Observation on marrow-derived mesenchymal stem cells differentiating into functional cells in rabbit with smoke inhalation injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the homing and differentiation of marrow-derived mesenchymal stem cells (MSC) transplanted intravenously in smoke inhalation injured rabbits.</p><p><b>METHODS</b>Thirty-two New Zealand big ear rabbits were divided into normal control group (NC), inhalation injury group (II), normal control + MSC treatment group (NM), and MSC treatment group (MT) according to the random number table, with 8 rabbits in each group. Rabbits in NC group were injected with 10 mL phosphate buffered saline (PBS) via ear marginal vein. Rabbits in NM group were injected with 10 mL PBS containing the third generation MSC labeled by BrdU (1 × 10(7) per 10 mL PBS) via ear marginal vein. Severe smoke inhalation injury model was reproduced in the other two groups, among them rabbits in II group were treated as rabbits in NC group, rabbits in MT group treated as rabbits in NM group. On the 7th and 28th day post treatment (PTD), lung tissue and trachea tissue were harvested from four groups for observation on injury with HE staining. Homing of MSC in injured tissue was observed with immunohistochemistry staining. The differentiation of MSC into functional cells was observed with immunohistochemical double staining of combining nuclear marker BrdU with lung (trachea) membrane-specific marker aquaporin-5 (AQP-5), alkaline phosphatase (AKP), CD34, and cytokeratin respectively.</p><p><b>RESULTS</b>(1) MSC homing in lung and trachea tissue was observed in MT group on PTD 7, which was not observed in NM group. (2) AQP-5, AKP, and CD34 positive MSC were observed in lung tissue in MT group on PTD 28, while cytokeratin positive MSC was not observed in trachea tissue. No positively marked MSC was observed in NM group. (3) Injury in lung and trachea was less severe in MT group than in II group; and the proliferation of fibroblasts was less in MT group.</p><p><b>CONCLUSIONS</b>Intravenous injection of MSC to rabbits with smoke inhalation injury can migrate to lung and trachea tissue at obviously inflammatory site, and differentiate into alveolar epithelial cells typeI and II, and pulmonary vascular endothelial cells, which may participate in the process of tissue repair in smoke inhalation injury.</p>

Effect of bone marrow-derived mesenchymal stem cells transplantation on the inflammatory response and lung injury in rabbit with inhalation injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the effect of bone marrow-derived mesenchymal stem cells (MSC) transplantation on the major inflammatory cytokines content in peripheral blood, lung water mass fraction, and lung tissue injury in rabbits with smoke inhalation injury.</p><p><b>METHODS</b>Sixteen adult New Zealand big ear rabbits were subjected to smoke inhalation injury and then were divided into pure injury group (PI, n = 8) and MSC transplantation group (MT, n = 8) according to the random number table. Via ear marginal vein, rabbits in PI group were injected with 10 mL phosphate buffered saline (PBS); rabbits in MT group were injected with 10 mL PBS containing the third passage MSC (1 x 10⁷ cell) isolated from marrow of healthy young New Zealand big ear rabbit. Another 8 rabbits were enrolled as normal control group (NC). Rabbits in NC group were injected with 10 mL PBS via ear marginal vein without smoke inhalation injury. Blood was harvested from rabbits in PI and MT groups at post injury hour (PIH) 2, 4, 6. Contents of TNF-α, IL-1β, IL-6, and IL-10 in serum were determined with ELISA. At PIH 24, left lung was harvested for morphology and histopathology observation; the right lung tissue was obtained to measure and calculate lung water mass fraction. Blood and lung tissue of rabbits in NC group were harvested and determined in the same way. Data were processed with t test.</p><p><b>RESULTS</b>(1) Serum contents of TNF-α in PI and MT groups at each time point were obviously higher than that in NC group (t = 2.43 - 9.57, P < 0.05 or P < 0.01). Serum contents of IL-1β and IL-6 in PI group at each time point were obviously higher than those in NC group (t = 8.49 - 19.80, P values all below 0.01). Serum content of IL-1β in MT group at each time point was close to that in NC group (t = 0.11 - 0.92, P values all above 0.05). Serum content of IL-6 in MT group at PIH 2 was close to that in NC group (t = 2.12, P > 0.05), but that of MT group increased significantly at PIH 4 and 6 (t = 2.83, P values all below 0.05). Serum contents of TNF-α, IL-1β, and IL-6 in MT group at each time point were obviously lower than those in PI group (t = 2.35 - 12.45, P < 0.05 or P < 0.01). (2) Serum content of IL-10 in MT group at PIH 2, 4, and 6 was respectively (13.0 ± 3.6), (11.6 ± 8.5), (15.2 ± 4.4) pg/mL, and they were higher than those in PI group [(5.5 ± 3.4), (5.0 ± 1.7), (7.9 ± 3.5) pg/mL, with t value respectively 4.28, 2.15, 3.67, P values all below 0.01]. Serum contents of IL-10 in PI and MT groups were obviously higher than that in NC group (t = 2.46-8.14, P < 0.05 or P < 0.01). (3) Lung tissue injury in MT group was alleviated markedly as compared with that in PI group. (4) At PIH 24, lung water mass fraction in MT group was (69 ± 7)%, which was obviously lower than that in PI group [(87 ± 6)%, t = 5.49, P < 0.01]. Compared with that in NC group [(48 ± 3)%], lung water mass fraction in PI and MT groups were increased obviously (with t value respectively 16.93 and 7.22, P values all below 0.01).</p><p><b>CONCLUSIONS</b>MSC transplantation can decrease pro-inflammatory cytokines, increase anti-inflammatory cytokines, decrease lung water mass fraction, ameliorate systemic inflammatory response, and protect lung tissue in rabbits with smoke inhalation injury.</p>

Effects of glutamine enriched enteral feeding on immunoregulation in burn patients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of glutamine enriched enteral feeding on immunoregulation in burn patients.</p><p><b>METHODS</b>Twenty burn patients were randomly divided into enteral nutrition (EN) group and enteral immune nutrition (EIN) group, with 12 patients in each group. Patients in EN group received a standard enteral formula, while those in EIN group received an enteral formula enriched with glutamine after hospital admission. Nutritional support was continued for 10 days. Blood samples were obtained to determine plasma level of total protein (TP), albumin (ALB), prealbumin (PAB) and transferrin (TF) at 1, 4, 7, 10 post-burn days (PBD). At the same time the concentration of immunoglobulin (IgA, IgG and IgM) were determined, the percentage of CD3+, CD4+, CD8+ subpopulations of T lymphocytes, and the ratio of CD4+/CD8+ were determined by FCM.</p><p><b>RESULTS</b>(1) There were no obvious difference of the plasma level of TP, ALB, TF, CD3+, IgM between the two groups at each time-point (P > 0.05). (2) The plasma PAB contents in EIN group were significant higher than that in EN group on 4 PBD [(90 +/- 14 vs 60 +/- 15) mg/L, P < 0.05], 7 PBD [(92 +/- 16 vs 64 +/- 13) mg/L, P < 0.05] and 10 PBD [(106 +/- 21 vs 72 +/-16) mg/L, P < 0.05]. (3) The percentage of CD4+ subpopulation and ratio of CD4+/CD8+ in EIN group were obviously higher than those in EN group on 7 PBD [CD4+ (55 +/- 5 vs 45 +/- 5)%, CD4+/CD8+ (1.92 +/- 0.31 vs 1.53 +/- 0.27)%, P < 0.05] and 10 PBD [CD4+ (56 +/- 5 vs 49 +/- 5)%, CD4+/CD8+ (2.36 +/- 0.36 vs 1.72 +/- 0.42), P < 0.05]. (4) The concentration of IgA and IgG in EIN group were markedly higher than that in EN group on 7 PBD [IgA (2.8 +/- 0.6 vs 2.2 +/- 0.5) g/L, IgG (12.1 +/- 1.3 vs 9.8 +/- 1.2) g/L, P < 0.05] and 10 PBD [IgA (3.1 +/- 0.6 vs 2.5 +/- 0.5) g/L, IgG (14.2 +/- 1.3 vs 10.4 +/- 1.3) g/L, P < 0.05].</p><p><b>CONCLUSION</b>These findings suggest that glutamine enriched enteral feeding can improve nutritional status by promoting the synthesis of IgA, IgG, and increasing the PAB concentration, and corrected immunologic dysfunction in burn patients.</p>