Formation Mechanism of a Coastal Zone Environment Collaborative Governance Relationship: A Qualitative Comparative Analysis Based on fsQCA.

The coastal zone is an area where terrestrial and marine ecosystems intersect. This region may be subject to outstanding environmental issues, as influenced by many stakeholders. Based on the framework of collaborative governance, the starting conditions for forming a coastal zone environment collaborative governance relationship are proposed as follows: coastal zone environment, balanced level of power and resources, superior-level government participation, and previous cooperation experience. The coastal environmental governance practices of 14 cities along the continental coastal zone of the East China Sea are selected as cases, in order to test the interactions between and influence mechanisms of the starting conditions. As qualitative comparative analysis (QCA), based on set theory and Boolean algebra, is a popular tool to explain complex collaboration situations in small-N cases; and as fuzzy-set qualitative comparative analysis (fsQCA) allows for fine classification of the membership degree (where the condition can be allocated any number between 0 and 1), we use fsQCA to analyze the collaborative governance relationships. The results of the analysis demonstrate that three combination configurations promote the formation of medium-high intensity collaborative governance relationships: high balance level of power and resources × high previous cooperation experience, high pollution of coastal zone environment × high balance level of power and resources × low superior-level government participation, and high pollution of coastal zone environment × high superior-level government participation × high previous cooperation experience. Based on this conclusion, we determine three types of relationship formation modes: wheel-, echo state network-, and umbrella-shaped modes. Notably, under certain conditions, superior-level government participation is not necessary for the formation of a medium-high intensity collaborative governance relationship.

Acetylation of ezrin regulates membrane-cytoskeleton interaction underlying CCL18-elicited cell migration.

Ezrin, a membrane-cytoskeleton linker protein, plays an essential role in cell polarity establishment, cell migration, and division. Recent studies show that ezrin phosphorylation regulates breast cancer metastasis by promoting cancer cell survivor and promotes intrahepatic metastasis via cell migration. However, it was less characterized whether there are additional post-translational modifications and/or post-translational crosstalks on ezrin underlying context-dependent breast cancer cell migration and invasion. Here we show that ezrin is acetylated by p300/CBP-associated factor (PCAF) in breast cancer cells in response to CCL18 stimulation. Ezrin physically interacts with PCAF and is a cognate substrate of PCAF. The acetylation site of ezrin was mapped by mass spectrometric analyses, and dynamic acetylation of ezrin is essential for CCL18-induced breast cancer cell migration and invasion. Mechanistically, the acetylation reduced the lipid-binding activity of ezrin to ensure a robust and dynamic cycling between the plasma membrane and cytosol in response to CCL18 stimulation. Biochemical analyses show that ezrin acetylation prevents the phosphorylation of Thr567. Using atomic force microscopic measurements, our study revealed that acetylation of ezrin induced its unfolding into a dominant structure, which prevents ezrin phosphorylation at Thr567. Thus, these results present a previously undefined mechanism by which CCL18-elicited crosstalks between the acetylation and phosphorylation on ezrin control breast cancer cell migration and invasion. This suggests that targeting PCAF signaling could be a potential therapeutic strategy for combating hyperactive ezrin-driven cancer progression.

Mitotic motor CENP-E cooperates with PRC1 in temporal control of central spindle assembly.

Error-free cell division depends on the accurate assembly of the spindle midzone from dynamic spindle microtubules to ensure chromatid segregation during metaphase-anaphase transition. However, the mechanism underlying the key transition from the mitotic spindle to central spindle before anaphase onset remains elusive. Given the prevalence of chromosome instability phenotype in gastric tumorigenesis, we developed a strategy to model context-dependent cell division using a combination of light sheet microscope and 3D gastric organoids. Light sheet microscopic image analyses of 3D organoids showed that CENP-E inhibited cells undergoing aberrant metaphase-anaphase transition and exhibiting chromosome segregation errors during mitosis. High-resolution real-time imaging analyses of 2D cell culture revealed that CENP-E inhibited cells undergoing central spindle splitting and chromosome instability phenotype. Using biotinylated syntelin as an affinity matrix, we found that CENP-E forms a complex with PRC1 in mitotic cells. Chemical inhibition of CENP-E in metaphase by syntelin prevented accurate central spindle assembly by perturbing temporal assembly of PRC1 to the midzone. Thus, CENP-E-mediated PRC1 assembly to the central spindle constitutes a temporal switch to organize dynamic kinetochore microtubules into stable midzone arrays. These findings reveal a previously uncharacterized role of CENP-E in temporal control of central spindle assembly. Since CENP-E is absent from yeast, we reasoned that metazoans evolved an elaborate central spindle organization machinery to ensure accurate sister chromatid segregation during anaphase and cytokinesis.

Acetylation of ACAP4 regulates CCL18-elicited breast cancer cell migration and invasion.

Tumor metastasis represents the main causes of cancer-related death. Our recent study showed that chemokine CCL18 secreted from tumor-associated macrophages regulates breast tumor metastasis, but the underlying mechanisms remain less clear. Here, we show that ARF6 GTPase-activating protein ACAP4 regulates CCL18-elicited breast cancer cell migration via the acetyltransferase PCAF-mediated acetylation. CCL18 stimulation elicited breast cancer cell migration and invasion via PCAF-dependent acetylation. ACAP4 physically interacts with PCAF and is a cognate substrate of PCAF during CCL18 stimulation. The acetylation site of ACAP4 by PCAF was mapped to Lys311 by mass spectrometric analyses. Importantly, dynamic acetylation of ACAP4 is essential for CCL18-induced breast cancer cell migration and invasion, as overexpression of the persistent acetylation-mimicking or non-acetylatable ACAP4 mutant blocked CCL18-elicited cell migration and invasion. Mechanistically, the acetylation of ACAP4 at Lys311 reduced the lipid-binding activity of ACAP4 to ensure a robust and dynamic cycling of ARF6-ACAP4 complex with plasma membrane in response to CCL18 stimulation. Thus, these results present a previously undefined mechanism by which CCL18-elicited acetylation of the PH domain controls dynamic interaction between ACAP4 and plasma membrane during breast cancer cell migration and invasion.

[Inhibition of COL1A1 and COL3A1 expression by RNA interference in human skin fibroblasts].

OBJECTIVE: To suppress COL1A1 and COL3A1 gene expressions in human skin fibroblasts (HSFs) by means of RNA interference (RNAi). METHODS: Three small interfering RNA (siRNA) expression cassette (SEC) sequences were designed for each of the COL1A1 and COL3A1 gene sequences available in GenBank. The synthesized SECs capable of effective gene suppression were transfected into cultured HSFs, either after cloning into the expression vector or mediated by Lipofectamine 2000, and the suppression of the target genes at both mRNA and protein levels was determined by quantitative fluorescence RT-PCR and Western blotting, respectively. RESULTS: Transfection of the SECs into HSFs resulted in specific depression of COL1A1 and COL3A1 expressions (down to 5.00% and 6.48%, respectively). The expression vector-mediated RNAi established a HSF cell line with persistent gene knockdown for over 30 days (to 25.21% and 22.12%, respectively). CONCLUSION: COL1A1 and COL3A1 gene expressions can be specifically and efficiently inhibited in HSFs by either liposome- or vector-mediated SEC transfection.

[Localization and differentiation of hair follicle stem cells].

OBJECTIVE: To identify the localization of hair follicles stem cell (HFSC) in different stages of hair and explore the differentiating capacity of HFSC into epidermis in vitro. METHODS: HFSC were detected by K19 immunostaining in normal human skin. Then, the isolated HFSC through enzyme digestion were seeded on dermal equivalent (DE) and cultured between the air-liquid interfaces for 14 days. Skin-equivalents was harvested and used for evaluation. RESULTS: HFSC mainly located in outer root sheet in hair follicle and human anagen hair follicles containing two distinct reservoirs for K19-positive cells located in the bulge and bulb of the follicle. These two reservoirs fused in line of outer root sheets during the catagen-telogen transition phase and individualized again in the newly forming anagen hair follicle. Based on DE, growing HFSC built a multilayered and confined epidermis. CONCLUSION: HFSC located in outer root sheets can promote hair cycle and differentiate into epidermis in vitro.

Effects of ATRA, acitretin and tazarotene on growth and apoptosis of Tca8113 cells.

To investigate the effects of ATRA, acitretin and tazarotene on the growth and apoptosis of human tongue squamous cell carcinoma cell line Tca8113. The effect of retinoids on growth of Tca8113 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis with double staining with Annexin V-FITC and PI, and active caspase-3 analysis with the staining of FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. Streptavidin-biotin complex (SABC) immunocytochemical assays were employed for the detections of Bax/Bcl-2 proteins expressions. Our results showed that the retinoids inhibited growth of Tca8113 cells in a dose- and time-dependent manner with maximal inhibition 24 h after treatment of 10(-5) mol/L. 10(-5) mol/L retinoids altered cell cycle distribution of Tca8113 cells, revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. 10(-5) mol/L retinoids significantly induced apoptosis of Tca8113 cells (all P < 0.05), elevated the cells population with detectable active caspase-3 (P < 0.05 for all), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (all P < 0.05). Acitretin played a most prominent role among the retinoids. It is concluded that the inhibition of cell cycle progress of Tca8113 cells by ATRA, acitretin and tazarotene is one of the possible mechanisms for proliferation arrest of Tca8113 cells elicited by the retinoids. The retinoids mediate apoptosis in Tca8113 cells that may be caspase-dependent through mitochondria pathway. High concentration retinoids inhibit growth of Tca8113 cells in vitro by interfering with proliferation and inducing apoptosis of cells. Acitretin may be an alternative medicine for the prevention and treatment of tongue squamous cell carcinoma.

[Effects of histamine on proliferation, apoptosis and differentiation of human keratinocytes].

OBJECTIVE: To investigate the effects of histamine on the proliferation, apoptosis and differentiation of human keratinocytes (HKC) and the mechanisms. METHODS: The effect of histamine on the growth of HKC in vitro was examined by MTT assay and trypan blue exclusion assay. Cell cycle analysis and early apoptosis analysis by double staining with Annexin V-FITC and PI were carried out by flow cytometry. DNA ladder assay was performed for the detection of cell apoptosis. HKC free calcium concentration ([Ca(2+)](i)) was measured by laser scanning confocal microscopy in combination with calcium fluorescence probe Fluo-3/AM. HKC differentiation markers keratin 10 (K10) and involucrin was detected by streptavidinbiotin complex immunocytochemical assay. RESULTS: Histamine at high concentration inhibited the proliferation of HKC with cell viability ratio of 65.6% at 1 x 10(-4) mol/L, while histamine at low concentrations promoted proliferation of HKC with the cell viability ratio of 130.7% at 1 x 10(-8) mol/L. Histamine at 1 x 10(-4) mol/L altered cell cycle distribution of HKC with an increase in G0/G1-phase cell population to 30.97%, a decrease in S-phase population to 73.81% and inhibition of G1/S switching. Histamine at 1 x 10(-4) mol/L induced obvious apoptosis of HKC with early apoptosis ratio of 18.64% as compared with the control (5.60%, P<0.05). Histamine 1 x 10(-4) mol/L induced an increase of HKC [Ca(2+)](i) up to 58.9% and cimetidine (an H(2) receptor antagonist) decreased HKC [Ca(2+)](i) down to 25.4%. Histamine at this concentration down-regulated the expressions of K10 and involucrin of HKC but these changes were not significantly different from those of the control (P>0.05). CONCLUSIONS: Histamine at high concentrations inhibits cell cycle progress of HKC, mediates cell apoptosis and induces the increase of [Ca(2+)](i), which might be a partial explanation for growth arrest of HKC elicited by histamine. Histamine may regulate epidermal tissue turnover under physiological conditions, whereas under pathological circumstances of the skin as in trauma and inflammation, histamine at high concentrations may inhibit the regeneration of epidermis and the differentiation of HKC.

[Effects of all-trans-retinoic acid, acitretin and tazarotene on apoptosis and Bax/Bcl-2 expressions of human melanoma cells A375 and the significance].

OBJECTIVE: To investigate the effects of all-trans retinoic acid (ATRA), acitretin and tazarotene on apoptosis and Bax/Bcl-2 protein expressions of human melanoma A375 cells. METHODS: The effects of retinoids on apoptosis and Bax/Bcl-2 protein expressions of A375 cells in vitro were examined. Apoptosis analysis with double staining with annexin V-FITC and PI was performed using flow cytometer. SABC immunocytochemistry was employed for detection of Bax/Bcl-2 protein expressions. RESULTS: At the concentration of 1 x 10(-5) mol/L, ATRA, acitretin and tazarotene all induced apoptosis of A375 cells with apoptosis ratio of 5.03% (P<0.05), 13.42% (P<0.05) and 2.88% (P>0.05), respectively, and acitretin induced more significant apoptosis than the other two agents (P<0.05). In addition, all the three agents significantly increased the number of cells positive for Bax expression and decreased the number of cells expressing Bcl-2 (P<0.05), among which acitretin had the strongest effects. CONCLUSIONS: ATRA, acitretin and tazarotene mediate apoptosis of A375 cells possibly through, at least partially, the mitochondrial pathway. Acitretin may be utilized as a valuable alternative for treating melanoma.