LL37/FPR2 regulates neutrophil mPTP promoting the development of neutrophil extracellular traps in diabetic retinopathy.

Diabetic retinopathy (DR) is characterized by chronic, low-grade inflammation. This state may be related to the heightened production of neutrophil extracellular traps (NETs) induced by high glucose (HG). Human cathelicidin antimicrobial peptide (LL37) is an endogenous ligand of G protein-coupled chemoattractant receptor formyl peptide receptor 2 (FPR2), expressed on neutrophils and facilitating the formation and stabilization of the structure of NETs. In this study, we detected neutrophils cultured under different conditions, the retinal tissue of diabetic mice, and fibrovascular epiretinal membranes (FVM) samples of patients with proliferative diabetic retinopathy (PDR) to explore the regulating effect of LL37/FPR2 on neutrophil in the development of NETs during the process of DR. Specifically, HG or NG with LL37 upregulates the expression of FPR2 in neutrophils, induces the opening of mitochondrial permeability transition pore (mPTP), promotes the increase of reactive oxygen species and mitochondrial ROS, and then leads to the rise of NET production, which is mainly manifested by the release of DNA reticular structure and the increased expression of NETs-related markers. The PI3K/AKT signaling pathway was activated in neutrophils, and the phosphorylation level was enhanced by FPR2 agonists in vitro. In vivo, increased expression of NETs markers was detected in the retina of diabetic mice and in FVM, vitreous fluid, and serum of PDR patients. Transgenic FPR2 deletion led to decreased NETs in the retina of diabetic mice. Furthermore, in vitro, inhibition of the LL37/FPR2/mPTP axis and PI3K/AKT signaling pathway decreased NET production induced by high glucose. These results suggested that FPR2 plays an essential role in regulating the production of NETs induced by HG, thus may be considered as one of the potential therapeutic targets.

Ginkgo biloba for Tardive Dyskinesia and Plasma MnSOD Activity: Association with MnSOD Ala-9Val Variant.

BACKGROUND: Excessive free radicals are implicated in the pathophysiology of tardive dyskinesia (TD), and Ginkgo biloba extract (EGb761) scavenges free radicals, thereby enhancing antioxidant enzymes such as mitochondrial manganese superoxide dismutase (MnSOD). This study examined whether EGb761 treatment would improve TD symptoms and increase MnSOD activity, particularly in TD patients with specific MnSOD Val-9Ala genotype. METHODS: An EGb761 (240 mg/day) 12-week double-blind clinical trial with 157 TD patients was randomized. The severity of TD was measured by the Abnormal Involuntary Movement Scale (AIMS) and plasma MnSOD activity was assayed before and after 12 weeks of treatment. Further, in an expanded sample, we compared MnSOD activity in 159 TD, 227 non-TD and 280 healthy controls, as well as the allele frequencies and genotypes for the MnSOD Ala-9Val polymorphism in 352 TD, 486 non-TD and 1150 healthy controls. RESULTS: EGb761 significantly reduced TD symptoms and increased MnSOD activity in TD patients compared to placebo (both p < 0.01). Moreover, we found an interaction between genotype and treatment response (p < 0.001). Furthermore, in the EGb761 group, patients carrying the Ala allele displayed a significantly lower AIMS total score than patients with the Val/Val genotype. In addition, MnSOD activity was significantly lower at baseline in TD patients compared with healthy controls or non-TD patients. CONCLUSION: EGb761 treatment enhanced low MnSOD activity in TD patients and produced greater improvement in TD symptoms in patients with the Ala allele of the MnSOD Ala-9Val polymorphism.

Time-varying metasurface driven broadband radar jamming and deceptions.

Conventional radar jamming and deception systems typically necessitate the custom design of complex circuits and algorithms to transmit an additional radio signal toward a detector. Consequently, they are often cumbersome, energy-intensive, and difficult to operate in broadband electromagnetic environment. With the ongoing trend of miniaturization of various devices and the improvement of radar system performance, traditional techniques no longer meet the requirements for broadband, seamless integration, and energy efficiency. Time-varying metasurfaces, capable of manipulating electromagnetic parameters in both temporal and spatial domains, have thus inspired many contemporary research studies to revisit established fields. In this paper, we introduce a time-varying metasurface driven radar jamming and deception system (TVM-RJD), which can perfectly overcome the aforementioned intrinsic challenges. Leveraging a programmable bias voltage, the TVM-RJD can alter the spectrum distribution of incident waves, thereby deceiving radar into making erroneous judgments about the target's location. Experimental outcomes affirm that the accuracy deviation of the TVM-RJD system is less than 0.368 meters, while achieving a remarkable frequency conversion efficiency of up to 96.67%. The TVM-RJD heralds the expansion into a wider application of electromagnetic spatiotemporal manipulation, paving the way for advancements in electromagnetic illusion, radar invisibility, etc.

The Association Between Rumination and Craving in Chinese Methamphetamine-Dependent Patients: The Masking Effect of Depression.

BACKGROUND: Craving is a core feature of addiction. Rumination and depression play a crucial role in the process of methamphetamine addiction. The aim of this study was to examine the relationship between rumination, depression and craving in methamphetamine patients, which has not been explored yet. METHODS: A total of 778 patients with methamphetamine user disorder (MUD) at the Xinhua Drug Rehabilitation Center, located in Mianyang City, Sichuan Province, China. We used a set of self-administered questionnaires that included socio-demographic, detailed drug use history, rumination, depression and craving information. The Rumination Response Scale (RRS) was used to measure rumination, the Beck Depression Inventory (BDI) to measure depression and the Visual Analogue Scale (VAS) to measure craving. RESULTS: There was a significant positive correlation between rumination and craving, or depression, and between depression and craving. Furthermore, depression mediated between rumination and craving, with a mediation effect of 160%. CONCLUSIONS: Our findings suggest that there is a close interrelationship between rumination, craving and depression in MUD patients, and that depression may play a mediating role between rumination and craving.

This is the first study to investigate the relationship between rumination and craving during withdrawal in methamphetamine dependent patients and the mediating role of depression.Among methamphetamine patients, it was found that reflection was positively correlated with rumination and depression, depression and craving, rumination and craving, and depression plays the mediating role between rumination and craving.These findings suggest that interventions to reduce depression and rumination may also be effective for withdrawal and relapse reduction in methamphetamine patients, providing further rationale for the treatment of methamphetamine patients.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

Purpose: The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. Methods: MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Results: Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. Conclusion: This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

A Meta-Analysis of MiRNA-497 and Prognosis of Hepatocellular Carcinoma.

Background: Recently, microRNA-497 (miR-497) has been reported as a prognostic marker for hepatocellular carcinoma (HCC). However, there is no systematic study summarizing these data. Herein, we elucidated the prognostic role of miR497 in HCC by using meta-analysis. Methods: We systematically searched Embase, PubMed, Web of Science, and, China National Knowledge Infrastructure for relevant studies. The two researchers conducted data extraction and quality evaluation independently. We used hazard ratios (HRs), odds ratios (ORs), and their 95% confidence interval (95% CI) to evaluate the relationship between miR-497 expression level and HCC prognosis. Results: A total of 6 studies involving 457 participants were included in this meta-analysis. There was a significant association between the lower level of miR-497 expression and the shorter overall survival (HR = 2.17, 95% CI: 1.67-2.84, P < 0.001). Meanwhile, patients with low miR-497 expression were more prone to vascular infiltration (OR = 2.73, 95%: 1.79-4.17, P < 0.001). However, the lower expression level of miR-497 had no significant correlation with TNM (tumor-node-metastasis) stage (OR = 1.47, 95% CI: 0.17-12.49, P=0.47). Conclusions: MiR-497 might serve as a prognostic biomarker in HCC, but more clinical studies are needed to confirm this view.

Childhood abuse and craving in methamphetamine-dependent individuals: the mediating role of alexithymia.

Individuals with a history of childhood abuse (CA, including neglect and abuse by caregivers before the age of 18 years) have more severe substance dependence problems than those without a history of childhood abuse. However, whether a history of CA exacerbates craving and the mechanism of this effect remain largely unknown. The aim of this study was to explore the role of alexithymia in the effects of CA on craving in a large sample of methamphetamine-dependent individuals based on latent vulnerability theory. A total of 324 methamphetamine-dependent individuals who met DSM-5 criteria for substance use disorder were recruited. CA, alexithymia, and craving data were collected from the Childhood Trauma Questionnaire, the Toronto Alexithymia Scale-20, and the Obsessive Compulsive Drug Use Scale, respectively. t tests and ANCOVA were conducted to compare variables between the CA and non-CA groups, while partial correlation and mediation analyses were conducted to examine the potential mediating role of alexithymia in the relationship between CA and craving. Abused methamphetamine-dependent individuals reported higher levels of craving and higher levels of alexithymia than those of non-abused methamphetamine-dependent individuals. Alexithymia partially mediated the link between CA and craving, especially the effect of CA on craving frequency was fully mediated by alexithymia. Our findings reveal that a history of childhood abuse has a lasting effect on craving in stimulant-dependent individuals, and alexithymia contributes to some extent to the severity of substance abuse problems in abused methamphetamine-dependent individuals.

A Curcumin-Decorated Nanozyme with ROS Scavenging and Anti-Inflammatory Properties for Neuroprotection.

Disordered reactive oxygen/nitrogen species are a common occurrence in various diseases, which usually cause cellular oxidative damage and inflammation. Despite the wide range of applications for biomimetic nanoparticles with antioxidant or anti-inflammatory properties, designs that seamlessly integrate these two abilities with a synergistic effect in a simple manner are seldom reported. In this study, we developed a novel PEI-Mn composite nanoparticle (PM NP) using a chelation method, and the curcumin was loaded onto PM NPs via metal-phenol coordination to form PEI-Mn@curcumin nanoparticles (PMC NPs). PMC NPs possessed excellent dispersibility and cytocompatibility, was engineered to serve as an effective nanozyme, and exhibited specific SOD-like and CAT-like activities. In addition, the incorporation of curcumin granted PMC NPs the ability to effectively suppress the expression of inflammatory cytokines in microglia induced by LPS. As curcumin also has antioxidant properties, it further amplified the synergistic efficiency of ROS scavenging. Significantly, PMC NPs effectively scavenged ROS triggered by H2O2 in SIM-A9 microglia cells and Neuro-2a cells. PMC NPs also considerably mitigated DNA and lipid oxidation in Neuro-2a cells and demonstrated an increase in cell viability under various H2O2 concentrations. These properties suggest that PMC NPs have significant potential in addressing excessive ROS and inflammation related to neural diseases.

Application of Bioactive Materials for Osteogenic Function in Bone Tissue Engineering.

Bone tissue defects present a major challenge in orthopedic surgery. Bone tissue engineering using multiple versatile bioactive materials is a potential strategy for bone-defect repair and regeneration. Due to their unique physicochemical and mechanical properties, biofunctional materials can enhance cellular adhesion, proliferation, and osteogenic differentiation, thereby supporting and stimulating the formation of new bone tissue. 3D bioprinting and physical stimuli-responsive strategies have been employed in various studies on bone regeneration for the fabrication of desired multifunctional biomaterials with integrated bone tissue repair and regeneration properties. In this review, biomaterials applied to bone tissue engineering, emerging 3D bioprinting techniques, and physical stimuli-responsive strategies for the rational manufacturing of novel biomaterials with bone therapeutic and regenerative functions are summarized. Furthermore, the impact of biomaterials on the osteogenic differentiation of stem cells and the potential pathways associated with biomaterial-induced osteogenesis are discussed.

Copious Dislocations Defect in Amorphous/Crystalline/Amorphous Sandwiched Structure P-NiMoO4 Electrocatalyst toward Enhanced Hydrogen Evolution Reaction.

The design and synthesis of efficient, inexpensive, and long-term stable heterostructured electrocatalysts with high-density dislocations for hydrogen evolution reaction in alkaline media and seawater are still a great challenge. An amorphous/crystalline/amorphous sandwiched structure with abundant dislocations were synthesized through thermal phosphidation strategies. The dislocations play an important role in the hydrogen evolution reactions. Copious dislocation defects, combined with cracks, and the synergistic interfacial effect between crystalline phase and amorphous phase regulate the electronic structure of electrocatalyst, provide more active sites, and thus endow the electrocatalysts with excellent catalytic activity under alkaline water and seawater. The overpotentials of P-NiMoO4 at 10 mA/cm2 in 1 M KOH aqueous solution and seawater are 45 and 75 mV, respectively. Additionally, the P-NiMoO4 electrocatalyst exhibits long-term stability over 100 h. This study provides a simple approach for synthesizing amorphous/crystalline/amorphous sandwiched non-noble-metal electrocatalysts with abundant dislocations for hydrogen evolution reaction.

Positive Correlation Between Motor Function and Neuropathic Pain-Like Behaviors After Spinal Cord Injury: A Longitudinal Study of Mice.

Abstract With the recovery of motor function, some spinal cord injury (SCI) patients still suffer from severe pain-like behaviors symptoms. Whether motor function correlates with neuropathic pain-like behaviors remain unclear. In this study, a longitudinal cohort study of mice with moderate thoracic 10 contusion was performed to explore the characteristics of neuropathic pain-like behaviors and its correlation with motor function in different sexes. Pain-like behaviors data up to 42 days post-injury (dpi) were collected and compared. Mice of both sexes were divided into three groups based on their Basso Mouse Scale at 42 dpi. There was no significant difference in motor function recovery between the sexes. Female mice showed more significant mechanical allodynia than males at 14 dpi, which was sustained until 42 dpi without significant dynamic changes. However, males showed a gradually worsening state and more severe mechanical allodynia than females at 28 dpi, and then the differences disappeared. Interestingly, male mice obtained more severe cold hyperalgesia symptoms than females. Additionally, we found that there was a correlation between the occurrence of mechanical allodynia and cold and thermal hyperalgesia. Importantly, motor function recovery was positively associated with the outcomes of neuropathic pain-like behaviors after SCI, which was more obvious in female mice. Our data not only revealed the characteristics of neuropathic pain-like behaviors but also clarified the correlations between motor function recovery and neuropathic pain-like behaviors after SCI. These findings may provide new opinions and suggestions for promoting the clinical diagnosis and treatment of neuropathic pain-like behaviors after SCI.

Differences in the prevalence and clinical correlates of depressive symptoms in male patients with methamphetamine and heroin use disorder in a Chinese Han population.

BACKGROUND AND OBJECTIVES: Comorbidity of substance use disorders and depression is a common phenomenon. It is well known that opioid addiction is neurobiologically distinct from psychostimulant addiction. However, direct comparisons of comorbid depressive symptoms in patients with methamphetamine (METH) use disorder (MAUD) and heroin use disorders (HUD) have been lacking until now. METHODS: A total of 353 patients with methamphetamine use disorder, 76 patients with HUD, and 203 healthy controls were recruited. The Beck Depression Inventory (BDI-SF), the Desires for Drug Questionnaire (DDQ) and the short form of the Childhood Trauma Questionnaire (CTQ-SF) were used to measure participants' depressive symptoms, drug craving, and childhood abuse or neglect, respectively. RESULTS: The prevalence of depressive symptoms was 35.41% (125/353) in MAUD and 56.57% (43/76) in MAUD, significantly higher than the 22.66% (46/203) in healthy controls. Furthermore, there was a significant difference in the total BDI score between the MAUD and HUD groups (F = 5.02, df = 1, 372, p = .026). Among MAUD, years of education, history of incarceration, month of abstinence and negative reinforcement scores were associated with depressive symptoms (all p < .05). Among HUD, duration of drug use, childhood emotional abuse and sexual abuse were associated with depressive symptoms (all p < .05). CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: The prevalence and correlates of depressive symptoms differ between MAUD and HUD, adding to the existing literature. Therefore, treatment and intervention programs should be designed to address these unique correlates in HUD and MAUD patients.

Cell Death Pathway Regulation by Functional Nanomedicines for Robust Antitumor Immunity.

Cancer immunotherapy has become a mainstream cancer treatment over traditional therapeutic modes. Cancer cells can undergo programmed cell death including ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis which are find to have intrinsic relationships with host antitumor immune response. However, direct use of cell death inducers or regulators may bring about severe side effects that can also be rapidly excreted and degraded with low therapeutic efficacy. Nanomaterials are able to carry them for long circulation time, high tumor accumulation and controlled release to achieve satisfactory therapeutic effect. Nowadays, a large number of studies have focused on nanomedicines-based strategies through modulating cell death modalities to potentiate antitumor immunity. Herein, immune cell types and their function are first summarized, and state-of-the-art research progresses in nanomedicines mediated cell death pathways (e.g., ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis) with immune response provocation are highlighted. Subsequently, the conclusion and outlook of potential research focus are discussed.

Association between drug craving and aggression in Chinese male methamphetamine-dependent patients with and without depressive symptoms.

Depressive symptoms and aggression are common in patients with substance use disorder. Drug craving is one of the main drivers of drug-seeking behavior. This study aimed to explore the relationship between drug craving and aggression in methamphetamine use disorder (MAUD) patients with and without depressive symptoms. Totally, 613 male patients with MAUD were recruited in this study. Patients with depressive symptoms were identified by the 13-item Beck Depression Inventory (BDI-13). Drug craving and aggression were assessed by the Desires for Drug Questionnaire (DDQ) and the Buss & Perry Aggression Questionnaire (BPAQ), respectively. 374 patients (61.01%) were confirmed to meet the criteria of depressive symptoms. Patients with depressive symptoms had significantly higher DDQ and BPAQ total scores than those without depressive symptoms. DDQ desire and intention were positively correlated with verbal aggression and hostility in patients with depressive symptoms, whereas they were correlated with self-directed aggression in patients without depressive symptoms. In patients with depressive symptoms, DDQ negative reinforcement and a history of suicide attempts were independently associated with BPAQ total score. Our study suggests that male MAUD patients have a high incidence of depressive symptoms and that patients with depressive symptoms may have greater drug cravings and aggression. Depressive symptoms may play a role in the association between drug craving and aggression in patients with MAUD.

Meta-analysis of ultrasound-guided and traditional femoral artery puncture.

Objective: To compare the ultrasound guidance and traditional methods in femoral artery puncture. Methods: We searched the databases to evaluate the rate of success on first attempt and the incidence of hematoma. The random effects model was used for performing a meta-analysis to estimate the odds ratio (ORs), mean difference (MD), and 95% confidence interval (CI). Results: A total of nine articles including 2,361 patients were included in this meta-analysis. The rate of success on first attempt were 79.6% (1,289/1,619) and 54.1% (883/1,644) in patients of the ultrasound group and traditional method group, respectively [OR = 3.14 (95% CI = 2.30-4.28), combined OR value Z = 7.23 (P < 0.00001)]. The rates of incidence of hematoma in the ultrasound group and traditional puncture group patients were 1.4% (16/1,168) and 3.8% (45/1,193), respectively (OR = 0.41, 95% CI = 0.17-1.00, p = 0.05). Conclusion: Ultrasound-guided femoral artery puncture has certain advantages compared with traditional puncture with regard to success on first attempt and the incidence of hematoma. Moreover, ultrasound-guided puncture reduces the incidence of hematoma in the retrograde puncture group patients.

Investigation of personal data protection mechanism based on blockchain technology.

Blockchain technology is increasingly being used in personal data protection. Inspired by the importance of data security, this paper proposes a personal data protection mechanism based on blockchain, combined with distributed hash tables and cryptography, to enhance users' control over the data generated using web applications. This paper designs this mechanism's system model and describes the three aspects in detail: data storage mechanism, data encryption mechanism, and data trading mechanism. Among them, the data storage mechanism restricts user data to be stored only in the local storage space of the user terminal, the decentralized blockchain network, and the distributed hash table network to ensure that enterprises providing network applications cannot privately store user interaction data, the encryption mechanism is responsible for encrypting all user data recorded in the network and allows users to control the key of the data to ensure the security of the user data in the blockchain and distributed hash tables, the data transaction mechanism allows users to trade their data, and to incentivize enterprises to assist users in collecting personal data, data transaction contracts are built into the data transaction mechanism, allowing enterprises to receive a share of the revenue from user data transactions. Then, for data transactions, use the Stackelberg game to simulate the revenue sharing between users and service providers in data trading to incentivize enterprises providing web services to assist users in collecting their data. The simulation results show that when the number of users is 1000, the revenues of this scheme for service providers are 31%, 561%, and 19% higher than the existing scheme. Finally, the personal data protection platform is implemented by code to verify the feasibility of the theory proposed in this paper in personal data protection.

Recycling Coal Fly Ash for Super-Thermal-Insulating Aerogel Fiber Preparation with Simultaneous Al2O3 Extraction.

A large quantity of coal fly ash is generated worldwide from thermal power plants, causing a serious environmental threat owing to disposal and storage problems. In this work, for the first time, coal fly ash is converted into advanced and novel aerogel fibers and high-purity α-Al2O3. Silica-bacterial cellulose composite aerogel fibers (CAFs) were synthesized using an in situ sol-gel process under ambient pressure drying. Due to the unique "nanoscale interpenetrating network" (IPN) structure, the CAFs showed wonderful mechanical properties with an optimum tensile strength of 5.0 MPa at an ultimate elongation of 5.8%. Furthermore, CAFs with a high porosity (91.8%) and high specific surface area (588.75 m2/g) can inherit advanced features, including excellent thermal insulation, stability over a wide temperature range, and hydrophobicity (contact angle of approximately 144°). Additionally, Al2O3 was simultaneously extracted from the coal fly ash to ensure that the coal fly ash was fully exploited. Overall, low-cost woven CAFs fabrics are suitable for wearable applications and offer a great approach to comprehensively use coal fly ash to address environmental threats.

Porous N-Doped Carbon Decorated with Atomically Dispersed Independent Dual Metal Sites from Energetic Zeolite Imidazolate Frameworks as Bidirectional Catalysts for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries have ultrahigh theoretical specific capacity and energy density, which are considered to be very promising energy storage devices. However, the slow redox kinetics of polysulfides are the main reason for the rapid capacity decay of Li-S batteries. A reasonable electrocatalyst for the Li-S battery should reduce the reaction barrier and accelerate the reaction kinetics of the bidirectional catalytic conversion of lithium polysulfides (LiPSs), thereby reducing the cumulative concentration of LiPSs in the electrolyte. In this report, porous N-doped carbon nanofibers decorated with independent dual metal sites as catalysts for Li-S batteries were fabricated in one step using a fusion-foaming method. Experimental and theoretical analyses demonstrate that the synergistic effect of independent dual metal sites provides strong LiPS affinity, improved electronic conductivity, and enhanced redox kinetics of polysulfides. Therefore, the assembled Li-S battery exhibits high rate performance (discharge specific capacity of 771 mA h g-1 at 2C) and excellent cycle stability (capacity decay rate of 0.51% after 1000 cycles at 1C).

Quantitative profiling of carboxylic compounds by gas chromatography-mass spectrometry for revealing biomarkers of diabetic kidney disease.

Diabetic kidney disease (DKD), a common microvascular complication of diabetes, currently lacks specific diagnostic indicators and therapeutic targets, resulting in miss of early intervention. To profile metabolic conditions in complex and precious biological samples and screen potential biomarkers for DKD diagnosis and prognosis, a rapid, convenient and reliable quantification method for carboxyl compounds by gas chromatography-mass spectrometry (GC-MS) was established with isobutyl chloroformate derivatization. The derivatives were extracted with hexane, injected into GC-MS and quantified with selected ion monitoring mode. This method showed excellent linearity(R2 > 0.99), good recoveries (81.1%-115.5%), good repeatability (RSD < 20%) and sensitivity (LODs: 0.20-499.90 pg, LOQs: 2.00-1007.00 pg). Among the 37 carboxyl compounds analyzed, 12 metabolites in short-chain fatty acids (SCFAs) metabolism pathway and amino acid metabolism pathway were linked with DKD development and among them, 6 metabolites were associated with both development and prognosis of DKD in mice. In conclusion, a reliable, convenient and sensitive method based on isobutyl chloroformate derivatization and GC-MS analysis is established and successfully applied to quantify 37 carboxyl compounds in biological samples of mice and 12 potential biomarkers for DKD development and prognosis are screened.

Hypoxic Preconditional Engineering Small Extracellular Vesicles Promoted Intervertebral Disc Regeneration by Activating Mir-7-5p/NF-Κb/Cxcl2 Axis.

Chronic low back pain (LBP) caused by intervertebral disc (IVD) degradation is a serious socioeconomic burden that can cause severe disabilities. Addressing the underlying pathogenic mechanisms of IVD degeneration may inspire novel therapeutic strategy for LBP. Herein, hypoxic preconditioning improves both the biological function of MSCs in hostile microenvironments and enhances the production of small extracellular vesicles (sEVs) with desirable therapeutic functions. In vitro results reveal that hypoxic preconditional engineering sEVs (HP-sEVs) alleviate the inflammatory microenvironments of IVD degradation, enhance the proliferation of nucleus pulposus (NP) cells, and promote proteoglycan synthesis and collagen formation. Transcriptomic sequencing reveales the excellent therapeutic effects of HP-sEVs in promoting extracellular matrix regeneration through the delivery of microRNA(miR)-7-5p, which further suppresses p65 production and thus the inhibition of Cxcl2 production. Moreover, in vivo results further confirm the robust therapeutic role of HP-sEVs in promoting IVD regeneration through the same mechanism mediated by miR-7-5p delivery. In conclusion, this study provides a novel therapeutic strategy for treating IVD degradation and is thus valuable for understanding the mechanism-of-action of HP-sEVs in IVD regeneration associated with chronic lower back pain.