Biomechanical analysis of adjacent segments after correction surgery for adult idiopathic scoliosis: a finite element analysis.

The biomechanical aspects of adjacent segment degeneration after Adult Idiopathic Scoliosis (AdIS) corrective surgery involving postoperative changes in motion and stress of adjacent segments have yet to be investigated. The objective of this study was to evaluate the biomechanical effects of corrective surgery on adjacent segments in adult idiopathic scoliosis by finite element analysis. Based on computed tomography data of the consecutive spine from T1-S1 of a 28-year-old male patient with adult idiopathic scoliosis, a three-dimensional finite element model was established to simulate the biomechanics. Two posterior long-segment fixation and fusion operations were designed: Strategy A, pedicle screws implanted in all segments of both sides, and Strategy B, alternate screws instrumentation on both sides. The range of motion (ROM), Maximum von Mises stress value of intervertebral disc (IVD), and Maximum von Mises stress of the facet joint (FJ) at the fixation adjacent segment were calculated and compared with data of the preoperative AdIS model. Corrective surgery decreased the IVD on the adjacent segments, increased the FJ on the adjacent segments, and decreased the ROM of the adjacent segments. A greater decrease of Maximum von Mises stress was observed on the distal adjacent segment compared with the proximal adjacent segment. The decrease of Maximum von Mises stress and increment of Maximum von Mises stress on adjacent FJ in strategy B was greater than that in strategy A. Under the six operation modes, the change of the Maximum von Mises stress on the adjacent IVD and FJ was significant. The decrease in ROM in the proximal adjacent segment was greater than that of the distal adjacent segment, and the decrease of ROM in strategy A was greater than that in strategy B. This study clarified the biomechanical characteristics of adjacent segments after AdIS corrective surgery, and further biomechanical analysis of two different posterior pedicle screw placement schemes by finite element method. Our study provides a theoretical basis for the pathogenesis, prevention, and treatment of adjacent segment degeneration after corrective surgery for AdIS.

Mechanistic computational modeling of monospecific and bispecific antibodies targeting interleukin-6/8 receptors.

The spread of cancer from organ to organ (metastasis) is responsible for the vast majority of cancer deaths; however, most current anti-cancer drugs are designed to arrest or reverse tumor growth without directly addressing disease spread. It was recently discovered that tumor cell-secreted interleukin-6 (IL-6) and interleukin-8 (IL-8) synergize to enhance cancer metastasis in a cell-density dependent manner, and blockade of the IL-6 and IL-8 receptors (IL-6R and IL-8R) with a novel bispecific antibody, BS1, significantly reduced metastatic burden in multiple preclinical mouse models of cancer. Bispecific antibodies (BsAbs), which combine two different antigen-binding sites into one molecule, are a promising modality for drug development due to their enhanced avidity and dual targeting effects. However, while BsAbs have tremendous therapeutic potential, elucidating the mechanisms underlying their binding and inhibition will be critical for maximizing the efficacy of new BsAb treatments. Here, we describe a quantitative, computational model of the BS1 BsAb, exhibiting how modeling multivalent binding provides key insights into antibody affinity and avidity effects and can guide therapeutic design. We present detailed simulations of the monovalent and bivalent binding interactions between different antibody constructs and the IL-6 and IL-8 receptors to establish how antibody properties and system conditions impact the formation of binary (antibody-receptor) and ternary (receptor-antibody-receptor) complexes. Model results demonstrate how the balance of these complex types drives receptor inhibition, providing important and generalizable predictions for effective therapeutic design.

Lumbar instability remodels cartilage endplate to induce intervertebral disc degeneration by recruiting osteoclasts via Hippo-CCL3 signaling.

Degenerated endplate appears with cheese-like morphology and sensory innervation, contributing to low back pain and subsequently inducing intervertebral disc degeneration in the aged population.1 However, the origin and development mechanism of the cheese-like morphology remain unclear. Here in this study, we report lumbar instability induced cartilage endplate remodeling is responsible for this pathological change. Transcriptome sequencing of the endplate chondrocytes under abnormal stress revealed that the Hippo signaling was key for this process. Activation of Hippo signaling or knockout of the key gene Yap1 in the cartilage endplate severed the cheese-like morphological change and disc degeneration after lumbar spine instability (LSI) surgery, while blocking the Hippo signaling reversed this process. Meanwhile, transcriptome sequencing data also showed osteoclast differentiation related gene set expression was up regulated in the endplate chondrocytes under abnormal mechanical stress, which was activated after the Hippo signaling. Among the discovered osteoclast differentiation gene set, CCL3 was found to be largely released from the chondrocytes under abnormal stress, which functioned to recruit and promote osteoclasts formation for cartilage endplate remodeling. Over-expression of Yap1 inhibited CCL3 transcription by blocking its promoter, which then reversed the endplate from remodeling to the cheese-like morphology. Finally, LSI-induced cartilage endplate remodeling was successfully rescued by local injection of an AAV5 wrapped Yap1 over-expression plasmid at the site. These findings suggest that the Hippo signaling induced osteoclast gene set activation in the cartilage endplate is a potential new target for the management of instability induced low back pain and lumbar degeneration.

The Relationship Between MRI Findings of Posterior Ligamentous Complex and Lumbar Instability in Degenerative Spondylolisthesis.

Background: To determine the factors in posterior ligamentous complex indicating lumbar instability in patients diagnosed with degenerative spondylolisthesis on conventional magnetic resonance imaging (MRI). Methods: We retrospectively analyzed patients who underwent PLIF surgery for degenerative spondylolisthesis at our institution between 2018 and 2020 and who had complete eligible preoperative imaging data for review and study, including lumbar MRI and anteroposterior and flexion-extension radiographs. Results: Fifty-three patients were confirmed to have lumbar instability (Unstable Group, 44%), while sixty-seven patients (Stable Group, 56%) did not have instability on radiographs. The patients in the stable group had more advanced status of the degeneration of intervertebral disc than in the unstable group (p<0.05). The degeneration of supraspinous ligament (SSL) was more severe in the unstable group (p<0.05). Compared with the patients with rotatory instability, advanced degeneration of interspinous ligament (ISL) and SSL was observed in patients with translatory instability (p<0.05). However, there was no significant difference with regard to the height of the spinous process and the interspinous distance in patients with or without instability. Conclusion: This MRI analysis showed that abnormal segmental motion is closely associated with the pathological characteristics of supraspinal ligament. Advanced degeneration of SSL in patients with degenerative spondylolisthesis should raise the suspicion for lumbar instability and additional evaluations. The status of ISL and ligamentum flavum (LF) may not be helpful for the diagnosis of lumbar instability. Functional radiographs combined with MRI may provide valuable information when diagnosing lumbar instability in patients with mechanical back pain.

Arachidonic acid in aging: New roles for old players.

BACKGROUND: Arachidonic acid (AA), one of the most ubiquitous polyunsaturated fatty acids (PUFAs), provides fluidity to mammalian cell membranes. It is derived from linoleic acid (LA) and can be transformed into various bioactive metabolites, including prostaglandins (PGs), thromboxanes (TXs), lipoxins (LXs), hydroxy-eicosatetraenoic acids (HETEs), leukotrienes (LTs), and epoxyeicosatrienoic acids (EETs), by different pathways. All these processes are involved in AA metabolism. Currently, in the context of an increasingly visible aging world population, several scholars have revealed the essential role of AA metabolism in osteoporosis, chronic obstructive pulmonary disease, and many other aging diseases. AIM OF REVIEW: Although there are some reviews describing the role of AA in some specific diseases, there seems to be no or little information on the role of AA metabolism in aging tissues or organs. This review scrutinizes and highlights the role of AA metabolism in aging and provides a new idea for strategies for treating aging-related diseases. KEY SCIENTIFIC CONCEPTS OF REVIEW: As a member of lipid metabolism, AA metabolism regulates the important lipids that interfere with the aging in several ways. We present a comprehensivereviewofthe role ofAA metabolism in aging, with the aim of relieving the extreme suffering of families and the heavy economic burden on society caused by age-related diseases. We also collected and summarized data on anti-aging therapies associated with AA metabolism, with the expectation of identifying a novel and efficient way to protect against aging.

Heat stress-induced NO enhanced perylenequinone biosynthesis of Shiraia sp. via calcium signaling pathway.

Perylenequinones (PQs) are natural photosensitizing compounds used as photodynamic therapy, and heat stress (HS) is the main limiting factor of mycelial growth and secondary metabolism of fungi. This study aimed to unravel the impact of HS-induced Ca2+ and the calcium signaling pathway on PQ biosynthesis of Shiraia sp. Slf14(w). Meanwhile, the intricate interplay between HS-induced NO and Ca2+ and the calcium signaling pathway was investigated. The outcomes disclosed that Ca2+ and the calcium signaling pathway activated by HS could effectively enhance the production of PQs in Shiraia sp. Slf14(w). Further investigations elucidated the specific mechanism through which NO signaling molecules induced by HS act upon the Ca2+/CaM (calmodulin) signaling pathway, thus propelling PQ biosynthesis in Shiraia sp. Slf14(w). This was substantiated by decoding the downstream positioning of the CaM/CaN (calcineurin) pathway in relation to NO through comprehensive analyses encompassing transcript levels, enzyme assays, and the introduction of chemical agents. Concurrently, the engagement of Ca2+ and the calcium signaling pathway in heat shock signaling was also evidenced. The implications of our study underscore the pivotal role of HS-induced Ca2+ and the calcium signaling pathway, which not only participate in heat shock signal transduction but also play an instrumental role in promoting PQ biosynthesis. Consequently, our study not only enriches our comprehension of the mechanisms driving HS signaling transduction in fungi but also offers novel insights into the PQ synthesis paradigm within Shiraia sp. Slf14(w). KEY POINTS: • The calcium signaling pathway was proposed to participate in PQ biosynthesis under HS. • HS-induced NO was revealed to act upon the calcium signaling pathway for the first time.

Critical bloodstream infection caused by Chromobacterium violaceum: a case report in a 15-year-old male with sepsis-induced cardiogenic shock and purpura fulminans.

Chromobacterium violaceum (C. violaceum) is a gram-negative bacillus that is widespread in tropical and subtropical areas. Although C. violaceum rarely infects humans, it can cause critical illness with a mortality rate above 50%. Here, we report the successful treatment of a 15-year-old male who presented with bloodstream infection of C. violaceum along with sepsis, specific skin lesions, and liver abscesses. Cardiogenic shock induced by sepsis was reversed by venoarterial extracorporeal membrane oxygenation (VA ECMO). Moreover, C. violaceum-related purpura fulminans, which is reported herein for the first time, was ameliorated after treatment. This case report demonstrates the virulence of C. violaceum with the aim of raising clinical awareness of this disease.

Percutaneous kyphoplasty with or without posterior pedicle screw fixation for the management of severe osteoporotic vertebral compression fractures with nonunion.

OBJECTIVE: To assess the radiographic outcomes, clinical outcomes and complications of percutaneous kyphoplasty (PKP) with and without posterior pedicle screw fixation (PPSF) in the treatment of severe osteoporotic vertebral compression fractures (sOVCF) with nonunion. METHODS: This study involved 51 patients with sOVCF with nonunion who underwent PKP or PPSF + KP. The operation time, intraoperative blood loss, volume of injected bone cement, operation costs and hospital stays were all recorded. In addition, the Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI) were assessed separately for each patient before and after surgery. RESULTS: Compared with the PPSF + KP group, the PKP group had shorter operation time, less intraoperative blood loss, shorter hospital stays and fewer operation costs. However, cobb's angle improvement (13.4 ± 4.3° vs. 21.4 ± 5.3°), VWR improvement ratio (30.4 ± 11.5% vs. 52.8 ± 12.7%), HA (34.9 ± 9.0% vs. 63.7 ± 7.6%) and HM (28.4 ± 11.2% vs. 49.6 ± 7.7%) improvement ratio were all higher in PPSF + KP group than that in PKP group. In addition, the ODI index and VAS score in both groups were significantly decreased at the postoperative and final follow-up. PKP group's postoperative VAS score was significantly lower than that in PPSF + KP group, but there was no statistically significant difference in VAS score at the last follow-up. CONCLUSION: PKP and PPSF + KP can both effectively relieve the pain associated with sOVCF with nonunion. PPSF + KP can achieve more satisfactory vertebral reduction effects compared to PKP. However, PKP was less invasive and it has more advantages in shortening operation time and hospital stay, as well as decreasing intraoperative blood loss and operation costs.

Reactive Oxygen Species Induced Upregulation of TRPV1 in Dorsal Root Ganglia Results in Low Back Pain in Rats.

Background: Dorsal root ganglia (DRGs) contain sensory neurons that innervate intervertebral discs (IVDs) and may play a critical role in mediating low-back pain (LBP), but the potential pathophysiological mechanism needs to be clarified. Methods: A discogenic LBP model in rats was established by penetration of a lumbar IVD. The severity of LBP was evaluated through behavioral analysis, and the gene and protein expression levels of pro-algesic peptide substance P (SP) and calcitonin gene-related peptide (CGRP) in DRGs were quantified. The level of reactive oxygen species (ROS) in bilateral lumbar DRGs was also quantified using dihydroethidium staining. Subsequently, hydrogen peroxide solution or N-acetyl-L-cysteine was injected into DRGs to evaluate the change in LBP, and gene and protein expression levels of transient receptor potential vanilloid-1 (TRPV1) in DRGs were analyzed. Finally, an inhibitor or activator of TRPV1 was injected into DRGs to observe the change in LBP. Results: The rats had remarkable LBP after disc puncture, manifesting as mechanical and cold allodynia and increased expression of the pro-algesic peptides SP and CGRP in DRGs. Furthermore, there was significant overexpression of ROS in bilateral lumbar DRGs, while manipulation of the level of ROS in DRGs attenuated or aggravated LBP in rats. In addition, excessive ROS in DRGs stimulated upregulation of TRPV1 in DRGs. Finally, activation or inhibition of TRPV1 in DRGs resulted in a significant increase or decrease of discogenic LBP, respectively, suggesting that ROS-induced TRPV1 has a strong correlation with discogenic LBP. Conclusion: Increased ROS in DRGs play a primary pathological role in puncture-induced discogenic LBP, and excessive ROS-induced upregulation of TRPV1 in DRGs may be the underlying pathophysiological mechanism to cause nerve sensitization and discogenic LBP. Therapeutic targeting of ROS or TRPV1 in DRGs may provide a promising method for the treatment of discogenic LBP.

Lumbar lordosis and sacral slope do not differ in two types of postoperative lumbar disc re-herniation: a cross-sectional observational study.

BACKGROUND: To identify the differences of lumbar lordosis (LL) and sacral slope (SS) angles between two types of postoperative lumbar disc re-herniation, including the recurrence of same level and adjacent segment herniation (ASH). METHODS: We searched the medical records of lumbar disc herniation (LDH) patients with re-herniation with complete imaging data (n = 58) from January 1, 2013 to December 30, 2020 in our hospital. After matching for age and sex, 58 patients with LDH without re-herniation from the same period operated by the same treatment group in our hospital were served as a control group. Re-herniation patients were divided into two groups, same-level recurrent lumbar disc herniation group (rLDHG) and adjacent segment herniation group with or without recurrence (ASHG). The preoperative, postoperative and one month after operation LL and SS were measured on standing radiographs and compared with the control group by using t-test, ANOVA, and rank-sum test. Next, we calculated the odds ratios (ORs) by unconditional logistic regression, progressively adjusted for other confounding factors. RESULTS: Compared with the control group, the postoperative LL and SS were significantly lower in LDH patients with re-herniation. However, there were no differences in LL and SS between ASHG and rLDHG at any stage. After progressive adjustment for confounding factors, no matter what stage is, LL and SS remained unassociated with the two types of re-herniation. CONCLUSIONS: Low postoperative LL and SS angles are associated with degeneration of the remaining disc. Low LL and SS may be independent risk factors for re-herniation but cannot determine type of recurrence (same or adjacent disc level).

N6-methyladenosine-modified circTEAD1 stabilizes Yap1 mRNA to promote chordoma tumorigenesis.

BACKGROUND: Chordoma, a rare bone tumour with aggressive local invasion and high recurrence rate with limited understanding of its molecular mechanisms. Circular RNAs (circRNAs) have been extensively implicated in tumorigenesis, yet their involvement in chordoma remains largely unexplored. N6-methyladenosine (m6A) modification holds a crucial function in regulating protein translation, RNA degradation and transcription. METHODS: Initially, screening and validation of circTEAD1 in chordoma were conducted by high-throughput sequencing. Subsequently, sh-circTEAD1 and an overexpression plasmid were constructed. Colony formation assays, cell counting kit-8, Transwell and wound healing assays were utilized to validate the function of circTEAD1 in vitro. RNA pull-down assays identified the binding proteins of circTEAD1, which underwent verification through RNA immunoprecipitation (RIP). Methylated RIP assays were conducted to detect the m6A binding sites. Following this, luciferase assay, RT-qPCR, RIP and Western blotting analyses were conducted, revealing that Yap1 was the direct target of circTEAD1. Afterwards, the same methods were utilized for the validation of the function of Yap1 in chordoma in vitro. Finally, the regulatory relationship between circTEAD1 and Yap1 in chordoma was verified by an in vivo tumour formation assay. RESULTS: CircTEAD1 was identified as an upregulated circRNA in chordoma specimens, with heightened circTEAD1 expression emerging as a prognostic indicator. In vitro experiments convincingly demonstrated that circTEAD1 significantly promoted chordoma cell invasion, migration and aggressiveness. Furthermore, the analysis revealed that methyltransferase-like 3-mediated m6A modification facilitated the cytoplasmic export of circTEAD1. The circTEAD1/IGF2BP3/Yap1 mRNA RNA-protein ternary complex not only bolstered the stability of Yap1 mRNA but also exerted a pivotal role in driving chordoma tumorigenesis. CONCLUSIONS: In this study, the role of m6A-modified circTEAD1 in chordoma was identified. The findings offer novel insights into the potential molecular targets for chordoma therapy, shedding light on the intricate interplay between circRNAs, m6A modification and Yap1 mRNA in chordoma pathogenesis.

Intra-Articular Injection of PLGA/Polydopamine Core-Shell Nanoparticle Attenuates Osteoarthritis Progression.

Osteoarthritis (OA) is a common joint disease characterized by progressive cartilage degeneration. Unfortunately, currently available clinical drugs are mainly analgesics and cannot alleviate the development of OA. Kartogenin (KGN) has been found to promote the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocytes for the treatment of cartilage damage in early OA. However, KGN, as a small hydrophobic molecule, is rapidly cleared from the synovial fluid after intra-articular injection. This study synthesized a KGN-loaded nanocarrier based on PLGA/polydopamine core/shell structure to treat OA. The fluorescence signal of KGN@PLGA/PDA-PEG-E7 nanoparticles lasted for 4 weeks, ensuring long-term sustained release of KGN from a single intra-articular injection. In addition, the polyphenolic structure of PDA enables it to effectively scavenge reactive oxygen species, and the BMSC-targeting peptide E7 (EPLQLKM) endows KGN@PLGA/PDA-PEG-E7 NPs with an effective affinity for BMSCs. As a result, the KGN@PLGA/PDA-PEG-E7 nanoparticles could effectively induce cartilage in vitro and protect the cartilage and subchondral bone in a rat ACLT model. This therapeutic strategy could also be extended to the delivery of other drugs, targeting other tissues to treat joint diseases.

Persistent Colonization of Ciprofloxacin-Resistant and Extended-Spectrum ß-Lactamase (ESBL)-Producing Salmonella enterica Serovar Kentucky ST198 in a Patient with Inflammatory Bowel Disease.

Objective: Salmonella enterica serovar Kentucky ST198 has emerged as a global threat to humans. In this study, we aimed to characterize the prolonged carriage of ciprofloxacin-resistant and extended-spectrum ß-lactamase (ESBL)-producing S. Kentucky ST198 in a single patient with inflammatory bowel disease (IBD). Methods: Three S. Kentucky strains were collected from a single patient with IBD on 11th January, 23rd January, and 8th February, 2022, respectively. Antimicrobial susceptibility testing, whole-genome sequencing, and phylogenetic analysis with 38 previously described Chinese S. Kentucky ST198 strains from patients and food were performed. Results: All three S. Kentucky isolates belonged to ST198. They carried identical 16 resistance genes, such as blaCTX-M-55, tet(A), and qnrS1, and had identical mutations within gyrA (S83F and D87N) and parC (S80I). Therefore, they exhibited identical multidrug-resistant profiles, including the clinically important antibiotics cephalosporins (ceftazidime and cefepime), fluoroquinolones (ciprofloxacin and levofloxacin), and third-generation tetracycline (tigecycline). Our three S. Kentucky strains were classified into the subclade ST198.2-2, and were genetically identical (2-6 SNPs) to each other. They exhibited a close genetic similarity (15-20 SNPs) to the isolate NT-h3189 from a patient and AH19MCS1 from chicken meat in China, indicating a possible epidemiological link between these S. Kentucky ST198 isolates from the patients and chicken meat. Conclusion: Long-term colonization of ciprofloxacin-resistant and ESBL-producing S. Kentucky ST198 in a single patient is a matter of concern. Due to the potential transfer of S. Kentucky ST198 from food sources to humans, ongoing surveillance of this particular clone in animals, animal-derived food products, and humans should be strengthened.

Sequential treatment of concomitant odontoid fracture and lower cervical fracture-dislocation: A case report.

INTRODUCTION AND IMPORTANCE: To report the sequential treatment of a Type II odontoid fracture combined with a severe lower cervical (C6-7) fracture-dislocation featuring bilateral facet joint interlocking. CASE PRESENTATION: A 58-year-old male who had suffered an injury in a car accident, He presented neck pain and extremity paralysis. His neurological function was classified as per the American Spinal Injury Association (ASIA) impairment scale as Grade A, indicating complete deficits below the C6 spinal cord level. A cervical CT scan and magnetic resonance image showed a type II odontoid fracture, C6 slipped anteriorly, C6-7 bilateral facet joint fracture and interlocking, slightly compression change of C7 upper endplate. CLINICAL DISCUSSION: Emergency closed reduction using cranial tong traction was success 6 h after the injury. A subsequent CT scan proved the successful reduction of bilateral facet joint dislocations and the odontoid fracture. After careful overall assessment, anterior cervical decompression and fusion (ACDF) was performed at C5-6 and C6-7 segments three days later，while odontoid fracture was treated conservatively. At the 4 months follow-up, a CT scan demonstrated solid bone fusion at C5-6, C6-7 segments, along with successful healing at the odontoid fracture site. However, spinal cord was necrosis at C5-7 segments, and the patient's neurological function had no improvement. CONCLUSION: The initial closed reduction could restore the alignment and preliminary stability of cervical spine at sub-axial cervical fracture-dislocation segment as well as displaced odontoid fracture. This timely and effective closed reduction significantly diminished sequential surgical trauma and mitigated associated risks.

Naodesheng decoction regulating vascular function via G-protein-coupled receptors: network analysis and experimental investigations.

Introduction: Ischemic stroke (IS) is a detrimental neurological disease with limited treatment options. Recanalization of blocked blood vessels and restoring blood supply to ischemic brain tissue are crucial for post-stroke rehabilitation. The decoction Naodesheng (NDS) composed of five Chinese botanical drugs, including Panax notoginseng (Burk.) F. H. Chen, Ligusticum chuanxiong Hort., Carthamus tinctorius L., Pueraria lobata (Willd.) Ohwi, and Crataegus pinnatifida Bge., is a blood-activating and stasis-removing herbal medicine commonly used for the clinical treatment of cerebrovascular diseases in China. However, the material basis of NDS on the effects of blood circulation improvement and vascular tone regulation remains unclear. Methods: A database comprising 777 chemical metabolites of NDS was constructed. Then, the interactions between various herbal metabolites of NDS and five vascular tone modulation G-protein-coupled receptors (GPCRs), including 5-HT1AR, 5-HT1BR, ß2-AR, AT1R, and ETBR, were assessed by molecular docking. Using network analysis and vasomotor experiment of the cerebral basilar artery, the potential material basis underlying the vascular regulatory effects of NDS was further explored. Results: The Naodesheng Effective Component Group (NECG) was found to induce relaxation of rat basilar artery rings precontracted using Endothelin-1 (ET-1) and KCl in vitro in a dose-dependent manner. Several metabolites of NDS, including C. tinctorius, C. pinnatifida, and P. notoginseng, were found to be the main plant resources of metabolites with high docking scores. Furthermore, several metabolites in NDS, including formononetin-7-glucoside, hydroxybenzoyl-coumaric anhydride, methoxymecambridine, puerarol, and pyrethrin II, were found to target multiple vascular GPCRs. Metabolites with moderate-to-high binding energy were verified to have good rat basilar artery-relaxing effects, and the maximum artery relaxation effects of all three metabolites, namely, isorhamnetin, kaempferol, and daidzein, were found to exceed 90%. Moreover, metabolites of NDS were found to exert a synergistic effect by interacting with vascular GPCR targets, and these metabolites may contribute to the cerebrovascular regulatory function of NDS. Discussion: The study reports that various metabolites of NDS contribute to its vascular tone regulating effects and demonstrates the multi-component and multi-target characteristics of NDS. Among them, metabolites with moderate-to-high binding scores in NDS may play an important role in regulating vascular function.

Pan-histone deacetylase inhibitor vorinostat suppresses osteoclastic bone resorption through modulation of RANKL-evoked signaling and ameliorates ovariectomy-induced bone loss.

BACKGROUND: Estrogen deficiency-mediated hyperactive osteoclast represents the leading role during the onset of postmenopausal osteoporosis. The activation of a series of signaling cascades triggered by RANKL-RANK interaction is crucial mechanism underlying osteoclastogenesis. Vorinostat (SAHA) is a broad-spectrum pan-histone deacetylase inhibitor (HDACi) and its effect on osteoporosis remains elusive. METHODS: The effects of SAHA on osteoclast maturation and bone resorptive activity were evaluated using in vitro osteoclastogenesis assay. To investigate the effect of SAHA on the osteoclast gene networks during osteoclast differentiation, we performed high-throughput transcriptome sequencing. Molecular docking and the assessment of RANKL-induced signaling cascades were conducted to confirm the underlying regulatory mechanism of SAHA on the action of RANKL-activated osteoclasts. Finally, we took advantage of a mouse model of estrogen-deficient osteoporosis to explore the clinical potential of SAHA. RESULTS: We showed here that SAHA suppressed RANKL-induced osteoclast differentiation concentration-dependently and disrupted osteoclastic bone resorption in vitro. Mechanistically, SAHA specifically bound to the predicted binding site of RANKL and blunt the interaction between RANKL and RANK. Then, by interfering with downstream NF-κB and MAPK signaling pathway activation, SAHA negatively regulated the activity of NFATc1, thus resulting in a significant reduction of osteoclast-specific gene transcripts and functional osteoclast-related protein expression. Moreover, we found a significant anti-osteoporotic role of SAHA in ovariectomized mice, which was probably realized through the inhibition of osteoclast formation and hyperactivation. CONCLUSION: These data reveal a high affinity between SAHA and RANKL, which results in blockade of RANKL-RANK interaction and thereby interferes with RANKL-induced signaling cascades and osteoclastic bone resorption, supporting a novel strategy for SAHA application as a promising therapeutic agent for osteoporosis.

Melatonin-encapsuled silk fibroin electrospun nanofibers promote vascularized bone regeneration through regulation of osteogenesis-angiogenesis coupling.

The repair of critical-sized bone defects poses a significant challenge due to the absence of periosteum, which plays a crucial role in coordinating the processes of osteogenesis and vascularization during bone healing. Herein, we hypothesized that melatonin-encapsuled silk Fibronin electrospun nanofibers (SF@MT) could provide intrinsic induction of both osteogenesis and angiogenesis, thereby promoting vascularized bone regeneration. The sustained release of melatonin from the SF@MT nanofibers resulted in favorable biocompatibility and superior osteogenic induction of bone marrow mesenchymal stem cells (BMMSCs). Interestingly, melatonin promoted the migration and tube formation of human umbilical vein endothelial cells (HUVECs) in a BMMSC-dependent manner, potentially through the upregulation of vascular endothelial growth factor (VEGFA) expression in SF@MT-cultured BMMSCs. SF@MT nanofibers enhanced the BMMSC-mediated angiogenesis by activating the PI3K/Akt signaling pathway. In vivo experiments indicated that the implantation of SF@MT nanofibers into rat critical-sized calvarial defects significantly enhances the production of bone matrix and the development of new blood vessels, leading to an accelerated process of vascularized bone regeneration. Consequently, the utilization of melatonin-encapsulated silk Fibronin electrospun nanofibers shows great promise as a potential solution for artificial periosteum, with the potential to regulate the coupling of osteogenesis and angiogenesis in critical-sized bone defect repair.

Microenvironment-responsive bilayer hydrogel microspheres with gelatin-shell for osteoarthritis treatment.

Osteoarthritis is a long-term degenerative condition of the joints that is characterized by the breakdown of cartilage and inflammation of the synovial membrane. The presence of an inflammatory microenvironment and the degradation of the extracellular matrix produced by chondrocytes leads to the aggravation of cartilage injury, hindering the treatment of osteoarthritis. A promising approach to address this issue is to apply a combined strategy that is sensitive to the specific conditions in osteoarthritic joints and possesses properties that can reduce inflammation and promote cartilage healing. Here, inspired by the structure of chocolate-covered peanuts, we developed an injectable, environment-responsive bilayer hydrogel microsphere using microfluidics technology. The microsphere applied chondroitin sulfate methacryloyl (ChsMA) as its core and was coated with a methacryloyl gelatin (GelMA) shell that was loaded with celecoxib (CLX) liposomes (ChsMA+CLX@Lipo@GelMA). CLX was released from the liposomes when the GelMA shell rapidly degraded in response to the osteoarthritic microenvironment and suppressed the generation of inflammatory agents, demonstrating a beneficial impact of the outer shell in reducing inflammation. While the inner methacryloyl microsphere core degraded, chondroitin sulfate was released to promote chondrocyte anabolism and facilitate cartilage repair. Thus, the synthesized bilayer hydrogel microspheres hold great potential for treating osteoarthritis.

An injectable hydrogel microsphere-integrated training court to inspire tumor-infiltrating T lymphocyte potential.

Although tumor-infiltrating T lymphocytes (TIL-Ts) play a crucial role in solid tumor immunotherapy, their clinical application has been limited because of the immunosuppressive microenvironment. Herein, we developed an injectable hydrogel microsphere-integrated training court (MS-ITC) to inspire the function of TIL-Ts and amplify TIL-Ts, through grafting with anti-CD3 and anti-CD28 antibodies and bovine serum albumin nanoparticles encapsulated with IL-7 and IL-15. MS-ITC provided the T-cell receptor and co-stimulatory signals required for TIL-Ts activation and IL-7/IL-15 signals for TIL-Ts expansion. Afterward, the MS-ITC was injected locally into the osteosarcoma tumor tissue in mice. MS-ITC suppressed the growth of primary osteosarcoma by more than 95 %, accompanied with primed and expanded TIL-Ts in the tumor tissues, compromising significantly increased CD8+ T and memory T cells, thereby enhancing the anti-tumor effect. Together, this work provides an injectable hydrogel microsphere-integrated training platform capable of inspiring TIL-Ts potential for a range of solid tumor immunotherapy.