BACKGROUND: Because of complicated physiological environment and difficulty to control experimental conditions, it is difficult to get satisfactory results from in vivo studies of cell mechanics.OBJECTIVE: To study the action and mechanism of p38MAPK signaling pathways on myoblast apoptosis based on successful construction of in vitro mechanical stimulation models.METHODS: The C2C12 cells cultured in vitro were divided into control group and SB203580 treatment group. Cyclic tensile stress was applied on the C2C12 myoblast cells for 0, 6, 12 and 24 hours in each group. The Flexcell Strain Unit-5000T was used to expose C2C12 myoblast cell to an equiaxial cyclic of 15% magnitude and a frequency of 10 cycles/min, each cycle including the 3 s stretch and 3 s relaxation. Hoechst 33258 fluorescent staining and optical microscope were used to detect cell apoptosis. RT-PCR, flow cytometric analysis were used to observe the apoptosis of C2C12 myoblast cells and Western blotting were used to detect the activity of p38MAPK and p-p38MAPK. RESULTS AND CONCLUSION: The optical microscope tested the change in the morphology. Hoechst 33258 staining showed that after treatment with cyclic stress, the cell took the typical appearance of apoptosis with chromatin condensation and apoptotic bodies. RT-PCR and flow cytometry showed that with the extension of time the rate of the apoptosis of C2C12 myoblast cell increased. And cells imposed SB203580 before imposing cyclical tensile stress, the results showed that the apoptosis was markedly affected, and the p-p38MAPK expression declined apparently. These findings demonstrate that p38MAPK signaling pathways in stress mediated into C2C12 myoblast cell apoptosis plays an important role.

Objective To study the relationship between serum neutrophil gelatinase-associated lipocalin (NGAL),kerbs von lungren 6 antigen (KL-6) and bronchopulmonary dysplasia (BPD) in preterm infants.Method From Jan.2015 to Dec.2015,preterm infants admitted to NICU of Guangzhou Women and Childrem's Medical Center with gestational age less than 32 weeks and birth weight less than 1 500 g were enrolled.The serum levels of procalcitonin (PCT),NGAL and KL-6 protein were detected at 24 h,7 d and 14 d after birth.At the 28 d after birth,according to the presence of BPD or not,the infants were assigned into BPD group and non-BPD group.The differences of the serum levels of PCT,NGAL and KL-6 between the two groups were compared.Result A total of 55 cases were included in the study (BPD group 20 cases,non-BPD group 35 cases).No significant differences existed in gender,birth weight and gestational age between the two groups (P ＞ 0.05).The incidence of respiratory distress syndrome were siginificantly higher in the BPD group (P ＜ 0.05) and the duration of mechanical ventilation and oxygen therapy were siginifantly longer in the BPD group (P ＜ 0.05).No significant difference between the two groups in the level of PCT at 24 h after birth (P ＞ 0.05).The levels of serum PCT at 7 d and 14 d after birth in BPD group were significantly higher than non-BPD group [7 d:(1.5 ± 1.7) ng/ml vs.(0.4 ± 0.2)ng/ml,14 d:(0.8 ± 0.7) ng/ml vs.(0.2 ± 0.1) ng/ml] (P ＜ 0.001).The levels of serum NGAL at 24 h,7 d and 14 d were significantly higher than non-BPD group [24 h:(1.6 ± 0.3) pg/ml vs.(0.8 ±0.2) pg/ml,7 d:(2.3 ±0.5) pg/ml vs.(0.7 ±0.2) pg/ml,14 d:(2.5 ±0.3) pg/ml vs.(0.8 ±0.2)pg/ml] (P ＜0.001).The levels of serum NGAL at 7 d and 14 d after birth in BPD group were significantly higher than 24 h in BPD group (P ＜ 0.05).No significant difference between KL-6 at 24 h after birth in BPD group and non-BPD group (P ＞0.05).The levels of serum KL-6 at 7 d and 14 d after birth in BPD group were significantly higher than non-BPD group [7 d:(1.2 ± 0.2) ng/ml vs.(0.8 ± 0.1) ng/ml,14 d:(1.3 ±0.2) ng/ml vs.(0.8 ±0.9) ng/ml] (P ＜0.001).The level of serum KL-6 at 7 d and 14 d after birth in BPD group were significantly higher than 24 h in BPD group (P ＜ 0.05).Conclusion Respiratory distress syndrome and prolonged mechanical ventilation were risk factors of BPD.The rising of serum NGAL and KL-6 early after birth might be involved in the development of BPD,which had predictive value of BPD.

【Objective】 To analyze and evaluate the occurrence of adverse reactions to incompatible blood component transfusion in patients undergoing ABO-incompatible allogeneic hematopoietic stem cell transplantation (ABO-incompatible allo-HSCT) in our hospital, and provide a basis for clinical safety management of incompatible blood component transfusion. 【Methods】 The case data of 467 ABO-incompatible allo-HSCT patients with incompatible blood components transfused in our hospital from June 2021 to December 2021 were retrospectively analyzed, and the adverse reactions to blood transfusion that occurred were diagnosed according to the clinical manifestations and changes before and after blood transfusion as well as the results of related laboratory tests. The evaluation was based on three aspects as the degree of certainty of the type of reaction, the severity of it, and its probablity associated with blood transfusion. 【Results】 The overall incidence of adverse reactions to transfusion of incompatible blood components was 30.19% (141/467). The incidence occurred in suspended red blood cells were 42.86%(15/35), apheresis platelets 39.25%(73/186), frozen plasma 28.26%(26/92), cryoprecipitated coagulation factors 19.05%(8/42) and washed red blood cells 16.96%(19/112). The incidence of adverse reactions of washed red blood cells and suspended red blood cells was statistically different(P<0.05). The types of adverse reactions were mainly allergic reactions (67.37%, 95/141), followed by non-hemolytic febrile reactions (22.69%, 32/141), transfusion-related graft-versus-host disease(2.84%, 4/141), acute hemolytic transfusion reactions(2.84%, 4/141), transfusion-related hypotension(2.84%, 4/141) and 2 cases (1.42%, 2/141) of other adverse reactions. A total of 141 adverse reactions were graded: 113 cases (80.14%, 113/141) were " sure" , 20 cases (14.19%, 20/141) were " basically sure" , 8 cases were " suspected" (5.67%, 8/141); 130 cases (92.20%, 130/141) were " mild" , and 10 cases (7.09%, 10/141) were" moderate" , 1 case was " severe" (0.71%, 1/141). As to the occurrence associated with blood transfusion: 117 cases (82.98%, 117/141) were " highly correlated" , 17 cases (12.06%, 17/141) were " likely correlated" , and 7 cases (4.96%, 7/141) were " less correlated" . 【Conclusion】 Evaluating and grading the adverse reactions to transfusion of incompatible blood components can deepen the cognition of clinical medical staff, increase the accuracy and rigor of their judgment of adverse reactions, and avoid the missed and false reports of adverse reactions to a certain extent, which laid the foundation for the establishment of a unified standard for adverse reactions to incompatible blood transfusion.

Insulin-like growth factor-1 receptor (IGF-1R) has been made an attractive anticancer target due to its overexpression in cancers. However, targeting it has often produced the disappointing results as the role played by cross talk with numerous downstream signalings. Here, we report a disobliging IGF-1R signaling which promotes growth of cancer through triggering the E3 ubiquitin ligase MEX3A-mediated degradation of RIG-I. The active β-arrestin-2 scaffolds this disobliging signaling to talk with MEX3A. In response to ligands, IGF-1Rβ activated the basal βarr2 into its active state by phosphorylating the interdomain domain on Tyr64 and Tyr250, opening the middle loop (Leu130‒Cys141) to the RING domain of MEX3A through the conformational changes of βarr2. The models of βarr2/IGF-1Rβ and βarr2/MEX3A could interpret the mechanism of the activated-IGF-1R in triggering degradation of RIG-I. The assay of the mutants βarr2^Y64A and βarr2^Y250A further confirmed the role of these two Tyr residues of the interlobe in mediating the talk between IGF-1Rβ and the RING domain of MEX3A. The truncated-βarr2 and the peptide ATQAIRIF, which mimicked the RING domain of MEX3A could prevent the formation of βarr2/IGF-1Rβ and βarr2/MEX3A complexes, thus blocking the IGF-1R-triggered RIG-I degradation. Degradation of RIG-I resulted in the suppression of the IFN-I-associated immune cells in the TME due to the blockade of the RIG-I-MAVS-IFN-I pathway. Poly(I:C) could reverse anti-PD-L1 insensitivity by recovery of RIG-I. In summary, we revealed a disobliging IGF-1R signaling by which IGF-1Rβ promoted cancer growth through triggering the MEX3A-mediated degradation of RIG-I.

The well-known insulin-like growth factor 1 (IGF1)/IGF-1 receptor (IGF-1R) signaling pathway is overexpressed in many tumors, and is thus an attractive target for cancer treatment. However, results have often been disappointing due to crosstalk with other signals. Here, we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma (HCC) cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2 (SERCA2) activity. In response to ligand binding, IGF-1Rβ is translocated into the ER by β-arrestin2 (β-arr2). Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ. SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβ levels. ER IGF-1Rβ phosphorylates SERCA2 on Tyr⁹⁹⁰ to enhance its activity. Mutation of SERCA2-Tyr⁹⁹⁰ disrupted the interaction of ER IGF-1Rβ with SERCA2, and therefore ER IGF-1Rβ failed to promote SERCA2 activity. The enhancement of SERCA2 activity triggered Ca²⁺_ER perturbation, leading to an increase in autophagy. Thapsigargin blocked the interaction between SERCA2 and ER IGF-1Rβ and therefore SERCA2 activity, resulting in inhibition of HCC growth. In conclusion, the translocation of IGF-1R into the ER triggers Ca²⁺_ER perturbation by enhancing SERCA2 activity through phosphorylating Tyr⁹⁹⁰ in HCC.