Delivery room resuscitation and short-term outcomes of extremely preterm and extremely low birth weight infants: a multicenter survey in North China.

BACKGROUND: Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China. METHODS: The clinical data of EPI (gestational age [GA] <28 weeks) and ELBWI (birth weight [BW] <1000 g), admitted within 72 h of birth in 33 neonatal intensive care units from five provinces and cities in North China between 2017 and 2018, were analyzed. The primary outcomes were delivery room resuscitation and risk factors for delivery room intubation (DRI). The secondary outcomes were survival rates, incidence of bronchopulmonary dysplasia (BPD), and risk factors for BPD. RESULTS: A cohort of 952 preterm infants were enrolled. The incidence of DRI, chest compressions, and administration of epinephrine was 55.9% (532/952), 12.5% (119/952), and 7.0% (67/952), respectively. Multivariate analysis revealed that the risk factors for DRI were GA <28 weeks (odds ratio [OR], 3.147; 95% confidence interval [CI], 2.082-4.755), BW <1000 g (OR, 2.240; 95% CI, 1.606-3.125), and antepartum infection (OR, 1.429; 95% CI, 1.044-1.956). The survival rate was 65.9% (627/952) and was dependent on GA. The rate of BPD was 29.3% (181/627). Multivariate analysis showed that the risk factors for BPD were male (OR, 1.603; 95% CI, 1.061-2.424), DRI (OR, 2.094; 95% CI, 1.328-3.303), respiratory distress syndrome exposed to ≥2 doses of pulmonary surfactants (PS; OR, 2.700; 95% CI, 1.679-4.343), and mechanical ventilation ≥7 days (OR, 4.358; 95% CI, 2.777-6.837). However, a larger BW (OR, 0.998; 95% CI, 0.996-0.999), antenatal steroid (OR, 0.577; 95% CI, 0.379-0.880), and PS use in the delivery room (OR, 0.273; 95% CI, 0.160-0.467) were preventive factors for BPD (all P < 0.05). CONCLUSION: Improving delivery room resuscitation and management of respiratory complications are imperative during early management of the health of EPI and ELBWI.

[Effect of Knockdown of Vascular Cell Adhesion Molecule-1 on the Immunologic Regulation Capacity of Murine Mesenchymal Stem Cells].

OBJECTIVE: To establish the stably lower expression of vascular cell adhesion molecule-1 (VCAM-1) in MSC cell line (C3H10T1/2) by siRNA technology, and explore the effect of knockdown of VCAM-1 on the immunologic regulation capacity of murine MSC. METHODS: The mouse GV118-VCAM-1-RNAi retrovirus vector was constructed by gene recombination technology. The recombinant plasmid was identified by restriction analysis and sequencing, and then the recombinant plasmid GV118-VCAM-1-RNAi was transfected into 293 cells by Lipofectamine, and the supernatant was collected to transfect C3H10T1/2. Moreover, the VCAM-1 lower expression on MSC was evaluated by flow cytometry and fluorescent microscopy. The knockdown VCAM-1 MSC was sorted by flow cytometry. Furthermore, the inhibitory effect of the knockdown VCAM-1 MSC on lymphocyte proliferation was tested by lymphoblast transformation assay (LTT) and mixed lymphocyte reaction assay(MLR). RESULTS: The recombinant retroviral vector of knockdown VCAM-1 (GV118-VCAM-1-RNAi) was successfully constructed and transfected into mouse MSC cell line C3H10T1/2. The knockdown VCAM-1/MSC was obtained by flow cytometric sorting. The LTT and MLR assay showed that the immunosuppressive effect of MSC lower-expressing VCAM-1 dramatically decreased (P<0.05). CONCLUSION: Knockdown VCAM-1 in MSC can significantly down-regulate the inhibitory capability of MSC on the proliferation of T-cells. The data of this study laid an experimental foundation for studying effect of VCAM-1 transfecting into MSC on immune function.

[Effect of Vascular Cell Adhesion Molecule -1 Overexpression on Adipogenic Differentiation of Murine Mesenchymal Stem Cells and Its Mechanism].

OBJECTIVE: To investigate the effect of vascular cell adhesion molecule-1 (VCAM-1) gene overexpression on adipogenic differentiation of mouse mesenchymal stem cells(MSC) and explore its molecular mechanism. METHODS: VCAM-1 overexpression MSC (MIGR1-VCAM-1/MSC) and the empty plasmid transfection MSC (MIGR1/MSC) were induced to adipogenic differentiation, oil-red-O staining and real-time PCR were used to detect the adipogenic differentiation ability and the mRNA expression level of key transcription factors C/EBP α and PPAR γ. The activation of P38, ERK and JNK pathways were analyzed by Western blot. Furthermore, the specific chemical inhibitors of MAPK pathway (SB203580, PD98059 and JNK inhibitor II) were added to the induced culture system and the alteration of the MSC adipogenic differentiation ability were evaluated. RESULTS: no matter in self or induced differentiation groups, the lipid droplets in MIGR1-VCAM-1/MSC became larger, the amount of adipocyte increased than that in MIGR1/MSC (P<0.01), the mRNA expression level of C/EBPα and PPARγ were upregulated, and JNK pathway were down-regulated while the P38 and ERK pathway were significantly up-regulated. The inhibition of JNK pathway of MIGR1-VCAM-1/MSC could lead to increased mRNA expression level of C/EBP α and PPAR γ, the amount of adipocytes increased (P<0.01), however, the inhibition of the P38 and ERK pathway of MIGR1-VCAM-1/MSC could lead to decreased mRNA expression level of C/EBP α and PPAR γ, and the lipid droplets and the number of adipocytes became smaller and less. CONCLUSION: The overexpression of VCAM-1 may promote MSC to differentiate into adipocytes through inhibiting JNK signaling pathway, activating P38 and ERK pathways.

Intercellular adhesion molecule-1 inhibits osteogenic differentiation of mesenchymal stem cells and impairs bio-scaffold-mediated bone regeneration in vivo.

Mesenchymal stem cell (MSC) loaded bio-scaffold transplantation is a promising therapeutic approach for bone regeneration and repair. However, growing evidence shows that pro-inflammatory mediators from injured tissues suppress osteogenic differentiation and impair bone formation. To improve MSC-based bone regeneration, it is important to understand the mechanism of inflammation mediated osteogenic suppression. In the present study, we found that synovial fluid from rheumatoid arthritis patients and pro-inflammatory cytokines including interleukin-1α, interleukin-1ß, and tumor necrosis factor α, stimulated intercellular adhesion molecule-1(ICAM-1) expression and impaired osteogenic differentiation of MSCs. Interestingly, overexpression of ICAM-1 in MSCs using a genetic approach also inhibited osteogenesis. In contrast, ICAM-1 knockdown significantly reversed the osteogenic suppression. In addition, after transplanting a traceable MSC-poly(lactic-co-glycolic acid) construct in rat calvarial defects, we found that ICAM-1 suppressed MSC osteogenic differentiation and matrix mineralization in vivo. Mechanistically, we found that ICAM-1 enhances MSC proliferation but causes stem cell marker loss. Furthermore, overexpression of ICAM-1 stably activated the MAPK and NF-κB pathways but suppressed the PI3K/AKT pathway in MSCs. More importantly, specific inhibition of the ERK/MAPK and NF-κB pathways or activation of the PI3K/AKT pathway partially rescued osteogenic differentiation, while inhibition of the p38/MAPK and PI3K/AKT pathway caused more serious osteogenic suppression. In summary, our findings reveal a novel function of ICAM-1 in osteogenesis and suggest a new molecular target to improve bone regeneration and repair in inflammatory microenvironments.

[Effects of ICAM-1 gene transfection on the adipogenic differentiation of MSCs].

OBJECTIVE: To explore the effects of ICAM-1 gene transfection on the differentiation of MSCs to adipocytes. METHODS: The recombinant retroviral expression plasmid MIGR1-ICAM-1 containing full length of mouse ICAM-1 gene was constructed. The constructed plasmid MIGR1-ICAM-1, empty plasmid MIGR1 and packaging plasmid ECOS were transfected into T293 cell lines and then the supernatant generated from T293 cells were used to infect mouse MSCs cell line C3H10T 1/2. The transfective efficiency was determined by inverted fluorescence microscope, real-time PCR and flow cytometry. Furthermore, ICAM-1 overexpressing MSCs (C3H10T 1/2-ICAM-1) and empty vector transfection MSCs (C3H10T 1/2-MIGR1) were cultured in medium with or without induction reagents, Oil-red-O staining was used to detect the lipid accumulation, and the expression of transcriptional factors C/EBPα and PPARγ, which were key factors in the differentiation of MSCs to adipocytes, were tested by real-time-PCR. RESULTS: The recombinant retrovirus vector containing mouse ICAM-1 gene was successful constructed. After transfection into MSCs cell line C3H10T 1/2, the overexpression ICAM-1 MSCs cell line (C3H10T 1/2-ICAM-1) and control cell line (C3H10T 1/2-MIGR1) were obtained. Furthermore, these two cell lines were treated without or with adipocytic induction reagents, C3H10T 1/2-ICAM-1 showed significantly lower mRNA expression level for C/EBPα [(1.2 ± 0.7), (2.9 ± 0.9)] and PPARγ [(1557.6 ± 70.2), (7547.0 ± 442.2)] when compared with C3H10T 1/2-MIGR1 [(5.8 ± 0.5), (23.0 ± 2.3) and (2453.0 ± 215.6), (9856.3 ± 542.2)](P < 0.05). Moreover, little lipid droplet and decreased quantity of adipocytes were detected in C3H10T 1/2-ICAM-1 [(3.2 ± 0.5)/well, (12.2 ± 3.8)/well] than that in C3H10T 1/2-MIGR1 [(11.2 ± 0.4)/well, (51.3 ± 2.8)/well] (P < 0.05). CONCLUSION: Overexpression of ICAM-1 in MSCs can inhibit its adipocytic differentiation.