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Background: Ventilator-induced lung injury (VILI) is a common complication in the treatment of respiratory diseases with high morbidity and mortality. Matrix metalloprotein (MMP) 9 and Elk1 are involved in VILI, but the roles have not been fully elucidated. This study examined the mechanisms of the activation of MMP-9 and Elk1 regulating barrier function in VILI in vitro and in vivo.Methods: For the in vitro study, MLE-12 cells were pre-treated with Elk1 siRNA or MMP-9 siRNA for 48 h prior to cyclic stretch at 20% for 4 h. For the in vivo study, C57BL/6 mice were pre-treated with Elk1 siRNA or MMP-9 siRNA for 72 h prior to 4h of mechanical ventilation. The expressions of Elk1, MMP-9, E-cadherin, and occludin were measured by Western blotting. The intracellular distribution of E-cadherin and occluding was shown by immunofluorescence. The degree of pulmonary edema and lung injury were evaluated by HE staining, lung injury scores, W/D weight ratio, total cell counts, and Evans blue dye.Results: 20% cyclic stretch and high tidal volume could increase the expressions of Elk1 and MMP-9, decrease the E-cadherin and occludin level. Elk1 siRNA or MMP-9 siRNA could reverse the degradations of E-cadherin and occludin caused by cyclic stretch. Elk1 siRNA could decrease the MMP-9 level with or not 20% cyclic stretch and high tidal volume. Conclusions: This study demonstrated that mechanical stretch could lead to the transcriptional activation of Elk1, enhance the expression of MMP-9 and mediate the loss of E-cadherin and occludin in VILI, thus indicating the therapeutic potential of Elk1 to treat VILI.

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The Yiluo River Basin is located in the Central plains of China, an area commonly known as the center of origin of ancient Chinese civilization. Agriculture lays the foundation for social and economic development and triggers societal change and archaeobotany can provide important clues on this issue. archaeobotanical study is an important perspective on the relationship between agriculture and society development. However, relatively few archaeobotanical studies have been conducted in the Yiluo River basin, and the paucity of data has hindered our understanding of the relationship between agriculture and society. Therefore, the archaeobotanical analysis at the Suyang site in the middle reach of the Luo River provides an opportunity to understand how and why agriculture and society developed. Our analytical results of carbonized plant remains and phytolith, coupled with radiocarbon dating, showed that millet was the main crop in the late Yangshao culture (5,500–5000 BP), followed by rice. However, rice cultivation in the area expanded during the Longshan culture (5,000–4000 BP), and its importance as a crop possibly exceeded millet at Suyang. From the late Yangshao to Longshan, rice was cultivated in wet fields by utilizing the Luo River floodplain on a large scale. The proportion of rice at Suyang is the highest among contemporary sites in the Central Plains. It may be related to many reasons such as suitable environmental and geomorphological conditions, advanced water management, the influence of the Qujialing culture, and population growth. In the late Yangshao culture, crop processing seemed to have been concentrated in communal areas. However, during the Longshan culture, different steps of crop processing were scattered throughout the site. This change is hypothesized as a change in the family structure and economic production. After the Yangshao period, the nuclear family became the fundamental unit for social, cultural, and economic production in the Central Plains.