Picein alleviates oxidative stress and promotes bone regeneration in osteoporotic bone defect by inhibiting ferroptosis via Nrf2/HO-1/GPX4 pathway.

Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to abnormal oxidative stress and high levels of reactive oxygen species (ROS), a condition detrimental for bone formation, making the OP-related bone healing a significant clinical challenge. As the osteogenic differentiation ability of bone marrow mesenchymal stem cells (BMSCs) is closely related to bone regeneration; currently, this study assessed the effects of Picein on BMSCs in vitro and bone regeneration in osteoporotic bone defect in vivo. Cell viability was determined by CCK-8 assay. The production of (ROS), malonaldehyde, superoxide dismutase activities, and glutathione was evaluated by using commercially available kits, and a flow cytometry analysis was adopted to detect macrophage polarization. Osteogenic capacity of BMSCs was evaluated by alkaline phosphatase (ALP) activity, ALP staining, and Alizarin red S staining. The expression of osteogenic-related proteins (OPN, Runx-2, OCN) and osteogenic-related genes (ALP, BMP-4, COL-1, and Osterix) were evaluated by Western blotting and real-time PCR (RT-PCR). In addition, proliferation, migration ability, and angiogenic capacity of human umbilical vein endothelial cells (HUVECs) were evaluated by EdU staining, scratch test, transwell assay, and tube formation assay, respectively. Angiogenic-related genes (VEGF, vWF, CD31) were also evaluated by RT-PCR. Results showed that Picein alleviated erastin-induced oxidative stress, enhanced osteogenic differentiation capacity of BMSCs, angiogenesis of HUVECs, and protects cells against ferroptosis through Nrf2/HO-1/GPX4 axis. Moreover, Picein regulate immune microenvironment by promoting the polarization of M2 macrophages in vitro. In addition, Picein also reduce the inflammation levels and promotes bone regeneration in osteoporotic bone defect in OP rat models in vivo. Altogether, these results suggested that Picein can promote bone regeneration and alleviate oxidative stress via Nrf2/HO-1/GPX4 pathway, offering Picein as a novel antioxidant agent for treating osteoporotic bone defect.

Remodeling of the Intra-Conduit Inflammatory Microenvironment to Improve Peripheral Nerve Regeneration with a Neuromechanical Matching Protein-Based Conduit.

Peripheral nerve injury (PNI) remains a challenging area in regenerative medicine. Nerve guide conduit (NGC) transplantation is a common treatment for PNI, but the prognosis of NGC treatment is unsatisfactory due to 1) neuromechanical unmatching and 2) the intra-conduit inflammatory microenvironment (IME) resulting from Schwann cell pyroptosis and inflammatory-polarized macrophages. A neuromechanically matched NGC composed of regenerated silk fibroin (RSF) loaded with poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (P:P) and dimethyl fumarate (DMF) are designed, which exhibits a matched elastic modulus (25.1 ± 3.5 MPa) for the peripheral nerve and the highest 80% elongation at break, better than most protein-based conduits. Moreover, the NGC can gradually regulate the intra-conduit IME by releasing DMF and monitoring sciatic nerve movements via piezoresistive sensing. The combination of NGC and electrical stimulation modulates the IME to support PNI regeneration by synergistically inhibiting Schwann cell pyroptosis and reducing inflammatory factor release, shifting macrophage polarization from the inflammatory M1 phenotype to the tissue regenerative M2 phenotype and resulting in functional recovery of neurons. In a rat sciatic nerve crush model, NGC promoted remyelination and functional and structural regeneration. Generally, the DMF/RSF/P:P conduit provides a new potential therapeutic approach to promote nerve repair in future clinical treatments.

Rab32 facilitates Schwann cell pyroptosis in rats following peripheral nerve injury by elevating ROS levels.

BACKGROUND: Peripheral nerve injury (PNI) is commonly observed in clinical practice, yet the underlying mechanisms remain unclear. This study investigated the correlation between the expression of a Ras-related protein Rab32 and pyroptosis in rats following PNI, and potential mechanisms have been explored by which Rab32 may influence Schwann cells pyroptosis and ultimately peripheral nerve regeneration (PNR) through the regulation of Reactive oxygen species (ROS) levels. METHODS: The authors investigated the induction of Schwann cell pyroptosis and the elevated expression of Rab32 in a rat model of PNI. In vitro experiments revealed an upregulation of Rab32 during Schwann cell pyroptosis. Furthermore, the effect of Rab32 on the level of ROS in mitochondria in pyroptosis model has also been studied. Finally, the effects of knocking down the Rab32 gene on PNR were assessed, morphology, sensory and motor functions of sciatic nerves, electrophysiology and immunohistochemical analysis were conducted to assess the therapeutic efficacy. RESULTS: Silencing Rab32 attenuated PNI-induced Schwann cell pyroptosis and promoted peripheral nerve regeneration. Furthermore, our findings demonstrated that Rab32 induces significant oxidative stress by damaging the mitochondria of Schwann cells in the pyroptosis model in vitro. CONCLUSION: Rab32 exacerbated Schwann cell pyroptosis in PNI model, leading to delayed peripheral nerve regeneration. Rab32 can be a potential target for future therapeutic strategy in the treatment of peripheral nerve injuries.

Safety and Efficacy of Paxlovid Against Omicron Variants of Coronavirus Disease 2019 in Elderly Patients.

INTRODUCTION: Elderly patients are the most affected and vulnerable to COVID-19 and effective therapeutic interventions are urgently required. We clarified the safety and efficacy of Paxlovid in the treatment of elderly patients with coronavirus disease 2019 (COVID-19). METHODS: Patients aged over 60 years and with mild to moderate COVID-19 were admitted to the Zhongshan Hospital MinHang MeiLong Branch, Fudan University and received either Paxlovid treatment or only conventional therapy, between April 1 and May 31, 2022. Viral shedding time, duration of hospital stay, disease progression, and adverse events were analyzed, and multivariate Cox regression analysis was performed to detect the independent high-risk factors for COVID-19 progression in the patients. RESULTS: A total of 163 (82 and 81 in the treatment and control groups, respectively) patients had a median age of 82 (71-89) years, and 89.0% had at least one concomitant disease. The duration of hospitalization reduced from 15 to 13 days, and viral shedding time reduced from 20 to 16.5 days after Paxlovid treatment. The differences of these two variables between the groups were significant (p < 0.01). Moreover, no serious adverse events or obvious changes in laboratory test results were observed in patients treated with Paxlovid. One patient (1.2%) treated with Paxlovid experienced rebound 56 days after negative measurement. Multivariate analysis showed that Paxlovid therapy, age, hemoglobin, and nucleic acid Ct values at admission were independent risk factors for hospitalization within 14 days, and the differences were significant (p < 0.01). CONCLUSION: The use of Paxlovid in elderly patients may promote recovery from COVID-19 and reduce the viral load without adverse events. CLINICAL TRIAL REGISTRATION: www. CLINICALTRIALS: gov , ID: ChiCTR2200066990.

Injectable nanofiber-reinforced bone cement with controlled biodegradability for minimally-invasive bone regeneration.

Injectable materials show their special merits in regeneration of damaged/degenerated bones in minimally-invasive approach. Injectable calcium phosphate bone cement (CPC) has attracted broad attention for its bioactivity, as compared to non-degradable polymethyl methacrylate cement. However, its brittleness, poor anti-washout property and uncontrollable biodegradability are the main challenges to limit its further clinical application mainly because of its stone-like dense structure and fragile inorganic-salt weakness. Herein, we developed a kind of injectable CPC bone cement with porous structure and improved robustness by incorporating poly(lactide-co-glycolic acid) (PLGA) nanofiber into CPC, with carboxymethyl cellulose (CMC) to offer good injectability as well as anti-wash-out capacity. Furthermore, the introduction of PLGA and CMC also enabled a formation of initial porous structure in the cements, where PLGA nanofiber endowed the cement with a dynamically controllable biodegradability which provided room for cell movement and bone ingrowth. Interestingly, the reinforced biodegradable cement afforded a sustainable provision of Ca2+ bioactive components, together with its porous structure, to improve synergistically new bone formation and osteo-integration in vivo by using a rat model of femur condyle defect. Further study on regenerative mechanisms indicated that the good minimally-invasive bone regeneration may come from the synergistic enhanced osteogenic effect of calcium ion enrichment and the improved revascularization capacity contributed from the porosity as well as the lactic acid released from PLGA nanofiber. These results indicate the injectable bone cement with high strength, anti-washout property and controllable biodegradability is a promising candidate for bone regeneration in a minimally-invasive approach.

Excessive mechanical strain accelerates intervertebral disc degeneration by disrupting intrinsic circadian rhythm.

Night shift workers with disordered rhythmic mechanical loading are more prone to intervertebral disc degeneration (IDD). Our results showed that circadian rhythm (CR) was dampened in degenerated and aged NP cells. Long-term environmental CR disruption promoted IDD in rats. Excessive mechanical strain disrupted the CR and inhibited the expression of core clock proteins. The inhibitory effect of mechanical loading on the expression of extracellular matrix genes could be reversed by BMAL1 overexpression in NP cells. The Rho/ROCK pathway was demonstrated to mediate the effect of mechanical stimulation on CR. Prolonged mechanical loading for 12 months affected intrinsic CR genes and induced IDD in a model of upright posture in a normal environment. Unexpectedly, mechanical loading further accelerated the IDD in an Light-Dark (LD) cycle-disrupted environment. These results indicated that intrinsic CR disruption might be a mechanism involved in overloading-induced IDD and a potential drug target for night shift workers.

Decorin inhibits nucleus pulposus apoptosis by matrix-induced autophagy via the mTOR pathway.

Decorin (Dcn) is a member of the class I small leucine-rich proteoglycans, whose expression in the nucleus pulposus (NP) of intervertebral discs (IVDs) has been shown to increase with aging in humans and sheep. Dcn induces autophagy in endothelial cells; however, its precise role in NP and IVD degeneration during aging is not well understood. We addressed this question in the present study by treating rat nucleus pulposus cells (NPCs) with different concentrations of Dcn. The Western blot analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling assay results showed that Dcn treatment induced autophagy and decreased apoptosis caused by interleukin (IL)-1ß application. This effect was dependent on the protein kinase B/mechanistic target of rapamycin (mTOR)/p70 S6 kinase signaling. Dcn treatment also decreased the expression of matrix metalloproteinase-3 and -13 and decreased the IL-1ß-induced attenuation of collagen type II and aggrecan levels. The role of Dcn in stimulating autophagy was further supported by the fact that the observed effects were abrogated by knocking down autophagy-related protein 7 with Atg7 small interfering RNA. Thus, Dcn protects NPCs in IVDs from IL-1ß-induced apoptosis and degeneration by promoting autophagy through mTOR signaling.

Effects of Shen-Fu injection on mitochondrial function in the intestinal epithelial cells of rats with endotoxemia.

Recently, several studies have demonstrated that reactive oxygen species are responsible for inducing multiple organ failure and septic shock. Particularly, mitochondrial dysfunction has been demonstrated in the pathogenesis of multiple organ dysfunction syndrome (MODS). In cytopathic hypoxia, impairment of mitochondrial oxidative phosphorylation decreases aerobic adenosine triphosphate (ATP) production and potentially induces MODS. Shen-Fu (SF) injections are widely used in the treatment of various diseases. SF exhibits cardiovascular protective effects. For example, it can stretch the coronary artery, stabilize blood pressure, regulate IRI, and improve the overall heart function. Clinical studies have demonstrated that SF injections have notable therapeutic effects on septic and hemorrhagic shocks. In the present study, the effects of SF injection on mitochondrial function in the intestinal epithelial cells of rats with endotoxemia were analyzed.

Experimental study of airway pressure release ventilation in the treatment of acute respiratory distress syndrome.

Airway pressure release ventilation (APRV) is a ventilator mode which has demonstrated potential benefits in acute respiratory distress syndrome (ARDS) patients. We therefore sought to compare relevant pulmonary data and safety outcomes of this mode to the conventional ventilation and sustained inflation. Canines admitted after intravenous injection of oleic acid requiring mechanical ventilation were randomly divided into 3 groups (n=6), namely conventional ventilation group, low tidal volume ventilation with recruitment group (LTV+SI) and APRV group. The changes of oxygenation, ventilation, airway pressure, inflammatory reaction and hemodynamics at the basic state were observed at 0, 1, 2 and 4 h during the experiment. The levels of PaO2/FiO2 in APRV group were higher than LTV+SI group at 2 and 4 h (P<0.05). In APRV group, the PCO2 levels at 1, 2 and 4 h is much lower than LTV+SI group (P<0.05). Outcome variables showed no differences between APRV, LVT+SI and conventional mechanical ventilation for plateau airway pressure (24±1 vs. 29±3 vs. 25±4), mean arterial pressure (92.9±16.5 vs. 85.8±21.4 vs. 88.7±24.4), cardiac index (4.3±1.7 vs. 3.5±1.9 vs. 3.4±2.1), ERO2 (13.4±10.3 vs. 16.1±6.8 vs. 17.6±9.1), lac (2.5±1.7 vs. 3.1±1.6 vs. 3.9±1.9), tumor necrosis factor (TNF)-α (132±11 vs. 140±6 vs. 195±13) and matrix metalloproteinase (MMP)-9. For canines sustaining acute respiratory distress syndrome requiring mechanical ventilation, APRV can significantly improve oxygenation and keep hemodynamic stability compared with LTV+SI. The results of TNF-α and MMP-9 suggest that APRV could be as protective for ARDS as LTV with recruitment group.

Effect of the Shenfu Injection Combined with Early Goal-Directed Therapy on Organ Functions and Outcomes of Septic Shock Patients.

Shenfu injection (SFI) derived from traditional Chinese medicine has been widely used in cardiovascular diseases. The objective of this study was to determine the effect of SFI and conventional early goal-directed therapy (EGDT) on organ functions and outcomes of septic shock patients. For this purpose, a total of 45 septic shock patients were randomly divided into control group A (24 patients on EGDT) and experimental group B (21 patients on SFI + EGDT). SFI was administered (100@20 mL/h) twice daily. Hemodynamic status, lactic acid, and vasoactive drug use were observed before and after treatment. Other indicators included ventilator weaning time, ICU stay time, free of organ failure time, and 28-day hospital mortality. Regarding experimental group, compared with controls, BUN/creatinine decreased significantly at 3, 5, and 7 days while PaO2/FiO2 increased at 1 and 3 days (P < 0.05). APACHE-II and SOFA scores decreased in both groups at 3, 5, and 7 days (P < 0.05), whereas SOFA scores improved more in experimental group as compared with controls. Ventilator weaning time and ICU stay were significantly shorter in experimental group as compared with controls. In both groups, mean arterial pressure/systemic vascular resistance index post-treatment levels increased and lactic acid decreased at 6, 12, 24, 48, and 72 h (P < 0.05). Heart rate decreased at 24, 48, and 72 h (P < 0.05); while gamma-glutamyl transpeptidase and glutamate oxaloacetate transaminase levels increased at 1 day and 1 and 3 days, respectively (P < 0.05). Combined use of SFI and EGDT can improve hemodynamics, reduce the damage to vital organs, and shorten ventilation and ICU stay times in septic shock patients.