Table 1 Studies are presented in increasing order of shear stress and according to cell type

From: Changes in interstitial fluid flow, mass transport and the bone cell response in microgravity and normogravity

Authors

Shear Flow

Pattern

Cell Type

Outcome

Yi et al.76

3 dyn per cm2, 6 h (low)

Laminar/steady

hMSCs

Increased expression of Annexin A2 (P < 0.001), GAPDH (P < 0.001)

Arnsdorf et al.60

10 dyn per cm2, 1 Hz, 1 h

Oscillatory

Murine MSCs

Upregulation of RUNX2, SOX9, PPARγ [all (P < 0.01)]. Osteogenic differentiation via RhoA and ROCKII

Correia et al.74

400 μm·s−1 (1.64 mL·min−1; 4-5 mPa shear stress) to 1 200 μm·s−1 (4.92 mL·min−1; 12.5-15 mPa shear stress), 0.5 Hz for 2 h, followed by 10 h of steady flow over 5 weeks

Pulsating

MSCs

Optimal for osteogenesis was 2 weeks of steady flow with 3 weeks of pulsatile flow. Increased OPN, BSP, PGE2 (all P < 0.05).

Xing et al.232

5 dyn per cm2

Parallel plate

Rat Osteoblasts

Increased Col-I and proliferation. Decreased ALP, proliferation

Kämmerer et al.77

10 dyn per cm2, 24 h (shear at the center=1 dyn per cm2 with 10 dyn per cm2 at the periphery)

Rotating at 200 r·min−1

Osteoblasts

Actin filaments re-aligned themselves towards orientation of fluid flow

Malone et al.62

12 dyn per cm2, 1 Hz, 1 h

Oscillatory

Murine Osteoblasts

PGE2 increased 3-fold (P < 0.05). No increase in F-actin development

Tan et al.73

0.4-1.0 dyn per cm2, 5 Hz, 1 h Mean stress of 0.7 Pa

Pulsating 0.3 Pa

Chicken Osteocytes

NO production decreased (P < 0.05). Osteoclast formation inhibited via soluble factors in the conditioned medium after 60 mins of exposure

Li et al.233

5-50 dyn per cm2, 0.5-2 Hz, 1, 2 and 4 h. Peak stress of 0.5, 1, 2 and 5 Pa. oscillating frequency of 0.5, 1 and 2 Hz

Oscillatory

MLO-Y4 Osteocytes

Higher shear stress (5 Pa) and longer flows (4 h) increased COX2 (P < 0.05). Increased stress, frequency and duration increased RANKL/OPG ratio.

  1. GADPH glyceraldehyde-3-phosphate dehydrogenase, rpm revolutions per minute, NO nitric oxide, RUNX2 runt-related transcription factor 2, ALP alkaline phosphatase, PPAR peroxisome proliferator-activated receptor gamma, PGE2 prostaglandin e2, COX2 cyclooxygenase 2, RANKL receptor activator of nuclear factor kappa-B ligand, OPG osteoprotegerin, OPN osteopontin, BSP bone sialoprotein