Additional benefits of combined ceftriaxone and adipose-derived mesenchymal stem cells on revamping the outcomes in rodent after acute spinal infection

Abstract

This study tested whether combined ceftriaxone and adipose-derived mesenchymal stem cells (ADMSCs) would defend the spinal cord against acute spinal infection (ASI) in rodent. Adult-Male-SD rats were grouped into groups 1 (SC)/2 (ASI)/3 (ASI + ceftriaxone from days 2 to 28 after ASI induction)/4 (ASI + allogenic ADMSCs from day 2 for a total of 3 doses/3 consecutive intervals by intravenous injection)/5 (ASI + combined ceftriaxone and ADMSC) and spinal cord tissues were harvested by day 28. Circulatory levels of TNF-α/IL-6 at days 7 and 28, and these two parameters in spinal fluid at day 28 were lowest in group 1, highest in group 2, significantly lower in group 5 than in groups 3/4, and significantly lower in group 3 than in group 4 (all p < 0.0001). The day-28 bacterial colony formation unit (CFU) in vertebral bone and circulatory WBC counts at the time points of days 7/14/28, and the protein expressions of upstream (TRL-2/TLR-4/MYD88/TRAF6/IKKα/IKKβ /IKBβ/p-NF-κB) and downstream (IL-1β/IL-6/TNF-α/IFN-γ/iNOS) inflammatory signalings displayed a similar pattern of inflammatory biomarkers in spinal fluid among the groups (all p < 0.0001). By day 28, the bone injury score/bone marrow density/ratio of bone volume (BV) to the bone tissue volume (TV)/ratio of bone surface (BS) to BV/ratio of BS to bone TV/trabecular number exhibited an opposite, whereas the trabecular space exhibited an alike pattern of inflammatory biomarkers among the groups (all p < 0.0001). Combined ceftriaxone and ADMSCs therapy offered an additional benefit on protecting the vertebral bone/spinal cord against ASI damage.