Conditioned culture medium of bone marrow mesenchymal stem cells promotes phenotypic transformation of microglia by regulating mitochondrial autophagy.

Objective: To study the mechanism by which conditioned medium of bone marrow mesenchymal stem cells (BMSCs-CM) facilitates the transition of pro-inflammatory polarized microglia to an anti-inflammatory phenotype. Methods: BV2 cells, a mouse microglia cell line, were transformed into a pro-inflammatory phenotype using lipopolysaccharide. The expression of phenotypic genes in BV2 cells was detected using real-time quantitative PCR (RT-qPCR). Enzyme-linked immunosorbent assay was used to measure inflammatory cytokine levels in BV2 cells co-cultured with BMSCs-CM. The expressions of mitophagy-associated proteins were determined using western blot. The mitochondrial membrane potential and ATP levels in BV2 cells were measured using JC-1 staining and an ATP assay kit, respectively. Additionally, we examined the proliferation, apoptosis, and migration of C8-D1A cells, a mouse astrocyte cell line, co-cultured with BV2 cells. Results: After co- culture with BMSCs -CM, the mRNA expression of tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase significantly decreased in pro-inflammatory BV2 cells, whereas the expression of CD206 and arginase-1 significantly increased. Moreover, TNF-α and interleukin-6 levels significantly decreased, whereas transforming growth factor-ß and interleukin-10 levels significantly increased. Furthermore, co-culture with BMSCs-CM increased mitophagy-associated protein expression, ATP levels, mitochondrial and lysosomal co-localization in these cells and decreased reactive oxygen species levels. Importantly, BMSCs-CM reversed the decrease in the proliferation and migration of C8-D1A cells co-cultured with pro-inflammatory BV2 cells and inhibited the apoptosis of C8-D1A cells. Conclusion: BMSCs-CM may promote the transition of polarized microglia from a pro-inflammatory to an anti-inflammatory phenotype by regulating mitophagy and influences the functional state of astrocytes.

The ideal treatment timing for diabetic retinopathy: the molecular pathological mechanisms underlying early-stage diabetic retinopathy are a matter of concern.

Diabetic retinopathy (DR) is a prevalent complication of diabetes, significantly impacting patients' quality of life due to vision loss. No pharmacological therapies are currently approved for DR, excepted the drugs to treat diabetic macular edema such as the anti-VEGF agents or steroids administered by intraocular route. Advancements in research have highlighted the crucial role of early intervention in DR for halting or delaying disease progression. This holds immense significance in enhancing patients' quality of life and alleviating the societal burden associated with medical care costs. The non-proliferative stage represents the early phase of DR. In comparison to the proliferative stage, pathological changes primarily manifest as microangiomas and hemorrhages, while at the cellular level, there is a loss of pericytes, neuronal cell death, and disruption of components and functionality within the retinal neuronal vascular unit encompassing pericytes and neurons. Both neurodegenerative and microvascular abnormalities manifest in the early stages of DR. Therefore, our focus lies on the non-proliferative stage of DR and we have initially summarized the mechanisms involved in its development, including pathways such as polyols, that revolve around the pathological changes occurring during this early stage. We also integrate cutting-edge mechanisms, including leukocyte adhesion, neutrophil extracellular traps, multiple RNA regulation, microorganisms, cell death (ferroptosis and pyroptosis), and other related mechanisms. The current status of drug therapy for early-stage DR is also discussed to provide insights for the development of pharmaceutical interventions targeting the early treatment of DR.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential.

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

The crucial role and mechanism of insulin resistance in metabolic disease.

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Thiolated chitosan nanoparticles for stable delivery and smart release of As2O3 for liver cancer through dual actions.

In this work, multifunctional thiolated chitosan derivatives (DCA-CS-PEG-FA-NAC) were synthesized, and arsenic trioxide (ATO) was loaded onto the derivatives through glutathione (GSH)-sensitive AsIII-S bonds, and stable CS-ATO nanodrugs were prepared by simple self-assembly method. By adjusting the thiol substitution degree of CS, the drug loading capacity of the nanodrugs was significantly improved, which could reach 20 ATO per CS molecule (DCA10.7-CS-PEG3.1-FA-NAC20.2-ATO). In vitro release studies obviously showed the low leakage of ATO under physiological conditions while over 95 % ATO was released after 24 h under GSH. In vitro and in vivo investigations demonstrated that the DCA10.7-CS-PEG3.1-FA-NAC20.2-ATO nanodrug could significantly enhance the tumor intracellular accumulation of ATO, reduce the toxic and side effects of ATO on healthy organs, and improve the therapeutic effect of ATO on the HepG2 mice tumor model (tumor inhibition rate was as high as 86.4 %), indicating the potential application of ATO in clinical treatment of liver cancer.

A20 ameliorates disc degeneration by suppressing mTOR/BNIP3 axis-mediated mitophagy.

BACKGROUND: The pathological mechanism of intervertebral disc degeneration (IDD) is an unanswered question that we are committed to exploring. A20 is an anti-inflammatory protein of nucleus pulposus (NP) cells and plays a protective role in intervertebral disc degeneration. OBJECTIVE: This study aims to investigate the molecular mechanism by which A20 attenuates disc degeneration. METHODS: The proteins of interest were measured by immunoblotting, immunofluorescence, ELISA assay, and immunohistochemical technique to conduct related experiments. Immunofluorescence assays and mitochondrial membrane potential (JC-1) were used to assess mitophagy and mitochondrial fitness, respectively. RESULTS: Here, we demonstrated that A20 promoted mitophagy, attenuated pyroptosis, and inhibited the degradation of the extracellular matrix, consequently significantly ameliorating disc degeneration. Mechanistically, A20 reduces pyroptosis and further suppresses cellular mTOR activity. On the one hand, A20-induced mTOR inhibition triggers BNIP3-mediated mitophagy to ensure mitochondrial fitness under LPS stimulation, as a result of mitigating mitochondrial dysfunction induced by LPS. On the other hand, A20-induced mTOR inhibition reduces the loss of mitochondrial membrane potential and the generation of Mitochondrial ROS. CONCLUSION: The study revealed that A20 promotes BNIP3-mediated mitophagy by suppressing mTOR pathway activation against LPS-induced pyroptosis.

A nerve growth factor persistent delivery scaffold seeded with neurally differentiated bone marrow mesenchymal stem cells promoted the functional recovery of spinal cord injury in rats.

The objective was to design a scaffold that could continuously deliver nerve growth factor (NGF) combined with neurally differentiated bone marrow mesenchymal stem cells (BMSCs) to promote better recovery of spinal cord injury (SCI) in rats. BMSCs were induced to differentiate into neurons for 6 days in vitro, and then seeded on a NGF persistent delivery scaffold, both were transplanted to SCI rats in combination. Relevant extensive tests were conducted 1, 4 and 8 weeks after transplantation. The results showed that the scaffold had a stable ability to continuously release NGF and that the BMSCs on the scaffold could successfully differentiate into nerve cells. The results of Bacco, Beattie and Bresnahan (BBB) scores, inclined plane tests and electrophysiological investigations revealed that the rats in the combined regimen had better locomotor functional recovery. The results of H&E/Nissl staining, Golgi staining and immunofluorescence showed that the rats in the combined regimen retained the most neurons and had the least cavities and more formations of dendritic spines. Similarly, the positive rate was high for MAP2, NeuN and MBP, and low for GFAP. The graft of the NGF persistent delivery scaffold seeded with neurally differentiated BMSCs significantly reduced the formation of cavities and glial scars at the SCI sites and promoted neuronal survival, axonal regeneration and locomotor function recovery. Compared with the single graft of NGF persistent delivery scaffold or the single graft of neurally differentiated BMSCs, this combined scheme had a better effect in promoting the recovery of SCI.

Comparative analysis of three types of titanium mesh cages for anterior cervical single-level corpectomy and fusion in term of postoperative subsidence.

A titanium mesh cage (TMC) is a common device used for interbody fusion in anterior cervical corpectomy and fusion (ACCF) surgery, with postoperative subsidence being a common complication. Among the many influencing factors, there is a paucity of research on the end-covers of the TMC. A total of 62 patients with cervical spondylotic myelopathy were treated with single-level ACCF. TMC without end-covers (group A), traditional TMC with end-covers (group B) and new TMC with end-covers (group C) were used as the fusion device. We evaluated the surgery time, intraoperative blood loss, postoperative drainage volume, postoperative fusion, falling height of the fused segment, cervical curvature and severe subsidence rate (the number of falling height of the fused segment > 3 mm/total surgical cases in the group). In addition, the Japanese Orthopaedic Association score was used for neurological status assessment and a 10-point Visual Analog Scale for postoperative neck pain. The results showed that the falling height of the fused segment in group A (1.9 ± 0.6 mm) was significantly greater than in group B (0.9 ± 0.2 mm) and group C (0.8 ± 0.3 mm). The area of the end-covers increased gradually in group A, group B and group C, while the severe subsidence rate of group A (8/20, 40%), group B (5/22, 23%) and group C (2/20, 10%) gradually decreased. The surgery time and blood loss in group B (116.4 ± 12.2 min, 183.5 ± 36.4 mL) were higher than those in group A (90.22 ± 5.60 min, 110.4 ± 20.8 mL) and group C (92.8 ± 8.47 min, 114 ± 24.0 mL). These results showed that there was a correlation between the postoperative subsidence and the end-covers of TMC. The larger the end-cover area was, the lower the severe postoperative subsidence rate was. In addition, the design of the end-covers extending inward was more conducive to the operation.