Investigation of Metabolic and Inflammatory Disorder in the Aging FGF21 Knockout Mouse.

Aging is a physiological condition accomplished with persistent low-grade inflammation and metabolic disorders. FGF21 has been reported to act as a potent longevity determinant, involving inflammatory response and energy metabolism. In this study, we engineered aging FGF21 knockout mice of 36-40 weeks and observed that FGF21 deficiency manifests a spontaneous inflammatory response of lung and abnormal accumulation of lipids in liver. On one hand, inflamed state in lungs and increased circulating inflammatory cytokines were found in FGF21 knockout mice of 36-40 weeks. To evaluate the ability of FGF21 to suppress inflammation, a subsequent study found that FGF21 knockout aggravated LPS-induced pulmonary exudation and inflammatory infiltration in mice, while exogenous administration of FGF21 reversed these malignant phenotypes by enhancing microvascular endothelial junction. On the other hand, FGF21 knockout induces fatty liver in aging mice, characterized by excessive accumulation of triglycerides within hepatocytes. Further quantitative metabolomics and lipidomics analysis revealed perturbed metabolic profile in liver lacking FGF21, including disrupted glucose and lipids metabolism, glycerophospholipid metabolism, and amino acid metabolism. Taken together, this investigation reveals the protective role of FGF21 during aging by weakening the inflammatory response and balancing energy metabolism.

Peptide-Appended Nanosonosensitizers Targeting Tumor Glycolysis for Synergistic Sonodynamic-Immunometabolic Therapy of Spinal-Metastasized Tumors.

Despite recent advancements in cancer immunotherapy, challenges have yet to be surmounted to achieve two major goals of magnifying antitumor immunity and remodeling the immunosuppressive tumor microenvironment. Here, a nanosystem (ODM-R) that integrates oxygen-deficient molybdenum oxide (ODM) nanosonosensitizers and R7 peptides with tumor metabolism regulation effects is designed and fabricated for synergistic sonodynamic-immunometabolic therapy of spinal-metastasized tumors. The ODM generates reactive oxygen species upon ultrasound irradiation to implement sonodynamic therapy (SDT), inducing cancer cell apoptosis and immunogenic cell death. The R7 attached on ODM markedly inhibits the uptake of glucose and excretion of lactic acid in cancer cells by perturbing the glycolysis process. The combination of SDT and tumor glycolysis obstruction by ODM-R guarantees satisfactory efficacy in synergizing with PD-L1 antibody to eradicate spinal-metastasized tumors, achieving concurrent sonodynamic-triggered immune activation and immunosuppressive tumor microenvironment remodeling. This work provides a proof-of-concept of nanosonosensitizers for boosting cancer immunotherapy by SDT and tumor metabolic regulation.

MAT2A inhibits the ferroptosis in osteosarcoma progression regulated by miR-26b-5p.

Osteosarcoma (OS) is the most frequent primary malignant bone tumor. Ferroptosis, a form of regulated cell death, is a key tumor suppression mechanism. Although methionine adenosyltransferase II alpha (MAT2A) has been reported to inhibit several tumor cells, it is unclear whether inhibition of MAT2A in OS cells can reduce ferroptosis. CCK-8, flow cytometry, and Transwell assays were performed to evaluate cell viability, cell apoptosis/cycle, and cell migration, respectively. The levels of ferrous iron and glutathione (GSH) levels in cells were measured to evaluate the degree of cell ferroptosis. Western blot analysis was performed to detect protein levels of MAT2A, p-STAT3 (Ser727)/STAT3, and solute carrier family 7 member 11 (SLC7A11) in OS cells. MAT2A was significantly upregulated in OS specimens and high MAT2A expression was associated with a poorer prognosis in OS patients. shRNA targeting MAT2A significantly increased OS cell apoptosis, triggered cell cycle arrest in the G2 phase, and attenuated migration ability in vitro. MAT2A depletion dramatically inhibited tumor progression of OS in vivo. Overexpression of MAT2A rescued the tumor inhibition caused by miR-26b-5p. MAT2A knockdown promoted OS cell ferroptosis. miR-26b-5p/MAT2A regulates tumor malignant progression and OS cell ferroptosis by controlling p-STAT3 and SLC7A11 expressions. Taken together, our study displayed that miR-26b-5p/MAT2A triggers ferroptosis in OS cells by increasing intracellular ferrous iron levels and inhibiting the STAT3/SLC7A11 axis. Our results reveal a MAT2A-mediated ferroptosis defense mechanism used by OS cells and propose a potential ferroptosis-inducing strategy for the treatment of OS patients.

IRF2 Destabilizes Oncogenic KPNA2 to Modulate the Development of Osteosarcoma.

Osteosarcomas (OS) are the most common primary malignant bone tumor. Emerging evidence revealed that karyopherin alpha 2 (KPNA2) was strongly associated with the tumorigenesis and development of numerous human cancers. The aim of the present study was to investigate the expression pattern, biological functions, and underlying mechanism of KPNA2 in OS. Bioinformatics TFBIND online was applied to forecast transcription factor (TF) binding sites in the promoter region of KPNA2. The expression profile of KPNA2 in OS tissues were firstly assessed. CCK8, colony formation, wound healing, and Transwell assays were used to assess cell viability, proliferation, and migration in vitro, and in vivo experiments were performed to explore the effects of KPNA2 and interferon regulatory factor-2 (IRF2) on tumor growth. Furthermore, the correlation between IRF2 and KPNA2 was investigated using chromatin immunoprecipitation (ChIP), RT-qPCR, western blot, and dual-luciferase assays. KPNA2 was obviously upregulated, while IRF2 decreased significantly in OS tissues and cell lines, as well as negatively correlated with each other. KPNA2 removal remarkably suppressed OS cell growth, migration, invasion in vitro, and tumor growth in vivo, while IRF2 knockdown exerts an opposing effect. IRF2 binds to the KPNA2 promoter to modulate the malignant phenotypes of OS cells by regulating epithelial-to-mesenchymal transition (EMT). The present study demonstrated that KPNA2 performed the oncogenic function, possibly regulating tumor development through EMT. Importantly, it was confirmed that IRF2 serves as a potential upstream TF of KPNA2 involved in the regulation of EMT progress in OS.

Role of protein phosphatase 2A in kidney disease (Review).

Kidney disease affects millions of people worldwide and is a financial burden on the healthcare system. Protein phosphatase 2A (PP2A), which is involved in renal development and the function of ion-transport proteins, aquaporin-2 and podocytes, is likely to serve an important role in renal processes. PP2A is associated with the pathogenesis of a variety of different kidney diseases including podocyte injury, inflammation, tumors and chronic kidney disease. The current review aimed to discuss the structure and function of PP2A subunits in the context of kidney diseases. How dysregulation of PP2A in the kidneys causes podocyte death and the inactivation of PP2A in renal carcinoma tissues is discussed. Inhibition of PP2A activity prevents epithelial-mesenchymal transition and attenuates renal fibrosis, creating a favorable inflammatory microenvironment and promoting the initiation and progression of tumor pathogenesis. The current review also indicates that PP2A serves an important role in protection against renal inflammation. Understanding the detailed mechanisms of PP2A provides information that can be utilized in the design and application of novel therapeutics for the treatment and prevention of renal diseases.

Ultrasound-Guided Transplantation of Mesenchymal Stem Cells Improves Adriamycin Nephropathy in Rats Through the RIPK3/MLKL and TLR-4/NF-κB Signaling.

Bone marrow stromal cell (BMSC) treatment has been shown to be beneficial for Adriamycin nephropathy (ADR). However, the low transplantation rate is still the key factor that affects this strategy. This study is the first to investigate the efficacy and potential mechanism of ultrasound-guided transrenal arterial transfer of BMSCs for the treatment of ADR in rats. The ADR rat model was established by two injections of doxorubicin. In addition, the rats were randomly divided into four groups (10 rats per group): the normal group (no treatment), the medium control group (treated with medium), the Adriamycin group (treated with phosphate buffer), and the BMSC group (treated with BMSCs). After 4 weeks, the levels of serum creatinine (SCr), blood urea nitrogen (BUN), and urine albumin (ALb) were measured. In addition, pathological changes in kidney tissue were evaluated by pathological sectioning and electron microscopy. Western blotting was used to determine the levels of proteins in rat kidneys. Ultrasound-guided renal artery transplantation of BMSCs reduced the levels of SCr, BUN, and ALb and improved the pathological structure of rat kidneys compared with those in the Adriamycin group. This treatment inhibited renal cell necrosis by reducing the expression of receptor-interacting Serine/threonine Kinase 3 (RIPK3) and Mixed lineage kinase domain-like pseudokinase (MLKL) and inhibited renal inflammation and fibrosis by reducing the expression of Toll-Like receptor 4 (TLR4) and nuclear factor κB (NF-κB). Our study shows that ultrasound-guided transrenal artery transplantation of BMSCs can improve adriamycin-induced renal injury in rats by regulating the RIPK3/MLKL and TLR-4/NF-κB pathways and inhibiting renal necrosis, inflammation, and fibrosis.

Protective action of ultrasound-guided intraparenchymal transplantation of BMSCs in adriamycin nephropathy rats through the RIPK3/MLKL and NLRP3 pathways.

BACKGROUND: Bone marrow stromal cells (BMSCs) are an effective new strategy for the treatment of kidney diseases. At present, noninvasive and efficient transplantation approaches to homing BMSCs to the renal parenchyma is still a serious challenge. The aim of this study was to investigate the feasibility and potential mechanism of ultrasound-guided intraparenchymal transplantation of BMSCs for the treatment of adriamycin nephropathy (AN) in rats. MATERIALS AND METHODS: A rat AN model was induced by 2 injections of doxorubicin. The rats were randomly divided into 4 groups (n = 10 animals in each group) : normal group (N group, no treatment), control medium group (CM group, transplant medium 1.0 mL), adriamycin nephropathy group (ADR group, phosphate buffered saline 1.0 mL), or BMSCs group (BMSCs fluid 1.0 mL). Intraparenchymal injection was completed under ultrasound guidance. After 4 weeks of treatment, blood samples were collected for serum biochemical measurements and ELISAs. The kidneys were removed for histopathological examination, electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), and western blot analysis. RESULTS: No deaths occurred in any group after BMSCs transplantation through the renal parenchyma under ultrasound guidance. Compared with the N and CM groups, in the ADR group, blood serum creatinine (SCr), blood urea nitrogen (BUN) and urine albumin (ALb) were higher, glomerular and tubular dilatation was observed, the number of apoptotic cells was higher, and the protein levels of receptor-interacting protein kinase 3 (RIPK3)/mixed lineage kinase domain-like protein (MLKL) and nucleotide leukin-rich polypeptide 3 (NLRP3), key components of pathways in rat kidney, were significantly higher. Compared with those in the ADR group, the levels of SCr, BUN, ALb and serum proinflammatory cytokines in the BMSCs group were lower, the pathological structure of the kidney was improved, the number of apoptotic cells was lower, and the levels of RIPK3/MLKL and NLRP3 were significantly lower. CONCLUSION: Ultrasound-guided intraparenchymal transplantation of BMSCs regulated the RIPK3/MLKL and NLRP3 pathways in a minimally invasive and safe manner, thereby inhibiting renal necrosis and inflammation and playing a protective role in rat AN.

Peptide vaccine-conjugated mesoporous carriers synergize with immunogenic cell death and PD-L1 blockade for amplified immunotherapy of metastatic spinal.

The clinical treatment of metastatic spinal tumor remains a huge challenge owing to the intrinsic limitations of the existing methods. Programmed cell death protein 1 (PD1)/programmed cell death ligand 1 (PD-L1) pathway blockade has been explored as a promising immunotherapeutic strategy; however, their inhibition has a low response rate, leading to the minimal cytotoxic T cell infiltration. To ameliorate the immunosuppressive microenvironment of intractable tumor and further boost the efficacy of immunotherapy, we report an all-round mesoporous nanocarrier composed of an upconverting nanoparticle core and a large-pore mesoporous silica shell (UCMS) that is simultaneously loaded with photosensitizer molecules, the IDO-derived peptide vaccine AL-9, and PD-L1 inhibitor. The IDO-derived peptide can be recognized by the dendritic cells and presented to CD8+ cytotoxic T cells, thereby enhancing the immune response and promoting the killing of the IDO-expressed tumor cells. Meanwhile, the near-infrared (NIR) activated photodynamic therapy (PDT) could induce immunogenic cell death (ICD), which promotes the effector T-cell infiltration. By combining the PDT-elicited ICD, peptide vaccine and immune checkpoint blockade, the designed UCMS@Pep-aPDL1 successfully potentiated local and systemic antitumor immunity and reduced the progression of metastatic foci, demonstrating a synergistic strategy for cancer immunotherapy.

Rationally integrating peptide-induced targeting and multimodal therapies in a dual-shell theranostic platform for orthotopic metastatic spinal tumors.

Metastatic tumors present great challenges in diagnosis and treatment. Herein, a proof-of-concept theranostic nanoplatform composed of an Au nanoparticle core and a double-shell of metal-organic framework (MOF) and mesoporous silica (MS) is developed for combating spinal metastasis of lung cancer in an orthotopic model. Two drugs, Alpelisib (BYL719) as an inhibitor and cisplatin as a chemotherapeutic drug, are separately loaded into the double-shell with high loading content. A targeting peptide called dYNH and indocyanine green (ICG) are conjugated onto the outmost MS layer for specifically targeting metastatic tumor cells and enhancing photothermal effect. The resultant Au@MOF@MS-ICG -dYNH-PAA (AMMD) shows enhanced cellular uptake on tumor cells and accumulation at metastatic spinal tumors, as evidenced by fluorescent and photoacoustic imaging. Benefiting from this ultra-high affinity to tumor cells and the photothermal effect of ICG, the dual-drug-loaded AMMD (BCAMMD) modified with ICG exhibits superior therapeutic efficacy on spinal tumors. More importantly, bone destruction, which frequently occurs in bone-related tumors, is effectively suppressed by BYL719 in BCAMMD. Hence, by rationally integrating multiple functions, including excellent targeting ability, dual-drug loading, photothermal therapy, and photoacoustic imaging, the developed all-in-one theranostic nanoplatform provides a useful paradigm of employing nanomedicine to treat metastatic spinal tumors efficiently.

Metal-Tolerant Noncircular Orbit Design and Implementation on Robotic C-Arm Systems.

Metal artifacts are a major confounding factor for image quality in CT, especially in image-guided surgery scenarios where surgical tools and implants frequently occur in the field-of-view. Traditional metal artifact correction methods typically use algorithmic solutions to interpolate over the highly attenuated projection measurements where metal is present but cannot recover the missing information obstructed by the metal. In this work, we treat metal artifacts as a missing data problem and employ noncircular orbits to maximize data completeness in the presence of metal. We first implement a local data completeness metric based on Tuy's condition as the percentage of great circles sampled by a particular orbit and accounted for the presence of metal by discounting any rays that pass through metal. We then compute the metric over many locations and many possible metal locations to reflect data completeness for arbitrary metal placements within a volume of interest. We used this metric to evaluate the effectiveness of sinusoidal orbits of different magnitudes and frequencies in metal artifact reduction. We also evaluated noncircular orbits in two imaging systems for phantoms with different metal objects and metal arrangements. Among a circular, tilted circular, and a sinusoidal orbit of two cycles per rotation, the latter is shown to most effectively remove metal artifacts. The noncircular orbit not only reduce the extent of streaks, but allows better visualization of spatial frequencies that cannot be recovered by metal artifact correction algorithms. These results illustrate the potential of relatively simple noncircular orbits to be robust against metal implants which ordinarily present significant challenges in interventional imaging.

Bioabsorbable self-retaining PLA/nano-sized ß-TCP cervical spine interbody fusion cage in goat models: an in vivo study.

STUDY DESIGN: This is an experimental animal study. OBJECTIVE: The objective of this study was to compare an anterior cervical discectomy and interbody fusion of a novel polylactide/nano-sized ß-tricalcium phosphate (PLA/nß-TCP) bioabsorbable self-retaining cervical fusion cage (BCFC) with an autologous bone graft and polyetheretherketone (PEEK) cages. BACKGROUND: Although PLA cervical cages have potential advantages compared with traditional materials, they are not currently routinely used in spine surgery because of undesirable effects such as the lack of osteoconductivity and osteolysis around the implant. This study involved the manufacturing of a bioabsorbable cage from PLA/nß-TCP that was then used as a device for anterior cervical discectomy and fusion (ACDF) on a goat cervical spine fusion model. MATERIALS AND METHODS: Eighteen goats underwent C3/C4 discectomy and were randomly divided into three groups based on the following methods: Group A (n=6), an autologous bone graft; Group B (n=6), PEEK cage filled with an autologous graft; and Group C (n=6), BCFC filled with an autologous iliac bone. Radiography was performed preoperatively and postoperatively and at 1, 4, 8, and 12 weeks after the operation. Disc space height (DSH) was measured at the same time. After 12 weeks, the fused segments were harvested and evaluated with functional radiographic views, biomechanical testing, and histological analyses. RESULTS: Over a 12-week period, the BCFC and PEEK cage groups exhibited significantly higher DSH values than the bone graft group. Additionally, the BCFC group yielded a significantly lower range of motion in axial rotation than both the autologous bone graft and PEEK cage groups. A histologic evaluation revealed an increased intervertebral bone volume/total volume ratio and better interbody fusion in the BCFC group than in the other groups. CONCLUSION: The BCFC device exhibited better results than the autologous bone graft and PEEK cages in single-level ACDF models in vivo. This device may be a potential alternative to the current PEEK cages.

Retrospective analysis of treatment of thoracolumbar burst fracture using mono-segment pedicle instrumentation compared with short-segment pedicle instrumentation.

OBJECTIVE: To investigate the safety and therapeutic effects of mono-segmental pedicle instrumentation (MSPI) in treating thoracolumbar burst fracture (AO classification: A3.1 and A3.2). METHODS: A retrospective analysis was conducted on 60 cases with thoracolumbar burst fracture (AO classification: A3.1 and A3.2) between April 2005 and February 2010. Half of the 60 inpatients were treated with MSPI, and the other half was treated with short-segment pedicle instrumentation (SSPI). The mean operation time, blood loss, visual analog scale (VAS) and vertebral kyphotic angle before and after surgery were compared. RESULTS: In the MSPI group, the mean operation time was 90 ± 25 min, and the blood loss at operation was 180 ± 62 ml. The vertebral kyphotic angles were 17.3° ± 9.3° before surgery, 6.5° ± 6.5° one week after surgery, and 9.5° ± 6.4° for the latest follow-up. The VAS scores were 7.5 ± 1.4 before surgery, 2.5 ± 0.7 one week after surgery, and 1.4 ± 0.8 for the latest follow-up. In the SSPI group, the mean operation time was 101 ± 28 min, and the blood loss at operation was 203 ± 88 ml. The follow-up duration was 12-64 months. The vertebral kyphotic angles were 16.5° ± 9.1° before surgery, 7.1° ± 6.9° one week after surgery, and 7.5° ± 5.2° for the latest follow-up. The VAS scores were 6.7 ± 1.5 before surgery, 3.0 ± 0.4 one week after surgery, and 1.1 ± 0.6 for the latest follow-up. There were no statistically significant differences between these two groups in the operation time, blood loss at operation, VAS score and vertebral kyphotic angle before and after surgery (p > 0.05). The post-surgical VAS scores and vertebral kyphotic angles were significantly decreased in both groups, compared to before surgery (p < 0.05). CONCLUSIONS: It is safe and effective to treat thoracolumbar burst fractures (AO 3.1 and AO 3.2) with MSPI. The mean operation time, blood loss at operation, post-surgical VAS and vertebral kyphotic angle of the MSPI group are similar, compared to the SSPI group. Further research is needed to find out whether therapeutic effects of MSPI are better than those of conservative treatment in these cases.

Three-level anterior cervical discectomy and fusion with self-locking stand-alone polyetheretherketone cages.

Anterior cervical plating is regarded as standard practice after multilevel anterior cervical discectomy and fusion. However, plate implantation in the anterior cervical spine poses a substantial risk of hardware-related complications. We retrospectively analyzed the efficacy and outcomes of 15 consecutive patients treated with a 3-level anterior cervical fusion using self-locking stand-alone polyetheretherketone (PEEK) cages. Patients were evaluated preoperatively and postoperatively using the Japanese Orthopedic Association (JOA) scale scores and radiographs. Clinical results were assessed using Odom's criteria. The mean JOA score (± standard deviation) improved significantly from 7.3 ± 1.5 points to 14.1 ± 1.3 points (p < 0.05) at the final follow-up. The outcomes were excellent for four patients (26.7%), good for nine patients (60%) and fair for two patients (13.3%). None of the patients experienced a poor clinical outcome. Thirteen patients achieved a solid fusion, after an average time of 5.7 months. The radiographic fusion rate of this procedure was 93.3%. Of 45 cages inserted in total, only four (8.89%) cages, in three patients, were found to have subsided. The degree of spinal curvature before surgery differed significantly from that immediately after surgery, and from that at the final follow-up examination (p < 0.05). Self-locking stand-alone PEEK cages packed with excised local osteophytes and calcium sulfate are safe and effective. This procedure can effectively restore cervical lordosis, obviate the complications related to graft harvest and screw-plate fixation, and lead to satisfactory outcomes.

[The treatment of monosegmental fixation and short-segment fixation on thoracolumbar burst fracture a retrospective controlled study].

OBJECTIVE: To investigate the safety and therapeutic effects of monosegment pedicle instrumentation in treating incomplete thoracolumbar burst fracture. METHODS: A retrospective analysis was conducted on 56 inpatients with incomplete thoracolumbar burst fracture (AO classification: A3.1 and A3.2) from April 2005 to January 2010. There were 28 cases were fixed with monosegment pedicle instrumentation (MSPI), 28 cases were fixed with short segment pedicle instrumentation (SSPI). The operative time, blood loss, visual analogue scale (VAS) and vertebral kyphotic angle (VK) before and after surgery were evaluated. RESULTS: In the group of MSPI, the mean operative time was (93 ± 20) min; the intraoperative blood loss was (184 ± 64) ml; the VK angle was 17° ± 10° before operation, 7° ± 7° at one week after operation, and 10° ± 7° at latest follow-up; VAS score was 7.6 ± 1.5 before operation, 2.4 ± 0.8 at one week after operation, and 1.5 ± 0.9 at latest follow-up; no adjacent segment degeneration was found. In the group of SSPI, the operative time was (102 ± 30) min; the intraoperative blood loss was (203 ± 88) ml; the VK angle was 17° ± 9° before operation, 7° ± 7° at one week after operation, and 8° ± 5° at latest follow-up; VAS score was 6.8 ± 1.3 before operation, 3.1 ± 0.5 at one week after operation, and 1.2 ± 0.7 at latest follow-up. One case of adjacent segment degeneration was found in 36 months after operation. There were no significantly statistical differences between two groups in operative time, blood loss, VAS score and VK angle before and after surgery (P > 0.05). The VAS score and VK angle at one week after surgery and latest follow-up all decreased obviously than preoperative ones in both groups (P < 0.05). CONCLUSIONS: MSPI for incomplete thoracolumbar burst fracture is effective and safe. The operative blood loss, the mean operative time, the improvement of VAS score and the VK angle in group MSPI are equal to those in group SSPI.