An injectable recombinant human milk fat globule-epidermal growth factor 8-loaded copolymer system for spinal cord injury reduces inflammation through NF-κB and neuronal cell death

MiR-10b-5p attenuates spinal cord injury and alleviates LPS-induced PC12 cells injury by inhibiting TGF-β1 decay and activating TGF-β1/Smad3 pathway through PTBP1

Spinal cord injury (SCI) is a debilitating condition characterized by significant sensory, motor, and autonomic dysfunctions, leading to severe physical, psychological, and financial burdens. The current therapeutic approaches for SCI show limited effectiveness, highlighting the urgent need for innovative treatments. MicroRNAs (miRNAs) like miR-10b-5p are known to play pivotal roles in gene expression regulation and have been implicated in various neurodegenerative diseases, including SCI. Polypyrimidine tract binding protein 1 (PTBP1) has also been associated with neural injury responses and recovery. This study aims to explore the interaction between miR-10b-5p and PTBP1 in the context of SCI, hypothesizing that miR-10b-5p regulates PTBP1 to influence SCI pathogenesis and recovery using a rat model of SCI and lipopolysaccharide (LPS)-induced PC12 cells. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to measure miR-10b-5p levels, revealing its low expression in SCI rats. We then assessed neurological function, histopathological changes, and spinal cord water content. We found that administering the agomiR-10b-5p significantly improved neurological function and decreased the spinal cord water content and normal motor neuron loss in SCI rats. Additionally, we explored the functions of miR-10b-5p in LPS-treated PC12 cells. Our results showed that miR-10b-5p repressed LPS-stimulated apoptosis, inflammation, and oxidative stress in PC12 cells. PTBP1 was predicted as a potential target gene of miR-10b-5p using the TargetScan database. Pulldown and luciferase reporter assays further demonstrated that miR-10b-5p binds to the 3' untranslated region (UTR) of PTBP1. RT-qPCR revealed that miR-10b-5p negatively modulated PTBP1 expression both in vivo and in vitro. Furthermore, rescue assays indicated that miR-10b-5p alleviated SCI in rats and LPS-triggered injury in PC12 cells by downregulating PTBP1. We also investigated the regulation of miR-10b-5p and PTBP1 on the transforming growth factor-beta 1 (TGF-β1)/small mother against decapentaplegic (Smad3) pathway. We found that miR-10b-5p targeted PTBP1 to repress TGF-β1 decay and facilitated TGF-β1/Smad3 pathway activation. In conclusion, our results demonstrate that miR-10b-5p alleviates SCI by repressing TGF-β1 decay and inducing TGF-β1/Smad3 pathway activation through PTBP1 downregulation. This study provides novel insights into potential targeted therapy plans for SCI.

Outcomes after intranasal human milk therapy in preterm infants with intraventricular hemorrhage

OBJECTIVE

Intraventricular hemorrhage (IVH) is a common cause of brain injury in preterm infants. Fresh human milk (HM) contains stem cells (SCs) that could potentially be delivered via intranasal HM (IHM). In this IHM pilot study, we describe outcomes.

STUDY DESIGN

Infants <33 weeks gestation with IVH were given IHM until maximum 28 days of age. Short-term neurologic outcomes and follow-up testing were compared to historic HM-fed infants. Longitudinal outcomes were plotted using linear mixed models. Weighted G-computation quantified treatment effects. Propensity score models calculated inverse probability weights for IVH grade, gestational age, and sex.

RESULT

37 infants (35.1% grade 3-4 IVH) were compared to 191 historic controls (17.8% grade 3-4 IVH). Post-hemorrhagic ventricular dilatation was common (25.7% IHM patients). Most weighted outcomes, although not significant, favored IHM at 4-12 and 18 months corrected age.

CONCLUSION

This phase 1 study suggests powered trials of IHM for brain injury are needed. CLINICAL TRIAL REGISTRY NAME: clinicaltrials.gov identifier NCT04225286.

Modern advances in spinal cord regeneration: hydrogel combined with neural stem cells

Severe spinal cord injuries (SCI) lead to loss of functional activity of the body below the injury site, affect a person's ability to self-care and have a direct impact on performance. Due to the structural features and functional role of the spinal cord in the body, the consequences of SCI cannot be completely overcome at the expense of endogenous regenerative potential and, developing over time, lead to severe complications years after injury. Thus, the primary task of this type of injury treatment is to create artificial conditions for the regenerative growth of damaged nerve fibers through the area of the SCI. Solving this problem is possible using tissue neuroengineering involving the technology of replacing the natural tissue environment with synthetic matrices (for example, hydrogels) in combination with stem cells, in particular, neural/progenitor stem cells (NSPCs). This approach can provide maximum stimulation and support for the regenerative growth of axons of damaged neurons and their myelination. In this review, we consider the currently available options for improving the condition after SCI (use of NSC transplantation or/and replacement of the damaged area of the SCI with a matrix, specifically a hydrogel). We emphasise the expediency and effectiveness of the hydrogel matrix + NSCs complex system used for the reconstruction of spinal cord tissue after injury. Since such a complex approach (a combination of tissue engineering and cell therapy), in our opinion, allows not only to creation of conditions for supporting endogenous regeneration or mechanical reconstruction of the spinal cord, but also to strengthen endogenous regeneration, prevent the spread of the inflammatory process, and promote the restoration of lost reflex, motor and sensory functions of the injured area of spinal cord.

Spinal Lymphatic Dysfunction Aggravates the Recovery Process After Spinal Cord Injury

We aimed to evaluate the role of the spinal lymphatic system in spinal cord injury and whether it has an impact on recovery after spinal cord injury. Flow cytometry was used to evaluate the changes in the number of microvesicles after spinal cord injury. Evans blue extravasation was used to evaluate the function of the lymphatic system. Evans blue extravasation and immunofluorescence were used to evaluate the permeability of blood spinal cord barrier. The spinal cord edema was evaluated by dry and wet weight.Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was used to evaluate apoptosis after spinal cord injury. Nuclear factor-kappa B pathway was detected by Western blot. Behavioral tests were used to evaluate limb function. Microvesicles released after spinal cord injury can enter the thoracic duct and then enter the blood through the lymph around the spine. After ligation of the thoracic duct, it can aggravate the neuropathological manifestations and limb function after spinal cord injury. The potential mechanism may involve nuclear factor-kappa B pathway.

MFG-E8 Alleviates Cognitive Impairments Induced by Chronic Cerebral Hypoperfusion by Phagocytosing Myelin Debris and Promoting Remyelination

Chronic cerebral hypoperfusion is one of the pathophysiological mechanisms contributing to cognitive decline by causing white matter injury. Microglia phagocytosing myelin debris in a timely manner can promote remyelination and contribute to the repair of white matter. However, milk fat globule-epidermal growth factor-factor 8 (MFG-E8), a microglial phagocytosis-related protein, has not been well studied in hypoperfusion-related cognitive dysfunction. We found that the expression of MFG-E8 was significantly decreased in the brain of mice after bilateral carotid artery stenosis (BCAS). MFG-E8 knockout mice demonstrated more severe BCAS-induced cognitive impairments in the behavioral tests. In addition, we discovered that the deletion of MFG-E8 aggravated white matter damage and the destruction of myelin microstructure through fluorescent staining and electron microscopy. Meanwhile, MFG-E8 overexpression by AAV improved white matter injury and increased the number of mature oligodendrocytes after BCAS. Moreover, in vitro and in vivo experiments showed that MFG-E8 could enhance the phagocytic function of microglia via the αVβ3/αVβ5/Rac1 pathway and IGF-1 production to promote the differentiation of oligodendrocyte progenitor cells into mature oligodendrocytes. Interestingly, we found that MFG-E8 was mainly derived from astrocytes, not microglia. Our findings suggest that MFG-E8 is a potential therapeutic target for cognitive impairments following cerebral hypoperfusion.

Harnessing the power of biological macromolecules in hydrogels for controlled drug release in the central nervous system: A review

Hydrogels have immense potential in revolutionizing central nervous system (CNS) drug delivery, improving outcomes for neurological disorders. They serve as promising tools for controlled drug delivery to the CNS. Available hydrogel types include natural macromolecules (e.g., chitosan, hyaluronic acid, alginate), as well as hybrid hydrogels combining natural and synthetic polymers. Each type offers distinct advantages in terms of biocompatibility, mechanical properties, and drug release kinetics. Design and engineering considerations encompass hydrogel composition, crosslinking density, porosity, and strategies for targeted drug delivery. The review emphasizes factors affecting drug release profiles, such as hydrogel properties and formulation parameters. CNS drug delivery applications of hydrogels span a wide range of therapeutics, including small molecules, proteins and peptides, and nucleic acids. However, challenges like limited biodegradability, clearance, and effective CNS delivery persist. Incorporating 3D bioprinting technology with hydrogel-based CNS drug delivery holds the promise of highly personalized and precisely controlled therapeutic interventions for neurological disorders. The review explores emerging technologies like 3D bioprinting and nanotechnology as opportunities for enhanced precision and effectiveness in hydrogel-based CNS drug delivery. Continued research, collaboration, and technological advancements are vital for translating hydrogel-based therapies into clinical practice, benefiting patients with CNS disorders. This comprehensive review article delves into hydrogels for CNS drug delivery, addressing their types, design principles, applications, challenges, and opportunities for clinical translation.

Schwann Cell-Derived Exosomes and Methylprednisolone Composite Patch for Spinal Cord Injury Repair

Spinal cord injury (SCI) can cause permanent loss of sensory and motor function, and there is no effective clinical treatment, to date. Due to the complex pathological process involved after injury, synergistic treatments are very urgently needed in clinical practice. We designed a nanofiber scaffold hyaluronic acid hydrogel patch to release both exosomes and methylprednisolone to the injured spinal cord in a non-invasive manner. This composite patch showed good biocompatibility in the stabilization of exosome morphology and toxicity to nerve cells. Meanwhile, the composite patch increased the proportion of M2-type macrophages and reduced neuronal apoptosis in an in vitro study. In vivo, the functional and electrophysiological performance of rats with SCI was significantly improved when the composite patch covered the surface of the hematoma. The composite patch inhibited the inflammatory response through macrophage polarization from M1 type to M2 type and increased the survival of neurons by inhibition neuronal of apoptosis after SCI. The therapeutic effects of this composite patch can be attributed to TLR4/NF-κB, MAPK, and Akt/mTOR pathways. Thus, the composite patch provides a medicine-exosomes dual-release system and may provide a non-invasive method for clinical treatment for individuals with SCI.

Dual Thermal- and Oxidation-Responsive Polymers Synthesized by a Sequential ROP-to-RAFT Procedure Inherently Temper Neuroinflammation

This study is about multiple responsiveness in biomedical materials. This typically implies "orthogonality" (i.e., one response does not affect the other) or synergy (i.e., one increases efficacy or selectivity of the other), but an antagonist effect between responses may also occur. Here, we describe a family of very well-defined amphiphilic and micelle-forming block copolymers, which show both oxidative and temperature responses. They are produced via successive anionic ring-opening polymerization of episulfides and RAFT polymerization of dialkylacrylamides and differ only in the ratio between inert (N,N-dimethylacrylamide, DMA) and temperature-sensitive (N,N-diethylacrylamide, DEA) units. By scavenging Reactive Oxygen Species (ROS), these polymers are anti-inflammatory; through temperature responsiveness, they can macroscopically aggregate, which may allow them to form depots upon injection. The localization of the anti-inflammatory action is an example of synergy. An extensive evaluation of toxicity and anti-inflammatory effects on in vitro models, including BV2 microglia, C8D30 astrocytes and primary neurons, shows a link between capacity of aggregation and detrimental effects on viability which, albeit mild, can hinder the anti-inflammatory potential (antagonist action). Although limited in breadth (e.g., only in vitro models and only DEA as a temperature-responsive unit), this study suggests that single-responsive controls should be used to allow for a precise assessment of the (synergic or antagonist) potential of double-responsive systems.

Thermosensitive hydrogel-based GPR124 delivery strategy for rebuilding blood-spinal cord barrier

Spinal cord injury (SCI) causes blood-spinal cord barrier (BSCB) disruption, leading to secondary damage, such as hemorrhagic infiltration, inflammatory response, and neuronal cell death. It is of great significance to rebuild the BSCB at the early stage of SCI to alleviate the secondary injury for better prognosis. Yet, current research involved in the reconstruction of BSCB is insufficient. Accordingly, we provide a thermosensitive hydrogel-based G protein-coupled receptor 124 (GPR124) delivery strategy for rebuilding BSCB. Herein, we firstly found that the expression of GPR124 decreased post-SCI and demonstrated that treatment with recombinant GPR124 could partially alleviate the disruption of BSCB post-SCI by restoring tight junctions (TJs) and promoting migration and tube formation of endothelial cells. Interestingly, GPR124 could also boost the energy metabolism of endothelial cells. However, the absence of physicochemical stability restricted the wide usage of GPR124. Hence, we fabricated a thermosensitive heparin-poloxamer (HP) hydrogel that demonstrated sustained GPR124 production and maintained the bioactivity of GPR124 (HP@124) for rebuilding the BSCB and eventually enhancing functional motor recovery post-SCI. HP@124 hydrogel can encapsulate GPR124 at the lesion site by injection, providing prolonged release, preserving wounded tissues, and filling injured tissue cavities. Consequently, it induces synergistically efficient integrated regulation by blocking BSCB rupture, decreasing fibrotic scar formation, minimizing inflammatory response, boosting remyelination, and regenerating axons. Mechanistically, giving GPR124 activates energy metabolism via elevating the expression of phosphoenolpyruvate carboxykinase 2 (PCK2), and eventually restores the poor state of endothelial cells. This research demonstrated that early intervention by combining GPR124 with bioactive multifunctional hydrogel may have tremendous promise for restoring locomotor recovery in patients with central nervous system disorders, in addition to a translational approach for the medical therapy of SCI.

Modulating neuroinflammation through molecular, cellular and biomaterial-based approaches to treat spinal cord injury

The neuroinflammatory response that is elicited after spinal cord injury contributes to both tissue damage and reparative processes. The complex and dynamic cellular and molecular changes within the spinal cord microenvironment result in a functional imbalance of immune cells and their modulatory factors. To facilitate wound healing and repair, it is necessary to manipulate the immunological pathways during neuroinflammation to achieve successful therapeutic interventions. In this review, recent advancements and fresh perspectives on the consequences of neuroinflammation after SCI and modulation of the inflammatory responses through the use of molecular-, cellular-, and biomaterial-based therapies to promote tissue regeneration and functional recovery will be discussed.

Aucubin promoted neuron functional recovery by suppressing inflammation and neuronal apoptosis in a spinal cord injury model

BACKGROUND

Spinal cord injury (SCI) can cause severe motor impairment. Post-SCI treatment has focused primarily on secondary injury, with neuroinflammation and neuronal apoptosis as the primary therapeutic targets. Aucubin (Au), a Chinese herbal medicine, exerts anti-inflammatory and neuroprotective effects. The therapeutic effects of Aucubin in SCI have not been reported.

METHODS

In this study, we carried out an in vivo SCI model and a series of in vitro experiments to explore the therapeutic effect of Aucubin. Western Blotting and immunofluorescence were used to study the effect of Aucubin on microglial polarization and neuronal apoptosis and its underlying mechanism.

RESULTS

We found that Aucubin can promote axonal regeneration by reducing neuroinflammation and neuronal apoptosis, which is beneficial to motor recovery after spinal cord injury in rats. Our further in vitro experiments showed that Aucubin can activate the toll-like receptor 4 (TLR4)/myeloid differentiation protein-88 (MyD88)/IκBα/nuclear factor kappa B (NF-κB) signaling pathway to reduce neuroinflammation and reverse mitochondrial dysfunction to reduce neuronal apoptosis.

CONCLUSIONS

In summary, these results suggest that Aucubin may ameliorate secondary injury after SCI by reducing neuroinflammation and neuronal apoptosis. Therefore, Au may be a promising post-SCI therapeutic drug.

Effect and Safety Analysis of PRP and Yifu Combined with Ultrapulsed CO2 Lattice Laser in Patients with Sunken Acne Scar

Objective

To investigate the effect and safety of PRP and Yifu combined with ultrapulsed CO₂ lattice laser in patients with sunken acne scar.

Methods

700 subjects were selected from the group of patients with sunken acne scar treated in our hospital from November 2010 to December 2020. They were divided into control group (n = 350) and study group (n = 350). The grouping was mainly based on the random number table method. Patients in the control group were treated with ultrapulse CO₂ lattice laser, while those in the study group were treated with ultrapulse CO₂ lattice laser combined with PRP and Yifu. The clinical effect, scar improvement and quality of life before and after treatment, and adverse events during treatment were compared between the two groups. The clinical effect was categorized into cure after treatment, significant effect, effective, and ineffective. The total effective rate = 1 − ineffective rate.

Results

After treatment, the total effective rate of the study group (81.43%) was higher than that of the control group (70.00%). After treatment, ECCA, VSS scores, daily activities, symptoms and feelings, work and study, leisure and entertainment, interpersonal relationship, treatment status, and total scores were all lower in both groups than before treatment, and the study group was lower than the control group. During the treatment, the incidence of adverse events in the study group (17.33%) was lower than that in the control group (28.57%), P < 0.05.

Conclusion

PRP and Yifu combined with ultrapulse CO₂ lattice laser in the treatment of sunken acne scar can effectively improve the scar, reduce the incidence of adverse events, and the treatment effect is obvious, which can improve the quality of life of the patients.

MFG-E8 Maintains Cellular Homeostasis by Suppressing Endoplasmic Reticulum Stress in Pancreatic Exocrine Acinar Cells

Excessive endoplasmic reticulum (ER) stress contributes significantly to the pathogenesis of exocrine acinar damage in acute pancreatitis. Our previous study found that milk fat globule EGF factor 8 (MFG-E8), a lipophilic glycoprotein, alleviates acinar cell damage during AP via binding to αvβ3/5 integrins. Ligand-dependent integrin-FAK activation of STAT3 was reported to be of great importance for maintaining cellular homeostasis. However, MFG-E8's role in ER stress in pancreatic exocrine acinar cells has not been evaluated. To study this, thapsigargin, brefeldin A, tunicamycin and cerulein + LPS were used to induce ER stress in rat pancreatic acinar cells in vitro. L-arginine- and cerulein + LPS-induced acute pancreatitis in mice were used to study ER stress in vivo. The results showed that MFG-E8 dose-dependently inhibited ER stress under both in vitro and in vivo conditions. MFG-E8 knockout mice suffered more severe ER stress and greater inflammatory response after L-arginine administration. Mechanistically, MFG-E8 increased phosphorylation of FAK and STAT3 in cerulein + LPS-treated pancreatic acinar cells. The presence of specific inhibitors of αvβ3/5 integrin, FAK or STAT3 abolished MFG-E8's effect on cerulein + LPS-induced ER stress in pancreatic acinar cells. In conclusion, MFG-E8 maintains cellular homeostasis by alleviating ER stress in pancreatic exocrine acinar cells.

DCI after Aneurysmal Subarachnoid Hemorrhage Is Related to the Expression of MFG-E8

Objective

To explore the predictive value of milk fat globule epidermal growth factor 8 (MFG-E8) in the occurrence of delayed cerebral ischemia (DCI) after an aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We recruited 32 patients with aSAH as the case group and 24 patients with unruptured aneurysms as the control group. Serum MFG-E8 levels were measured by western blot and enzyme-linked immunosorbent assay. We analyzed the relationship between MFG-E8 levels and the risk of DCI.

Results

The levels of serum MFG-E8 in the case group (mean = 11160.9 pg/mL) were significantly higher than those in the control group (mean = 3081.0 pg/mL, p < 0.001). MFG-E8 levels highly correlated with the World Federation of Neurosurgical Societies (WFNS) and modified Fisher scores (r = -0.691 and - 0.767, respectively, p < 0.001). In addition, MFG-E8 levels in patients with DCI (5882.7 ± 3162.4 pg/mL) were notably higher than those in patients without DCI (15818.2 ± 3771.6 pg/mL, p < 0.001). A receiver operating characteristic curve showed that the occurrence of DCI could effectively be predicted by MFG-E8 (area under the curve = 0.976, 95%CI = 0.850-1.000). Kaplan-Meier survival analysis showed a remarkable decrease in the incidence of DCI in case group individuals with high levels of MFG-E8 (≥11160.9 pg/mL, p < 0.001).

Conclusion

MFG-E8 may be a useful predictive marker for DCI after an aSAH and could be a promising surrogate end point.

Injectable thermoresponsive hydrogels as drug delivery system for the treatment of central nervous system disorders: A review

The central nervous system (CNS), consisting of the brain, spinal cord, and retina, superintends to the acquisition, integration and processing of peripheral information to properly coordinate the activities of the whole body. Neurodegenerative and neurodevelopmental disorders, trauma, stroke, and brain tumors can dramatically affect CNS functions resulting in serious and life-long disabilities. Globally, the societal and economic burden associated with CNS disorders continues to grow with the ageing of the population thus demanding for more effective and definitive treatments. Despite the variety of clinically available therapeutic molecules, medical interventions on CNS disorders are mostly limited to treat symptoms rather than halting or reversing disease progression. This is attributed to the complexity of the underlying disease mechanisms as well as to the unique biological microenvironment. Given its central importance, multiple barriers, including the blood brain barrier and the blood cerebrospinal fluid barrier, protect the CNS from external agents. This limits the access of drug molecules to the CNS thus contributing to the modest therapeutic successes. Loco-regional therapies based on the deposition of thermoresponsive hydrogels loaded with therapeutic agents and cells are receiving much attention as an alternative and potentially more effective approach to manage CNS disorders. In this work, the current understanding and challenges in the design of thermoresponsive hydrogels for CNS therapy are reviewed. First, the biological barriers that hinder mass and drug transport to the CNS are described, highlighting the distinct features of each barrier. Then, the realization, characterization and biomedical application of natural and synthetic thermoresponsive hydrogels are critically presented. Advantages and limitations of each design and application are discussed with the objective of identifying general rules that could enhance the effective translation of thermoresponsive hydrogel-based therapies for the treatment of CNS disorders.

Rea regulates microglial polarization and attenuates neuronal apoptosis via inhibition of the NF-κB and MAPK signalings for spinal cord injury repair

Inflammation and neuronal apoptosis aggravate the secondary damage after spinal cord injury (SCI). Rehmannioside A (Rea) is a bioactive herbal extract isolated from Rehmanniae radix with low toxicity and neuroprotection effects. Rea treatment inhibited the release of pro-inflammatory mediators from microglial cells, and promoted M2 polarization in vitro, which in turn protected the co-cultured neurons from apoptosis via suppression of the NF-κB and MAPK signalling pathways. Furthermore, daily intraperitoneal injections of 80 mg/kg Rea into a rat model of SCI significantly improved the behavioural and histological indices, promoted M2 microglial polarization, alleviated neuronal apoptosis, and increased motor function recovery. Therefore, Rea is a promising therapeutic option for SCI and should be clinically explored.