G-CSF treatment promotes apoptosis of autoreactive T cells to restrict the inflammatory cascade and accelerate recovery in experimental allergic encephalomyelitis

Effect of granulocyte colony-stimulating factor (G-CSF) in functional outcome of acute spinal cord injury patients: A single-blinded randomized controlled trial

Background

Spinal Cord Injury (SCI) is a major public health issue causing significant disability and economic burden. Current treatments primarily focus on mitigating secondary injury, with limited effective therapies available. This study explores the efficacy of the Granulocyte Colony-Stimulating Factor (G-CSF) in improving functional outcomes in acute SCI patients.

Materials and methods

This single-blinded randomized control trial was conducted at JIPMER's orthopedic department. Patients with acute spinal cord injury (SCI) were enrolled based on specific inclusion and exclusion criteria. Participants were divided into two groups: Group A (n = 16) received a G-CSF injection whereas Group B (n = 18) received a placebo (normal saline) injection. The primary evaluation was based on the changes in the ASIA impairment scale at 1-, 3-, and 6-months post-injury.

Results

The study involved 34 participants, predominantly male. Initial assessments showed significant differences in ASIA scores between the groups. Group A demonstrated marked improvement in neurological status at 1, 3, and 6 months post-treatment compared to Group B. The frequency of adverse events was comparable between the two groups.

Conclusion

G-CSF showed significant improvement in ASIA scores at various time points post-administration compared to placebo. These findings suggest G-CSF as a potential therapeutic agent in acute SCI treatment. However, due to the small sample size, further research is necessary to confirm these results.

Filgrastim, a Recombinant Form of Granulocyte Colony-stimulating Factor, Ameliorates 3-nitropropionic Acid and Haloperidol-induced Striatal Neurotoxicity in Rats

Striatal neurotoxicity is the pathological hallmark for a heterogeneous group of movement disorders like Tardive dyskinesia (TD) and Huntington's disease (HD). Both diseases are characterized by progressive impairment in motor function. TD and HD share common features at both cellular and subcellular levels. Filgrastim, a recombinant methionyl granulocyte colony-stimulating factor (GCSF), shows neuroprotective properties in in-vivo models of movement disorders. This study seeks to evaluate the neuroprotective effect of filgrastim in haloperidol and 3-NP-induced neurotoxicity in rats. The study was divided into two: in study one, rats were administered with haloperidol for 21 days, filgrastim at the dose of (20, 40, 60 µg/kg,s.c.) was administered once a day before haloperidol treatment and the following parameters (orofacial movements, rotarod, actophotometer) were performed to assess TD. Similarly, in the second study, rats were administered with 3-NP for 21 days, filgrastim at a dose of (20 and 40 µg/kg, s.c.) was administered, and the following parameters (rotarod, narrow beam walk, and open field test) were assessed for HD. On the 22nd day, animals were sacrificed and cortex and striatum isolated for oxidative stress (LPO, GSH, SOD, catalase, and nitrate) marker assessment. Results revealed that haloperidol and 3-NP treatment significantly impaired motor coordination, and oxidative defense inducing TD and HD-like symptoms. Treatment with filgrastim significantly averted haloperidol and 3-NP-induced behavioral and biochemical alterations. Conclusively, the neuroprotective effect of filgrastim is credited to its antioxidant properties. Hence, filgrastim might be a novel therapeutic candidate for the management of TD and HD.

Decoding lymphomyeloid divergence and immune hyporesponsiveness in G-CSF-primed human bone marrow by single-cell RNA-seq

Granulocyte colony-stimulating factor (G-CSF) has been widely used to mobilize bone marrow hematopoietic stem/progenitor cells for transplantation in the treatment of hematological malignancies for decades. Additionally, G-CSF is also accepted as an essential mediator in immune regulation, leading to reduced graft-versus-host disease following transplantation. Despite the important clinical roles of G-CSF, a comprehensive, unbiased, and high-resolution survey into the cellular and molecular ecosystem of the human G-CSF-primed bone marrow (G-BM) is lacking so far. Here, we employed single-cell RNA sequencing to profile hematopoietic cells in human bone marrow from two healthy donors before and after 5-day G-CSF administration. Through unbiased bioinformatics analysis, our data systematically showed the alterations in the transcriptional landscape of hematopoietic cells in G-BM, and revealed that G-CSF-induced myeloid-biased differentiation initiated from the stage of lymphoid-primed multipotent progenitors. We also illustrated the cellular and molecular basis of hyporesponsiveness of T cells and natural killer (NK) cells caused by G-CSF stimulation, including the potential direct mechanisms and indirect regulations mediated by ligand–receptor interactions. Taken together, our data extend the understanding of lymphomyeloid divergence and potential mechanisms involved in hyporesponsiveness of T and NK cells in human G-BM, which might provide basis for optimization of stem cell transplantation in hematological malignancy treatment.

Combination regimen of granulocyte colony-stimulating factor and recombinant human thrombopoietin improves the curative effect on elderly patients with leukemia through inducing pyroptosis and ferroptosis of leukemia cells

Leukemia ranks as the one of most common causes of death from tumor. 51.4% of patients with leukemia are over 65 years old. However, the median overall survival (OS) of elderly leukemia patients is less than one year. It is urgent to explore more effective treatments for elderly patients with leukemia. Our recent prospective phase II single-arm study has revealed that combination regimen of granulocyte colony-stimulating factor (G-CSF) and recombinant human thrombopoietin (rhTPO) could improve the curative effect on elderly patients with leukemia, yet the precise mechanism remains unknown. This study demonstrated that combination of G-CSF and rhTPO showed greater effect on suppressing leukemia growth than G-CSF or rhTPO alone in vitro and in vivo. Mechanistically, G-CSF induced pyroptosis through ELANE in leukemia cells. Besides, rhTPO triggered ferroptosis by EP300 in leukemia cells. Moreover, rhTPO suppressed glutathione peroxidase 4 (GPX4) expression to induce ferroptosis through blocking the interaction between EP300 and GPX4 gene promoter via associating with EP300. In summary, this study illuminated that combination regimen of G-CSF and rhTPO improved the curative effect on elderly patients with leukemia through inducing pyroptosis and ferroptosis of leukemia cells. Therefore, our results provided a theoretical basis for combination regimen of G-CSF and rhTPO treating leukemia and potential therapeutic targets for leukemia.

Dysregulation of Blood-Brain Barrier and Exacerbated Inflammatory Response in Cx47-Deficient Mice after Induction of EAE

Induction of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), in connexin 32 (Cx32) or Cx47 knockout (KO) mice with deficiency in oligodendrocyte gap junctions (GJs) results in a more severe disease course. In particular, Cx47 KO EAE mice experience an earlier EAE onset and more pronounced disease severity, accompanied by dysregulated pro-inflammatory responses preceding the disease manifestations. In this study, analysis of relevant pro-inflammatory cytokines in wild type EAE, Cx32 KO EAE, and Cx47 KO EAE mice revealed altered expression of Vcam-1 preceding EAE [7 days post injection (dpi)], of Ccl2 at the onset of EAE (12 dpi), and of Gm-csf at the peak of EAE (24 dpi) in Cx47 KO EAE mice. Moreover, Cx47 KO EAE mice exhibited more severe blood-spinal cord barrier (BSCB) disruption, enhanced astrogliosis with defects in tight junction formation at the glia limitans, and increased T-cell infiltration prior to disease onset. Thus, Cx47 deficiency appears to cause dysregulation of the inflammatory profile and BSCB integrity, promoting early astrocyte responses in Cx47 KO EAE mice that lead to a more severe EAE outcome. Further investigation into the role of oligodendrocytic Cx47 in EAE and multiple sclerosis pathology is warranted.

The impact of trophic and immunomodulatory factors on oligodendrocyte maturation: Potential treatments for encephalopathy of prematurity

Encephalopathy of prematurity (EoP) is a major cause of morbidity in preterm neonates, causing neurodevelopmental adversities that can lead to lifelong impairments. Preterm birth-related insults, such as cerebral oxygen fluctuations and perinatal inflammation, are believed to negatively impact brain development, leading to a range of brain abnormalities. Diffuse white matter injury is a major hallmark of EoP and characterized by widespread hypomyelination, the result of disturbances in oligodendrocyte lineage development. At present, there are no treatment options available, despite the enormous burden of EoP on patients, their families, and society. Over the years, research in the field of neonatal brain injury and other white matter pathologies has led to the identification of several promising trophic factors and cytokines that contribute to the survival and maturation of oligodendrocytes, and/or dampening neuroinflammation. In this review, we discuss the current literature on selected factors and their therapeutic potential to combat EoP, covering a wide range of in vitro, preclinical and clinical studies. Furthermore, we offer a future perspective on the translatability of these factors into clinical practice.

The role of follistatin and granulocyte-colony stimulating factor in HIV-associated pre-eclampsia

KwaZulu-Natal has a high burden of HIV infection and high blood pressure, specifically pre-eclampsia (PE) in pregnancy. Follistatin (FS) and granulocyte-colony stimulating factor (G-CSF) are two glycoproteins involved in PE pathogenesis. In light of the high maternal mortality and morbidity in South Africa (SA), we investigated the expression of FS and G-CSF in the duality of HIV-associated PE. Serum samples of normotensive and pre-eclamptic women were analysed using the Bio-Plex Multiplex Immunoassay. FS expression was significantly reduced in pre-eclamptic (median = 372.0, IQR = 719.2) compared to normotensive (median = 1569.0, IQR = 2043.0) (p < 0.0001). Furthermore, we detected significant FS expression across all study groups. There was a significant difference between HIV -ve normotensive (median = 9.0, IQR = 7.0) vs HIV +ve normotensive (median = 12.0, IQR = 5.0) groups. Additionally, G-CSF expression was notably higher in HIV +ve normotensive when compared to all study groups. This study demonstrated a downregulation of FS and G-CSF expression in PE, compared to normotensive pregnancies. This finding may be attributed to oxidative stress and its immunoregulatory role in the hyperinflammatory milieu of PE. HIV status had no effect on both analytes, albeit upregulated due to immune reconstitution emanating from highly active antiretroviral therapy. Our novel findings suggest that FS and G-CSF may have a potential predictor test value in early pregnancy, hence work on this is ongoing.

Stimulations of the Culture Medium of Activated Microglia and TNF-Alpha on a Scrapie-Infected Cell Line Decrease the Cell Viability and Induce Marked Necroptosis That Also Occurs in the Brains from the Patients of Human Prion Diseases

Activation of microglia and increased expression of TNF-α are frequently observed in the brains of human and animal prion diseases. As an important cytokine, TNF-α participates in not only pro-inflammatory responses but also in cellular communication, cell differentiation, and cell death. However, the role of TNF-α in the pathogenesis of prion disease remains ambiguous. In this study, the activities of a scrapie-infected cell line SMB-S15 and its normal partner SMB-PS exposed to the supernatant of a LPS-activated microglia cell line BV2 were evaluated. After it was exposed to the LPS-stimulated supernatant of BV2 cells, the cell viability of SMB-S15 cells was markedly decreased, whereas that of the SMB-PS cells remained unchanged. The level of TNF-α was significantly increased in the LPS-stimulated supernatant of BV2 cells. Further, we found that the recombinant TNF-α alone induced the decreased cell viability of SMB-S15 and the neutralizing antibody for TNF-α completely antagonized the decreased cell viability caused by the LPS-stimulated supernatant of BV2 cells. Stimulation with TNF-α induced the remarkable increases of apoptosis-associated proteins in SMB-PS cells, such as cleaved caspase-3 and RIP1, whereas an obvious increase of necroptosis-associated protein in SMB-S15 cells, such as p-MLKL. Meanwhile, the upregulation of caspase-8 activity in SMB-PS cells was more significant than that of SMB-S15 cells. The decreased cell viability of SMB-S15 and the increased expression of p-MLKL induced by TNF-α were completely rescued by Necrostatin-1. Moreover, we verified that removal of PrP^Sc propagation in SMB-S15 cells by resveratrol partially rescues the cell tolerance to the stimulation of TNF-α. These data indicate that the prion-infected cell line SMB-S15 is more vulnerable to the stimulations of activated microglia and TNF-α, which is likely due to the outcome of necroptosis rather than apoptosis. Furthermore, significant upregulation of p-MLKL, MLKL, and RIP3 was detected in the post-mortem cortical brains of the patients of various types of human prion diseases, including sporadic Creutzfeldt-Jakob disease (sCJD), G114 V-genetic CJD (gCJD), and fatal familial insomnia (FFI).

The relevance of ceramides and their synthesizing enzymes for multiple sclerosis

Ceramide synthases (CerS) synthesize chain length specific ceramides (Cer), which mediate cellular processes in a chain length-dependent manner. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed that the genetic deletion of CerS2 suppresses EAE pathology by interaction with granulocyte-colony stimulating factor (G-CSF) signaling and CXC motif chemokine receptor 2 (CXCR2) expression, leading to impaired neutrophil migration. In the present study, we investigated the importance of Cers and their synthesizing/metabolizing enzymes in MS. For this purpose, a longitudinal study with 72 MS patients and 25 healthy volunteers was performed. Blood samples were collected from healthy controls and MS patients over 1- or 3-year periods, respectively. Immune cells were counted using flow cytometry, ceramide levels were determined using liquid chromatography-tandem mass spectrometry, and mRNA expression was analyzed using quantitative PCR. In white blood cells, C16-LacCer and C24-Cer were down-regulated in MS patients in comparison with healthy controls. In plasma, C16-Cer, C24:1-Cer, C16-GluCer, and C24:1-GluCer were up-regulated and C16-LacCer was down-regulated in MS patients in comparison with healthy controls. Blood samples from MS patients were characterized by an increased B-cell number. However, there was no correlation between B-cell number and Cer levels. mRNA expression of Cer metabolizing enzymes and G-CSF signaling enzymes was significantly increased in MS patients. Interestingly, G-CSF receptor (G-CSFR) and CXCR2 mRNA expression correlated with CerS2 and UDP-glucose Cer glucosyltransferase (UGCG) mRNA expression. In conclusion, our results indicate that Cer metabolism is linked to G-CSF signaling in MS.

Sarcodon imbricatus polysaccharides improve mouse hematopoietic function after cyclophosphamide-induced damage via G-CSF mediated JAK2/STAT3 pathway

Sarcodon imbricatus, a rare medicinal and edible fungus, has various pharmacological bioactivities. We investigated the effects of S. imbricatus polysaccharides (SIPS) on hematopoietic function and identified the underlying mechanisms using in vitro experiments with CHRF, K562, and bone marrow mononuclear cells (BMMNCs) and in vivo experiments with a mouse model of cyclophosphamide-induced hematopoietic dysfunction. We found that SIPS induced proliferation and differentiation of CHRF and K562 cells and upregulated the expression of hematopoietic-related proteins, including p90 ribosomal S6 kinases (RSK1p90), c-Myc, and ETS transcription factor, in the two cell lines. After 28 days of treatment, SIPS enhanced the bodyweight and thymus indices of the mice, alleviated enlargement of the spleen and liver, and contributed to the recovery of peripheral blood to normal levels. More importantly, the percentages of B lymphocytes and hematopoietic stem cells or hematopoietic progenitor cells were significantly elevated in bone marrow. Based on an antibody chip analysis and enzyme-linked immunosorbent assay, SIPS were found to successfully regulate 12 cytokines to healthy levels in serum and spleen. The cytokines included the following: interleukins 1Ra, 2, 3, 4, 5, and 6, tumor necrosis factor α, interferon⁻γ, granulocyte colony-stimulating factor (G-CSF) and macrophage colony-stimulating factor (M-CSF), C-C motif chemokine1, and monocyte chemoattractant protein⁻1. Moreover, SIPS upregulated the phosphorylation levels of janus kinase 2 (JAK2) and the signal transducer and activator of transcription 3 (STAT3) in the spleen, and similar results were validated in CHRF cells, K562 cells, and BMMNCs. The data indicate that SIPS activated the JAK2/STAT3 pathway, possibly by interactions among multiple cytokines, particularly G-CSF. We found that SIPS was remarkably beneficial to the bone marrow hematopoietic system, and we anticipate that it could improve myelosuppression induced by long-term radiotherapy or chemotherapy.

Neuroprotective effects of G-CSF administration in microglia-mediated reactive T cell activation in vitro

G-CSF is a growth factor that has known neuroprotective effects in a variety of experimental brain injury models. As both antigen-presenting microglia and reactive T cells are key components in the development and progression of EAE, the aim of this study is to investigate the neuroprotective effects of recombinant human G-CSF, as administered in microglia-mediated reactive T cell assay in vitro. Our results indicate that G-CSF treatment has no apparent effect for the resting un-activated microglia. G-CSF pre-protection of microglia increased protective cytokine IL-4 production and effectively inhibited the productions of NO and other inflammatory mediators (IFN-γ, TNF-α, IL-1β, IL-17, and chemokine MCP-1) after LPS stimulation. G-CSF suppressed the proliferative response of microglia-mediated MOG_35-55 reactive T cells. G-CSF-microglia-T cells increased IL-4 and IL-10 secretions and decreased IFN-γ, TNF-α, and IL-17 productions. G-CSF significantly elevated CD4⁺CD25⁺ regulatory T cell subset in microglia-mediated reactive T cells. Moreover, G-CSF inhibited MHC-II expression of microglia after LPS activation or in the interactions of microglia and reactive T cells. G-CSF administration induced the apoptosis and enhanced the G0/G1 to S phase transition and elevated the gene expression of apoptosis markers in microglia-mediated reactive T cells after stimulated by specific antigen MOG_35-55. These findings reveal that G-CSF administration potently neuroprotects the central nervous system (CNS) from immune-mediated damage in microglia-mediated reactive T cell activation. Apoptosis of reactive T cells in CNS is important in attenuating the development of autoimmune CNS diseases. G-CSF administration has neuroprotective effects in CNS and the potential to be a therapeutic agent in multiple sclerosis.