[Research advances on the roles of exosomes derived from mesenchymal stem cells in wound healing and prevention and treatment of hypertrophic scars].

Skin is an important defense barrier of human body and one of the most vulnerable organs. Wounds are the result of damage to the integrity of skin. Chronic wounds and hypertrophic scar formation are the results of abnormal wound healing, and are also the clinical problems those need to be resolved urgently in the field of wound repair. In recent years, researchers have found that mesenchymal stem cells (MSCs) can promote wound healing, improve wound healing quality, and reduce scar formation. The therapeutic effect of MSCs may be derived from the exosomes derived from them. This paper reviews the research advances of exosomes derived from MSCs in wound healing and prevention and treatment of hypertrophic scars in recent years and looks up to the prospect for the clinical application.

[Risk factors for mortality in pediatric acute respiratory distress syndrome requiring extracorporeal membrane oxygenation support].

Objective: To explore the risk factors for mortality in pediatric acute respiratory distress syndrome (PARDS) requiring extracorporeal membrane oxygenation (ECMO) support. Methods: Clinical data of 109 patients with severe PARDS supported by ECMO, who were hospitalized in 6 ECMO centers in China from September 2012 to February 2020, were retrospectively analyzed. They were divided into survival group and death group according to the prognosis. Chi-square test and rank sum test were used to compare the variables between the two groups, including the demographic data, laboratory examination results, clinical data before and after ECMO, and other supportive treatment. Univariate and multivariate Logistic regression models were used to analyze the prognostic risk factors. Results: In these 109 cases, 54 died and 55 survived. Compared with the survival group, the death group had higher incidences of acute kidney injury (AKI) (48.1% (26/54) vs. 21.8% (12/55), χ²=8.318, P=0.004) and coagulation dysfunction (22.2% (12/54) vs. 7.3% (4/55), χ²=4.862, P=0.027), and higher rate of renal replacement therapy (48.1% (26/54) vs. 21.8% (12/55), χ²=9.694, P=0.008) during ECMO support. Logistic regression analysis showed that continuous renal replacement therapy (CRRT) and AKI were independent risk factors for death in patients with severe PARDS requiring ECMO support (HR=3.88,95%CI 1.04-14.52, HR=4.84,95%CI 1.21-19.46, both P<0.05). Conclusion: AKI and CRRT are independent risk factors for predicting mortality in patients with severe PARDS requiring ECMO support.

[Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice].

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 µL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 µL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P<0.01). On day 7 in culture, the content of IL-12 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=13.226, P<0.01), and the content of arginase 1 and IL-10 was significantly higher than that in macrophage alone group (t=30.172, 31.406, P<0.01). (2) On PID 1, a large number of inflammatory cells infiltration were observed in the skin wounds of both groups. On PID 3, the inflammatory cells infiltration in the skin wounds increased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 7, the inflammatory cells infiltration in the wounds decreased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 14, no obvious inflammatory cells infiltration was observed in the wounds in the two groups. (3) On PID 1 and 14, the percentages of CD68 and iNOS double positive cells and CD68 and arginase 1 double positive cells in the wounds were similar in the two groups (t(1 d)=0.134, 0.693, t(14 d)=1.146, 2.585, P>0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P<0.01), while the percentages of CD68 and arginase 1 double positive cells were significantly higher than those of PBS group (t=3.928, 4.473, P<0.01). (4) On PID 1, the mRNA expressions of IL-10 in the wounds of mice in the two groups were similar (t=2.005, P>0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

[Effect of silencing FABP3 gene on LPS-induced apoptosis and endoplasmic reticulum stress in alveolar epithelial cells].

Objective: To investigate the effect of silencing fatty acid binding protein 3 (FABP3) gene on lipopolysaccharide (LPS)-induced apoptosis and endoplasmic reticulum stress in alveolar epithelial cells A549. Methods: According to the processing method, A549 cells were divided into control group(A549 cells cultured for 24 h), LPS group (10 mg/L LPS treated A549 cells for 24 h), LPS+si-con group (10 mg/L LPS was used to treat A549 cells transfected with si-con for 24 h) and LPS+si-FABP3 group (10 mg/L LPS was used to treat A549 cells transfected with si-FABP3 for 24 h). Then quantitative real-time PCR was used to detect the level of FABP3, methylthiazoletrazolium was used to detect the cell proliferation, flow cytometry was used to detect the apoptosis, and Western Blot was used to detect the levels of FABP3, CyclinD1, cleaved-caspase-3, GRP78, ATF4, CHOP, cleaved-caspase-12 and p-Akt and PI3Kp110α protein expression. Enzyme-linked immunosorbent assay was used to detect the levels of IL-6, IL-8 and TNF-αlevels. Results: In the LPS group, FABP3 protein level (1.00±0.09) and mRNA (2.15±0.22), apoptosis rate [(26.1±2.6)%], inflammatory factor IL-6 [(554.4±55.4) ng/L], IL-8 [(389.3±38.5) ng/L] and TNF-α [(601.3±60.0) ng/L], cleaved-caspase-3 (1.00±0.11), GRP78 (1.05±0.11), ATF4 (1.20±0.12)), CHOP (1.05±0.10), cleaved-caspase-12 (1.10±0.11), p-Akt (0.88±0.08) and PI3Kp110α (0.75±0.08) protein levels were significantly higher than the control group [(0.53±0.05), (1.00±0.10), (4.5±0.5)%, (75.4±7.5) ng/L, (25.2±2.5) ng/L, (66.5±6.7) ng/L, (0.34±0.05), (0.35±0.05), (0.43±0.05), (0.37±0.04), (0.45±0.05), (0.16±0.04), (0.35±0.05)] (all P<0.05). Cell viability [(50.1±5.4)%] and CyclinD1 protein level (0.40±0.05) in LPS group were significantly lower than those in the control group [(100.1±12.4)%, (1.25±0.12)] (both P<0.05). Cell viability [(89.1±8.5)%] and CyclinD1 protein level (1.15±0.11) in LPS+si-FABP3 group were significantly higher than those in LPS+si-con group [(53.1±5.4)%, (0.42±0.05)] (both P<0.05). Apoptosis rate [(10.5±1.1)%], IL-6[(301.3±30.0) ng/L], IL-8[(189.4±19.0) ng/L], TNF-α [(400.1±40.1) ng/L], cleaved-caspase-3 (0.45±0.05), GRP78 (0.48±0.05), ATF4 (0.60±0.06), CHOP (0.55±0.05), cleaved-caspase-12 (0.60±0.06), p-Akt (0.50±0.05) and PI3Kp110α(0.45±0.05) in LPS+si-FABP3 group were significantly lower than those in LPS+si-con group [(28.1±2.8)%, (536.3±53.6) ng/L, (400.2±40.2) ng/L, (623.1±62.3) ng/L, (0.96±0.10), (1.02±0.10), (1.15±0.12), (1.10±0.11), (1.15±0.12), (0.90±0.09), (0.72±0.07)] (all P<0.05). Conclusion: Silencing FABP3 gene can inhibit LPS-induced alveolar epithelial cell apoptosis and endoplasmic reticulum stress, which may act by inhibiting the PI3K/Akt signaling pathway.

[Clinical effects of superior gluteal artery perforator island flap in repair of sacral pressure ulcer].

Objective: To explore the clinical effects of superior gluteal artery perforator island flap in repair of sacral pressure ulcer. Methods: From May 2012 to May 2017, 20 patients with sacral pressure ulcers (14 males and 6 females, aged 27 to 67 years) were admitted to our department. According to the consensus staging system of National Pressure Ulcer Advisory Panel in 2016, 6 cases were in 3 stages, 14 cases were in 4 stages, with the area of pressure ulcers ranging from 5.0 cm×4.0 cm to 10.0 cm×8.0 cm. After debridement and vacuum sealing drainage, the superior gluteal artery perforator island flaps were used to repair the pressure wounds, with the area of flaps ranging from 6 cm×5 cm to 13 cm×8 cm. The donor sites were sutured directly. The survival of flaps after operation, the healing of wounds, and the follow-up of patients were observed. Results: After surgery, flaps of 20 patients survived well without reoperation. The length of hospital stay of patients was 20 to 40 days, with an average of 25 days. Eighteen patients were followed up for 6 to 24 months, with an average of 12.2 months. The flaps were in good shape and elastic recovery. There were no complications such as seroma or hematoma in the donor sites. Both the patients and family members expressed satisfaction with the shape and texture of the flap and shape of hip. Conclusions: The superior gluteal artery perforator island flap is reliable in blood supply and easy to rotate. The flap can carry a little muscle to increase the anti-infective ability. Moreover, the donor site can be directly sutured with slight damage. Thus, it is one of the good methods for repairing sacral pressure ulcers.

[Interfacility transport with extracorporeal membrane oxygenation in pediatric patients: a multicenter study in China].

Objective: To investigate application and safety of pediatric interfacility-transport with extracorporeal membrane oxygenation (ECMO) in China. Methods: The data of 48 patients transported inter-hospital from February 2016 to May 2018 were collected from the following 4 centers: pediatric intensive care unit (PICU) of Bayi Children's Hospital Affiliated to the 7th Medical Center of PLA General Hospital, Pediatric Hospital of Fudan University, Henan Provincial People's Hospital and Children's Hospital of Zhejiang University School of Medicine. The data of patients' characteristics, ECMO mode and wean rate, and mortality were reviewed, which was further compared with the data of 57 compatible inner-hospital ECMO cases with t test, Rank sum test or chi-square test. Results: All the 48 interfacility-transports were accomplished by ambulance on land, with an average transfer distance of (435±422) km. The incidence of ECMO complications was 13% (6 case), without death. There were no significant differences in lactic acid, PaO(2) or SaO(2) before and after transport (4.0 (2.0, 7.5) vs. 3.0 (1.5, 6.0) mmol/L, Z=-1.579, P>0.05; 112(47, 405) vs. 166(122, 240) mmHg (1 mmHg=0.133 kPa), Z=-0.104, P>0.05; 0.97±0.02 vs. 0.96±0.03, t=1.570, P>0.05). Instead, PaCO(2) and pH were significantly different ((47±8) vs. (42±5) mmHg, t=2.687, P<0.05; 7.3±0.2 vs. 7.5±0.2, t=3.379, P<0.05). The total ECMO weaned rate was 73% (35/48) and the survival rate was 67% (32/48). No significant differences in demographic characteristics, ECMO mode or duration, transport distance or duration, or complications existed between the survival group and the death group (7/25 vs. 2/14, χ(2)=0.615, P>0.05; 4/28 vs. 2/14, χ(2)=0, P>0.05; (405±404) vs. (493±465) km, t=0.525, P>0.05; (5±4) vs. (5±5) h, t=0.388, P>0.05; 166 (128, 239) vs. 187(52, 405) h, Z=-0.104, P>0.05; 3/32 vs. 3/16, χ(2)=0.734, P>0.05). The lowest lactate value in survival group before ECMO transport was significantly lower than that in the death group ((5±5) vs. (8±6) mmol/L, t=2.151, P<0.05). There were neither significant differences in age, ECMO mode or support pattern (9/39 vs. 15/42, χ(2)=0.845, P>0.05; 6/42 vs. 7/50, χ(2)=0.001, P>0.05; 29/19 vs. 38/19, χ(2)=0.441, P>0.05), nor in ECMO weaned rate, survival rate or complications between interfacility-transport group and inner-hospital group (35/48 vs. 37/57, χ(2)=0.775, P>0.05; 32/48 vs. 35/57, χ(2)=0.313, P>0.05; 20/48 vs. 22/57, χ(2)=0.102, P>0.05). Conclusion: With appropriate transport equipment and mature teams who handle problems timely during the transport, critically ill children could be safely transported to the destination with ECMO.

CalliSpheres® drug-eluting beads (DEB) transarterial chemoembolization (TACE) is equally efficient and safe in liver cancer patients with different times of previous conventional TACE treatments: a result from CTILC study.

PURPOSE: To assess the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) in liver cancer patients with different times of previous conventional transarterial chemoembolization (cTACE) treatments. METHODS: 367 liver cancer patients about to receive DEB-TACE treatment were enrolled in this prospective cohort study. All patients were divided into no previous cTACE group (NPC group), 1-2 times previous cTACE group (PC group) and triple or above previous cTACE group (TPC group) according to the times of previous cTACE treatments. RESULTS: There was no difference in complete response (CR) (P = 0.671) and objective response rate (ORR) (P = 0.062) among three groups. Additionally, no difference in overall survival (OS) among groups (P = 0.899) was found. As to liver function, most liver function indexes were deteriorative at 1 week after DEB-TACE operation, but returned to baseline at 1-3 months after DEB-TACE operation in all three groups, while percentage of abnormal total bile acid (TBA) patients was higher in TPC group than NPC and PC groups at 1-3 month post-DEB-TACE (P = 0.018). As for safety profiles, the incidence of pain during DEB-TACE operation was lower in TPC group compared to NPC and PC groups (P = 0.005), while no difference of other adverse events was found during and 1 month post-DEB-TACE treatment among three groups. CONCLUSION: DEB-TACE treatment was equally efficient and tolerated in liver cancer patients with different times of previous cTACE treatments.

Panel sequencing for clinically oriented variant screening and copy number detection in 142 untreated multiple myeloma patients.

We employed a customized Multiple Myeloma (MM)-specific Mutation Panel (M(3)P) to screen a homogenous cohort of 142 untreated MM patients for relevant mutations in a selection of disease-specific genes. M(3)Pv2.0 includes 77 genes selected for being either actionable targets, potentially related to drug-response or part of known key pathways in MM biology. We identified mutations in potentially actionable genes in 49% of patients and provided prognostic evidence of STAT3 mutations. This panel may serve as a practical alternative to more comprehensive sequencing approaches, providing genomic information in a timely and cost-effective manner, thus allowing clinically oriented variant screening in MM.

PYK2 links G(q)alpha and G(13)alpha signaling to NF-kappa B activation.

Signaling via a variety of G-protein-coupled receptors (GPCRs) leads to activation of nuclear factor (NF)-kappa B. Evidence exists for a signaling pathway initiated by the B2 type bradykinin receptor via G(q) activation, which leads to the sequential stimulation of phosphoinositide 3-kinase (PI3K), the serine/threonine kinase Akt, I kappa B kinases, and finally nuclear factor NF-kappa B-dependent transcription. GPCR-mediated G(q)alpha or G(13)alpha activation also potently stimulates the tyrosine kinase PYK2. In this study we tested whether G(q)alpha- and/or G(13)alpha-induced PYK2 activation contributes to GPCR-mediated NF-kappa B activation. Among the GTPase-deficient forms of G alpha tested, G(13)alpha and G(q)alpha most potently stimulated an NF-kappa B-dependent reporter gene. PYK2 activated the same reporter gene and synergized with either G(q)alpha Q209L (QL) or G(13)alpha Q226L (QL). Placing PYK2 upstream of both PI3K and Akt activation, PYK2 activated Akt through a PI3K-dependent pathway, and either a dominant negative form of Akt or the PI3K inhibitor LY294002 blocked PYK2-stimulated NF-kappa B-dependent transcription. Placing PYK2 downstream of G-protein activation, a kinase-dead form of PYK2, PYK2 (KD), blocked NF-kappa B-dependent transcription triggered by signaling through the muscarinic receptor type 1 and either G(q)alpha QL or G(13)alpha QL. PYK2 (KD) also blocked Akt activation by the same stimuli. These results indicate that PYK2 can link G-protein activation through PI3K, Akt, and I kappa B kinase to NF-kappa B activation.

Regulator of G-protein signaling 3 (RGS3) inhibits Gbeta1gamma 2-induced inositol phosphate production, mitogen-activated protein kinase activation, and Akt activation.

Regulator of G-protein signaling 3 (RGS3) enhances the intrinsic rate at which Galpha(i) and Galpha(q) hydrolyze GTP to GDP, thereby limiting the duration in which GTP-Galpha(i) and GTP-Galpha(q) can activate effectors. Since GDP-Galpha subunits rapidly combine with free Gbetagamma subunits to reform inactive heterotrimeric G-proteins, RGS3 and other RGS proteins may also reduce the amount of Gbetagamma subunits available for effector interactions. Although RGS6, RGS7, and RGS11 bind Gbeta(5) in the absence of a Ggamma subunit, RGS proteins are not known to directly influence Gbetagamma signaling. Here we show that RGS3 binds Gbeta(1)gamma(2) subunits and limits their ability to trigger the production of inositol phosphates and the activation of Akt and mitogen-activated protein kinase. Co-expression of RGS3 with Gbeta(1)gamma(2) inhibits Gbeta(1)gamma(2)-induced inositol phosphate production and Akt activation in COS-7 cells and mitogen-activated protein kinase activation in HEK 293 cells. The inhibition of Gbeta(1)gamma(2) signaling does not require an intact RGS domain but depends upon two regions in RGS3 located between acids 313 and 390 and between 391 and 458. Several other RGS proteins do not affect Gbeta(1)gamma(2) signaling in these assays. Consistent with the in vivo results, RGS3 inhibits Gbetagamma-mediated activation of phospholipase Cbeta in vitro. Thus, RGS3 may limit Gbetagamma signaling not only by virtue of its GTPase-activating protein activity for Galpha subunits, but also by directly interfering with the activation of effectors.

RGS3 is a GTPase-activating protein for g(ialpha) and g(qalpha) and a potent inhibitor of signaling by GTPase-deficient forms of g(qalpha) and g(11alpha).

Many Regulators of G protein Signaling (RGS) proteins accelerate the intrinsic GTPase activity of G(ialpha) and G(qalpha)-subunits [i.e., behave as GTPase-activating proteins (GAPs)] and several act as G(qalpha)-effector antagonists. RGS3, a structurally distinct RGS member with a unique N-terminal domain and a C-terminal RGS domain, and an N-terminally truncated version of RGS3 (RGS3CT) both stimulated the GTPase activity of G(ialpha) (except G(zalpha)) and G(qalpha) but not that of G(salpha) or G(12alpha). RGS3 and RGS3CT had G(qalpha) GAP activity similar to that of RGS4. RGS3 impaired signaling through G(q)-linked receptors, although RGS3CT invariably inhibited better than did full-length RGS3. RGS3 potently inhibited G(qalpha)Q209L- and G(11alpha)Q209L-mediated activation of a cAMP-response element-binding protein reporter gene and G(qalpha)Q209L induced inositol phosphate production, suggesting that RGS3 efficiently blocks G(qalpha) from activating its downstream effector phospholipase C-beta. Whereas RGS2 and to a lesser extent RGS10 also inhibited signaling by these GTPase-deficient G proteins, other RGS proteins including RGS4 did not. Mutation of residues in RGS3 similar to those required for RGS4 G(ialpha) GAP activity, as well as several residues N terminal to its RGS domain impaired RGS3 function. A greater percentage of RGS3CT localized at the cell membrane than the full-length version, potentially explaining why RGS3CT blocked signaling better than did full-length RGS3. Thus, RGS3 can impair Gi- (but not Gz-) and Gq-mediated signaling in hematopoietic and other cell types by acting as a GAP for G(ialpha) and G(qalpha) subfamily members and as a potent G(qalpha) subfamily effector antagonist.

G13alpha-mediated PYK2 activation. PYK2 is a mediator of G13alpha -induced serum response element-dependent transcription.

G(12)alpha/G(13)alpha transduces signals from G-protein-coupled receptors to stimulate growth-promoting pathways and the early response gene c-fos. Within the c-fos promoter lies a key regulatory site, the serum response element (SRE). Here we show a critical role for the tyrosine kinase PYK2 in muscarinic receptor type 1 and G(12)alpha/G(13)alpha signaling to an SRE reporter gene. A kinase-inactivate form of PYK2 (PYK2 KD) inhibits muscarinic receptor type 1 signaling to the SRE and PYK2 itself triggers SRE reporter gene activation through a RhoA-dependent pathway. Placing PYK2 downstream of G-protein activation but upstream of RhoA, the expression of PYK2 KD blocks the activation of an SRE reporter gene by GTPase-deficient forms of G(12)alpha or G(13)alpha but not by RhoA. The GTPase-deficient form of G(13)alpha triggers PYK2 kinase activity and PYK2 tyrosine phosphorylation, and co-expression of the RGS domain of p115 RhoGEF inhibits both responses. Finally, we show that in vivo G(13)alpha, although not G(12)alpha, readily associates with PYK2. Thus, G-protein-coupled receptors via G(13)alpha activation can use PYK2 to link to SRE-dependent gene expression.

Regulator of G protein signaling 1 (RGS1) markedly impairs Gi alpha signaling responses of B lymphocytes.

Regulator of G protein signaling (RGS) proteins modulate signaling through pathways that use heterotrimeric G proteins as transducing elements. RGS1 is expressed at high levels in certain B cell lines and can be induced in normal B cells by treatment with TNF-alpha. To determine the signaling pathways that RGS1 may regulate, we examined the specificity of RGS1 for various G alpha subunits and assessed its effect on chemokine signaling. G protein binding and GTPase assays revealed that RGS1 is a Gi alpha and Gq alpha GTPase-activating protein and a potential G12 alpha effector antagonist. Functional studies demonstrated that RGS1 impairs platelet activating factor-mediated increases in intracellular Ca+2, stromal-derived factor-1-induced cell migration, and the induction of downstream signaling by a constitutively active form of G12 alpha. Furthermore, germinal center B lymphocytes, which are refractory to stromal-derived factor-1-triggered migration, express high levels of RGS1. These results indicate that RGS proteins can profoundly effect the directed migration of lymphoid cells.

Adaptor proteins CRK and CRKL associate with the serine/threonine protein kinase GCKR promoting GCKR and SAPK activation.

STE20-related kinases play significant regulatory roles in a range of cellular responses to environmental stimuli. GCKR (also referred to as KHS1) is a serine/threonine protein kinase that has an STE20-like protein kinase domain and that stimulates the stress-activated protein kinase (SAPK, also referred to as Jun kinase or JNK) pathway. GCKR has a large C-terminal regulatory domain that provides sites for interactions with other proteins. Adaptor proteins mediate the interactions between signaling molecules. In this study we showed that the adaptor proteins Crk and CrkL associated with GCKR. When Crk-I, Crk-II, or CrkL was transiently expressed in HEK 293T cells along with GCKR, each coimmunoprecipitated with GCKR. Furthermore, in the Bcr-Abl transformed cell line, K562 endogenous GCKR and CrkL coimmunoprecipitated, indicating a constitutive association. Detection of the CrkL-GCKR interaction required the SH3 domains of CrkL and 2 regions in GCKR-1 between amino acids 387 and 395 that contains a consensus SH3 binding motif and the other between amino acids 599 and 696. Crk or CrkL overexpression increased GCKR catalytic activity. A dominant negative form of Ras abolished Crk- or CrkL-induced GCKR activation, suggesting a dependence on Ras activation for their activation of GCKR. Finally, we showed impairment of the known ability of CrkL to activate the SAPK pathway by a catalytically inactive form of GCKR or by a GCKR antisense construct. Thus, GCKR associates with other proteins through interactions mediated by SH2/SH3 adaptor proteins, which can lead to GCKR and SAPK activation.

TNF-mediated activation of the stress-activated protein kinase pathway: TNF receptor-associated factor 2 recruits and activates germinal center kinase related.

TNF-induced activation of stress activated protein kinases (SAPKs, Jun NH2-terminal kinases) requires TNF receptor associated factor 2 (TRAF2). TRAF2 is a potent activator of a 95-kDa serine/threonine kinase termed germinal center kinase related (GCKR, also referred to as KHS1), which signals activation of the SAPK pathway. Consistent with a role for GCKR in TNF- induced SAPK activation, a kinase-inactive mutant of GCKR is a dominant negative inhibitor of TRAF2-induced SAPK activation. Here we show that TRAF2 interacts with GCKR. This interaction depended upon the TRAF domain of TRAF2 and the C-terminal 150 aa of GCKR. The full activation of GCKR by TRAF2 required the TRAF2 RING finger domain. TNF treatment of a T cell line, Jurkat, increased both GCRK and SAPK activity and enhanced the coimmunoprecipitation of GCKR with TRAF2. Similar results were found with the B cell line HS-Sultan. These findings are consistent with a model whereby TNF signaling results in the recruitment and activation of GCKR by TRAF2, which leads to SAPK activation.

GCKR links the Bcr-Abl oncogene and Ras to the stress-activated protein kinase pathway.

The Bcr-Abl oncogene, found in Philadelphia chromosome-positive myelogenous leukemia (CML), activates Ras and triggers the stress-activated protein kinase (SAPK or Jun NH2-terminal kinase [JNK]) pathway. Interruption of Ras or SAPK activation dramatically reduces Bcr-Abl-mediated transformation. Here, we report that Bcr-Abl through a Ras-dependent pathway signals the serine/threonine protein kinase GCKR (Germinal Center Kinase Related) leading to SAPK activation. Either an oncogenic form of Ras or Bcr-Abl enhances GCKR catalytic activity and its activation of SAPK, whereas inhibition of GCKR impairs Bcr-Abl-induced SAPK activation. Bcr-Abl mutants that are impaired for GCKR activation are also unable to activate SAPK. Consistent with GCKR being a functional target in CML, GCKR is constitutively active in CML cell lines and found in association with Bcr-Abl. Our results indicate that GCKR is a downstream target of Bcr-Abl and strongly implicate GCKR as a mediator of Bcr-Abl in its transformation of cells.

Activation of stress-activated protein kinase/c-Jun N-terminal kinase, but not NF-kappaB, by the tumor necrosis factor (TNF) receptor 1 through a TNF receptor-associated factor 2- and germinal center kinase related-dependent pathway.

A key step by which tumor necrosis factor (TNF) signals the activation of nuclear factor-kappaB (NF-kappaB) and the stress-activated protein kinase (SAPK, also called c-Jun N-terminal kinase or JNK) is the recruitment to the TNF receptor of TNF receptor-associated factor 2 (TRAF2). However, the subsequent steps in TRAF2-induced SAPK and NF-kappaB activation remain unresolved. Here we report the identification of a TNF-responsive serine/threonine protein kinase termed GCK related (GCKR) that likely signals via mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase kinase 1 (MEKK1) to activate the SAPK pathway. TNF, TRAF2, and ultraviolet (UV) light, which in part uses the TNF receptor signaling pathway, all increased GCKR activity. A TRAF2 mutant, which inhibits both TRAF2-induced NF-kappaB and SAPK activation, blocked TNF-induced GCKR activation. Finally, interference with GCKR expression impeded TRAF2- and TNF-induced SAPK activation but not that of NF-kappaB. This suggests a divergence in the TNF signaling pathway that leads to SAPK and NF-kappaB activation, which is located downstream of TRAF2 but upstream of GCKR.

Prevalence of primary Sjögren's syndrome in China.

OBJECTIVE: To determine the prevalence rate of primary Sjögren's syndrome (SS) in a community population of 2066 adults in a Beijing suburban village, and 100 inpatients, who were not necessarily admitted for rheumatic diseases. METHODS: Questionnaire and serological studies of antinuclear antibodies, rheumatoid factor, and anti-SSA, anti-SSB antibodies were done. Possible positive subjects were given eye and oral examinations for objective evidence of xerostomia and keratoconjunctivitis sicca. RESULTS: According to the Copenhagen criteria, the prevalence rate of primary Sjögren's syndrome in China was 0.77%, and it was 0.33% by modified San Diego criteria. In 100 inpatients, we found 4 cases of primary Sjögren's syndrome by Copenhagen criteria, and one case by modified San Diego criteria. CONCLUSION: Primary Sjögren's syndrome is not a rare disease in China, but most cases are overlooked or misdiagnosed.

Extracting direction and curvature features of jaw movement traces with chain code.

Frontal chewing patterns have been classified in a manual and visual way on recorded movement tracks. The main aim of this study was to use a chain code method to extract the direction and curvature features of the tracks in the frontal plane. The test results indicate that the chain code can stand for the direction and curvature. The chewing movement tracks in the frontal plane can be clustered into chain code values. The method therefore appears to be useful in the classification of chewing movements.