SIRT6 inhibition delays peripheral nerve recovery by suppressing migration, phagocytosis and M2-polarization of macrophages

Abstract Background Silent information regulator 6 (SIRT6) is a mammalian homolog of the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin family. Prior evidences suggested that the anti-inflammatory function of SIRT6 after spinal cord and brain injury, and it plays a crucial role in macrophages polarization of adipose tissue and skin. However, the role of SIRT6 in macrophages involved peripheral nerve injury is still unknown. Given the prominent role of macrophages in peripheral nerve recovery, we aim to investigate the role of SIRT6 in the regulation of phenotypes shift and functions in macrophages after peripheral nerve injury. Results In the present study, we first identified a significant increase of SIRT6 expression during nerve degeneration and macrophages phagocytosis. Next, we found nerve recovery was delayed after SIRT6 silencing by injected shRNA lentivirus into the crushed sciatic nerve, which exhibited a reduced expression of myelin-related proteins (e.g., MAG and MBP), severer myoatrophy of target muscles, and inferior nerve conduction compared to the shRNA control injected mice. In vitro, we found that SIRT6 inhibition by being treated with a selective inhibitor OSS_128167 or lentivirus transfection impairs migration and phagocytosis capacity of bone marrow-derived macrophages (BMDM). In addition, SIRT6 expression was discovered to be reduced after M1 polarization, but SIRT6 was enhanced after M2 polarization in the monocyte-macrophage cell line RAW264.7 and BMDM. Moreover, SIRT6 inhibition increased M1 macrophage polarization with a concomitant decrease in M2 polarization both in RAW264.7 and BMDM via activating NF-κB and TNF-α expression, and SIRT6 activation by UBCS039 treatment could shift the macrophages from M1 to M2 phenotype. Conclusion Our findings indicate that SIRT6 inhibition impairs peripheral nerve repair through suppressing the migration, phagocytosis, and M2 polarization of macrophages. Therefore, SIRT6 may become a favorable therapeutic target for peripheral nerve injury.

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Histone lactylation drives oncogenesis by facilitating m6A reader protein YTHDF2 expression in ocular melanoma

Genome Biology ◽

10.1186/s13059-021-02308-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jie Yu ◽

Peiwei Chai ◽

Minyue Xie ◽

Shengfang Ge ◽

Jing Ruan ◽

...

Keyword(s):

Macrophage Polarization ◽

Regulation Of Gene Expression ◽

Metabolic Stress ◽

Ocular Melanoma ◽

Rna Modifications ◽

M1 Macrophage ◽

Melanoma Therapy

Abstract Background Histone lactylation, a metabolic stress-related histone modification, plays an important role in the regulation of gene expression during M1 macrophage polarization. However, the role of histone lactylation in tumorigenesis remains unclear. Results Here, we show histone lactylation is elevated in tumors and is associated with poor prognosis of ocular melanoma. Target correction of aberrant histone lactylation triggers therapeutic efficacy both in vitro and in vivo. Mechanistically, histone lactylation contributes to tumorigenesis by facilitating YTHDF2 expression. Moreover, YTHDF2 recognizes the m6A modified PER1 and TP53 mRNAs and promotes their degradation, which accelerates tumorigenesis of ocular melanoma. Conclusion We reveal the oncogenic role of histone lactylation, thereby providing novel therapeutic targets for ocular melanoma therapy. We also bridge histone modifications with RNA modifications, which provides novel understanding of epigenetic regulation in tumorigenesis.

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Role of Histamine H3 and H4 Receptors in Mechanical Hyperalgesia following Peripheral Nerve Injury

NeuroImmunoModulation ◽

10.1159/000125048 ◽

2007 ◽

Vol 14 (6) ◽

pp. 317-325 ◽

Cited By ~ 33

Author(s):

Fiona M. Smith ◽

Hila Haskelberg ◽

David J. Tracey ◽

Gila Moalem-Taylor

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Mechanical Hyperalgesia

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Chitin conduits modified with DNA-peptide coating promote the peripheral nerve regeneration

Biofabrication ◽

10.1088/1758-5090/ac3bdc ◽

2021 ◽

Author(s):

Songyang Liu ◽

Liping Zhou ◽

Ci Li ◽

Tiantian Min ◽

Changfeng Lu ◽

...

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Amide Bond ◽

Primary Amines ◽

Direct Reaction ◽

Ct Dna ◽

Peptide Coating

Abstract Peripheral nerve injury (PNI) is one of the common clinical injuries which needs to be addressed. Previous studies demonstrated the effectiveness of using biodegradable chitin (CT) conduits small gap tubulization technology as a substitute for traditional epineurial neurorrhaphy. Aiming to improve the effectiveness of CT conduits in repairing PNI, we modified their surface with a DNA-peptide coating. The coating consisted of single strand DNA (ssDNA) and its complementary DNA’-peptide mimics. First, we immobilize ssDNA (DNA1+2) on CT conduits by EDC/NHS method to construct CT/DNA conduits. EDC/NHS was used to activate carboxyl groups of modified ssDNA for direct reaction with primary amines on the chitin via amide bond formation. Then, DNA1’-BDNF+DNA2’-VEGF mimic peptide （RGI+KLT）were bonded to CT/DNA conduits by complementary base pairing principle at room temperature to form CT/RGI+KLT conduits. When the surrounding environment rose to a certain point (37℃), the CT/RGI+KLT conduits achieved sustainable release of DNA’-peptide. In vitro, the CT conduits modified with the DNA-peptide coating promoted the proliferation and secretion of Schwann cells by maintaining their repair state. It also promoted the proliferation of HUVECs and axon outgrowth of DRG explants. In vivo, CT/RGI+KLT conduits promoted regeneration of injured nerves and functional recovery of target muscles, which was facilitated by the synergistic contribution of angiogenesis and neurogenesis. Our research brings DNA and DNA-peptide hybrids into the realm of tissue engineering to repair peripheral nerve injury.

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Role of the Excitability Brake Potassium Current I KD in Cold Allodynia Induced by Chronic Peripheral Nerve Injury

Journal of Neuroscience ◽

10.1523/jneurosci.3553-16.2017 ◽

2017 ◽

Vol 37 (12) ◽

pp. 3109-3126 ◽

Cited By ~ 21

Author(s):

Alejandro González ◽

Gonzalo Ugarte ◽

Carlos Restrepo ◽

Gaspar Herrera ◽

Ricardo Piña ◽

...

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Potassium Current ◽

Cold Allodynia

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Positioning-Related Peripheral Nerve Injury During Spine Surgery and the Role of Intraoperative Neuromonitoring

Contemporary Spine Surgery ◽

10.1097/01.css.0000802036.45406.16 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6-6

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Spine Surgery ◽

Peripheral Nerve Injury ◽

Intraoperative Neuromonitoring

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M1 macrophage infiltration exacerbate muscle/bone atrophy after peripheral nerve injury

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-3069-z ◽

2020 ◽

Vol 21 (1) ◽

Cited By ~ 1

Author(s):

Nobuhiro Shimada ◽

Asuka Sakata ◽

Takashi Igarashi ◽

Mamoru Takeuchi ◽

Satoshi Nishimura

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Macrophage Infiltration ◽

M1 Macrophage ◽

Bone Atrophy

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The gut microbial metabolite trimethylamine N-oxide aggravates GVHD by inducing M1 macrophage polarization in mice

Blood ◽

10.1182/blood.2019003990 ◽

2020 ◽

Vol 136 (4) ◽

pp. 501-515 ◽

Cited By ~ 8

Author(s):

Kunpeng Wu ◽

Yan Yuan ◽

Huihui Yu ◽

Xin Dai ◽

Shu Wang ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Macrophage Polarization ◽

Short Chain Fatty Acids ◽

Inflammasome Activation ◽

Microbial Metabolites ◽

M1 Macrophage ◽

The Impact

Abstract The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage’s response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.

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