Niacin stimulates EPH4EV mammary epithelial cell proliferation and mammary gland development in pubertal mice through activation of AKT/mTOR and ERK1/2 signaling pathways

Association between dietary niacin intake and lung function among American adults: A cross-sectional analysis from national health and nutrition examination survey, 2007-2012

Background

The pathogenesis of pulmonary senescence involves immune system dysregulation, oxidative stress, and mitochondrial dysfunction. The effects on lung function of niacin, an essential coenzyme involved in mitochondrial energy metabolism with known antioxidant properties, are poorly understood.

Methods

This cross-sectional study used data from the 2007-2012 National Health and Nutrition Examination Survey, including spirometry data and niacin intake information of 9706 adults. This study investigated various spirometry measures, such as forced expiratory volume in 1 s, forced vital capacity, pulse expiratory flow, (forced expiratory volume in 1 s)/(forced vital capacity)ratio, and predicted forced expiratory volume in 1 s and forced vital capacity percentages. Additionally, a secondary analysis was conducted using Global Initiative for Chronic Obstructive Lung Disease and chronic obstructive pulmonary disease. Foundation Spirometry Grade criteria to assess the relationship between niacin intake, airflow limitation, and obstruction. Multivariate regression models were used to adjust for relevant covariates.

Results

The study included 9706 U S. adults (4788 men and 4918 women) with a median age of 46.2 years. After adjusting for relevant factors, a positive correlation was observed between niacin intake and lung function. Compared to the lowest quintile of niacin intake (Q1, ≤14.5 mg/day), individuals in the highest quintile (Q5, >34.5 mg/day) exhibited significant increases in lung function parameters, including forced expiratory volume in 1s (69.84 mL, p = 0.003), pulse expiratory flow (254.48 mL, p < 0.001), (forced expiratory volume in 1 s)/(forced vital capacity)(0.01, p = 0.041), percent predicted forced expiratory volume in 1 s(2.05, p = 0.002), and percent predicted forced vital capacity(1.29, p = 0.042).Subset analyses of individuals with spirometry-defined airflow obstruction showed associations of high niacin intake with significantly improved forced expiratory volume, pulse expiratory flow, and percent predicted pulse expiratory flow and an interaction among race, education, and smoking status with respect to the relationship between niacin intake and lung function parameters.

Conclusions

Higher niacin intake was associated with increased measures of lung function. A diet rich in niacin-containing foods may play a role in improving lung health.

Regulatory roles of dopamine D2 receptor in milk protein production and apoptosis in mammary epithelial cells

Dopamine D2 receptors (D2Rs) play crucial roles in regulating diverse physiological functions of the central nervous system and peripheral organs. D2Rs are also expressed in mammary glands. However, which cell types express D2Rs and whether they are involved in milk production remains unclear. The present findings revealed that D2Rs are expressed in the apical regions of the lateral membranes of mammary epithelial cells (MECs) in lactating mice. We also investigated the effects of the D2R agonist bromocriptine and/or antagonist domperidone on intracellular cAMP levels, milk protein production, and apoptosis in a lactation culture model of MECs that produce major milk components like lactating MECs in vivo. We found that bromocriptine decreased intracellular cAMP levels, whereas domperidone dose-dependently neutralized this effect. Bromocriptine also inhibited casein and lactoferrin production and suppressed activities of STAT5 and glucocorticoid receptors (GRs). Domperidone neutralized the inhibition of casein production as well as STAT5 and GR inactivation induced by bromocriptine. Furthermore, D2R activation by bromocriptine induced apoptosis and inactivated ERK, a signaling molecule responsible for promoting cell proliferation and survival. Domperidone attenuated ERK inactivation and apoptosis induced by bromocriptine. These findings suggest that D2Rs play regulatory roles in milk protein production and apoptosis in MECs.

Molecular Characteristics of JAK2 and Its Effect on the Milk Fat and Casein Synthesis of Ovine Mammary Epithelial Cells

In addition to its association with milk protein synthesis via the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, JAK2 also affects milk fat synthesis. However, to date, there have been no reports on the effect of JAK2 on ovine mammary epithelial cells (OMECs), which directly determine milk yield and milk contents. In this study, the coding sequence (CDS) region of ovine JAK2 was cloned and identified and its tissue expression and localization in ovine mammary glands, as well as its effects on the viability, proliferation, and milk fat and casein levels of OMECs, were also investigated. The CDS region of ovine JAK2, 3399 bp in length, was cloned and its authenticity was validated by analyzing its sequence similarity with JAK2 sequences from other animal species using a phylogenetic tree. JAK2 was found to be expressed in six ovine tissues, with the highest expression being in the mammary gland. Over-expressed JAK2 and three groups of JAK2 interference sequences were successfully transfected into OMECs identified by immunofluorescence staining. When compared with the negative control (NC) group, the viability of OMECs was increased by 90.1% in the pcDNA3.1-JAK2 group. The over-expression of JAK2 also increased the number and ratio of EdU-labeled positive OMECs, as well as the expression levels of three cell proliferation marker genes. These findings show that JAK2 promotes the viability and proliferation of OMECs. Meanwhile, the triglyceride content in the over-expressed JAK2 group was 2.9-fold higher than the controls and the expression levels of four milk fat synthesis marker genes were also increased. These results indicate that JAK2 promotes milk fat synthesis. Over-expressed JAK2 significantly up-regulated the expression levels of casein alpha s2 (CSN1S2), casein beta (CSN2), and casein kappa (CSN3) but down-regulated casein alpha s1 (CSN1S1) expression. In contrast, small interfered JAK2 had the opposite effect to JAK2 over-expression on the viability, proliferation, and milk fat and milk protein synthesis of OMECs. In summary, these results demonstrate that JAK2 promotes the viability, proliferation, and milk fat synthesis of OMECs in addition to regulating casein expression in these cells. This study contributes to a better comprehension of the role of JAK2 in the lactation performance of sheep.

Cancer invasion and metastasis: Insights from murine pubertal mammary gland morphogenesis

Cancer invasion and metastasis accounts for the majority of cancer related mortality. A better understanding of the players that drive the aberrant invasion and migration of tumors cells will provide critical targets to inhibit metastasis. Postnatal pubertal mammary gland morphogenesis is characterized by highly proliferative, invasive, and migratory normal epithelial cells. Identifying the molecular regulators of pubertal gland development is a promising strategy since tumorigenesis and metastasis is postulated to be a consequence of aberrant reactivation of developmental stages. In this review, we summarize the pubertal morphogenesis regulators that are involved in cancer metastasis and revisit pubertal mammary gland transcriptome profiling to uncover both known and unknown metastasis genes. Our updated list of pubertal morphogenesis regulators shows that most are implicated in invasion and metastasis. This review highlights molecular linkages between development and metastasis and provides a guide for exploring novel metastatic drivers.

Birt-Hogg-Dubé Syndrome: A Rare Genodermatosis Presenting as Skin Papillomas

The authors present a rare case of Birt-Hogg-Dubé (BHD) syndrome that presented primarily as an aesthetic case. Previous providers failed to accurately diagnose BHD, despite the patient's history of pneumothoraces. This female patient complained of numerous recurrent, small skin-colored growths on the face and neck and patchy hypopigmentation from the multiple treatments she had to undergo for her "bumpy skin." She also suffered 4 spontaneous pneumothoraces. Following histopathologic and genetic testing, the patient was diagnosed with BHD. Computed tomography and ultrasound scans revealed multiple cysts in both lungs and an angiomyolipoma in both kidneys. This patient had undergone a variety of treatments to aesthetically remove and heal her skin bumps from several healthcare providers, all of whom had misdiagnosed her condition.

Level of Evidence 5

WITHDRAWN: RNA binding protein Musashi2 regulates dairy cows' mastitis by activating the TGFβ signaling pathway

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Mechanical stimulation on a microfluidic device to highly enhance small extracellular vesicle secretion of mesenchymal stem cells

Small extracellular vesicles (sEVs) are recognized as promising detection biomarkers and attractive delivery vehicles, showing great potential in diagnosis and treatment of diseases. However, the applications of sEVs are usually restricted by their poor secretion amount from donor cells under routine cell culture conditions, which is especially true for mesenchymal stem cells (MSCs) due to their limited expansion and early senescence. Here, a microfluidic device is proposed for boosting sEV secretion from MSCs derived from human fetal bone marrow (BM-MSCs). As the cells rapidly pass through a microfluidic channel with a series of narrow squeezing ridges, mechanical stimulation permeabilizes the cell membrane, thus promoting them to secrete more sEVs into extracellular space. In this study, the microfluidic device demonstrates that mechanical-squeezing effect could increase the secretion amount of sEVs from the BM-MSCs by approximately 4-fold, while maintaining cellular growth state of the stem cells. Further, the secreted sEVs are efficiently taken up by immortalized human corneal epithelial cells and accelerate corneal epithelial wound healing in vitro, indicating that this technique wound not affect the functionality of sEVs and demonstrating the application potentials of this technique.

Lysine stimulates the development of the murine mammary gland at puberty via PI3K/AKT/mTOR signalling axis

Lysine is one of the essential amino acids. The effect of lysine on milk protein and milk fat anabolism has been reported, but the effect on mammary glands development has not been studied in detail. The normal development of the mammary glands at puberty is crucial to lactation of mammals. In this study, to explore the effect of lysine on mammary glands development, we fed different concentrations of lysine (0.025%, 0.05%, 0.1%) to pubertal mice and found that the addition of 0.1% lysine to drinking water significantly promoted mammary glands development. Furthermore, we treated mMECs (mouse mammary epithelial cells) with different concentrations of lysine (0, 0.2, 0.4, 0.6, 0.8 and 1 mM) to explore the underlying mechanism, and found that lysine promoted the proliferation of mMECs and development of mammary glands through PI3K/AKT/mTOR signalling pathway in pubertal mice. Overall, the results of this study revealed that lysine activated the PI3K/AKT/mTOR signal axis, elevated protein concentrations of cell proliferation markers, such as PCNA, Cyclin D1 and D3, and enhanced the proliferation of mMECs, finally promoted the murine mammary glands development at puberty.

The alleviating effect and mechanism of Bilobalide on ulcerative colitis

Dysfunction of the intestinal epithelial barrier and intestinal microbiota dysbiosis can drive the onset or aggravation of ulcerative colitis (UC). Bilobalide (BI) is an extract of Ginkgo biloba that has been shown to exhibit a range of anti-inflammatory properties. Herein, we explored functional and mechanistic effects of BI treatment in a rodent model of DSS-induced UC. These analyses revealed that BI treatment was sufficient to reduce disease severity, increase colon length, and normalize colon histological characteristics relative to those observed in DSS-treated model mice. BI also enhanced the expression of tight junction proteins associated with intestinal barrier integrity including ZO-1, Occludin, and Claudin-3. Through 16S rDNA sequencing analyses, BI was also found to influence the overall richness of the intestinal microbiome, promoting the proliferation of probiotic species including Lactobacillus. Consistent with these in vivo findings, BI treatment protected RAW264.7 cells against lipopolysaccharide (LPS)-induced inflammatory damage, suppressing the activation of the AKT/NF-κB p65 and MAPK signaling pathways in this experimental context. In summary, these findings revealed that BI can suppress MAPK and AKT/NF-κB p65 signaling, thereby suppressing the production of inflammatory cytokines including IL-1β, IL-6, and TNF-α, while additionally alleviating UC severity by facilitating repair of the intestinal epithelial barrier and the remodeling of intestinal microbial communities.