Specific microRNA signatures responsible for immune disturbance related to hip fracture in aged rats

Whether pinocembrin (PCN) could be utilized to alleviate hip fracture-induced pain is investigated in this research. Aged rats with hip fractures were treated with vehicle or 80 mg/kg/day PCN from week 3 to week 4. Then hind paw mechanical allodynia, unweighting, warmth, and thickness were measured. The microglia and astrocytes activation and proliferation markers in the spinal dorsal horn were detected with real-time PCR and immunofluorescence staining. The relative expression of substance P and its receptor, tachykinin receptor 1 (Tacr1), were detected with enzyme-linked immunosorbent assay (ELISA) and Western blots. The antinociceptive effect of Tacr1 inhibitor LY303870 was also testified. PCN alleviated hip fracture-induced hind paw nociceptive (allodynia and unweighting) and vascular changes (warmth and thickness) in aged rats with diminished microglia and astrocytes activation and proliferation in the spinal dorsal horn. Up-regulated substance P and Tacr1 were induced after hip fracture, which could be reversed by PCN treatment. Furthermore, LY303870 treatment partially reversed both spinal nociceptive sensitization and vascular changes after hip fracture. Substance P signaling contributes to the nociceptive and vascular changes observed in the hip fracture, which could be alleviated by PCN.

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Systemic Inflammatory Responses and Lung Injury following Hip Fracture Surgery Increases Susceptibility to Infection in Aged Rats

Mediators of Inflammation ◽

10.1155/2013/536435 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 11

Author(s):

Hao Zhang ◽

Tiansheng Sun ◽

Zhi Liu ◽

Jianzheng Zhang ◽

Xiaowei Wang ◽

...

Keyword(s):

Hip Fracture ◽

Lung Injury ◽

Inflammatory Response ◽

Systemic Inflammatory Response ◽

Pulmonary Injury ◽

Aged Rats ◽

Hip Fracture Surgery ◽

Susceptibility To Infection ◽

Intramedullary Pinning ◽

Fracture Surgery

Pulmonary infections frequently occur following hip fracture surgery in aged patients. However, the underlying reasons are not fully understood. The present study investigates the systemic inflammatory response and pulmonary conditions following hip fracture surgery as a means of identifying risk factors for lung infections using an aged rodent model. Aged, male Sprague-Dawley rats (8 animals per group) underwent a sham procedure or hip fracture plus femoral intramedullary pinning. Animals were sacrificed 1, 3, and 7 days after the injury. Markers of systemic inflammation and pulmonary injury were analyzed. Both sham-operated and injured/surgical group animals underwent intratracheal inoculation withPseudomonas aeruginosa1, 3, and 7 days after surgery.P. aeruginosacounts in blood and bronchoalveolar lavage (BAL) fluid and survival rates were recorded. Serum TNF-α, IL-6, IL-1β, and IL-10 levels and markers of pulmonary injury were significantly increased at 1 and 3 days following hip fracture and surgery. Animals challenged withP. aeruginosaat 1 and 3 days after injury had a significantly decreased survival rate and moreP. aeruginosarecovered from blood and BAL fluid. This study shows that hip fracture and surgery in aged rats induced a systemic inflammatory response and lung injury associated with increased susceptibility to infection during the acute phase after injury and surgery.

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