Oncogenic KRAS, Mucin 4, and Activin A-Mediated Fibroblast Activation Cooperate for PanIN Initiation.

Over 90% of patients with pancreatic ductal adenocarcinoma (PDAC) have oncogenic KRAS mutations. Nevertheless, mutated KRAS alone is insufficient to initiate pancreatic intraepithelial neoplasia (PanIN), the precursor of PDAC. The identities of the other factors/events required to drive PanIN formation remain elusive. Here, optic-clear 3D histology is used to analyze entire pancreases of 2-week-old Pdx1-Cre; LSL-KrasG12D/+ (KC) mice to detect the earliest emergence of PanIN and observed that the occurrence is independent of physical location. Instead, it is found that the earliest PanINs overexpress Muc4 and associate with αSMA+ fibroblasts in both transgenic mice and human specimens. Mechanistically, KrasG12D/+ pancreatic cells upregulate Muc4 through genetic alterations to increase proliferation and fibroblast recruitments via Activin A secretion and consequently enhance cell transformation for PanIN formation. Inhibition of Activin A signaling using Follistatin (FST) diminishes early PanIN-associated fibroblast recruitment, effectively curtailing PanIN initiation and growth in KC mice. These findings emphasize the vital role of interactions between oncogenic KrasG12D/+ -driven genetic alterations and induced microenvironmental changes in PanIN initiation, suggesting potential avenues for early PDAC diagnostic and management approaches.

Different traditional Chinese medicine constitution is associated with dietary and lifestyle behaviors among adults in Taiwan.

The World Health Organization states prevention of chronic diseases should be based on good lifestyle behaviors and healthy diets as they can reduce the risk of chronic diseases by 80%. The theory of traditional Chinese medicine constitution (TCMC) emphasizes the congenital differences of TCMC stem from the genes of parents, while acquired differences in TCMC are caused by factors as living environments, lifestyle behaviors, and dietary habits. From the perspective of preventive medicine, this study explores the correlation between dietary habits and lifestyle behaviors as potential risk factors for different types of TCMC-balanced constitution, Yang deficiency, Yin deficiency, and Phlegm stasis. Research data were collected from 2760 subjects aged 30 to 70 years participating in a survey conducted by Taiwan Biobank in 2012 to 2017. The survey included basic demographic characteristics, lifestyle behaviors, and dietary habits along with a Body Constitution Questionnaire. Compared to men, women were 3 to 4 times more likely to develop Yang-deficiency, Yin-deficiency, and Phlegm stasis. Variables that affected TCMC were smoking, midnight snack consumption, consumption of gravy-soaked or lard-soaked rice/noodles, deep-fried soybean products, bread spread, pickled vegetables as side dishes for the main course of a meal, and the dietary habit of vegetables or fruits instead of high-fat desserts. Poor dietary habits and lifestyle behaviors are the cause of unbalanced TCMCs. Understanding the specific TCMC of individual can provide useful information and predictions to maintain physical health and achieve early disease prevention to meet the goal of preventive medicine.

Factors Affecting Physical Activity of People with Knee Osteoarthritis in Southern Taiwan: A Multiple Logistic Regression Analysis.

Background: Physical activity (PA) is a basic and initiative conservative management for people with knee osteoarthritis (KOA). This study aimed to explore the potential indicators of PA levels in people with KOA. Methods: We designed a cross-sectional study where people with KOA were consecutively approached by the Orthopedic Outpatient Department in a hospital in southern Taiwan. People older than 50 years that could communicate and consent to the present study were enrolled. As a dependent variable, the Chinese version of the Physical Activity Scale for the Elderly (PASE-C) was used to assess the participant's PA levels. Considering differences in sex, a PASE-C score cut-off point of 140 for men and 120 for women was used. Participants were then divided into "active" and "inactive" groups. We measured independent variables consisting of the demographic and clinical characteristics, such as comorbidities measured by the Charlson Comorbidity Index (CCI), depression status measured by the Geriatric Depression Scale-5, body mass index, KOA history (<5, 5-<10, and ≥10 years), knee pain (unilateral or bilateral), the severity of symptoms measured by the Western Ontario and McMaster Universities Osteoarthritis Index, and 6-meter preferred walking speed. Multiple logistic regression was performed to identify significant relationships between PA among people with KOA. Results: We analyzed a total of 188 people with KOA (56 men and 132 women) with a mean age of 69.4 ± 7.9 (range: 51 to 90 years). Approximately 72.9% (n = 137) were categorized as "inactive PA," while 27.1% (n = 51) of participants were categorized as "active PA" (male: 32.1%; female: 25.0%). Multiple logistic regression showed a positive association of 6-meter preferred walking speed with active PA (OR: 7.08; 95% CI:1.14-44.13), whereas advanced age and comorbidity (CCI≥1 vs. CCI<1) were negatively associated with active PA with an OR (95% CI) score of 0.91 (0.86-0.97) and 0.37 (0.15-0.87), respectively. Conclusions: People with KOA require appropriate lifestyle management to increase PA. Walking speed may be an effective factor for predicting PA among people with KOA. Healthcare providers treating KOA patients should be aware of their PA levels, especially those at risk.

Homophilic ATP1A1 binding induces activin A secretion to promote EMT of tumor cells and myofibroblast activation.

Tumor cells with diverse phenotypes and biological behaviors are influenced by stromal cells through secretory factors or direct cell-cell contact. Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia with fibroblasts as the major cell type. In the present study, we observe enrichment of myofibroblasts in a juxta-tumoral position with tumor cells undergoing epithelial-mesenchymal transition (EMT) that facilitates invasion and correlates with a worse clinical prognosis in PDAC patients. Direct cell-cell contacts forming heterocellular aggregates between fibroblasts and tumor cells are detected in primary pancreatic tumors and circulating tumor microemboli (CTM). Mechanistically, ATP1A1 overexpressed in tumor cells binds to and reorganizes ATP1A1 of fibroblasts that induces calcium oscillations, NF-κB activation, and activin A secretion. Silencing ATP1A1 expression or neutralizing activin A secretion suppress tumor invasion and colonization. Taken together, these results elucidate the direct interplay between tumor cells and bound fibroblasts in PDAC progression, thereby providing potential therapeutic opportunities for inhibiting metastasis by interfering with these cell-cell interactions.

5-methoxytryptophan protects MSCs from stress induced premature senescence by upregulating FoxO3a and mTOR.

5-methoxytryptophan (5-MTP) is a newly discovered tryptophan metabolite which controls stress-induced inflammatory signals. To determine whether 5-MTP protects against stress-induced mesenchymal stem cell (MSC) senescence, we incubated bone marrow-derived MSC (BM-MSC) in high-glucose medium or regular medium for 2 weeks followed by addiction of 5-MTP (10 µM) or vehicle for 48 h. 5-MTP reduced p16 and p21 expression, senescence-associated ß-Gal (SA-ß-Gal) and IL-6 secretion and increased BrdU incorporation. 5-MTP exerted a similar effect on BM-MSC senescence induced by a sublethal concentration of H2O2. 5-MTP enhanced FoxO3a expression and increased superoxide dismutase and catalase activities in HG BM-MSCs. Silencing of FoxO3a with siRNA abrogated 5-MTP-mediated reduction of SA-ß-Gal and IL-6 secretion but not p21 or p16. Since mechanistic target of rapamycin (mTOR) is involved in cellular senescence, we determined whether 5-MTP influences mTOR expression. Our data reveal that mTOR protein level was depressed in HG-MSC which was rescued by 5-MTP. Rapamycin abrogated 5-MTP-mediated suppression of p16, p21, SA-ß-Gal and IL-6 and rise of BrdU incorporation. Our findings suggest that 5-MTP protects MSCs against stress-induced senescence via FoxO3a and mTOR upregulation and has potential to improve cell expansion for cell therapy.

High glucose induces bone marrow-derived mesenchymal stem cell senescence by upregulating autophagy.

Hyperglycemia was reported to cause bone marrow hematopoietic niche dysfunction, and high glucose (HG) in the cultured medium induces MSC senescence. The underlying mechanism is unclear. Here, we investigated the role of HG-induced autophagy in bone-marrow-derived mesenchymal stem cell (BMSC) senescence. HG (25 mM) increased expression of Beclin-1, Atg 5, 7 and 12, generation of LC3-II and autophagosome formation which was correlated with development of cell senescence. Pretreatment of HG-MSC with 3-methyladenine (3-MA) prevented senescence but increased apoptosis. N-acetylcysteine (NAC) was effective in abrogating HG-induced autophagy accompanied by prevention of senescence. Diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase, blocked autophagy and senescence in a manner comparable to NAC. 3-MA, NAC and DPI inhibited HG-induced interleukin-6 production in BMSCs. These results suggest that hyperglycemia induces MSC senescence and local inflammation via a novel oxidant-mediated autophagy which contributes to bone marrow niche dysfunction and hematopoietic impairment.

Blockade of JAK2 activity suppressed accumulation of ß-catenin in leukemic cells.

The Wnt/ß-catenin pathway has been implicated in leukemogenesis. We found ß-catenin abnormally accumulated in both human acute T cell leukemia Jurkat cells and human erythroleukemia HEL cells. ß-Catenin can be significantly down-regulated by the Janus kinase 2 specific inhibitor AG490 in these two cells. AG490 also reduces the luciferase activity of a reporter plasmid driven by LEF/ß-catenin promoter. Similar results were observed in HEL cells infected with lentivirus containing shRNA against JAK2 gene. After treatment with 50 µM AG490 or shRNA, the mRNA expression levels of ß-catenin, APC, Axin, ß-Trcp, GSK3α, and GSK3ß were up-regulated within 12-16 h. However, only the protein levels of GSK3ß and ß-Trcp were found to have increased relative to untreated cells. Knockdown experiments revealed that the AG490-induced inhibition of ß-catenin can be attenuated by shRNA targeting ß-TrCP. Taken together; these results suggest that ß-Trcp plays a key role in the cross-talk between JAK/STAT and Wnt/ß-catenin signaling in leukemia cells.