Aggregation of human osteoblasts unlocks self-reliant differentiation and constitutes a microenvironment for 3D-co-cultivation with other bone marrow cells.

Skeletal bone function relies on both cells and cellular niches, which, when combined, provide guiding cues for the control of differentiation and remodeling processes. Here, we propose an in vitro 3D model based on human fetal osteoblasts, which eases the study of osteocyte commitment in vitro and thus provides a means to examine the influences of biomaterials, substances or cells on the regulation of these processes. Aggregates were formed from human fetal osteoblasts (hFOB1.19) and cultivated under proliferative, adipo- and osteoinductive conditions. When cultivated under osteoinductive conditions, the vitality of the aggregates was compromised, the expression levels of the mineralization-related gene DMP1 and the amount of calcification and matrix deposition were lower, and the growth of the spheroids stalled. However, within spheres under growth conditions without specific supplements, self-organization processes occur, which promote extracellular calcium deposition, and osteocyte-like cells develop. Long-term cultivated hFOB aggregates were free of necrotic areas. Moreover, hFOB aggregates cultivated under standard proliferative conditions supported the co-cultivation of human monocytes, microvascular endothelial cells and stromal cells. Overall, the model presented here comprises a self-organizing and easily accessible 3D osteoblast model for studying bone marrow formation and in vitro remodeling and thus provides a means to test druggable molecular pathways with the potential to promote life-long bone formation and remodeling.

Gouqi-derived nanovesicles (GqDNVs) inhibited dexamethasone-induced muscle atrophy associating with AMPK/SIRT1/PGC1α signaling pathway.

With the increasing trend of global aging, sarcopenia has become a significant public health issue. Goji berry, also known as "Gou qi zi" in China, is a traditional Chinese herb that can enhance the structure and function of muscles and bones. Otherwise, previous excellent publications illustrated that plant-derived exosome-like nanoparticles can exert good bioactive functions in different aging or disease models. Thus, we issued the hypothesis that Gouqi-derived nanovesicles (GqDNVs) may also have the ability to improve skeletal muscle health, though the effect and its mechanism need to be explored. Hence, we have extracted GqDNVs from fresh berries of Lycium barbarum L. (goji) and found that the contents of GqDNVs are rich in saccharides and lipids. Based on the pathway annotations and predictions in non-targeted metabolome analysis, GqDNVs are tightly associated with the pathways in metabolism. In muscle atrophy model mice, intramuscular injection of GqDNVs improves the cross-sectional area of the quadriceps muscle, grip strength and the AMPK/SIRT1/PGC1α pathway expression. After separately inhibiting AMPK or PGC1α in C2C12 cells with dexamethasone administration, we have found that the activated AMPK plays the chief role in improving cell proliferation induced by GqDNVs. Furthermore, the energy-targeted metabolome analysis in the quadriceps muscle demonstrates that the GqDNVs up-regulate the metabolism of amino sugar and nucleotide sugar, autophagy and oxidative phosphorylation process, which indicates the activation of muscle regeneration. Besides, the Spearman rank analysis shows close associations between the quality and function of skeletal muscle, metabolites and expression levels of AMPK and SIRT1. In this study, we provide a new founding that GqDNVs can improve the quality and function of skeletal muscle accompanying the activated AMPK/SIRT1/PGC1α signaling pathway. Therefore, GqDNVs have the effect of anti-aging skeletal muscle as a potential adjuvant or complementary method or idea in future therapy and research.

Vitamin D3 deficiency and osteopenia in spastic paraplegia type 5 indicate impaired bone homeostasis.

Hereditary spastic paraplegia type 5 (SPG5) is an autosomal recessively inherited movement disorder characterized by progressive spastic gait disturbance and afferent ataxia. SPG5 is caused by bi-allelic loss of function mutations in CYP7B1 resulting in accumulation of the oxysterols 25-hydroxycholesterol and 27-hydroxycholesterol in serum and cerebrospinal fluid of SPG5 patients. An effect of 27- hydroxycholesterol via the estrogen and liver X receptors was previously shown on bone homeostasis. This study analyzed bone homeostasis and osteopenia in 14 SPG5 patients as a non-motor feature leading to a potential increased risk for bone fractures. T-Scores in CT bone density measurements were reduced, indicating osteopenia in SPG5 patients. Further, we analyzed various metabolites of bone homeostasis by ELISA in serum samples of these patients. We identified a lack of vitamin D3 metabolites (Calcidiol and Calcitriol), an increase in Sclerostin as a bone formation/mineralization inhibiting factor, and a decrease in cross-linked N-telopeptide of type I collagen (NTX), a marker indicating reduced bone resorption. As statin treatment has been found to lower oxysterol levels, we evaluated its effect in samples of the STOP-SPG5 trial and found atorvastatin to normalize the increased sclerostin levels. In summary, our study identified osteopenia as a non-motor feature in SPG5 and suggests the need for vitamin D3 substitution in SPG5 patients. Sclerostin may be considered a therapeutic target and biomarker in upcoming therapeutical trials in SPG5.

AZU1: a new promising marker for infection in orthopedic and trauma patients?

Early and reliable detection of infection is vital for successful treatment. Serum markers such as C-reactive protein (CRP) and procalcitonin (PCT) are known to increase with a time lag. Azurocidin 1 (AZU1) has emerged as a promising marker for septic patients, but its diagnostic value in orthopedic and trauma patients remains unexplored. Between July 2020 and August 2023, all patients necessitating inpatient treatment for periprosthetic joint infection (PJI), peri-implant infection (II), soft tissue infection, chronic osteomyelitis, septic arthrodesis, bone non-union with and without infection were enrolled. Patients undergoing elective total joint arthroplasty (TJA) served as the control group. Blood samples were collected and analyzed for CRP, white blood cell count (WBC), PCT, and AZU1. Based on the inclusion and exclusion criteria 222 patients were included in the study (trauma = 38, soft tissue infection = 75, TJA = 33, PJI/II = 39, others = 37). While sensitivity and specificity were comparably high for AZU1 (0.734/0.833), CRP and PCT had higher specificity (0.542/1 and 0.431/1, respectively), and WBC a slightly higher sensitivity (0.814/0.455) for septic conditions. Taken together, the area under the curve (AUC) showed the highest accuracy for AZU1 (0.790), followed by CRP (0.776), WBC (0.641), and PCT (0.656). The Youden-Index was 0.57 for AZU1, 0.54 for CRP, 0.27 for WBC, and 0.43 for PCT. Elevated AZU1 levels effectively distinguished patients with a healthy condition from those suffering from infection. However, there is evidence suggesting that trauma may influence the release of AZU1. Additional research is needed to validate the diagnostic value of this new biomarker and further explore its potential clinical applications.

Cilostazol Stimulates Angiogenesis and Accelerates Fracture Healing in Aged Male and Female Mice by Increasing the Expression of PI3K and RUNX2.

Fracture healing in the aged is associated with a reduced healing capacity, which often results in delayed healing or non-union formation. Many factors may contribute to this deterioration of bone regeneration, including a reduced 'angiogenic trauma response'. The phosphodiesterase-3 (PDE-3) inhibitor cilostazol has been shown to exert pro-angiogenic and pro-osteogenic effects in preclinical studies. Therefore, we herein analyzed in a stable closed femoral fracture model whether this compound also promotes fracture healing in aged mice. Forty-two aged CD-1 mice (age: 16-18 months) were daily treated with 30 mg/kg body weight cilostazol (n = 21) or vehicle (control, n = 21) by oral gavage. At 2 and 5 weeks after fracture, the femora were analyzed by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry, and Western blotting. These analyses revealed a significantly increased bending stiffness at 2 weeks (2.2 ± 0.4 vs. 4.3 ± 0.7 N/mm) and an enhanced bone formation at 5 weeks (4.4 ± 0.7 vs. 9.1 ± 0.7 mm3) in cilostazol-treated mice when compared to controls. This was associated with a higher number of newly formed CD31-positive microvessels (3.3 ± 0.9 vs. 5.5 ± 0.7 microvessels/HPF) as well as an elevated expression of phosphoinositide-3-kinase (PI3K) (3.6 ± 0.8 vs. 17.4 ± 5.5-pixel intensity × 104) and runt-related transcription factor (RUNX)2 (6.4 ± 1.2 vs. 18.2 ± 2.7-pixel intensity × 104) within the callus tissue. These findings indicate that cilostazol accelerates fracture healing in aged mice by stimulating angiogenesis and the expression of PI3K and RUNX2. Hence, cilostazol may represent a promising compound to promote bone regeneration in geriatric patients.

Associations of Various Physical Activities with Mortality and Life Expectancy are Mediated by Telomere Length.

OBJECTIVES: Physical activity (PA) and telomeres both contribute to healthy aging and longevity. To investigate the optimal dosage of various PA for longevity and the role of telomere length in PA and mortality. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: A total of 333,865 adults (mean age of 56 years) from the UK Biobank were analyzed. METHODS: Walking, moderate PA (MPA), and vigorous PA (VPA) were self-reported via questionnaire, and leukocyte telomere length (LTL) was measured. Cox proportional hazards regression was used to predict all-cause mortality risk. A flexible parametric Royston-Parmar survival model was used to estimate life expectancy. RESULTS: During a median follow-up of 13.8 years, 19,789 deaths were recorded. Compared with the no-walking group, 90 to 720 minutes/week of walking was similarly associated with 27% to 31% of lower mortality and about 6 years of additional life expectancy. We observed nearly major benefits for mortality and life expectancy among those meeting the PA guidelines [151-300 minutes/wk for MPA: hazard ratio (HR) 0.80, 95% CI 0.75-0.85, 3.40-3.42 additional life years; 76-150 minutes/wk for VPA: HR 0.78, 95% CI 0.75-0.82, 2.61 years (2.33-2.89)] vs the no-PA group. Similar benefits were also observed at 76-150 and 301-375 minutes/wk of MPA (18%-19% lower mortality, 3.20-3.42 gained years) or 151-300 minutes/wk of VPA (20%-26% lower mortality, 2.41-2.61 gained years). The associations between MPA, VPA, and mortality risk were slightly mediated by LTL (≈1% mediation proportion, both P < .001). CONCLUSIONS AND IMPLICATIONS: Our study suggests a more flexible range of PA than the current PA guidelines, which could gain similar benefits and is easier to achieve: 90 to 720 minutes/wk of walking, 75 to 375 minutes/wk of MPA, and 75 to 300 minutes/wk of VPA. Telomeres might be a potential mechanism by which PA promotes longevity.

Organic-inorganic composite of polypropylene fumarate and nanohydroxyapatite as carrier of antibiotics for the treatment of bone infections.

Current treatment approaches in clinics to treat the infectious lesions have partial success thus demanding the need for development of advanced treatment modalities. In this study we fabricated an organic-inorganic composite of polypropylene fumarate (PPF) and nanohydroxyapatite (nHAP) by photo-crosslinking as a carrier of two clinically used antibiotics, ciprofloxacin (CIP) and rifampicin (RFP) for the treatment of bone infections. Carboxy terminal-PPF was first synthesized by cis-trans isomerization of maleic anhydride which was then photo-crosslinked using diethylfumarate (DEF) as crosslinker and bis-acylphosphine oxide (BAPO) as photo-initiator under UV lights (P). A composite of PPF and nHAP was fabricated by incorporating 40 % of nHAP in the polymeric matrix of PPF (PH) which was then characterized for different physicochemical parameters. CIP was added along with nHAP to fabricated CIPloaded composite scaffolds (PHC) which was then coated with RFP to synthesize RFP coated CIP-loaded scaffolds (PHCR). It was observed that there was a temporal separation in the in vitro release of two antibiotics after coating PHC with RFP with 80.48 ± 0.40 % release of CIP from PHC and 62.43 ± 0.21 % release of CIP from PHCR for a period of 60 days. Moreover, in vitro protein adsorption was also found to be maximum in PHCR (154.95 ± 0.07 µg/mL) as observed in PHC (75.42 ± 0.06 µg/mL), PH (24.47 ± 0.08 µg/mL) and P alone (4.47 ± 0.02 µg/mL). The scaffolds were also evaluated using in vivo infection model to assess their capacity in reducing the bacterial burden at the infection site. The outcome of this study suggests that RFP coated CIP-loaded PPF composite scaffolds could reduce bacterial burden and simultaneously augment bone healing during infection related fractures.

Advantages and Limitations of Diabetic Bone Healing in Mouse Models: A Narrative Review.

Diabetes represents a major risk factor for impaired fracture healing. Type 2 diabetes mellitus is a growing epidemic worldwide, hence an increase in diabetes-related complications in fracture healing can be expected. However, the underlying mechanisms are not yet completely understood. Different mouse models are used in preclinical trauma research for fracture healing under diabetic conditions. The present review elucidates and evaluates the characteristics of state-of-the-art murine diabetic fracture healing models. Three major categories of murine models were identified: Streptozotocin-induced diabetes models, diet-induced diabetes models, and transgenic diabetes models. They all have specific advantages and limitations and affect bone physiology and fracture healing differently. The studies differed widely in their diabetic and fracture healing models and the chosen models were evaluated and discussed, raising concerns in the comparability of the current literature. Researchers should be aware of the presented advantages and limitations when choosing a murine diabetes model. Given the rapid increase in type II diabetics worldwide, our review found that there are a lack of models that sufficiently mimic the development of type II diabetes in adult patients over the years. We suggest that a model with a high-fat diet that accounts for 60% of the daily calorie intake over a period of at least 12 weeks provides the most accurate representation.

Establishing the Callus-Based Isolation of Extracellular Vesicles from Cissus quadrangularis and Elucidating Their Role in Osteogenic Differentiation.

Extracellular vesicles (EVs) are nano-sized vehicles secreted by all live cells to establish communication with adjacent cells. In recent years, mammalian EVs (MEVs) have been widely investigated for their therapeutic implications in human disease conditions. As the understanding of MEV composition and nature is advancing, scientists are constantly exploring alternatives for EV production with similar therapeutic potential. Plant-derived exosome-like nanovesicles (PDEVs) may be a better substitute for MEVs because of their widespread sources, cost-effectiveness, and ease of access. Cissus quadrangularis (CQ), known as "bone setter or Hadjod", is a perennial plant utilized for its osteogenic potential. Its crude powder extract formulations are widely used as tablets and syrups. The present work elucidates the isolation of exosome-like nanovesicles (henceforth exosomes) from the culture supernatants of an in vitro cultured callus tissue derived from CQ. The physical and biological properties of the exosomes were successfully investigated using different characterization techniques. The therapeutic potential of the CQ exosomes was found to ameliorate the wound scratch injury and oxidative stress conditions in human-derived mesenchymal stem cells (hMSCs) and the pre-osteoblast (MC3T3) cell line. These exosomes also induced the proliferation and differentiation of hMSCs, as observed by alkaline phosphatase activity. These findings may serve as a proof of concept for further investigating the CQ exosomes as a nanocarrier for drug molecules in various therapeutic bone applications.

The Impact of Blue Light Irradiation on Keratinocytes in Vitro.

BACKGROUND: This study examined the effects of irradiation with blue light on HaCaT keratinocytes. As irradiation with blue light is known to be antimicrobial, it offers a promising alternative therapy for contaminated wounds. There is evidence that red light promotes wound healing, but the potential benefits of irradiation with blue light have not yet been adequately investigated. METHODS: The rate of wound closure in sterile and contaminated cells was measured using an in vitro scratch assay wound-healing model. Additionally, cell viability after treatment was determined using a Sulforhodamine B (SRB) assay. RESULTS: In both the sterile and contaminated groups, treated cells showed delayed wound closure when compared with cells not irradiated with blue light. Additionally, treatment with blue light resulted in poorer viability in the treatment groups. CONCLUSION: Although irradiation with blue light may offer a promising alternative therapy for reducing bacterial colonization, our data indicate that re-epithelization may be negatively influenced by blue light. Further research is needed to clarify possible wound healing applications.

NET Formation Was Reduced via Exposure to Extremely Low-Frequency Pulsed Electromagnetic Fields.

Fracture-healing is a highly complex and timely orchestrated process. Non-healing fractures are still a major clinical problem and treatment remains difficult. A 16 Hz extremely low-frequency pulsed electromagnetic field (ELF-PEMF) was identified as non-invasive adjunct therapy supporting bone-healing by inducing reactive oxygen species (ROS) and Ca2+-influx. However, ROS and Ca2+-influx may stimulate neutrophils, the first cells arriving at the wounded site, to excessively form neutrophil extracellular traps (NETs), which negatively affects the healing process. Thus, this study aimed to evaluate the effect of this 16 Hz ELF-PEMF on NET formation. Neutrophils were isolated from healthy volunteers and exposed to different NET-stimuli and the 16 Hz ELF-PEMF. NETs were quantified using Sytox Green Assay and immunofluorescence, Ca2+-influx and ROS with fluorescence probes. In contrast to mesenchymal cells, ELF-PEMF exposure did not induce ROS and Ca2+-influx in neutrophils. ELF-PEMF exposure did not result in basal or enhanced PMA-induced NET formation but did reduce the amount of DNA released. Similarly, NET formation induced by LPS and H2O2 was reduced through exposure to ELF-PEMF. As ELF-PEMF exposure did not induce NET release or negatively affect neutrophils, the ELF-PEMF exposure can be started immediately after fracture treatment.

A Shadow of Knowledge in Stem Cell Science.

"Theory of Forms" implies that a genuine version of creatures exists beyond the shapes in this world. Stem cell
technology has adopted developmental cues to mimic real life. However, the functionality of the lab-made cells is far
from primary ones. Perhaps it is time to switch from analytical to systematic perspective in stem cell science. This
may be the way to define new horizons based on the systematic perspective and convergence of science in stem cell
biology, bridging the current gap between the shadows of real knowledge in current research and reality in future.

Increased Levels of BAMBI Inhibit Canonical TGF-ß Signaling in Chronic Wound Tissues.

Chronic wounds affect more than 2% of the population worldwide, with a significant burden on affected individuals, healthcare systems, and societies. A key regulator of the entire wound healing cascade is transforming growth factor beta (TGF-ß), which regulates not only inflammation and extracellular matrix formation but also revascularization. This present work aimed at characterizing wound tissues obtained from acute and chronic wounds regarding angiogenesis, inflammation, as well as ECM formation and degradation, to identify common disturbances in the healing process. Serum and wound tissues from 38 patients (N = 20 acute and N = 18 chronic wounds) were analyzed. The patients' sera suggested a shift from VEGF/VEGFR to ANGPT/TIE2 signaling in the chronic wounds. However, this shift was not confirmed in the wound tissues. Instead, the chronic wound tissues showed increased levels of MMP9, a known activator of TGF-ß. However, regulation of TGF-ß target genes, such as CTGF, COL1A1, or IL-6, was absent in the chronic wounds. In wound tissues, all three TGF-ß isoforms were expressed with increased levels of TGF-ß1 and TGF-ß3 and a reporter assay confirmed that the expressed TGF-ß was activated. However, Western blots and immunostaining showed decreased canonical TGF-ß signaling in the respective chronic wound tissues, suggesting the presence of a TGF-ß inhibitor. As a potential regulatory mechanism, the TGF-ß proteome profiler array suggested elevated levels of the TGF-ß pseudo-receptor BAMBI. Also, tissue expression of BAMBI was significantly increased not only in chronic wounds (10.6-fold) but also in acute wounds that had become chronic (9.5-fold). In summary, our data indicate a possible regulatory role of BAMBI in the development of chronic wounds. The available few in vivo studies support our findings by postulating a therapeutic potential of BAMBI for controlling scar formation.

Insulin Can Delay Neutrophil Extracellular Trap Formation In Vitro-Implication for Diabetic Wound Care?

Diabetes is a worldwide evolving disease with many associated complications, one of which is delayed or impaired wound healing. Appropriate wound healing strongly relies on the inflammatory reaction directly after injury, which is often altered in diabetic wound healing. After an injury, neutrophils are the first cells to enter the wound site. They have a special defense mechanism, neutrophil extracellular traps (NETs), consisting of released DNA coated with antimicrobial proteins and histones. Despite being a powerful weapon against pathogens, NETs were shown to contribute to impaired wound healing in diabetic mice and are associated with amputations in diabetic foot ulcer patients. The anti-diabetic drugs metformin and liraglutide have already been shown to regulate NET formation. In this study, the effect of insulin was investigated. NET formation after stimulation with PMA (phorbol myristate acetate), LPS (lipopolysaccharide), or calcium ionophore (CI) in the presence/absence of insulin was analyzed. Insulin led to a robust delay of LPS- and PMA-induced NET formation but had no effect on CI-induced NET formation. Mechanistically, insulin induced reactive oxygen species, phosphorylated p38, and ERK, but reduced citrullination of histone H3. Instead, bacterial killing was induced. Insulin might therefore be a new tool for the regulation of NET formation during diabetic wound healing, either in a systemic or topical application.

Herbal Extracts of Ginseng and Maqui Berry Show Only Minimal Effects on an In Vitro Model of Early Fracture Repair of Smokers.

Smoking is a major risk factor for delayed fracture healing, affecting several aspects of early fracture repair, including inflammation, osteogenesis, and angiogenesis. Panax ginseng (GE) and maqui berry extract (MBE) were shown in our previous studies to reduce smoke-induced cellular damage in late bone-healing in vitro models. We aimed here to analyze their effects on the early fracture repair of smokers in a 3D co-culture model of fracture hematomas and endothelial cells. Both extracts did not alter the cellular viability at concentrations of up to 100 µg/mL. In early fracture repair in vitro, they were unable to reduce smoking-induced inflammation and induce osteo- or chondrogenicity. Regarding angiogenesis, smoking-induced stress in HUVECs could not be counteracted by both extracts. Furthermore, smoking-impaired tube formation was not restored by GE but was harmed by MBE. However, GE promoted angiogenesis initiation under smoking conditions via the Angpt/Tie2 axis. To summarize, cigarette smoking strikingly affected early fracture healing processes in vitro, but herbal extracts at the applied doses had only a limited effect. Since both extracts were shown before to be very effective in later stages of fracture healing, our data suggest that their early use immediately after fracture does not appear to negatively impact later beneficial effects.

Human milk extracellular vesicles enhance muscle growth and physical performance of immature mice associating with Akt/mTOR/p70s6k signaling pathway.

Extracellular vesicles (EVs) play an important role in human and bovine milk composition. According to excellent published studies, it also exerts various functions in the gut, bone, or immune system. However, the effects of milk-derived EVs on skeletal muscle growth and performance have yet to be fully explored. Firstly, the current study examined the amino acids profile in human milk EVs (HME) and bovine milk EVs (BME) using targeted metabolomics. Secondly, HME and BME were injected in the quadriceps of mice for four weeks (1 time/3 days). Then, related muscle performance, muscle growth markers/pathways, and amino acids profile were detected or measured by grip strength analysis, rotarod performance testing, Jenner-Giemsa/H&E staining, Western blotting, and targeted metabolomics, respectively. Finally, HME and BME were co-cultured with C2C12 cells to detect the above-related indexes and further testify relative phenomena. Our findings mainly demonstrated that HME and BME significantly increase the diameter of C2C12 myotubes. HME treatment demonstrates higher exercise performance and muscle fiber densities than BME treatment. Besides, after KEGG and correlation analyses with biological function after HME and BME treatment, results showed L-Ornithine acts as a "notable marker" after HME treatment to affect mouse skeletal muscle growth or functions. Otherwise, L-Ornithine also significantly positively correlates with the activation of the AKT/mTOR pathway and myogenic regulatory factors (MRFs) and can also be observed in muscle and C2C12 cells after HME treatment. Overall, our study not only provides a novel result for the amino acid composition of HME and BME, but the current study also indicates the advantage of human milk on skeletal muscle growth and performance.

The new European Medical Device Regulation: Friend or foe for hospitals and patients?

The new EU Medical Device Regulation (MDR) was introduced in 2017 to increase the safety and quality of medical devices in the European Union. Theoretically, several hundred thousand medical devices must be approved under the new MDR guidelines, although the majority of these products have been and will be in daily use in countless operations on the European market for decades. The expected expenditure of time and money until the MDR is fully implemented is associated with high costs, patient disadvantages but also manufacturer problems. The following briefly summarizes the current situation in many European countries and presents the consequences for patients and hospitals and in this context also emphasizes the interdependence between hospitals, patients and manufacturers.

Diclofenac, a NSAID, delays fracture healing in aged mice.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, belong to the most prescribed analgesic medication after traumatic injuries. However, there is accumulating evidence that NSAIDs impair fracture healing. Because bone regeneration in aged patients is subject to significant changes in cell differentiation and proliferation as well as a markedly altered pharmacological action of drugs, we herein analyzed the effects of diclofenac on bone healing in aged mice using a stable closed femoral facture model. Thirty-three mice (male n = 14, female n = 19) received a daily intraperitoneal injection of diclofenac (5 mg/kg body weight). Vehicle-treated mice (n = 29; male n = 13, female n = 16) served as controls. Fractured mice femora were analyzed by means of X-ray, biomechanics, micro computed tomography (µCT), histology and Western blotting. Biomechanical analyses revealed a significantly reduced bending stiffness in diclofenac-treated animals at 5 weeks after fracture when compared to vehicle-treated controls. Moreover, the callus tissue in diclofenac-treated aged animals exhibited a significantly reduced amount of bone tissue and higher amounts of fibrous tissue. Further histological analyses demonstrated less lamellar bone after diclofenac treatment, indicating a delay in callus remodeling. This was associated with a decreased number of osteoclasts and an increased expression of osteoprotegerin (OPG) during the early phase of fracture healing. These findings indicate that diclofenac delays fracture healing in aged mice by affecting osteogenic growth factor expression and bone formation as well as osteoclast activity and callus remodeling.

Bone Marrow Mesenchymal Stem-Cell-Derived Exosomes Ameliorate Deoxynivalenol-Induced Mice Liver Damage.

Deoxynivalenol (DON) is a kind of Fusarium toxin that can cause a variety of toxic effects. DON is mainly metabolized and detoxified by the liver. When the concentration of DON exceeds the metabolic capacity of the liver, it will trigger acute or chronic damage to the liver tissue. Previous studies demonstrated that bone marrow mesenchymal stem-cell-secreted exosomes (BMSC-exos) reduce liver injury. Therefore, we issue a hypothesis that in vitro-cultured rat BMSC-secreted exos could ameliorate liver damage after 2 mg/kg bw/day of DON exposure. In total, 144 lipids were identified in BMEC-exos, including high polyunsaturated fatty acid (PUFA) levels. BMSC-exos treatment alleviated liver pathological changes and decreased levels of alanine aminotransferase, aspartate aminotransferase, inflammatory factors interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and lipid peroxidation. Otherwise, low or high BMSC-exos treatment obviously changes DON-induced hepatic oxylipin patterns. According to the results from our correlation network analysis, Pearson correlation coefficient analysis, and hierarchical clustering analysis, the top 10% oxidized lipids can be classified into two categories: one that was positively correlated with copper-zinc superoxide dismutase (Cu/Zn SOD) and another that was positively correlated with liver injury indicators. Altogether, BMSC-exos administration maintained normal liver function and reduced oxidative damage in liver tissue. Moreover, it could also significantly change the oxylipin profiles under DON conditions.

Intermittent Exposure to a 16 Hz Extremely Low Frequency Pulsed Electromagnetic Field Promotes Osteogenesis In Vitro through Activating Piezo 1-Induced Ca2+ Influx in Osteoprogenitor Cells.

Exposure to extremely low frequency pulsed electromagnetic fields (ELF-PEMF) is supposed to simulate local EMF generated during mechanical stimulation of bone and may therefore be used to improve bone regeneration. This study aimed at optimizing the exposure strategy and investigating the underlying mechanisms of a 16 Hz ELF-PEMF, previously reported to boost osteoblast function. Comparing influences of daily continuous (30 min every 24 h) and intermittent (10 min every 8 h) exposure to the 16 Hz ELF-PEMF on osteoprogenitor cells revealed that the intermittent exposure strategy enhanced the 16 Hz ELF-PEMF effects regarding cell numbers and osteogenic function. Gene expression of piezo 1 and related Ca2+ influx were significantly increased in SCP-1 cells with the daily intermittent exposure. Pharmacological inhibition of piezo 1 with Dooku 1 largely abolished the positive effect of the 16 Hz ELF-PEMF exposure on osteogenic maturation of SCP-1 cells. In summary, the intermittent exposure strategy enhanced the positive effects of 16 Hz continuous ELF-PEMF exposure in terms of cell viability and osteogenesis. This effect was shown to be mediated by an increased expression of piezo 1 and related Ca2+ influx. Thus, the intermittent exposure strategy is a promising way to further optimize the therapeutic effects of the 16 Hz ELF-PEMF regarding fracture healing or osteoporosis.