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Phototherapy suppresses inflammation in human nucleus pulposus cells for intervertebral disc degeneration

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Abstract

The etiology of intervertebral disc (IVD) degeneration accompanied by low back pain (LBP) is largely unknown, and there are no curative therapies. Painful IVD degeneration is associated with infiltrated macrophage-mediated inflammatory response of human nucleus pulposus (NP) cells. The present study aimed to address the hypothesis that pro-inflammatory cytokines derived from macrophages lead to the altered molecular phenotype of human NP cells and to investigate the effects of phototherapy (630, 525, 465 nm with 16, 32, 64 J/cm2) on pain-related cytokine interleukin (IL)-6 and chemokine IL-8 under inflammatory conditions in human NP cells. Human NP cells were treated with soluble factors derived from macrophages in an inflammatory microenvironment, similar to that found in degenerative IVD. Human NP cells were also treated with phototherapy (630, 525, 465 nm with 16, 32, 64 J/cm2), and their cytokine and chemokine levels were detected. The soluble factors caused modulated expression of IL-6, IL-8, and matrix metalloproteinases (MMPs) at the gene and protein levels, causing a shift toward matrix catabolism through the expression of MMPs and increased pain-related factors via preferential activation of the nuclear factor-kappa B (NF-κB) p50 protein. Importantly, phototherapy attenuated the protein and gene expression of pain-related factor IL-6 at all doses and wavelengths. Interestingly, phototherapy also modulated the protein and gene expression of IL-8, which is responsible for the anabolic response, at a wavelength of 465 nm at all doses, in human NP cells. These findings suggested that phototherapy, at an optimal dose and wavelength, might be a useful therapeutic tool to treat IVD degeneration.

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Abbreviations

2-ME:

2-mercaptoethanol

AF:

annulus fibrosus

ANOVA:

analysis of variance

BSA:

bovine serum albumin

DAPI:

4′, 6-diamidino-2-phenylindol

DRG:

dorsal root ganglion

ELISA:

enzyme linked immunosorbent assay

EP:

endplate

FBS:

fetal bovine serum

HBSS:

Hank’s balanced salt solution

IL:

interleukin

InGaAIP:

indium gallium aluminum phosphide

IVD:

intervertebral disc

LBP:

low back pain

LDH:

lactate dehydrogenase

LED:

light-emitting diode

MCM:

macrophage-conditioned medium

MMPs:

matrix metalloproteinases

NF-κB:

nuclear factor-kappa B

NP:

nucleus pulposus

NPM:

NP cells exposed to macrophages

P/S:

penicillin/streptomycin

PBS:

phosphate-buffered saline

PMA:

phorbol myristate acetate

qPCR:

quantitative real-time polymerase chain reaction

TNF-α:

tumor necrosis factor-alpha

References

  1. Maniadakis N, Gray A (2000) The economic burden of back pain in the UK. Pain 84(1):95–103

    Article  PubMed  CAS  Google Scholar 

  2. Vos T, Flaxman AD, Naghavi M, Lozano R, Michaud C, Ezzati M, Shibuya K, Salomon JA, Abdalla S, Aboyans V (2013) Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the global burden of disease study 2010. Lancet 380(9859):2163–2196

    Article  Google Scholar 

  3. Huang Y-C, Urban JP, Luk KD (2014) Intervertebral disc regeneration: do nutrients lead the way? Nat Rev Rheumatol 10(9):561–566

    Article  PubMed  Google Scholar 

  4. Sakai D, Andersson GB (2015) Stem cell therapy for intervertebral disc regeneration: obstacles and solutions. Nat Rev Rheumatol 11(4):243–256

    Article  PubMed  Google Scholar 

  5. Feng C, Liu H, Yang M, Zhang Y, Huang B, Zhou Y (2016) Disc cell senescence in intervertebral disc degeneration: causes and molecular pathways. Cell Cycle 15(13):1674–1684

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  6. Yu L-P, Qian W-W, Yin G-Y, Ren Y-X, Hu Z-Y (2012) MRI assessment of lumbar intervertebral disc degeneration with lumbar degenerative disease using the Pfirrmann grading systems. PLoS One 7(12):e48074

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  7. Adams MA, Roughley PJ (2006) What is intervertebral disc degeneration, and what causes it? Spine 31(18):2151–2161

    Article  PubMed  Google Scholar 

  8. David S, Kroner A (2011) Repertoire of microglial and macrophage responses after spinal cord injury. Nat Rev Neurosci 12(7):388

    Article  PubMed  CAS  Google Scholar 

  9. Podichetty VK (2007) The aging spine: the role of inflammatory mediators in intervertebral disc degeneration. Cell Mol Biol (Noisy-le-Grand, France) 53(5):4–18

    CAS  Google Scholar 

  10. Urban JP, Roberts S (2003) Degeneration of the intervertebral disc. Arthritis Res Ther 5(3):120

    Article  PubMed  PubMed Central  Google Scholar 

  11. Le Maitre CL, Freemont AJ, Hoyland JA (2005) The role of interleukin-1 in the pathogenesis of human intervertebral disc degeneration. Arthritis Res Ther 7(4):R732

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  12. Le Maitre CL, Hoyland JA, Freemont AJ (2007) Catabolic cytokine expression in degenerate and herniated human intervertebral discs: IL-1β and TNFα expression profile. Arthritis Res Ther 9(4):R77

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  13. Risbud MV, Shapiro IM (2014) Role of cytokines in intervertebral disc degeneration: pain and disc content. Nat Rev Rheumatol 10(1):44–56

    Article  PubMed  CAS  Google Scholar 

  14. Shen J, Xu S, Zhou H, Liu H, Jiang W, Hao J, Hu Z (2017) IL-1β induces apoptosis and autophagy via mitochondria pathway in human degenerative nucleus pulposus cells. Sci Rep 7

  15. Yang H, Cao C, Wu C, Yuan C, Gu Q, Shi Q, Zou J (2015) TGF-βl suppresses inflammation in cell therapy for intervertebral disc degeneration. Sci Rep 5

  16. Freemont A, Peacock T, Goupille P, Hoyland J, O'brien J, Jayson M (1997) Nerve ingrowth into diseased intervertebral disc in chronic back pain. Lancet 350(9072):178–181

    Article  PubMed  CAS  Google Scholar 

  17. Moon HJ, Yurube T, Lozito TP, Pohl P, Hartman RA, Sowa GA, Kang JD, Vo N (2014) Effects of secreted factors in culture medium of annulus fibrosus cells on microvascular endothelial cells: elucidating the possible pathomechanisms of matrix degradation and nerve in-growth in disc degeneration. Osteoarthr Cartil 22(2):344–354

    Article  PubMed  CAS  Google Scholar 

  18. Pohl PH, Lozito TP, Cuperman T, Yurube T, Moon HJ, Ngo K, Tuan RS, St Croix C, Sowa GA, Rodrigues LM (2016) Catabolic effects of endothelial cell-derived microparticles on disc cells: implications in intervertebral disc neovascularization and degeneration. J Orthop Res 34(8):1466–1474

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  19. Hwang MH, Kim KS, Yoo CM, Shin JH, Nam HG, Jeong JS, Kim JH, Lee KH, Choi H (2016) Photobiomodulation on human annulus fibrosus cells during the intervertebral disk degeneration: extracellular matrix-modifying enzymes. Lasers Med Sci 31(4):767–777

    Article  PubMed  Google Scholar 

  20. Hwang MH, Shin JH, Kim KS, Yoo CM, Jo GE, Kim JH, Choi H (2015) Low level light therapy modulates inflammatory mediators secreted by human annulus fibrosus cells during intervertebral disc degeneration in vitro. Photochem Photobiol 91(2):403–410

    Article  PubMed  CAS  Google Scholar 

  21. Ökmen K, Ökmen BM (2017) One-year follow-up results of intradiscal diode laser, radiofrequency, and pulsed radiofrequency therapies: a retrospective study. Lasers Med Sci 32(1):137–142

    Article  PubMed  Google Scholar 

  22. Tomazoni SS, Leal-Junior EC, Pallotta RC, Teixeira S, de Almeida P, Lopes-Martins RÁB (2017) Effects of photobiomodulation therapy, pharmacological therapy, and physical exercise as single and/or combined treatment on the inflammatory response induced by experimental osteoarthritis. Lasers Med Sci 32(1):101–108

    Article  PubMed  Google Scholar 

  23. Khadra M, Lyngstadaas SP, Haanæs HR, Mustafa K (2005) Effect of laser therapy on attachment, proliferation and differentiation of human osteoblast-like cells cultured on titanium implant material. Biomaterials 26(17):3503–3509

    Article  PubMed  CAS  Google Scholar 

  24. Zare D, Haerian A, Molla R, Vaziri F (2014) Evaluation of the effects of diode (980 nm) laser on gingival inflammation after nonsurgical periodontal therapy. J Lasers Med Sci 5(1):27

    PubMed  PubMed Central  Google Scholar 

  25. AlGhamdi KM, Kumar A, Moussa NA (2012) Low-level laser therapy: a useful technique for enhancing the proliferation of various cultured cells. Lasers Med Sci 27(1):237–249

    Article  PubMed  Google Scholar 

  26. Saygun I, Karacay S, Serdar M, Ural AU, Sencimen M, Kurtis B (2008) Effects of laser irradiation on the release of basic fibroblast growth factor (bFGF), insulin like growth factor-1 (IGF-1), and receptor of IGF-1 (IGFBP3) from gingival fibroblasts. Lasers Med Sci 23(2):211–215

    Article  PubMed  Google Scholar 

  27. de Sousa APC, Paraguassú GM, Silveira NTT, de Souza J, Cangussú MCT, dos Santos JN, Pinheiro ALB (2013) Laser and LED phototherapies on angiogenesis. Lasers Med Sci 28(3):981–987

    Article  PubMed  Google Scholar 

  28. Corazza AV, Jorge J, Kurachi C, Bagnato VS (2007) Photobiomodulation on the angiogenesis of skin wounds in rats using different light sources. Photomed Laser Surg 25(2):102–106

    Article  PubMed  Google Scholar 

  29. Wagner VP, Curra M, Webber LP, Nör C, Matte U, Meurer L, Martins MD (2016) Photobiomodulation regulates cytokine release and new blood vessel formation during oral wound healing in rats. Lasers Med Sci 31(4):665–671

    Article  PubMed  Google Scholar 

  30. Santos LA, Marcos RL, Tomazoni SS, Vanin AA, Antonialli FC, dos Santos Grandinetti V, Albuquerque-Pontes GM, de Paiva PRV, Lopes-Martins RÁB, de Tarso Camillo de Carvalho P (2014) Effects of pre-irradiation of low-level laser therapy with different doses and wavelengths in skeletal muscle performance, fatigue, and skeletal muscle damage induced by tetanic contractions in rats. Lasers Med Sci 29(5):1617–1626

    Article  PubMed  Google Scholar 

  31. Laraia EMS, Silva IS, Pereira DM, dos Reis FA, Albertini R, de Almeida P, Leal-Junior EC, de Tarso Camillo de Carvalho P (2012) Effect of low-level laser therapy (660 nm) on acute inflammation induced by tenotomy of Achilles tendon in rats. Photochem Photobiol 88(6):1546–1550

    Article  PubMed  CAS  Google Scholar 

  32. Aver Vanin A, De Marchi T, Silva Tomazoni S, Tairova O, Leão Casalechi H, de Tarso Camillo de Carvalho P, Bjordal JM, Leal-Junior EC (2016) Pre-exercise infrared low-level laser therapy (810 nm) in skeletal muscle performance and postexercise recovery in humans, what is the optimal dose? A randomized, double-blind, placebo-controlled clinical trial. Photomed Laser Surg 34(10):473–482

    Article  PubMed  CAS  Google Scholar 

  33. de Oliveira AR, Vanin AA, Tomazoni SS, Miranda EF, Albuquerque-Pontes GM, De Marchi T, dos Santos Grandinetti V, de Paiva PRV, Imperatori TBG, de Tarso Camillo de Carvalho P (2017) Pre-exercise infrared photobiomodulation therapy (810 nm) in skeletal muscle performance and Postexercise recovery in humans: what is the optimal power output? Photomed Laser Surg 35(11):595–603

    Article  PubMed  CAS  Google Scholar 

  34. de Almeida P, Tomazoni SS, Frigo L, de Tarso Camillo de Carvalho P, Vanin AA, Santos LA, Albuquerque-Pontes GM, De Marchi T, Tairova O, Marcos RL (2014) What is the best treatment to decrease pro-inflammatory cytokine release in acute skeletal muscle injury induced by trauma in rats: low-level laser therapy, diclofenac, or cryotherapy? Lasers Med Sci 29(2):653–658

    Article  PubMed  Google Scholar 

  35. Tomazoni SS, Frigo L, dos Reis Ferreira TC, Casalechi HL, Teixeira S, de Almeida P, Muscara MN, Marcos RL, Serra AJ, de Tarso Camillo de Carvalho P (2017) Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats—part 1: morphological and functional aspects. Lasers Med Sci 32(9):2111–2120

    Article  PubMed  Google Scholar 

  36. Tomazoni SS, Frigo L, dos Reis Ferreira TC, Casalechi HL, Teixeira S, de Almeida P, Muscara MN, Marcos RL, Serra AJ, de Tarso Camillo de Carvalho P (2017) Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats—part 2: biochemical aspects. Lasers Med Sci 32(8):1879–1887

    Article  PubMed  Google Scholar 

  37. Marcos RL, Leal-Junior EC, de Moura Messias F, Catelli de Carvalho MH, Pallotta RC, Frigo L, dos Santos RA, Ramos L, Teixeira S (2011) Infrared (810 nm) low-level laser therapy in rat Achilles tendinitis: a consistent alternative to drugs. Photochem Photobiol 87(6):1447–1452

    Article  PubMed  CAS  Google Scholar 

  38. Marcos RL, Leal-Junior EC, Arnold G, Magnenet V, Rahouadj R, Wang X, Demeurie F, Magdalou J, de Carvalho MHC, Lopes-Martins RÁB (2012) Low-level laser therapy in collagenase-induced Achilles tendinitis in rats: analyses of biochemical and biomechanical aspects. J Orthop Res 30(12):1945–1951

    Article  PubMed  CAS  Google Scholar 

  39. da Rosa AS, dos Santos AF, da Silva MM, Facco GG, Perreira DM, Alves ACA, Leal-Junior EC, de Tarso Camillo de Carvalho P (2012) Effects of low-level laser therapy at wavelengths of 660 and 808 nm in experimental model of osteoarthritis. Photochem Photobiol 88(1):161–166

    Article  PubMed  CAS  Google Scholar 

  40. Almeida P, Lopes-Martins RÁB, Tomazoni SS, Albuquerque-Pontes GM, Santos LA, Vanin AA, Frigo L, Vieira RP, Albertini R, de Tarso Camillo de Carvalho P (2013) Low-level laser therapy and sodium diclofenac in acute inflammatory response induced by skeletal muscle trauma: effects in muscle morphology and mRNA gene expression of inflammatory markers. Photochem Photobiol 89(2):501–507

    Article  PubMed  CAS  Google Scholar 

  41. de Almeida P, Lopes-Martins RÁB, Tomazoni SS, Silva JA Jr, de Tarso Camillo de Carvalho P, Bjordal JM, Leal-Junior EC (2011) Low-level laser therapy improves skeletal muscle performance, decreases skeletal muscle damage and modulates mRNA expression of COX-1 and COX-2 in a dose-dependent manner. Photochem Photobiol 87(5):1159–1163

    Article  PubMed  CAS  Google Scholar 

  42. Aparecida Da Silva A, Leal-Junior EC, Alves ACA, Rambo CS, Dos Santos SA, Vieira RP, de Tarso Camillo de Carvalho P (2013) Wound-healing effects of low-level laser therapy in diabetic rats involve the modulation of MMP-2 and MMP-9 and the redistribution of collagen types I and III. J Cosmet Laser Ther 15(4):210–216

    Article  PubMed  Google Scholar 

  43. Alves ACA, Albertini R, dos Santos SA, Leal-Junior EC, Santana E, Serra AJ, Silva JA, de Tarso Camillo de Carvalho P (2014) Effect of low-level laser therapy on metalloproteinase MMP-2 and MMP-9 production and percentage of collagen types I and III in a papain cartilage injury model. Lasers Med Sci 29(3):911–919

    PubMed  Google Scholar 

  44. Yun SH, Kwok SJ (2017) Light in diagnosis, therapy and surgery. Nature Biomed Eng 1:0008

    Article  Google Scholar 

  45. Kawaguchi S, Yamashita T, Katahira G-i, Yokozawa H, Torigoe T, Sato N (2002) Chemokine profile of herniated intervertebral discs infiltrated with monocytes and macrophages. Spine 27(14):1511–1516

    Article  PubMed  Google Scholar 

  46. Bian Q, Jain A, Xu X, Kebaish K, Crane JL, Zhang Z, Wan M, Ma L, Riley LH, Sponseller PD (2016) Excessive activation of TGFβ by spinal instability causes vertebral endplate sclerosis. Sci Rep 6

  47. Guerra FDR, Vieira CP, Almeida MS, Oliveira LP, de Aro AA, Pimentel ER (2013) LLLT improves tendon healing through increase of MMP activity and collagen synthesis. Lasers Med Sci 28(5):1281–1288

    Article  Google Scholar 

  48. Chen AC, Arany PR, Huang Y-Y, Tomkinson EM, Sharma SK, Kharkwal GB, Saleem T, Mooney D, Yull FE, Blackwell TS (2011) Low-level laser therapy activates NF-kB via generation of reactive oxygen species in mouse embryonic fibroblasts. PLoS One 6(7):e22453

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  49. Zhang L, Xing D, Gao X, Wu S (2009) Low-power laser irradiation promotes cell proliferation by activating PI3K/Akt pathway. J Cell Physiol 219(3):553–562

    Article  PubMed  CAS  Google Scholar 

  50. Wu J-Y, Chen C-H, Wang C-Z, Ho M-L, Yeh M-L, Wang Y-H (2013) Low-power laser irradiation suppresses inflammatory response of human adipose-derived stem cells by modulating intracellular cyclic AMP level and NF-κB activity. PLoS One 8(1):e54067

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  51. Scheller J, Chalaris A, Schmidt-Arras D, Rose-John S (2011) The pro-and anti-inflammatory properties of the cytokine interleukin-6. Biochim Biophys Acta (BBA) Mol Cell Res 1813(5):878–888

    Article  CAS  Google Scholar 

  52. Murata Y, Nannmark U, Rydevik B, Takahashi K, Olmarker K (2008) The role of tumor necrosis factor-α in apoptosis of dorsal root ganglion cells induced by herniated nucleus pulposus in rats. Spine 33(2):155–162

    Article  PubMed  Google Scholar 

  53. Murata Y, Rydevik B, Nannmark U, Larsson K, Takahashi K, Kato Y, Olmarker K (2011) Local application of interleukin-6 to the dorsal root ganglion induces tumor necrosis factor-alpha in the dorsal root ganglion and results in apoptosis of the dorsal root ganglion cells. Spine 36(12):926–932

    Article  PubMed  Google Scholar 

  54. Cuellar JM, Borges PM, Cuéllar VG, Yoo A, Scuderi GJ, Yeomans DC (2013) Cytokine expression in the epidural space: a model of non-compressive disc herniation-induced inflammation. Spine 38(1):17

    Article  PubMed  PubMed Central  Google Scholar 

  55. Séguin CA, Pilliar RM, Roughley PJ, Kandel RA (2005) Tumor necrosis factorα modulates matrix production and catabolism in nucleus pulposus tissue. Spine 30(17):1940–1948

    Article  PubMed  Google Scholar 

  56. Tomazoni SS, Leal-Junior EC, Frigo L, Pallotta RC, Teixeira S, de Almeida P, Bjordal JM, Lopes-Martins RÁB (2016) Isolated and combined effects of photobiomodulation therapy, topical nonsteroidal anti-inflammatory drugs, and physical activity in the treatment of osteoarthritis induced by papain. J Biomed Opt 21(10):108001–108001

    Article  PubMed  Google Scholar 

  57. Alves ACA, de Tarso Camillo de Carvalho P, Parente M, Xavier M, Frigo L, Aimbire F, Leal-Junior EC, Albertini R (2013) Low-level laser therapy in different stages of rheumatoid arthritis: a histological study. Lasers Med Sci 28(2):529–536

    Article  PubMed  Google Scholar 

  58. Kuelling FA, Foley KT, Liu JJ, Liebenberg E, Sin AH, Matsukawa A, Lotz JC (2014) The anabolic effect of plasma-mediated ablation on the intervertebral disc: stimulation of proteoglycan and interleukin-8 production. Spine J 14(10):2479–2487

    Article  PubMed  Google Scholar 

  59. Rennekampff H-O, Hansbrough JF, Kiessig V, Doré C, Sticherling M, Schröder J-M (2000) Bioactive interleukin-8 is expressed in wounds and enhances wound healing. J Surg Res 93(1):41–54

    Article  PubMed  CAS  Google Scholar 

  60. Rhyu K-W, Walsh AJ, O'Neill CW, Bradford DS, Lotz JC (2007) The short-term effects of electrosurgical ablation on proinflammatory mediator production by intervertebral disc cells in tissue culture. Spine J 7(4):451–458

    Article  PubMed  Google Scholar 

  61. Ahn S-H, Cho Y-W, Ahn M-W, Jang S-H, Sohn Y-K, Kim H-S (2002) mRNA expression of cytokines and chemokines in herniated lumbar intervertebral discs. Spine 27(9):911–917

    Article  PubMed  Google Scholar 

  62. Kepler CK, Markova DZ, Dibra F, Yadla S, Vaccaro AR, Risbud MV, Albert TJ, Anderson DG (2013) Expression and relationship of proinflammatory chemokine RANTES/CCL5 and cytokine IL-1β in painful human intervertebral discs. Spine 38(11):873–880

    Article  PubMed  Google Scholar 

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Funding

This study was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1D1A1A09000962).

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  1. Min Ho Hwang and Hyeong Guk Son contributed equally to this work.

Authors and Affiliations

  1. Department of Medical Sciences, Graduate School of Medicine, Korea University, Seoul, South Korea

    Min Ho Hwang, Hyeong Guk Son, Jae Won Lee, Chang Min Yoo, Jae Hee Shin, Hyo Geun Nam, Hyun Jung Lim, Seung Min Baek, Jeong Hun Park & Hyuk Choi

  2. Department of Neurosurgery, Guro Hospital, College of Medicine, Korea University, Seoul, South Korea

    Joo Han Kim

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  1. Min Ho Hwang
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Correspondence to Hyuk Choi.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from all participants.

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Min Ho Hwang and Hyeong Guk Son are co-first authors.

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Hwang, M.H., Son, H.G., Lee, J.W. et al. Phototherapy suppresses inflammation in human nucleus pulposus cells for intervertebral disc degeneration. Lasers Med Sci 33, 1055–1064 (2018). https://doi.org/10.1007/s10103-018-2470-4

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