Bisphosphonate conjugation enhances the bone-specificity of NELL-1-based systemic therapy for spaceflight-induced bone loss in mice

Pin Ha; Jin Hee Kwak; Yulong Zhang; Jiayu Shi; Luan Tran; Timothy Pan Liu; Hsin-Chuan Pan; Samantha Lee; Jong Kil Kim; Eric Chen; Yasaman Shirazi-Fard; Louis S Stodieck; Andy Lin; Zhong Zheng; Stella Nuo Dong; Xinli Zhang; Benjamin M Wu; Kang Ting; Chia Soo

doi:10.1038/s41526-023-00319-7

Bisphosphonate conjugation enhances the bone-specificity of NELL-1-based systemic therapy for spaceflight-induced bone loss in mice

NPJ Microgravity. 2023 Sep 18;9(1):75. doi: 10.1038/s41526-023-00319-7.

Authors

Pin Ha^#^{1

2}, Jin Hee Kwak^#³, Yulong Zhang^#^{4

5}, Jiayu Shi⁶, Luan Tran^{1

2

6}, Timothy Pan Liu^{1

2}, Hsin-Chuan Pan⁶, Samantha Lee^{1

2}, Jong Kil Kim¹, Eric Chen⁶, Yasaman Shirazi-Fard⁷, Louis S Stodieck⁸, Andy Lin⁹, Zhong Zheng^{1

2}, Stella Nuo Dong⁶, Xinli Zhang⁶, Benjamin M Wu^{10

11

12

13}, Kang Ting¹⁴, Chia Soo^{15

16

17}

Affiliations

¹ Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
² Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
³ Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, 90089, USA.
⁴ Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
⁵ Forsyth Institute, Cambridge, MA, 02142, USA.
⁶ School of Dentistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
⁷ Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA.
⁸ BioServe Space Technologies and Aerospace Engineering Sciences, University of Colorado, Boulder, CO, 80303, USA.
⁹ Office of Advanced Research Computing, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
¹⁰ Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bwu@forsyth.org.
¹¹ Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bwu@forsyth.org.
¹² Forsyth Institute, Cambridge, MA, 02142, USA. bwu@forsyth.org.
¹³ School of Dentistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bwu@forsyth.org.
¹⁴ Forsyth Institute, Cambridge, MA, 02142, USA. erickangting@gmail.com.
¹⁵ Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bsoo@ucla.edu.
¹⁶ Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bsoo@ucla.edu.
¹⁷ Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA, 90095, USA. bsoo@ucla.edu.

^# Contributed equally.

Abstract

Microgravity-induced bone loss results in a 1% bone mineral density loss monthly and can be a mission critical factor in long-duration spaceflight. Biomolecular therapies with dual osteogenic and anti-resorptive functions are promising for treating extreme osteoporosis. We previously confirmed that NELL-like molecule-1 (NELL-1) is crucial for bone density maintenance. We further PEGylated NELL-1 (NELL-polyethylene glycol, or NELL-PEG) to increase systemic delivery half-life from 5.5 to 15.5 h. In this study, we used a bio-inert bisphosphonate (BP) moiety to chemically engineer NELL-PEG into BP-NELL-PEG and specifically target bone tissues. We found conjugation with BP improved hydroxyapatite (HA) binding and protein stability of NELL-PEG while preserving NELL-1's osteogenicity in vitro. Furthermore, BP-NELL-PEG showed superior in vivo bone specificity without observable pathology in liver, spleen, lungs, brain, heart, muscles, or ovaries of mice. Finally, we tested BP-NELL-PEG through spaceflight exposure onboard the International Space Station (ISS) at maximal animal capacity (n = 40) in a long-term (9 week) osteoporosis therapeutic study and found that BP-NELL-PEG significantly increased bone formation in flight and ground control mice without obvious adverse health effects. Our results highlight BP-NELL-PEG as a promising therapeutic to mitigate extreme bone loss from long-duration microgravity exposure and musculoskeletal degeneration on Earth, especially when resistance training is not possible due to incapacity (e.g., bone fracture, stroke).

Abstract

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