentally by histological analysis of the time-evolving collagen fiber crimp, which matches model predictions very closely. Interestingly, the remodeling model indicated that the basis for tissue homeostasis was maintenance of the collagen fiber ensemble stress for all orientations, and not individual collagen fiber stresses. Unlike other growth and remodeling models that traditionally treat changes in the external boundary conditions (e.g., changes in blood pressure) as the primary input stimuli, the driver herein is changes to the internal constituent collagen fiber themselves due to cellular mediated cross-linking.

Age-related mitophagy regulates orthodontic tooth movement by affecting PDLSCs mitochondrial function and RANKL/OPG.

A thorough comprehension of age-related variances in orthodontic tooth movement (OTM) and bone remodeling response to mechanical force holds significant implications for enhancing orthodontic treatment. Mitophagy plays a crucial role in bone metabolism and various age-related diseases. However, the impact of mitophagy on the bone remodeling process during OTM remains elusive. Using adolescent (6 weeks old) and adult (12 months old) rats, we established OTM models and observed that orthodontic force increased the expression of the mitophagy proteins PTEN-induced putative kinase 1 (PINK1) and Parkin, as well as the number of tartrate-resistant acid phosphatase-positive osteoclasts and osteocalcin-positive osteoblasts. These biological changes were found to be age-related. Invitro, compression force loading promoted PINK1/Parkin-dependent mitophagy in periodontal ligament stem cells (PDLSCs) derived from adolescents (12-16 years old) and adults (25-35 years old). Furthermore, adult PDLSCs exhibited lower levels of mitophagy, impaired mitochondrial function, and a decreased ratio of RANKL/OPG compared to young PDLSCs after compression. Transfection of siRNA confirmed that inhibition of mitophagy in PDLSC resulted in decreased mitochondrial function and reduced RANKL/OPG ratio. Application of mitophagy inducer Urolithin A enhanced bone remodeling and accelerated OTM in rats, while the mitophagy inhibitor Mdivi-1 had the opposite effect. These findings indicate that force-stimulated PDLSC mitophagy contributes to alveolar bone remodeling during OTM, and age-related impairment of mitophagy negatively impacts the PDLSC response to mechanical stimulus. Our findings enhance the understanding of mitochondrial mechanotransduction and offer new targets to tackle current clinical challenges in orthodontic therapy.

The value of percutaneous transcatheter mitral valve regurgitation repair in the combination treatment of chronic heart failure patients: Results from a 6-month observational prospective study

Rationale: Surgical interventions have been recognized as the main method to repair of valvular disorders. Percutaneous transcatheter intervention with a clipping system is being actively introduced into the treatment of chronic heart failure (CHF) patients and mitral valve insufficiency (MVI) for correction of mitral regurgitation (MR), along with drug therapy. Aim: To establish the effect of the mitral valve leaflet clipping in the combination treatment of CHF patients on the clinical course of heart failure and the remodeling process. Methods: This single center prospective comparative study included 80 patients with CHF NYHA class II–IV and secondary MR grade 3–4. The patients were on optimal medical treatment (OMT) for CHF for at least 3 months before inclusion into the study. The main group included 55 patients who underwent transcatheter mitral valve repair with the use of MitraClip system, and the control group consisted of 25 patients in whom the surgery for MR was waived for various reasons (refusal of the surgery by the patient, some valve characteristics), and only OMT for CHF was used. At baseline, main clinical and demographic characteristics of the patients in the both groups were comparable. The duration of the follow-up was 6 months. Echocardiography (echoCG), a 6-minute walk test, and measurements of the brain natriuretic propeptide level were performed in all patients at baseline and at 6 months of the follow-up. Results: At 6 months, there was a significant reduction in CHF NYHA class and an increase in the 6-minute walk test distance and a decrease in diuretic requirements (converted to furosemide, from 58.4 ± 17.2 to 38.1 ± 20.7 mg daily, р = 0.02) in the group with the MitraClip implant, but not in the control group. In the OMT only group, there were no changes over 6 months in the diuretic requirements (48.1 ± 6.68 and 43.8 ± 27.15 mg daily, respectively, р = 0.8). The number of hospital readmissions due to CHF decompensation was 7 (12.7%) in the implanted MitraClip group and 4 (16%) in the OMT group (р = 0.69). EchoCG performed at 6 months after the surgical intervention identified no cases of MR grade 2. In the MitraClip implant group, there was a decrease in the size and volumes of the left atrium (р = 0.02 and р = 0.05, respectively), left ventricle (for end-diastolic diameter p = 0.002, end-diastolic volume p = 0.03), mean pulmonary artery pressure (p = 0.03), as well as an increase in cardiac output (р = 0.04). In the patients receiving OMT only, there were no significant changes in EchoCG parameters over time. Conclusion: Our study has shown benefits of the implantation of the mitral valve leaflet clipping system, compared to OMT only, in CHF. The clipping procedure promotes a significant improvement in clinical course of CHF, reverse myocardial remodeling, and reduction in diuretic requirements.

Biomarkers of lung congestion and injury in acute heart failure.

Acute heart failure (AHF) classification and management are primarily based on lung congestion and/or hypoperfusion. The quantification of the vascular and tissue lung damage is not standard practice though biomarkers of lung injury may play a relevant role in this context. Haemodynamic stress promotes alveolar and vascular derangement with loss of functional units, impaired lung capillary permeability and fluid swelling. This culminates in a remodelling process with activation of inflammatory and cytokines pathways. Four families of lung surfactant proteins (i.e., SP-A, SP-B, SP-C, and SP-D), essential for the membrane biology and integrity are released by alveolar type II pneumocites. With deregulation of fluid handling and gas exchange pathways, SPs become sensitive markers of lung injury. We report the pathobiology of lung damage; the pathophysiological and clinical implications of alveolar SPs along with the newest evidence for some classical HF biomarkers that have also shown to reflect a vascular and/or a tissue lung-related activity.

Case Report: The Sausage Technique using Anorganic Bovine Bone Mineral for Horizontal Bone Augmentation at the Crestal Part of a Posterior Mandibular Ridge: A Case Report.

Following tooth extraction, the alveolar bone goes through a natural remodeling process resulting in a significant bone resorption which may complicate dental implant placement without prior bone augmentation treatment. The sausage technique is a modified guided bone regeneration (GBR) method that has been successfully used for horizontal bone augmentation. This technique was developed to increase the bone growth at the alveolar crest. Although the sausage technique uses a combination of autograft chips and xenograft particles with a native collagen membrane, several studies have questioned whether adding autograft chips is essential for bone formation with guided bone regeneration. Moreover, harvesting the bone graft may increase the donor site morbidity and patient discomfort. This case report aimed to investigate the bone gain radiologically when the sausage technique was applied to treat a healthy, thirty-year-old patient with a horizontal defect in the posterior mandibular region using anorganic bovine bone mineral (ABBM) particles with Jason membrane, assess the implant primary stability in the augmented ridge, and present the surgical procedure steps in details. After nine months of healing, the cone-beam computed tomography (CBCT) revealed approximately 4.32 mm of bone gain at the alveolar crest in the buccal-lingual direction. The graft particles were well integrated into the newly formed bone. Two implants were inserted with an insertion torque of 35 N/cm. The ISQ values were 76 for the most anterior implant and 78 for the posterior implant. Within the limitations of this case report, the sausage technique using ABBM particles without autograft chips was an effective approach in achieving the prerequisite bone width at the crest in cases with horizontal bone defects.

Calciprotein particle counts associate with vascular remodelling in chronic kidney disease.

Calciprotein particles (CPPs) are circulating calcium and phosphate nanoparticles associated with development of vascular calcification (VC) in chronic kidney disease (CKD). Although recent studies have been focusing on associations of CPPs with presence of VC in CKD, insights in the underlying processes and mechanisms by which CPPs might aggravate VC and vascular dysfunction in vivo are currently lacking. Here, we assessed overall burden of abdominal VC in healthy kidney donors and CKD patients, and subsequently performed transcriptome profiling in vascular tissue obtained from these subjects, linking outcome to CPP counts and calcification propensity. Calcification scores were quantified in renal arteries, iliac arteries and abdominal aorta, using computed tomography (CT) scans of kidney donors and CKD patients. Vascular tissue was collected from kidney donors (renal artery) and CKD patients (iliac artery), after which bulk RNA sequencing and gene set enrichment analysis (GSEA) was performed on a subset of patients. Calcification propensity (crystallization time, T50) was measured using nephelometry, and CPP counts with microparticle flow cytometric analysis. Increased calcification scores (based on CT) were found in CKD patients compared to kidney donors. Transcriptome profiling revealed enrichment for processes related to endothelial activation, inflammation, extracellular matrix (ECM) remodelling and ossification in CKD vascular biopsies compared to kidney donors. Calcification propensity was increased in CKD, as well as CPP counts, of which the latter significantly associated with markers of vascular remodelling. Our findings reveal that CKD is characterized by systemic VC with increased calcification propensity and CPP counts. Transcriptome profiling showed altered vascular gene expression with enrichment for endothelial activation, inflammation, ECM remodelling and ossification. Moreover, we demonstrate for the first time that vascular remodelling processes are associated with increased circulating CPP counts. Interventions targeting CPPs are promising avenues for alleviating vascular remodelling and VC in CKD.

Effect of Swimming Training on Bone Tissue in Humans

Introduction and purpose: The skeletal system performs many important functions in the human body. It primarily bears the heavy loads associated with movement, protects internal organs, and participates in the regulation of mineral homeostasis. Through continuous processes of bone remodeling and modeling, optimal levels of calcium and phosphorus in the serum are achieved. The balanced removal of old bone tissue by osteoclasts and the formation of new bone by osteoblasts maintain the mechanical properties necessary for the proper functioning of the musculoskeletal system. Bone modeling has been shown to be activated in response to mechanical loading from physical activity. Conversely, the absence of significant loading (as in space travel, i.e., microgravity conditions) leads to increased bone resorption. Osteocytes, as the most numerous group of cells in the skeletal system, are mechanosensitive and are thought to respond to stimuli such as fluid flow, mechanical deformations, and hydrostatic pressure. In response, they regulate the work of osteoclasts and osteoblasts, translating into the regulation of processes occurring in the bone matrix.[1] It is suspected that the type, intensity, and nature of physical exercises can significantly influence these processes. The aim of this work is to gather information on the impact of swimming training (an example of physical exercise in conditions of partial gravity reduction) on the human skeletal system.

TNF reduces osteogenic cell fate in PDL cells at transcriptional and functional levels without alteration of periodontal proliferative capacity.

To investigate the effect of tumor necrosis factor (TNF) on the growth of human periodontal ligament (PDL) cells, their osteogenic differentiation and modulation of their matrix secretion in vitro. The influence of 10 ng/ml TNF on proliferation and metabolic activity of PDL cells was analyzed by cell counting (DAPI [4',6-diamidino-2-phenylindole] staining) and the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. In addition, cells were cultured under control conditions and osteogenic conditions (media containing 10 mMβ-glycerophosphate). Quantitative expression analysis of genes encoding the osteogenic markers alkaline phosphatase (ALP), collagen typeI alpha1 chain (COL1A1), osteoprotegerin (OPG), and osteopontin (OPN) was performed after 7 and 14days of cultivation. Calcium deposits were stained with alizarin red. Our studies showed that 10 ng/ml TNF did not affect the survival and metabolic activity of PDL cells. Quantitative expression analysis revealed that long-term cultures with TNF impaired osteogenic cell fate at early and late developmental stages. Furthermore, TNF significantly reduced matrix secretion in PDL cells. The present data confirm TNF as aregulatory factor of proinflammatory remodeling that influences the differentiation behavior but not the metabolism and cell proliferation of the periodontium. Therefore, TNF represents an interesting target for the regulation of orthodontic remodeling processes in the periodontium.

Novel mathematical approach to accurately quantify 3D endothelial cell morphology and vessel geometry based on fluorescently marked endothelial cell contours: Application to the dorsal aorta of wild-type and Endoglin-deficient zebrafish embryos.

Endothelial cells, which line the lumen of blood vessels, locally sense and respond to blood flow. In response to altered blood flow dynamics during early embryonic development, these cells undergo shape changes that directly affect vessel geometry: In the dorsal aorta of zebrafish embryos, elongation of endothelial cells in the direction of flow between 48 and 72 hours post fertilization (hpf) reduces the vessel's diameter. This remodeling process requires Endoglin; excessive endothelial cell growth in the protein's absence results in vessel diameter increases. To understand how these changes in vessel geometry emerge from morphological changes of individual endothelial cells, we developed a novel mathematical approach that allows 3D reconstruction and quantification of both dorsal aorta geometry and endothelial cell surface morphology. Based on fluorescently marked endothelial cell contours, we inferred cross-sections of the dorsal aorta that accounted for dorsal flattening of the vessel. By projection of endothelial cell contours onto the estimated cross-sections and subsequent triangulation, we finally reconstructed 3D surfaces of the individual cells. By simultaneously reconstructing vessel cross-sections and cell surfaces, we found in an exploratory analysis that morphology varied between endothelial cells located in different sectors of the dorsal aorta in both wild-type and Endoglin-deficient zebrafish embryos: In wild-types, ventral endothelial cells were smaller and more elongated in flow direction than dorsal endothelial cells at both 48 hpf and 72 hpf. Although dorsal and ventral endothelial cells in Endoglin-deficient embryos had similar sizes at 48 hpf, dorsal endothelial cells were much larger at 72 hpf. In Endoglin-deficient embryos, elongation in flow direction increased between 48 hpf and 72 hpf in ventral endothelial cells but hardly changed in dorsal endothelial cells. Hereby, we provide evidence that dorsal endothelial cells contribute most to the disparate changes in dorsal aorta diameter in wild-type and Endoglin-deficient embryos between 48 hpf and 72 hpf.

Initial bone tissue reactions of hydroxyapatite/collagen-(3-glycidoxypropyl)trimethoxysilane injectable bone paste.

We have previously reported that a novel bioresorbable self-setting injectable bone paste composed of hydroxyapatite/collagen bone-like nanocomposite (HAp/Col) and (3-glycidoxypropyl)trimethoxysilane (GPTMS) was successfully prepared and was replaced with new bone within 3 months of implantation in defects created in porcine tibia. In this study, the HAp/Col-GPTMS paste was implanted into bone defects in rat tibiae to investigate the initial kinetics and bone tissue response. Even though more than 35% of GPTMS molecules should be eluted rapidly from directly injected pastes according to previously reported cell culture tests, in this study, energy-dispersive X-ray spectrometry did not detect Si (GPTMS) deposition in tissues surrounding the paste at 1 day postimplantation. Further, no abnormal inflammatory responses were observed in the surrounding tissues over the test period for both directly injected and prehardened pastes. Companying these observations with the results of the previous animal test (in which the paste was fully resorbed and was substituted with new bone), the eluted GPTMS resolved in no harm in vivo from the initial to final (completely resorbed) stages. Material resorption rates calculated from X-ray microcomputed tomography (μ-CT) images decreased with increasing in GPTMS concentration. Histological observations indicated that tartrate-resistant acid phosphatase (TRAP) active cells, (assumed to be osteoclasts), exist on the periphery of pastes. This result suggested that the paste was resorbed by osteoclasts in the same way as the HAp/Col. Since a good correlation was observed between TRAP active areas in histological sections and material resorption rate calculated from μ-CT, the TRAP activity coverage ratio offers the possibility to estimate the osteoclastic resorption ratio of materials, which are replaced with bone via bone remodeling process.