Bioinspired collagen-gelatin-hyaluronic acid-chondroitin sulfate tetra-copolymer scaffold biomimicking native cartilage extracellular matrix facilitates chondrogenesis of human synovium-derived stem cells.

The microenvironment plays a crucial role in stem cell differentiation, and a scaffold that mimics native cartilaginous extracellular components can promote chondrogenesis. In this study, a collagen-gelatin-hyaluronic acid-chondroitin sulfate tetra-copolymer scaffold with composition and architecture similar to those of hyaline cartilage was fabricated using a microfluidic technique and compared with a pure gelatin scaffold. The newly designed biomimetic scaffold had a swelling ratio of 1278 % ± 270 %, a porosity of 77.68 % ± 11.70 %, a compressive strength of 1005 ± 174 KPa, and showed a good resilience against compression force. Synovium-derived stem cells (SDSCs) seeded into the tetra-copolymer scaffold attached to the scaffold firmly and exhibited good mitochondrial activity, high cell survival with a pronounced glycosaminoglycan production. SDSCs cultured on the tetra-copolymer scaffold with chondrogenic induction exhibited upregulated mRNA expression of COL2A1, ChM-1, Nrf2, TGF-ß1, and BMP-7. Ex vivo study revealed that the SDSC-tetra-copolymer scaffold regenerated cartilage-like tissue in SCID mice with abundant type II collagen and S-100 production. BMP7 and COL2A1 expression in the tetra-copolymer scaffold group was much higher than that in the gelatin scaffold group ex vivo. The tetra-copolymer scaffold thus exhibits strong chondrogenic capability and will facilitate cartilage tissue engineering.

Arthroscopic treatment of stable nonunion, unstable nonunion, or nonunion of the scaphoid with early degenerative radioscaphoid arthritis.

BACKGROUND: This study was designed to analyze the clinical follow-up results (minimum of 2 years) in patients with stable nonunion, unstable nonunion, or nonunion of the scaphoid with early degenerative radioscaphoid arthritis (Lichtman classification stage I-III) treated with arthroscopic osteosynthesis with autogenous bone graft. METHODS: We retrospectively recruited 44 consecutive patients with scaphoid fracture nonunion treated with arthroscopy-assisted percutaneous internal fixation with autogenous bone grafts from January 2010 to November 2019. We recorded union and return to activity and analyzed data with regular clinical follow-up at a mean duration of 33 months (range 24-46 months). Clinical (i.e., visual analog scale pain score, grip strength, and range of motion), radiographic, and functional (Mayo Modified Wrist Score (MMWS)) outcomes at the final follow-up were compared with the preoperative assessments and analyzed in patients with different stages. RESULTS: We confirmed union in 39 of the 44 patients (88.6%) after a mean 15.4 weeks post-operatively according to clinical examinations and standard radiography. All clinical parameters improved significantly. For the MMWS, there were 25 excellent and 14 good results. Of the 44 patients, 40 (90.9%) returned to work or sports activities at their preinjury levels. Comparisons of the outcomes between patients in different stages of scaphoid nonunion revealed no significant difference in the aspect of union rate, VAS pain score, and functional score improvement. CONCLUSIONS: Arthroscopic osteosynthesis with autogenous bone grafts is a reliable and minimally invasive method for achieving nonunion healing and improving clinical outcomes in stage I-III scaphoid nonunion. LEVEL OF EVIDENCE: Level IV, case series.

An assessment of physical properties and the viability of osteoblast-like cells of cefazolin-impregnated calcium sulfate bone-void filler.

Calcium sulfate, an injectable and biodegradable bone-void filler, is widely used in orthopedic surgery. Based on clinical experience, bone-defect substitutes can also serve as vehicles for the delivery of drugs, for example, antibiotics, to prevent or to treat infections such as osteomyelitis. However, antibiotic additions change the characteristics of calcium sulfate cement. Moreover, high-dose antibiotics may also be toxic to bony tissues. Accordingly, cefazolin at varying weight ratios was added to calcium sulfate samples and characterized in vitro. The results revealed that cefazolin changed the hydration reaction and prolonged the initial setting times of calcium sulfate bone cement. For the crystalline structure identification, X-ray diffractometer revealed that cefazolin additive resulted in the decrease of peak intensity corresponding to calcium sulfate dihydrate which implying incomplete phase conversion of calcium sulfate hemihydrate. In addition, scanning electron microscope inspection exhibited cefazolin changed the morphology and size of the crystals greatly. A relatively higher amount of cefazolin additive caused a faster degradation and a lower compressive strength of calcium sulfate compared with those of uploaded samples. Furthermore, the extract of cefazolin-impregnated calcium sulfate impaired cell viability, and caused the death of osteoblast-like cells. The results of this study revealed that the cefazolin additives prolonged setting time, impaired mechanical strength, accelerated degradation, and caused cytotoxicity of the calcium sulfate bone-void filler. The aforementioned concerns should be considered during intra-operative applications.

Midterm outcomes of midfoot and hindfoot arthrodesis with strut allograft for Müller-Weiss disease.

BACKGROUND: Müller-Weiss disease (MWD), a rare dysplastic disorder of the foot, is characterized by deformity, sclerosis, and fragmentation of the lateral part of navicular bone. Arthrodesis is the mainstay treatment for MWD. Generally, arthrodesis can be achieved through internal fixation with metallic implants, and morselized chip bone may be packed into the gap for better bone union. However, with this procedure, the original foot size is not maintained and support for the foot arch is not provided. Sequela of short foot, or flatfoot is commonly observed even though these complications of surgery had not been reported with cases of MWD treated by arthrodesis. Herein, we present a retrospective analysis of treating MWD through midfoot and hindfoot arthrodesis combined with strut allograft. METHODS: From August 2006 to June 2019, 20 patients with MWD (mean age, 59.6 years; range, 40-80 years) underwent midfoot and hindfoot arthrodesis with strut bone allograft and were followed for at least 24 months. The patients were able to ambulate and participate in rehabilitation programs 3 months postoperatively. RESULTS: The used four radiographic parameters (Meary's angle in anteroposterior and lateral view, talonavicular coverage angle, calcaneal pitch) demonstrated significant differences (P < .05) preoperatively and postoperatively, but those between the postoperative values and the values at the last follow-up session did not, indicating that strut allograft was able to maintain normal alignment. The mean American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scores at 2 years postoperatively revealed significant improvement from baseline, from 60.2 to 84.2 (P < .05). The 12-item Short Form Health Survey scores also improved significantly (P < .05). All patients reported substantial pain relief and exhibited improved functional outcomes and gait patterns. CONCLUSIONS: For advanced-stage MWD, arthrodesis with a precisely shaped, size-matched strut allograft provided strong support for biomechanical alignment and enhanced functional performance.

Translational Medicine in Uremic Vascular Calcification: Scavenging ROS Attenuates p-Cresyl Sulfate-Activated Caspase-1, NLRP3 Inflammasome and Eicosanoid Inflammation in Human Arterial Smooth Muscle Cells.

We formerly proved that uremic vascular calcification (UVC) correlates tightly with oxidative elastic lamina (EL) injury and two cell fates (apoptosis and osteocytic conversion) in smooth muscle cells (SMC) of chronic kidney disease (CKD) patients and eliminating p-cresyl sulfate (PCS)-activated intracellular ROS ameliorates the MAPK signaling pathway in a human arterial SMC (HASMC) model. Nonetheless, whether ROS scavenger attenuates PCS-triggered inflammasome activation and eicosanoid inflammation in the UVC process remains unknown. Patients with lower extremity amputation were categorized into CKD and normal control group according to renal function. We used immunohistochemistry stain to analyze UVC in arterial specimens, including oxidative injury (8-hydroxy-2'-deoxyguanosine (8-OHdG) and internal EL disruption), cytosolic phospholipase A2 (cPLA2), cyclooxygenase 2 (COX2), interleukin-1 beta (IL-1ß), caspase-1 and NLRP3. To simulate the patho-mechanism of human UVC, the therapeutic effects of ROS scavenger on PCS-triggered inflammatory pathways was explored in a HASMC model. We found CKD patients had higher circulating levels of PCS and an increase in medial arterial calcification than the control group. In CKD arteries, the severity of UVC corresponded with expressions of oxidative EL disruption and 8-OHdG. Furthermore, coupling expressions of cPLA2 and COX2 were accentuated in CKD arteries, indicative of eicosanoid inflammation. Notably, tissue expressions of IL-1ß, caspase-1 and NLRP3 were enhanced in parallel with UVC severity, indicative of inflammasome activation. From bedside to bench, ROS scavenger attenuates PCS-activated expressions of cPLA2/COX2, pro-caspase-1 and NLRP3 in the HASMC model. UVC as an inevitable outcome is predictive of death in CKD patients. Nonetheless, UVC remain pharmacoresistant despite the evolution of treatment for mineral-parathyroid hormone-vitamin D axis. Beyond the mineral dysregulation, the stimulation of pro-oxidant PCS alone results in eicosanoid inflammation and inflammasome activation. Concerning the key role of Caspase-1 in pyroptosis, cell fates of HASMC in uremic milieu are not limited to apoptosis and osteogenesis. In view of this, reducing ROS and PCS may act as a therapeutic strategy for UVC-related cardiovascular events in CKD patients.

Circulating p-Cresyl Sulfate, Non-Hepatic Alkaline Phosphatase and Risk of Bone Fracture Events in Chronic Kidney Disease-Mineral Bone Disease.

Patients with chronic kidney disease (CKD), especially those undergoing hemodialysis, are at a considerably high risk of bone fracture events. Experimental data indicate that uremic toxins intricately involved in bone-related proteins exert multi-faced toxicity on bone cells and tissues, leading to chronic kidney disease-mineral and bone disorder (CKD-MBD). Nonetheless, information regarding the association between p-cresyl sulfate (PCS), non-hepatic alkaline phosphatase (NHALP) and skeletal events remains elusive. We aim to explore the association between PCS, NHALP and risk of bone fracture (BF) in patients with hemodialysis. Plasma concentrations of PCS and NHALP were ascertained at study entry. Cox proportional hazard regression analyses were used to determine unadjusted and adjusted hazard ratios (aHRs) of PCS for BF risk. In multivariable analysis, NHALP was associated with incremental risks of BFs [aHR: 1.06 (95% CI: 1.01-1.11)]. The association between the highest PCS tertile and BF risk remained robust [aHR: 2.87 (95% CI: 1.02-8.09)]. With respect to BF events, the interaction between NHALP and PCS was statistically significant (p value for the interaction term < 0.05). In addition to mineral dysregulation and hyperparathyroidism in hemodialysis patients, higher circulating levels of PCS and NHALP are intricately associated with incremental risk of BF events, indicating that a joint evaluation is more comprehensive than single marker. In light of the extremely high prevalence of CKD-MBD in the hemodialysis population, PCS may act as a pro-osteoporotic toxin and serve as a potential surrogate marker for skeletal events.

Curcumin-Loaded Hydrophobic Surface-Modified Hydroxyapatite as an Antioxidant for Sarcopenia Prevention.

Oxidative stress and later-induced chronic inflammation have been reported to play an important role on the progression of sarcopenia. Current treatments for sarcopenia are mainly administered to patients whom sarcopenia already developed. However, there has been no promising results shown in therapy. Therefore, the development of therapeutic and preventive strategies against sarcopenia would be necessary. Curcumin is a traditional medicine that possesses anti-inflammatory and antioxidative properties. In the present study, hydroxyapatite was subjected to hydrophobic surface modifications for curcumin loading (Cur-SHAP). It was, subsequently, utilized for delivery to the patient's body via intramuscular injection in order to achieve constant release for more than 2 weeks, preventing the progression of the sarcopenia or even leading to recovery from the early stage of the illness. According to the results of WST-1, LIVE/DEAD, DCFDA, and gene expression assays, Cur-SHAP exhibited good biocompatibility and showed great antioxidant/anti-inflammatory effects through the endocytic pathway. The results of the animal studies showed that the muscle endurance, grip strength, and fat/lean mass ratio were all improved in Cur-SHAP-treated rats from LPS-induced sarcopenia. In summary, we successfully synthesized hydrophobic surface modification hydroxyapatite for curcumin loading (Cur-SHAP) and drug delivery via the IM route. The LPS-induced sarcopenia rats were able to recover from disease after the Cur-SHAP treatment.

Selenium status is independently related to bone mineral density, FRAX score, and bone fracture history: NHANES, 2013 to 2014.

Selenium is an essential trace mineral element for humans. Although previous in vitro and animal studies have reported the vital role of selenium in bone, the results of the relationship between the selenium status and bone health were inconsistent in epidemiological studies. The risk of selenium deficiency is negligible for U.S. general population, however, the relationship between selenium status and bone health has never been surveyed in a nationally representative sample. In this study, we analyzed the data of 2983 adults (aged ≥40 years) in the National Health and Nutrition Examination Survey (NHANES) 2013-2014 to investigate the association among three markers of the selenium status (measured from whole blood, serum, and dietary intake), total spine and femur bone mineral density (BMD), and FRAX scores, and history of bone fractures. We found a one-unit increase in the ln-whole-blood selenium level was correlated with an increase in the total femur BMD of 0.064 g/cm2 (S.E. = 0.025; P = 0.022) in all participants and 0.086 g/cm2 (S.E. = 0.031; P = 0.013) in menopausal women. Additionally, a one-unit increase in the ln-selenium intake amount was associated with an increase in the total femur BMD of 0.014 g/cm2 (S.E. = 0.007; P = 0.043) in all participants. We also found that the dietary and whole-blood selenium statuses were negatively associated with the FRAX score, while levels of all the three selenium biomarkers were negatively associated with a history of bone fractures. In conclusion, increased selenium status is correlated with an increased total femur BMD, decreased FRAX scores, and a reduced incidence of previous bone fractures in the U.S. representative survey of adults. Further study is warranted to clarify the causal inference.

Effect of ErhBMP-2-loaded ß-tricalcium phosphate on ulna defects in the osteoporosis rabbit model.

PURPOSE: Autografts, the gold standard treatment for large bone defects, present complications, especially in conditions with reduced bone-repair capacity, such as osteoporosis. Escherichia coli-derived recombinant human bone morphogenesis protein-2 (ErhBMP-2), was used in this study to improve the osteoinductivity of ß-tricalcium phosphate (ß-TCP). This study evaluated the bone-repair capacity of ErhBMP-2-loaded ß-TCP on osteoporosis rabbit model, relative to the sole use of autograft and ß-TCP treatments. METHODS: The osteoporosis rabbit model was induced through ovariectomy and glucocorticoid dosing; 2-cm segmental ulnar defects were created, which were treated with either autograft, ß-TCP alone, or ErhBMP-2-loaded ß-TCP or left untreated. The quality of newly formed ulnae was evaluated 8 weeks after ulnar surgery through micro-CT, biomechanical, histological, and histomorphometric assessments. RESULTS: The osteoporosis rabbit model was developed and maintained till the end of the study. The maximal load and stiffness in the ErhBMP-2-loaded TCP group were significantly higher than those in the autograft group, whereas the TCP-alone group performed similarly as did the untreated group in the force loading and stiffness tests. According to the micro-CT evaluation, the ErhBMP-2-loaded TCP group had significantly higher bone volume relative to the autograft and TCP-alone groups. Histological assessments revealed better defect bridging and marrow formation in the ErhBMP-2-loaded TCP group relative to the TCP-alone group. Mineral apposition rates were significantly higher in the ErhBMP-2-loaded TCP and autograft groups than in the TCP-alone and untreated groups. CONCLUSION: Relative to autografts, ErhBMP-2-loaded TCP, as an alternative grafting material, provides better or comparable healing on critical-sized long bone defects in the osteoporosis rabbit model.

Therapeutic Effect of Calcimimetics on Osteoclast-Osteoblast Crosslink in Chronic Kidney Disease and Mineral Bone Disease.

We have previously demonstrated calcimimetics optimize the balance between osteoclastic bone resorption and osteoblastic mineralization through upregulating Wingless and int-1 (Wnt) signaling pathways in the mouse and cell model. Nonetheless, definitive human data are unavailable concerning therapeutic effects of Cinacalcet on chronic kidney disease and mineral bone disease (CKD-MBD) and osteoclast-osteoblast interaction. We aim to investigate whether Cinacalcet therapy improves bone mineral density (BMD) through optimizing osteocytic homeostasis in a human model. Hemodialysis patients with persistently high intact parathyroid hormone (iPTH) levels > 300 pg/mL for more than 3 months were included and received fixed dose Cinacalcet (25 mg/day, orally) for 6 months. Bone markers presenting osteoclast-osteoblast communication were evaluated at baseline, the 3rd and the 6th month. Eighty percent of study patients were responding to Cinacalcet treatment, capable of improving BMD, T score and Z score (16.4%, 20.7% and 11.1%, respectively). A significant correlation between BMD improvement and iPTH changes was noted (r = -0.26, p < 0.01). Nonetheless, baseline lower iPTH level was associated with better responsiveness to Cinacalcet therapy. Sclerostin, an inhibitor of canonical Wnt/ß-catenin signaling, was decreased from 127.3 ± 102.3 pg/mL to 57.9 ± 33.6 pg/mL. Furthermore, Wnt-10b/Wnt 16 expressions were increased from 12.4 ± 24.2/166.6 ± 73.3 pg/mL to 33.8 ± 2.1/217.3 ± 62.6 pg/mL. Notably, procollagen type I amino-terminal propeptide (PINP), a marker of bone formation and osteoblastic activity, was increased from baseline 0.9 ± 0.4 pg/mL to 91.4 ± 42.3 pg/mL. In contrast, tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), a marker of osteoclast activity, was decreased from baseline 16.5 ± 0.4 mIU/mL to 7.7 ± 2.2 mIU/mL. Moreover, C-reactive protein levels were suppressed from 2.5 ± 0.6 to 0.8 ± 0.5 mg/L, suggesting the systemic inflammatory burden may be benefited after optimizing the parathyroid-bone axis. In conclusion, beyond iPTH suppression, our human model suggests Cinacalcet intensifies BMD through inhibiting sclerostin expression and upregulating Wnt-10b/Wnt 16 signaling that activates osteoblastic bone formation and inhibits osteoclastic bone resorption and inflammation. From the perspective of translation to humans, this research trial brings a meaningful insight into the osteoblast-osteoclast homeostasis in Cinacalcet therapy for CKD-MBD.

Scavenging Intracellular ROS Attenuates p-Cresyl Sulfate-Triggered Osteogenesis through MAPK Signaling Pathway and NF-κB Activation in Human Arterial Smooth Muscle Cells.

Osteogenesis in human arterial smooth muscle cell (HASMC) is a key feature of uremic vascular calcification (UVC). Concerning pro-oxidant properties of p-cresyl sulfate (PCS), the therapeutic effect of reactive oxygen species (ROS) scavenger on PCS triggered inflammatory signaling transduction in osteogenesis was investigated in this translational research. Based on severity level of chronic kidney disease (CKD), arterial specimens with immunohistochemistry stain were quantitatively analyzed for UVC, oxidative injury and osteogenesis along with PCS concentrations. To mimic human UVC, HASMC model was used to explore whether PCS-induced ROS could trigger mitogen-activated protein kinase (MAPK) pathways with nuclear factor-κB (NF-κB) translocation that drive context-specific gene/protein expression, including Runt-related transcription factor 2 (Runx2) and alkaline phosphatase (ALP). In parallel with PCS accumulation, CKD arteries corresponded with UVC severity, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine), Runx2 and ALP. PCS directly phosphorylated extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK)/P38 (pERK/pJNK/pP38) and modulated NF-κB translocation to promote expressions of Runx2 and ALP in HASMC. Notably, intracellular ROS scavenger attenuated pERK signaling cascade and downstream osteogenic differentiation. Collectively, our data demonstrate PCS induces osteogenesis through triggering intracellular ROS, pERK/pJNK/pP38 MAPK pathways and NF-κB translocation to drive Runx2 and ALP expressions, culminating in UVC. Beyond mineral dysregulation, osteocytic conversion in HASMC could be the stimulation of PCS. Thus PCS may act as a pro-osteogenic and pro-calcific toxin. From the perspective of translational medicine, PCS and intracellular ROS could serve as potential therapeutic targets for UVC in CKD patients.

A Joint Evaluation of Neurohormone Vasopressin-Neurophysin II-Copeptin and Aortic Arch Calcification on Mortality Risks in Hemodialysis Patients.

Objective: Systemic hypoperfusion is intricately involved in neurohormone secretion, vascular calcification (VC) related impaired vasodilation, and luminal stenosis. We aimed to conduct a joint evaluation of vasopressin-neurophysin II-copeptin peptide (VP) and advanced aortic arch calcification (AAC) on all-cause and cardiovascular (CV) mortality in maintenance hemodialysis (MHD) patients. Methods: Unadjusted and adjusted hazard ratios (aHRs) of mortality risks were analyzed for different groups of VP and AAC in 167 MHD patients. The modification effect between higher VP and advanced AAC on mortality risk was examined using an interaction product term. Results: Interactions between VP and AAC with respect to all-cause and CV mortality were statistically significant. In multivariable analysis, higher VP predicted all-cause and CV mortality [aHR: 2.2 (95% confidence interval (CI): 1.1-4.5)] and 2.6 (95% CI: 1.1-4.6), respectively. Advanced AAC was associated with incremental risks of all-cause and CV mortality [aHR: 2.1 (95% CI: 1.1-4.0)and 2.5 (95% CI: 1.0-4.3), respectively]. Patients with combined higher VP (>101.5 ng/mL) and advanced AAC were at the greatest risk of all-cause and CV mortality [aHR: 4.7 (95% CI: 1.2-16.2)and 4.9 (95% CI: 1.1-18.9), respectively]. Conclusion: Combined VP and advanced AAC predict not only all-cause but also CV death in MHD patients, and a joint evaluation is more comprehensive than single marker. In light of hypoperfusion and ischemic events in vital organs, VP and AAC could act as more robust dual marker for prognostic assessment.

A Joint Evaluation of Impaired Cardiac Sympathetic Responses and Malnutrition-Inflammation Cachexia for Mortality Risks in Hemodialysis Patients.

Background: Cardiac sympathetic response (CSR) and malnutrition-inflammation syndrome (MIS) score are validated assessment tools for patients' health condition. We aim to evaluate the joint effect of CSR and MIS on all-cause and cardiovascular (CV) mortality in patients with hemodialysis (HD). Methods: Changes in normalized low frequency (ΔnLF) during HD were utilized for quantification of CSR. Unadjusted and adjusted hazard ratios (aHRs) of mortality risks were analyzed in different groups of ΔnLF and MIS score. Results: In multivariate analysis, higher ΔnLF was related to all-cause, CV and sudden cardiac deaths [aHR: 0.78 (95% confidence interval (CI): 0.72-0.85), 0.78 (95% CI: 0.70-0.87), and 0.74 (95% CI: 0.63-0.87), respectively]. Higher MIS score was associated with incremental risks of all-cause, CV and sudden cardiac deaths [aHR: 1.36 (95% CI: 1.13-1.63), 1.33 (95% CI: 1.06 - 1.38), and 1.50 (95% CI: 1.07-2.11), respectively]. Patients with combined lower ΔnLF (≤6.8 nu) and higher MIS score were at the greatest risk of all-cause and CV mortality [aHR: 5.64 (95% CI: 1.14-18.09) and 5.86 (95% CI: 1.64-13.65), respectively]. Conclusion: Our data indicate a joint evaluation of CSR and MIS score to identify patients at high risk of death is more comprehensive and convincing. Considering the extremely high prevalence of cardiac autonomic neuropathy and malnutrition-inflammation cachexia in HD population, a non-invasive monitoring system composed of CSR analyzer and MIS score calculator should be developed in the artificial intelligence-based prediction of clinical events.

Uremic Vascular Calcification Is Correlated With Oxidative Elastic Lamina Injury, Contractile Smooth Muscle Cell Loss, Osteogenesis, and Apoptosis: The Human Pathobiological Evidence.

Background: Uremic vascular calcification (UVC) is reminiscent of osteogenesis and apoptosis in vascular smooth muscle cell (VSMC). We aimed to identify how circulating procalcific particles dramatically leak into VSMC layer in human tissue models of vascular rings. Methods: According to baseline estimated glomerular filtration rate (eGFR), patients following lower extremity amputation were divided into three groups: normal renal function (eGFR ≧ 60 ml/min), mild-to-moderate (15 ml/min < eGFR ≧ 60 ml/min) and severe chronic kidney disease (CKD) (eGFR ≦ 15 ml/min). Arterial specimens with immunohistochemistry stain were quantitatively analyzed for UVC, internal elastic lamina (EL) disruption, α-SMA, osteogenesis, apoptosis, and oxidative injury. Correlations among UVC severity, eGFR, EL disruption, osteogenesis, and oxidative injury were investigated. Results: CKD arteries were associated with eGFR-dependent EL disruption corresponding to UVC severity. CKD arteries exhibited lower α-SMA, higher expressions of caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), indicative of contractile VSMC loss, and apoptosis. Enhanced expressions of alkaline phosphatase and Runx2 were presented in VSMCs of CKD arteries, indicative of osteogenic differentiation. Above eGFR-dependent UVC and EL disruption correlated expressions of 8-hydroxy-2'-deoxyguanosine (8-OHdG), indicating oxidative EL injury promoted procalcific processes. Conclusions: Circulating uremic milieu triggers vascular oxidative stress, leading to progressive internal EL disruption as a key event in disabling VSMC defense mechanisms and catastrophic mineral ion influx into VSMC layer. Oxidative EL injury begins in early CKD, corresponding with active VSMC re-programming, apoptosis, and ultimately irremediable UVC. In light of this, therapeutic strategies targeting oxidative tissue injury might be of vital importance to hinder the progression of UVC related cardiovascular events.

Evaluation of the post-treatment anti-inflammatory capacity of osteoarthritic chondrocytes: An in vitro study using baicalein.

INTRODUCTION: Targeting inflammatory cascades is considered a promising way to prevent knee osteoarthritis (OA) progression. In terms of down-regulating the expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and matrix metalloproteinases (MMPs), pre-treatment with the flavonoid baicalein reportedly protects articular chondrocytes against the cytotoxicity of IL-1ß. However, the benefits of post-treatment baicalein on osteoarthritic chondrocytes are not fully elucidated. METHODS: In this study, primary human chondrocytes were stimulated with IL-1ß prior to baicalein application to evaluate the therapeutic effect of post-treatment. RESULTS: Post-treatment baicalein alleviated cell death and partially restored mitochondrial viability, while the senescence-associated secretory phenotype was not improved in IL-1ß-stimulated chondrocytes. Post-treatment baicalein down-regulated the expressions of IL-1ß, tumor necrosis factor-alpha, MMP-3, MMP-9, and MMP-13 mRNA as well as the protein production in stimulated cells. Even so, the levels of these factors were relative higher than those in un-treated chondrocytes. Moreover, iNOS, IL-6, IL-8, and COL1A1 expressions were consistently high, and IL-10 protein synthesis steadily increased in IL-1ß-treated chondrocytes under baicalein treated status. Moreover, Western blot analyses showed that post-treatment baicalein suppressed nuclear factor kappa-light-chain-enhancer of activated B cells and p50 production while downstream cyclooxygenase-2 was still highly expressed. CONCLUSION: Baicalein post-treatment to osteoarthritic chondrocytes had a minor benefit to the homeostasis of cartilaginous extracellular matrix.

The associations among lead exposure, bone mineral density, and FRAX score: NHANES, 2013 to 2014.

Lead exposure has been suspected as a risk factor for osteoporosis. However, in epidemiological studies, the association between environmental lead exposure and bone health were inconsistent. With the decrease of lead exposure in recent decades, we evaluated the association between lead exposure and bone mineral density (BMD) in the general US population in this study. We analyzed data on 1859 adults (aged ≥40 years) from the National Health and Nutrition Examination Survey (NHANES) conducted in 2013-2014 to determine the relationship among lead exposure measured by both blood and urine lead concentration, BMD of total spine and femur, and FRAX score in a cross-sectional study. In premenopausal women, the results showed a 1-unit increase in natural log-transformed blood and urine lead levels was associated with a decrease in total femur BMD of 0.061 g/cm2 (S.E. = 0.015; p = 0.001) and 0.046 g/cm2 (S.E. = 0.018; p = 0.020), respectively. Moreover, in premenopausal women, a 1-unit increase in natural log-transformed blood level was associated with a decrease in total spine BMD of 0.054 g/cm2 (S.E. = 0.019; p = 0.013). Both FRAX scores were positively correlated with blood and urine lead levels in subjects without fractures, while the 10-year hip fracture risk score was positively associated with lead exposure in subjects with a history of fracture or vertebral fracture. In conclusion, lead exposure was associated with decreased total femur and spine BMD, and FRAX score in the general US population. Further research is needed to elucidate the causal relationship among lead exposure, BMD, and fracture risk.

CD24 expression indicates healthier phenotype and less tendency of cellular senescence in human nucleus pulposus cells.

Identification of specific cell markers is crucial for recognizing functionally healthy nucleus pulposus (NP) cells. The objective of this study was to investigate the role of CD24 expression in adult human NP cells. Cells were retrieved from NP tissues of 20 patients (aged 17-44) operated on for lumbar disc herniation. Based on CD24 expression, NP cells were separated by sorting and then used to examine phenotypic behavior, the effects of culture conditions and cellular senescence pathway related proteins. CD24 expression was positive in 35.5 ± 3.7% (range 9.1-65.2%) of NP cells. Consistently, normoxic expansion and serial passages in monolayers decreased percentage positivity for CD24 in NP cells. CD24- NP cells showed a markedly decreased GSK-3ß activity and increased mitogen-activated protein kinase phosphorylation accompanying by an increased ß-catenin expression. Higher levels of matrix metalloproteinases, as well as lower levels of ACAN and COL2 in CD24- cells, indicated the breakdown and reduced the formation of key extracellular matrix components. CD24+ NP cells presented a more favorable phenotype while CD24- cells showed a more prominent cellular senescence fate. CD24 in NP cells may be a surrogate marker of healthy cells, in the cell-based therapeutic treatment of degenerative disc disorders.

Conservative treatment of recurrent symptoms of an incomplete, atypical femoral fracture associated with glucocorticoid, bisphosphonate, and denosumab therapy in a patient with chronic obstructive pulmonary disease.

Background: Patients with chronic obstructive pulmonary disease have a high prevalence of osteoporosis, and different osteoporosis drugs are used to prevent fractures in these patients. Although the overall incidence of complete or incomplete, atypical femoral fracture (AFF) is low, long-term use of antiresorptive agents is associated with an increased risk of developing AFF. Methods: We present a patient with chronic obstructive pulmonary disease with recurrent symptoms of an incomplete AFF who had been treated with glucocorticoids, and sequentially with alendronate, zoledronic acid, strontium ranelate, raloxifene, denosumab and finally with teriparatide. The first episode occurred before osteoporosis therapies, the second after bisphosphonate treatments, and the third under denosumab. Results: Although her symptoms resolved along with gradually healing of fracture lines after conservative treatment without surgical intervention, progressive varus deformity of the proximal femur may have contributed to recurrence of AFF. Conclusion: Early treatment with anabolic agents and prophylactic fixation of incomplete AFF may alleviate symptoms and prevent recurrences.

Non-Hepatic Alkaline Phosphatase, hs-CRP and Progression of Vertebral Fracture in Patients with Rheumatoid Arthritis: A Population-Based Longitudinal Study.

BACKGROUND: Interactions and early warning effects of non-hepatic alkaline phosphatase (NHALP) and high-sensitivity C-reactive protein (hs-CRP) on the progression of vertebral fractures (VFs) in patients with rheumatoid arthritis (RA) remain unclear. We aim to explore whether serum concentrations of NHALP and hs-CRP could serve as a promising dual biomarker for prognostic assessment of VF progression. METHODS: Unadjusted and adjusted hazard ratios (aHRs) of VF progression were calculated for different categories of serum NHALP and hs-CRP using the Cox regression model in RA patients. The modification effect between serum NHALP and hs-CRP on VF progression was determined using an interaction product term. RESULTS: During 4489 person-years of follow-up, higher NHALP (>125 U/L) and hs-CRP (>3.0 mg/L) were robustly associated with incremental risks of VF progression in RA patients (aHR: 2.2 (95% confidence intervals (CIs): 1.2⁻3.9) and 2.0 (95% CI: 1.3⁻3.3) compared to the lowest HR category, respectively). The interaction between NHALP and hs-CRP on VF progression was statistically significant (p < 0.05). In the stratified analysis, patients with combined highest NHALP and hs-CRP had the greatest risk of VF progression (aHR: 4.9 (95% CI: 2.5⁻9.6)) compared to the lowest HR group (NHALP < 90 U/L and hs-CRP < 1 mg/L). CONCLUSIONS: In light of underdiagnoses of VFs and misleading diagnosis by single test, NHALP and hs-CRP could serve as compensatory biomarkers to predict subclinical VF progression in RA patients.