IGF-I, EGF, and sex steroids regulate autophagy in bovine mammary epithelial cells via the mTOR pathway

Programming effects of intrauterine hyperthermia on adrenal gland development

Maternal heat stress during late pregnancy can lead to intrauterine hyperthermia and affect fetal hypothalamic-pituitary-adrenal axis development and function. Herein, we investigated the effects of chronic environmental heat stress exposure of Holstein cows in the last 2 mo of gestation on their offspring's adrenal gland histomorphology and transcriptome. Cows in their last 54 ± 5 d of gestation were either heat stressed (housed under the shade of a freestall barn) or provided heat stress abatement via active cooling (via water soakers and fans) during a subtropical summer (temperature-humidity index >68). Respiration rate (RR) and skin temperature (ST) were elevated in heat-stressed dams relative to the cows with access to heat abatement (23 breaths/min and 2°C higher for RR and ST, respectively). Heifers born to heat-stressed cows experienced heat stress in utero (HS), whereas heifers born to actively cooled cows did not (CL). The adrenal gland was harvested from 6 heifers per group that were euthanized at birth (d 0; n = 12) or 1 wk after weaning (d 63; n = 12). Circulating cortisol was measured from blood samples collected weekly throughout the preweaning period. At d 63, heifers that experienced HS while developing in utero had heavier adrenal glands, with a greater total tissue surface area and thickness of the zona glomerulosa (ZG), fasciculata (ZF), and reticularis (ZR), compared with CL heifers. In addition, the adrenal gland of HS heifers had fewer cells in the ZG, more and larger cells in the ZF, and larger cells in the ZR, relative to CL heifers. Although no changes in circulating cortisol were observed through the preweaning period, the transcriptomic profile of the adrenal tissue was altered by fetal exposure to hyperthermia. Both at birth and on d 63, approximately 30 pathways were differentially expressed in the adrenal glands of HS heifers relative to CL. These pathways were associated with immune function, inflammation, prolactin signaling, cell function, and calcium transport. Upstream regulators significantly activated or inhibited in the adrenal glands of heifers exposed to intrauterine hyperthermia were identified. Maternal exposure to heat stress during late gestation caused an enlargement of their offspring's adrenal glands by inducing ZG and ZF cell hypertrophy, and caused gene expression changes. These phenotypic, histological, and molecular changes in the adrenal gland might lead to alterations in stress, immune, and metabolic responses later in life.

The constructive and destructive impact of autophagy on both genders' reproducibility, a comprehensive review

Reproduction is characterized by a series of massive renovations at molecular, cellular, and tissue levels. Recent studies have strongly tended to reveal the involvement of basic molecular pathways such as autophagy, a highly conserved eukaryotic cellular recycling, during reproductive processes. This review comprehensively describes the current knowledge, updated to September 2022, of autophagy contribution during reproductive processes in males including spermatogenesis, sperm motility and viability, and male sex hormones and females including germ cells and oocytes viability, ovulation, implantation, fertilization, and female sex hormones. Furthermore, the consequences of disruption in autophagic flux on the reproductive disorders including oligospermia, azoospermia, asthenozoospermia, teratozoospermia, globozoospermia, premature ovarian insufficiency, polycystic ovarian syndrome, endometriosis, and other disorders related to infertility are discussed as well.Abbreviations: AKT/protein kinase B: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ATG: autophagy related; E2: estrogen; EDs: endocrine disruptors; ER: endoplasmic reticulum; FSH: follicle stimulating hormone; FOX: forkhead box; GCs: granulosa cells; HIF: hypoxia inducible factor; IVF: in vitro fertilization; IVM: in vitro maturation; LCs: Leydig cells; LDs: lipid droplets; LH: luteinizing hormone; LRWD1: leucine rich repeats and WD repeat domain containing 1; MAP1LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-kB: nuclear factor kappa B; P4: progesterone; PCOS: polycystic ovarian syndrome; PDLIM1: PDZ and LIM domain 1; PI3K: phosphoinositide 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns3K: class III phosphatidylinositol 3-kinase; POI: premature ovarian insufficiency; ROS: reactive oxygen species; SCs: Sertoli cells; SQSTM1/p62: sequestosome 1; TSGA10: testis specific 10; TST: testosterone; VCP: vasolin containing protein.

Research progress in the role and mechanism of Leucine in regulating animal growth and development

Leucine, a branched-chain amino acid, is essential in regulating animal growth and development. Recent research has uncovered the mechanisms underlying Leucine's anabolic effects on muscle and other tissues, including its ability to stimulate protein synthesis by activating the mTORC1 signaling pathway. The co-ingestion of carbohydrates and essential amino acids enhances Leucine's anabolic effects. Moreover, Leucine has been shown to benefit lipid metabolism, and insulin sensitivity, making it a promising strategy for preventing and treating metabolic diseases, including type 2 diabetes and obesity. While emerging evidence indicates that epigenetic mechanisms may mediate Leucine's effects on growth and development, more research is needed to elucidate its mechanisms of action fully. Specific studies have demonstrated that Leucine promotes muscle growth and metabolic health in animals and humans, making it a promising therapeutic agent. However, it is essential to note that Leucine supplementation may cause digestive issues or interact with certain medications, and More study is required to determine definitively optimal dosages. Therefore, it is important to understand how Leucine interacts with other nutrients, dietary factors, and lifestyle habits to maximize its benefits. Overall, Leucine's importance in human nutrition is far-reaching, and its potential to prevent muscle loss and enhance athletic performance warrants further investigation.

ERBB Receptors and Their Ligands in the Developing Mammary Glands of Different Species: Fifteen Characters in Search of an Author

The ERBB tyrosine kinase receptors and their ligands belong to a complex family that has diverse biological effects and expression profiles in the developing mammary glands, where its members play an essential role in translating hormone signals into local effects. While our understanding of these processes stems mostly from mouse models, there is the potential for differences in how this family functions in the mammary glands of other species, particularly in light of their unique histomorphological features. Herein we review the postnatal distribution and function of ERBB receptors and their ligands in the mammary glands of rodents and humans, as well as for livestock and companion animals. Our analysis highlights the diverse biology for this family and its members across species, the regulation of their expression, and how their roles and functions might be modulated by varying stromal composition and hormone interactions. Given that ERBB receptors and their ligands have the potential to influence processes ranging from normal mammary development to diseased states such as cancer and/or mastitis, both in human and veterinary medicine, a more complete understanding of their biological functions should help to direct future research and the identification of new therapeutic targets.

Tetraconazole interrupts mitochondrial function and intracellular calcium levels leading to apoptosis of bovine mammary epithelial cells

Tetraconazole is a type of fungicide that eliminates pathogens in plants and fruit. To date, studies have focused on the direct exposure of plants and fruits to residual tetraconazole, but no studies have been conducted on the indirect effects of tetraconzaole. Given the importance of cows as milk-producing animals and their potential exposure to pesticides via plant consumption, we analyzed the mechanism by which tetraconazole influences milk production. Here, we confirmed that tetraconazole-induced apoptosis and inhibited cell viability and proliferation by regulating the cell cycle in bovine mammary epithelial cells (MAC-T). In addition, Ca²⁺ homeostasis in mitochondria was disrupted by tetraconazole, leading to the depolarization of mitochondrial membrane potential. Consistent with the proliferation-related findings, tetraconazole downregulated AKT, ERK1/2, P38, and JNK signaling pathways and proliferation-related proteins such as CCND1 and PCNA in MAC-T cells. Meanwhile, it upregulated cleaved caspase 3, BAX, and Cytochrome c under the same conditions in MAC-T cells. Furthermore, MAC-T exposed to tetraconazole causes a failure of proper autophagy functioning. In summary, the results of this study indicated that tetraconazole exposure may lead to a failure of milk production from bovine mammary epithelial cells by disrupting calcium homeostasis and mitochondrial function.

Sex and gender differences in myocarditis and dilated cardiomyopathy: An update

In the past decade there has been a growing interest in understanding sex and gender differences in myocarditis and dilated cardiomyopathy (DCM), and the purpose of this review is to provide an update on this topic including epidemiology, pathogenesis and clinical presentation, diagnosis and management. Recently, many clinical studies have been conducted examining sex differences in myocarditis. Studies consistently report that myocarditis occurs more often in men than women with a sex ratio ranging from 1:2-4 female to male. Studies reveal that DCM also has a sex ratio of around 1:3 women to men and this is also true for familial/genetic forms of DCM. Animal models have demonstrated that DCM develops after myocarditis in susceptible mouse strains and evidence exists for this progress clinically as well. A consistent finding is that myocarditis occurs primarily in men under 50 years of age, but in women after age 50 or post-menopause. In contrast, DCM typically occurs after age 50, although the age that post-myocarditis DCM occurs has not been investigated. In a small study, more men with myocarditis presented with symptoms of chest pain while women presented with dyspnea. Men with myocarditis have been found to have higher levels of heart failure biomarkers soluble ST2, creatine kinase, myoglobin and T helper 17-associated cytokines while women develop a better regulatory immune response. Studies of the pathogenesis of disease have found that Toll-like receptor (TLR)2 and TLR4 signaling pathways play a central role in increasing inflammation during myocarditis and in promoting remodeling and fibrosis that leads to DCM, and all of these pathways are elevated in males. Management of myocarditis follows heart failure guidelines and there are currently no disease-specific therapies. Research on standard heart failure medications reveal important sex differences. Overall, many advances in our understanding of the effect of biologic sex on myocarditis and DCM have occurred over the past decade, but many gaps in our understanding remain. A better understanding of sex and gender effects are needed to develop disease-targeted and individualized medicine approaches in the future.

1α,25(OH)2D3 Promotes the Autophagy of Porcine Ovarian Granulosa Cells as a Protective Mechanism against ROS through the BNIP3/PINK1 Pathway

Vitamin D (VD) is one of the important nutrients required by livestock; however, VD deficiency is reported to be widespread. Earlier studies have suggested a potential role for VD in reproduction. Studies on the correlation between VD and sow reproduction are limited. The aim of the current study was aimed to determine the role of 1,25-dihydroxy vitamin D₃ (1α,25(OH)₂D₃) on porcine ovarian granulosa cells (PGCs) in vitro to provide a theoretical basis for improving the reproductive efficiency of sows. We used chloroquine (autophagy inhibitor) and reactive oxygen species (ROS) scavenger N-acetylcysteine in conjunction with 1α,25(OH)₂D₃ to explore the effect on PGCs. The results showed that 10 nM of 1α,25(OH)₂D₃ increased PGC viability and ROS content. In addition, 1α,25(OH)₂D₃ induces PGC autophagy according to the gene transcription and protein expression levels of LC3, ATG7, BECN1, and SQSTM1 and promotes the generation of autophagosomes. 1α,25(OH)₂D₃-induced autophagy affects the synthesis of E₂ and P₄ in PGCs. We investigated the relationship between ROS and autophagy, and the results showed that 1α,25(OH)₂D₃-induced ROS promoted PGC autophagy. The ROS-BNIP3-PINK1 pathway was involved in PGC autophagy induced by 1α,25(OH)₂D₃. In conclusion, this study suggests that 1α,25(OH)₂D₃ promotes PGC autophagy as a protective mechanism against ROS via the BNIP3/PINK1 pathway.

Autophagy-related gene and protein expressions during blastocyst development

PURPOSE

This study aims to examine the expression of autophagic genes and proteins during blastocyst development and differentiation.

METHODS

This is a prospective cohort study. Between March 2018 and November 2019, 30 females aged 30.13 ± 4.83 years underwent an intracytoplasmic sperm injection (ICSI) cycle at Madina Fertility Center. ICSI was used to develop and incubate 82 leftover embryos to day 5. Then, the embryos were divided into two groups based on their developmental structure: group D (n = 49) included embryos that developed into blastocysts, whereas group A (n = 33) included arrested embryos. These embryos were used to investigate the autophagic gene and protein expressions. The current study was approved by the Clinical Trial Ethical Committee of the Faculty of Medicine, Alexandria University, following the ethical standards of scientific research (Registration no. 0303721).

RESULTS

Embryos that developed into blastocysts on day 5 (group D) had significantly higher relative expression of the LC3 gene (1.11 ± 0.52) and beclin-1 gene (1.43 ± 0.34) and beclin-1 protein expression (3.8 ± 0.028) than those that did not develop into blastocysts on day 5 (group A) [0.72 ± 0.18 (P = 0.03), 0.35 ± 0.12 (P = 0.0001), and 3.14 ± 0.05, (P = 0.0001), respectively]. In contrast, mTOR and PIK3C3 protein expression was significantly higher in group A (arrested embryos) than those in group D (developed embryos) (P = 0.007 and P = 0.0001, respectively). Furthermore, the expression of the eIF4E gene was significantly lower in group D embryos (0.32 ± 0.07) than that in group A embryos (4.38 ± 1.16) (P = 0.0001).

CONCLUSIONS

This work identifies  autophagy as a well regulated process required to maintain cell allocation and differentiation during late preimplantation embryo developmental stages.

PPARγ/mTOR Regulates the Synthesis and Release of Prostaglandins in Ovine Trophoblast Cells in Early Pregnancy

Trophoblast cells synthesize and secrete prostaglandins (PGs), which are essential for ruminants in early gestation to recognize pregnancy. Hormones in the intrauterine environment play an important role in regulating PGs synthesis during implantation, but the underlying mechanism remains unclear. In this study, co-treatment of sheep trophoblast cells (STCs) with progesterone (P4), estradiol (E2), and interferon-tau (IFN-τ) increased the ratio of prostaglandin E2 (PGE2) to prostaglandin F2α (PGF2α) and upregulated peroxisome proliferator-activated receptor γ (PPARγ) expression, while inhibiting the mechanistic target of rapamycin (mTOR) pathway and activating cellular autophagy. Under hormone treatment, inhibition of PPARγ activity decreased the ratio of PGE2/PGF2α and cellular activity, while activating expression of the mTOR downstream marker-the phosphorylation of p70S6K (p-p70S6K). We also found that the PPARγ/mTOR pathway played an important role in regulating trophoblast cell function. Inhibition of the mTOR pathway by rapamycin increased the ratio of PGE2/PGF2α and decreased the expression of apoptosis-related proteins after inhibiting PPARγ activity. In conclusion, our findings provide new insights into the molecular mechanism of prostaglandin regulation of trophoblast cells in sheep during early pregnancy, indicating that the PPARγ/mTOR pathway plays an important role in PGs secretion and cell viability.

The regulatory mechanism of amino acids on milk protein and fat synthesis in mammary epithelial cells: a mini review

Mammary epithelial cell (MEC) is the basic unit of the mammary gland that synthesizes milk components including milk protein and milk fat. MECs can sense to extracellular stimuli including nutrients such as amino acids though different sensors and signaling pathways. Here, we review recent advances in the regulatory mechanism of amino acids on milk protein and fat synthesis in MECs. We also highlight how these mechanisms reflect the amino acid requirements of MECs and discuss the current and future prospects for amino acid regulation in milk production.

Autophagy: A Novel Horizon for Hair Cell Protection

As a general sensory disorder, hearing loss was a major concern worldwide. Autophagy is a common cellular reaction to stress that degrades cytoplasmic waste through the lysosome pathway. Autophagy not only plays major roles in maintaining intracellular homeostasis but is also involved in the development and pathogenesis of many diseases. In the auditory system, several studies revealed the link between autophagy and hearing protection. In this review, we aimed to establish the correlation between autophagy and hair cells (HCs) from the aspects of ototoxic drugs, aging, and acoustic trauma and discussed whether autophagy could serve as a potential measure in the protection of HCs.

Diverse Roles of TgMIC1/4/6 in the Toxoplasma Infection

Toxoplasma gondii microneme is a specialized secretory organelle that discharges its contents at the apical tip of this apicomplexan parasite in a sequential and regulated manner. Increasing number of studies on microneme proteins (MICs) have shown them as a predominant and important role in host cell attachment, invasion, motility and pathogenesis. In this review, we summarize the research advances in one of the most important MICs complexes, TgMIC1/4/6, which will contribute to improve the understanding of the molecular mechanism of T. gondii infection and provide a theoretical basis for the effective control against T. gondii.

Endocrine Signals Altered by Heat Stress Impact Dairy Cow Mammary Cellular Processes at Different Stages of the Dry Period

Simple Summary

Late-gestation heat stress increases blood prolactin and decreases oestrogen concentrations in dry cows. These hormonal alterations may disturb mammary gland remodelling during the dry period, thereby being potentially responsible for the observed production impairments during the subsequent lactation. This project aimed to better understand the molecular mechanisms underlying subsequent impairments in mammary performance after dry period heat stress. For this, we studied the expression of genes encompassing prolactin and oestrogen pathways and key cellular process pathways under different thermal environments and in vitro hormonal milieus. The results of this study revealed that late-gestation heat stress impacted the expression of genes in the mammary gland involved in key cellular processes occurring during the dry period. Furthermore, our results indicated that these modifications are in part modulated by alterations of oestrogen and prolactin signalling.

Abstract

Hormonal alterations occurring under late gestation heat stress may disturb mammary gland remodelling, resulting in a reduced milk yield during the subsequent lactation. We investigated the effects of an altered endocrine environment on mammary gene expression at different stages of the dry period. Mammary gland biopsies from in vivo-cooled (CL) or heat-stressed (HT) cows were collected at d 3 and 35 relative to dry-off and divided into explants. Explants were incubated in vitro for 24 h in one of three media: Basal: no prolactin or estrogen; CL-mimic: Basal + low prolactin + high 17β-estradiol, or HT-mimic: Basal + high prolactin + low 17β-estradiol. Real time qPCR was used to quantify gene expression. We established that late-gestation heat stress changes the expression of prolactin and oestrogen receptors, downregulates genes involved in apoptosis, autophagy and proliferation at d 3 and upregulates genes related to those cellular processes at d 35. Moreover, compared with in vivo treatments, we showed that the expression of fewer genes was impacted by in vitro treatments which aimed to mimic the hormonal response of cows exposed to a different environment. Further research will continue to uncover the mechanisms behind the production impairments caused by late-gestation heat stress.

Inhibition of PI3K/Akt/mTOR pathway by ammonium chloride induced apoptosis and autophagy in MAC-T cell

Ammonia is a harmful gas with a pungent odor, participates in the regulation of a variety of apoptosis and autophagy, which in turn affects the growth and differentiation of cells. To test the regulation of NH₃ on the apoptosis and autophagy of mammary epithelial cells, we selected NH₄Cl as NH₃ donor in vitro model. MTT and CCK-8 assay kits were employed to detect cell activity. Real-time quantitative PCR and western blot methods were used to detect the abundance of inflammatory molecules, apoptosis markers, and autophagy genes. We selected TUNEL kit and the Annexin-FITC/PI method to detect apoptosis. TEM analysis was used to detect autophagic vesicles, and MDC stain evaluated the formation of autophagosome. The results indicated that NH₄Cl reduced cell viability in a concentration-dependent manner and promoted cell inflammatory response, apoptosis, and autophagy. NH₄Cl stimulation notable increased the autophagosomes number. Interestingly, we also detected that the addition of LY294002 and Rapamycin inhibited the PI3K/Akt pathway and the mTOR pathway, respectively, resulting in changes in both apoptosis and autophagy. Therefore, we draw a conclusion that NH₃ may regulate the apoptosis and autophagic response of bovine mammary epithelial cells through the PI3K/Akt/mTOR signaling pathway. Further investigations on ammonia's function in other physiological respects, will be critical to provide theoretical help for the improvement of production performance. It will be also helpful for controlling the harmful gas ammonia concentration in the livestock house to protect the health of dairy cows.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Feeding level regulates the expression of some genes involved with programed cell death and remodeling in goat and sheep mammary tissue

Mammary tissue (MT) turnover is characterized by programed cell death and remodeling which might be affected by both feeding level and animal species. Thus, twenty-four dairy goats and the same number of sheep were assigned to three homogenous sub-groups per animal species and fed the same diet in quantities which met 70% (FL70), 100% (FL100) and 130% (FL130) of their daily energy and crude protein requirements. Individual MT samples were taken by biopsy from the animals on the 30th and 60th experimental day. The results showed, in the first sampling time, a significant reduction in the mRNA abundance for selected genes involved in programed cell death in both FL 70 fed goats (STAT3 and BECN1) and sheep (CASPASE8 and BECN1) compared with the respective FL100 groups. The FL130, in comparison with the FL100, caused a significant increase in transcripts accumulation of STAT3 gene in both sampling times and CASPASE8 gene in the second sampling time in goat MT, while the opposite happened for the mRNA expression of CASPASE8 and BECN1 genes in sheep MT, but only in the first sampling time. Moreover, a significant up regulation in the mRNA levels of MMP2 gene in MT of FL130 fed sheep was observed. The FL130, in comparison with the FL70, caused an enhancement in the mRNA expression levels of BECN1, CASPASE8, BAX and STAT3 genes in goat MT only. It was also shown that apoptosis and autophagy can be affected simultaneously by the feeding level. Overfeeding affects MT programed cell death and remodeling by a completely different way in goats than sheep. In conclusion, feeding level and animal species have strong effects on both MT programed cell death (apoptosis and autophagy) and remodeling but the molecular mechanisms need further investigation.

Role of the JAK-STAT Pathway in Bovine Mastitis and Milk Production

Simple Summary

The cytokine-activated Janus kinase (JAK)—signal transducer and activator of transcription (STAT) pathway has an important role in the regulation of immunity and inflammation. In addition, the signaling of this pathway has been reported to be associated with mammary gland development and milk production. Because of such important functions, the JAK-STAT pathway has been widely targeted in both human and animal diseases as a therapeutic agent. Recently, the JAK2, STATs, and inhibitors of the JAK-STAT pathway, especially cytokine signaling suppressors (SOCSs), have been reported to be associated with milk production and mastitis-resistance phenotypic traits in dairy cattle. Thus, in the current review, we attempt to overview the development of the JAK-STAT pathway role in bovine mastitis and milk production.

Abstract

The cytokine-activated Janus kinase (JAK)—signal transducer and activator of transcription (STAT) pathway is a sequence of communications between proteins in a cell, and it is associated with various processes such as cell division, apoptosis, mammary gland development, lactation, anti-inflammation, and immunity. The pathway is involved in transferring information from receptors on the cell surface to the cell nucleus, resulting in the regulation of genes through transcription. The Janus kinase 2 (JAK2), signal transducer and activator of transcription A and B (STAT5 A & B), STAT1, and cytokine signaling suppressor 3 (SOCS3) are the key members of the JAK-STAT pathway. Interestingly, prolactin (Prl) also uses the JAK-STAT pathway to regulate milk production traits in dairy cattle. The activation of JAK2 and STATs genes has a critical role in milk production and mastitis resistance. The upregulation of SOCS3 in bovine mammary epithelial cells inhibits the activation of JAK2 and STATs genes, which promotes mastitis development and reduces the lactational performance of dairy cattle. In the current review, we highlight the recent development in the knowledge of JAK-STAT, which will enhance our ability to devise therapeutic strategies for bovine mastitis control. Furthermore, the review also explores the role of the JAK-STAT pathway in the regulation of milk production in dairy cattle.

Mechanisms of sex hormones in autoimmunity: focus on EAE

Sex-related differences in the occurrence of autoimmune diseases is well documented, with females showing a greater propensity to develop these diseases than their male counterparts. Sex hormones, namely dihydrotestosterone and estrogens, have been shown to ameliorate the severity of inflammatory diseases. Immunologically, the beneficial effects of sex hormones have been ascribed to the suppression of effector lymphocyte responses accompanied by immune deviation from pro-inflammatory to anti-inflammatory cytokine production. In this review, we present our view of the mechanisms of sex hormones that contribute to their ability to suppress autoimmune responses with an emphasis on the pathogenesis of experimental autoimmune encephalomyelitis.

Milk somatic cell derived transcriptome analysis identifies regulatory genes and pathways during lactation in Indian Sahiwal cattle (Bos indicus)

BACKGROUND

The present study is an effort to understand the genomic drivers of lactation in Sahiwal (Bos indicus), the best milch cattle breed of the tropics.

METHODS

RNA sequencing of four animals from early, mid and late lactation stages was performed using milk somatic cells as source of RNA.

RESULTS

The genes encoding the milk casein and whey proteins showed highest expression in early and mid lactation, with a declining trend towards the late stage. The enhanced expression of PLIN2, FABP5 and FABP3 genes in mid lactation suggests enrichment of the PPARα pathway which is linked to fatty acid metabolism. A gradual decline in the percentage of genes involved in metabolism of proteins, mRNA and insulin synthesis from early to late lactation reflected transition from lactogenesis to involution. Major biological pathways maintained throughout lactation were adaptive immune system, FGF signaling, EGFR signaling, activated TLR4 signaling, NFkB and MAP kinases activation mediated by TLR4 signaling repertoire. Differential expression analysis revealed 547, 1010 and 1313 differentially expressed genes (p < 0.05) between early-late, early-mid and mid-late stages, respectively. The topmost regulatory genes identified by network analysis from the differentially expressed genes, were involved in Chemokine receptor, GPCR and EGFR1 pathways.

CONCLUSION

The genes and pathways delineated in this study have regulatory implications in cell morphogenesis, lipid droplet formation and protein synthesis in the course of lactation. The study provides an insight into the expression profile of genes influencing milk properties and lactation in Sahiwal cattle.

Effect of heat stress during the early and late dry period on mammary gland development of Holstein dairy cattle

Dry period heat stress impairs subsequent milk yield. Our objective was to evaluate the effect of heat stress or cooling during the early and late dry period on mammary gland gene expression and microstructure. Cows were dried off ∼45 d before expected parturition and randomly assigned to 1 of 2 treatments: heat stress (HT, n = 39) or cooling (CL, n = 39) during the first 21 d of the dry period. On d 22, cows were switched or remained on HT and CL and this yielded 4 treatments: heat stress during the entire dry period (HTHT, n = 18); cooling during the entire dry period (CLCL, n = 20); HT for the first 21 d dry, then CL until calving (HTCL, n = 21); or CL for the first 21 d dry, then HT until calving (CLHT, n = 19). Data were analyzed in 2 periods: first 21 d dry (early dry period) and from 22 d until calving (late dry period) and analyzed using PROC MIXED or GLM in SAS (SAS Institute Inc., Cary, NC). Mammary biopsies (5-8 cows/treatment) were collected at -3, 3, 7, 14, and 25 d relative to dry-off to evaluate mammary gland gene expression and histology [i.e., cellular apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling) and proliferation (Ki67)]. Mammary alveoli number and connective tissue were visualized by hematoxylin and eosin and Mason's trichrome staining, respectively. During the early dry period, CL upregulated expression of CASP3, IGF1R, HSP90, HSF1, BECN1, ATG3, ATG5, and PRLR-LF relative to HT. However, in the late dry period, CLHT treatment upregulated expression of CASP3, CASP8, HSP70, HSP90, PRLR-LF, STAT5, CSN2, and ATG3 relative to CLCL. During the early dry period, cows exposed to HT had reduced mammary and stroma cell apoptosis and proliferation relative to CL. In addition to these findings, cows exposed to HT had lower connective tissue 3 d after dry-off relative to CL. However, in the late dry period, HTHT cows had higher connective tissue relative to CLCL. Also, in the early dry period, cows exposed to HT had greater alveoli number relative to CL, and HT decreased expression of genes related to autophagy and apoptosis in the early dry period, consistent with a delay in involution with HT. Thus, cows exposed to HT have extended involution with delayed apoptosis and autophagy signaling. Also, HT compromises mammary gland cell proliferation and leads to higher connective tissue later in the dry period. These results provide evidence that heat stress impairs overall mammary gland turnover during the dry period, which then affects secretory activity and productivity in the next lactation.

Epidermal Growth Factor Stimulates Fatty Acid Synthesis Mainly via PLC-γ1/Akt Signaling Pathway in Dairy Goat Mammary Epithelial Cells

Simple Summary

Goat milk contains an abundance of fatty acids which are benefit to human health. Epidermal growth factor (EGF) is a small peptide which could positively regulate the growth, development and differentiation of the mammary gland during lactation. However, little information is available about EGF in regulating lipid metabolism in the mammary gland. This study investigated the effects of EGF on the triglyceride (TG) synthesis, lipogenic genes expression and the downstream signal protein levels in goat mammary epithelial cells (GMECs). Our findings indicated EGF might be beneficial to improve milk fat synthesis of dairy goats.

Abstract

EGF acts as a ligand of the EGF receptor (EGFR) to activate the EGFR-mediated signaling pathways and is involved in the regulation of cell physiology. However, the roles of EGFR mediated signaling pathways in the regulation of lipid metabolism in goat mammary epithelial cells (GMECs) are poorly understood. To evaluate the impact of EGF on GMECs, the triglyceride (TG) content and lipid droplet were detected, using TG assay and immunofluorescence. Further, expression of lipogenic genes, the protein kinase B (Akt), phospholipase C-γ1 (PLC-γ1) and extracellular signal-regulated kinases (ERK)1/2 signaling pathways were measured by real-time polymerase chain reaction and Western blot, respectively. The results showed that the mRNA expression of EGFR gene was significantly upregulated in lactating goat mammary gland tissues compared to non-lactation period (p < 0.05). TG contents in EGF-treated GMECs were significantly increased (p < 0.05), and an increase of lipid droplets was also detected. In vitro studies demonstrated that the mRNA levels of lipogenesis-related FASN, ACC, SCD1, LXRa, LXRb and SP1 genes were positively correlated to the mRNA level of EGFR gene shown by gene overexpression and silencing (p < 0.05). The phosphorylations of Akt, ERK1/2 and PLC-γ1 in GMECs were greatly upregulated in the presence of EGF, and specific inhibitors were capable of blocking the phosphorylation of Akt, ERK1/2 and PLC-γ1. Compared with EGF-treated GMECs, the mRNA levels of FASN, ACC and SCD1 were significantly decreased in GMECs co-treated with PLC-γ1 and Akt inhibitor and EGF (p < 0.05), and TG content was also dropped significantly. These observations implied that EGFR plays an important role in regulating de novo fatty acid synthesis in GMECs, mainly mediated by Akt and PLC-γ1 signaling pathways.

Late gestation heat stress in dairy cows: Effects on dam and daughter

In dairy cattle, the final weeks before parturition are physiologically challenging and an important determinant of subsequent production performance. External stressors should be carefully managed during this period to avoid adding strain on the animals. Late-gestation heat stress impairs productivity in the dam and exerts transgenerational effects on progeny. Physiological responses are complex and detriments to performance are multifaceted. Late-gestation heat stress blunts mammary gland involution in the first half of the dry period and impairs cell proliferation as calving approaches. Moreover, cows that were exposed to prepartum heat-stress exhibit reduced adipose tissue mobilization and a lower degree of insulin resistance during early lactation. Prepartum heat exposure also depresses immune function and evidence links this decrease to altered prolactin signaling under heat stress. Placental functions are also impaired as reflected in a higher cotyledon mass but lower maternal circulating estrone sulfate concentrations, potentially resulting in lower nutrient supply and reduced calf birth weight. In addition, calves born to heat-stressed dams show impaired immune function and therefore higher disease susceptibly. Novel evidence reported that intrauterine heat stress alters the methylation profile of liver and mammary DNA, which may also contribute to the poorer performance during adulthood of calves exposed to heat stress in utero. Understanding the contribution of all altered biological systems during late-gestation heat stress can be used as a basis for improving cow management during the dry period. This article provides a review of the impacts of late-gestation heat stress and of the emerging understanding of the biological mechanisms that underlie the observed impairments of performance.

Autophagy regulates functional differentiation of mammary epithelial cells

Mitochondria operate as a central hub for many metabolic processes by sensing and responding to the cellular environment. Developmental cues from the environment have been implicated in selective autophagy, or mitophagy, of mitochondria during cell differentiation and tissue development. Mitophagy occurring in this context, termed programmed mitophagy, responds to cell state rather than mitochondrial damage and is often accompanied by a metabolic transition. However, little is known about the mechanisms that engage and execute mitophagy under physiological or developmental conditions. As the mammary gland undergoes post-natal development and lactation challenges mitochondrial homeostasis, we investigated the contribution of mitochondria to differentiation of mammary epithelial cells (MECs). Using lactogenic differentiation of the HC11 mouse MEC line, we demonstrated that HC11 cells transition to a highly energetic state during differentiation by engaging both oxidative phosphorylation and glycolysis. Interestingly, this transition was lost when autophagy was inhibited with bafilomycin A₁ or knockdown of Atg7 (autophagy related 7). To evaluate the specific targeting of mitochondria, we traced mitochondrial oxidation and turnover in vitro with the fluorescent probe, pMitoTimer. Indeed, we found that differentiation engaged mitophagy. To further evaluate the requirement of mitophagy during differentiation, we knocked down the expression of Prkn/parkin in HC11 cells. We found that MEC differentiation was impaired in shPrkn cells, implying that PRKN is required for MEC differentiation. These studies suggest a novel regulation of MEC differentiation through programmed mitophagy and provide a foundation for future studies of development and disease associated with mitochondrial function in the mammary gland.Abbreviations: AA: antimycin A; ATG5: autophagy related 5; BAF: bafilomycin A₁; BNIP3: BCL2 interacting protein 3; BNIP3L/NIX: BCL2 interacting protein 3 like; COX8A: cytochrome c oxidase subunit 8A; CQ: chloroquine; CSN2: casein beta; ECAR: extracellular acidification rate; FCCP: trifluoromethoxy carbonylcyanide phenylhydrazone; FUNDC1: FUN14 domain containing 1; HIF1A: hypoxia inducible factor 1 subunit alpha; L1: lactation day 1; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MEC: mammary epithelial cell; mitoQ: mitoquinol; mROS: mitochondrial reactive oxygen species; OCR: oxygen consumption rate; P: priming; P16: pregnancy day 16; PARP1: poly(ADP-ribose) polymerase 1; PINK1: PTEN induced kinase 1; PPARGC1A: PPARG coactivator 1 alpha; PRKN: parkin RBR E3 ubiquitin protein ligase; shNT: short hairpin non-targeting control; SQSTM1: sequestosome 1; STAT3: signal transducer and activator of transcription 3; TEM: transmission electron microscopy; TFAM: transcription factor A, mitochondrial; U: undifferentiated.

Degradation of the Tumor Suppressor PDCD4 Is Impaired by the Suppression of p62/SQSTM1 and Autophagy

PDCD4 (programmed cell death 4) is a tumor suppressor that plays a crucial role in multiple cellular functions, such as the control of protein synthesis and transcriptional control of some genes, the inhibition of cancer invasion and metastasis. The expression of this protein is controlled by synthesis, such as via transcription and translation, and degradation by the ubiquitin-proteasome system. The mitogens, known as tumor promotors, EGF (epidermal growth factor) and TPA (12-O-tetradecanoylphorbol-13-acetate) stimulate the degradation of PDCD4 protein. However, the whole picture of PDCD4 degradation mechanisms is still unclear, we therefore investigated the relationship between PDCD4 and autophagy. The proteasome inhibitor MG132 and the autophagy inhibitor bafilomycin A1 were found to upregulate the PDCD4 levels. PDCD4 protein levels increased synergistically in the presence of both inhibitors. Knockdown of p62/SQSTM1 (sequestosome-1), a polyubiquitin binding partner, also upregulated the PDCD4 levels. P62 and LC3 (microtubule-associated protein 1A/1B-light chain 3)-II were co-immunoprecipitated by an anti-PDCD4 antibody. Colocalization particles of PDCD4, p62 and the autophagosome marker LC3 were observed and the colocalization areas increased in the presence of autophagy and/or proteasome inhibitor(s) in Huh7 cells. In ATG (autophagy related) 5-deficient Huh7 cells in which autophagy was impaired, the PDCD4 levels were increased at the basal levels and upregulated in the presence of autophagy inhibitors. Based on the above findings, we concluded that after phosphorylation in the degron and ubiquitination, PDCD4 is degraded by both the proteasome and autophagy systems.

Epidermal growth factor improves intestinal morphology by stimulating proliferation and differentiation of enterocytes and mTOR signaling pathway in weaning piglets

Epidermal growth factor (EGF) has been shown to improve piglet intestinal morphology and epithelial recovery. In an attempt to further understand the mechanisms behind these improvements, this study tested the hypothesis that dietary EGF may affect intestinal morphology by stimulating the proliferation and differentiation of enterocytes in weaning piglets. In piglets receiving 200 µg kg-1 EGF, crypt depth and villus height increased (P<0.05). Adding 400 µg kg-1 EGF increased villus height-to-crypt depth ratio (P<0.05), but reduced crypt depth (P<0.05). Dietary supplementation with 200 µg kg-1 EGF significantly increased the number of Ki67-positive cells (P<0.01) and tended to increase the mRNA level of proliferating cell nuclear antigen (P<0.10). However, this supplementation decreased the expression level of intestinal fatty acid-binding protein (P<0.05). Piglets fed with 400 µg kg-1 EGF had an increased mRNA level of intestinal alkaline phosphatase (P<0.05). The phosphorylation of mTOR (mammalian target of rapamycin) was observed in the 200 µg kg-1 EGF group. These results suggest that dietary supplementation with a low level of EGF improved piglet intestinal morphology through stimulating the proliferation and differentiation of enterocytes, and the mTOR signaling pathway may partly be involved in this process.

IGF-1 Inhibits Apoptosis of Porcine Primary Granulosa Cell by Targeting Degradation of BimEL

Insulin-like growth factor-1 (IGF-1) is an intra-ovarian growth factor that plays important endocrine or paracrine roles during ovarian development. IGF-1 affects ovarian function and female fertility through reducing apoptosis of granulosa cells, yet the underlying mechanism remains poorly characterized. Here, we aimed to address these knowledge gaps using porcine primary granulosa cells and examining the anti-apoptotic mechanisms of IGF-1. IGF-1 prevented the granulosa cell from apoptosis, as shown by TUNEL and Annexin V/PI detection, and gained the anti-apoptotic index, the ratio of Bcl-2/Bax. This process was partly mediated by reducing the pro-apoptotic Bim_EL (Bcl-2 Interacting Mediator of Cell Death-Extra Long) protein level. Western blotting showed that IGF-1 promoted Bim_EL phosphorylation through activating p-ERK1/2, and that the proteasome system was responsible for degradation of phosphorylated Bim_EL. Meanwhile, IGF-1 enhanced the Beclin1 level and the rate of LC3 II/LC3 I, indicating that autophagy was induced by IGF-1. By blocking the proteolysis processes of both proteasome and autophagy flux with MG132 and chloroquine, respectively, the Bim_EL did not reduce and the phosphorylated Bim_EL protein accumulated, thereby indicating that both proteasome and autophagy pathways were involved in the degradation of Bim_EL stimulated by IGF-1. In conclusion, IGF-1 inhibited porcine primary granulosa cell apoptosis via degradation of pro-apoptotic Bim_EL. This study is critical for us to further understand the mechanisms of follicular survival and atresia regulated by IGF-1. Moreover, it provides a direction for the treatment of infertility caused by ovarian dysplasia, such as polycystic ovary syndrome and the improvement of assisted reproductive technology.

Induction of Chemerin on Autophagy and Apoptosis in Dairy Cow Mammary Epithelial Cells

Involution of the mammary gland is a complex process controlled by various endocrine hormones and cytokine. As a novel adipocytokine, Chemerin not only plays a pivotal role in physiological and pathological processes such as immune response and lipid metabolism, but is also involved in the regulation of programmed cell death, including autophagy and apoptosis. The purpose of the present study was to elucidate whether autophagy and apoptosis of bovine mammary epithelial cells (BMECs) was triggered by Chemerin. BMECs were cultured and treated with Chemerin in vitro. The expression of autophagosome-forming marker, microtubule-associated protein 1 light chain 3 II (LC3-II) and sequestosome-1 (SQSTM 1, best known as p62), a substrate of autophagosome degradation were detected. The result showed that Chemerin significantly decreased the expression of p62 and markedly induced the conversion of LC3-I to LC3-II. The ratio of Bcl2-associated X and B-cell lymphoma-2 (Bax/Bcl-2) and the activity of caspase-3 were up-regulated after being treated by Chemerin, and the apoptotic rate was also significantly increased. These results suggested that Chemerin promoted the occurrence of autophagy and apoptosis in BMECs. Chloroquine (CQ), which is an inhibitor of autophagy. To explore effects of Chemerin on apoptosis, we prevented Chemerin-induced autophagy by pre-adding CQ in BMECs. Interestingly, this part of the experiment helped us find that all effects of Chemerin on apoptosis of BMECs could be enhanced with the inhibition of autophagy. Our study demonstrates that Chemerin-induced autophagy and apoptosis are mutually regulated in BMECs, but the specific mechanism remains to be further researched.

CREB3 regulatory factor -mTOR-autophagy regulates goat endometrial function during early pregnancy

In domestic ruminants, a receptive endometrium is crucial for successful pregnancy. Although many essential molecular modulators and pathways have been identified during early pregnancy, the precise mechanisms regulating goat endometrial function remains largely unknown. Here, we describe a novel regulator during early pregnancy, whereby hormones increased CREB3 regulatory factor (CREBRF) expression and act as a potential activator of autophagy in endometrial epithelial cells (EECs) via the mTOR pathway. Our results showed that knockdown of CREBRF via shCREBRF hampered EECs proliferation by S-phase cell cycle arrest and significantly inhibited endometrial function. We also reported that CREBRF-mTOR-autophagy pathway plays a vital role in regulating endometrial function, with a blockade of the mTOR by rapamycin demonstrating the regulatory function on prostaglandin (PGs) secretion and cell attachment in EECs. Moreover, chloroquine pretreatment also proved the above conclusion. Collectively, our findings provide new insight into the molecular mechanisms of goat endometrial function and indicate that the CREBRF-mTOR-autophagy pathway plays a central role in PGs secretion and cell attachment.

Current Understanding of Autophagy in Pregnancy

Autophagy is an evolutionarily conserved process in eukaryotes to maintain cellular homeostasis under environmental stress. Intracellular control is exerted to produce energy or maintain intracellular protein quality controls. Autophagy plays an important role in embryogenesis, implantation, and maintenance of pregnancy. This role includes supporting extravillous trophoblasts (EVTs) that invade the decidua (endometrium) until the first third of uterine myometrium and migrate along the lumina of spiral arterioles under hypoxic and low-nutrient conditions in early pregnancy. In addition, autophagy inhibition has been linked to poor placentation—a feature of preeclamptic placentas—in a placenta-specific autophagy knockout mouse model. Studies of autophagy in human placentas have revealed controversial results, especially with regard to preeclampsia and gestational diabetes mellitus (GDM). Without precise estimation of autophagy flux, wrong interpretation would lead to fixed tissues. This paper presents a review of the role of autophagy in pregnancy and elaborates on the interpretation of autophagy in human placental tissues.

Interplay Between Toxoplasma gondii, Autophagy, and Autophagy Proteins

Survival of Toxoplasma gondii within host cells depends on its ability of reside in a vacuole that avoids lysosomal degradation and enables parasite replication. The interplay between immune-mediated responses that lead to either autophagy-driven lysosomal degradation or disruption of the vacuole and the strategies used by the parasite to avoid these responses are major determinants of the outcome of infection. This article provides an overview of this interplay with an emphasis on autophagy.

PHYSIOLOGY SYMPOSIUM: Effects of heat stress during late gestation on the dam and its calf12

Heat stress during late gestation in cattle negatively affects the performance of the dam and its calf. This brief exposure to an adverse environment before parturition affects the physiological responses, tissue development, metabolism, and immune function of the dam and her offspring, thereby limiting their productivity. During the dry period of a dairy cow, heat stress blunts mammary involution by attenuating mammary apoptosis and autophagic activity and reduces subsequent mammary cell proliferation, leading to impaired milk production in the next lactation. Dairy cows in early lactation that experience prepartum heat stress display reduced adipose tissue mobilization and lower degree of insulin resistance in peripheral tissues. Similar to mammary gland development, placental function is impaired by heat stress as evidenced by reduced secretion of placental hormones (e.g., estrone sulfate) in late gestation cows, which partly explains the reduced fetal growth rate and lighter birth weight of the calves. Compared with dairy calves born to dams that are exposed to evaporative cooling during summer, calves born to noncooled dry cows maintain lower BW until 1 yr of age, but display a stronger ability to absorb glucose during metabolic challenges postnatally. Immunity of the calves, both passive and cell-mediated immune function, is also impaired by prenatal heat stress, resulting in increased susceptibility of the calves to diseases in their postnatal life. In fact, dairy heifers born to heat-stressed dry cows without evaporative cooling have a greater chance leaving the herd before puberty compared with heifers born to dry cows provided with evaporative cooling (12.2% vs. 22.7%). Dairy heifers born to late-gestation heat-stressed dry cows have lower milk yield at maturity during their first and second lactations. Emerging evidence suggests that late-gestation heat stress alters the mammary gland microstructure of the heifers during the first lactation and exerts epigenetic alterations that might explain, in part, their impaired productivity.

COPS5 negatively regulates goat endometrial function via the ERN1 and mTOR-autophagy pathways during early pregnancy

In ruminant, adequate endometrial function is a major factor affecting implantation and economic efficiency. However, the precise mechanisms regulating goat endometrial function during the peri-implantation period of pregnancy are still unclear. Here, we investigated the functional role and signal transduction of the fifth component of the constitutive photomorphogenic-9 signalosome (COPS5) in the regulation of endometrial function in endometrial epithelial cells (EECs). Our results showed that hormones decreased COPS5 expression, and COPS5-mediated regulation of endometrial function. We also found that knockdown of COPS5 hindered EECs proliferation by the G1-phase cell cycle arrest. Hormones affected the activity of COPS5 through hormones receptors, while feedback from the expression of COPS5 regulated the transcription of the receptor. Moreover, knockdown of endoplasmic reticulum (ER) to nucleus signaling 1 (ERN1) via si-ERN1 partly inhibited endometrial function in shCOPS5 EECs. In addition, blocking the mTOR pathway by rapamycin promoted endometrial function in si-ERN1-transfected shCOPS5 EECs. Overall, these results suggest that COPS5 negatively regulates goat endometrial function via the ERN1 and mTOR-autophagy pathways and provide new insights into the mechanistic pathways of COPS5 during female reproductive development.

5-ARI induces autophagy of prostate epithelial cells through suppressing IGF-1 expression in prostate fibroblasts

Objectives

5α‐reductase inhibitor (5‐ARI) is a commonly used medicine in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Our study mainly focuses on the mechanism of BPH development after 5ARI treatment.

Materials and Methods

Prostate specimens from patients were collected. Insulin‐like growth factor 1 (IGF‐1), Beclin‐1, LC3 levels, was analysed by immunohistochemistry. The role IGF‐1 on autophagic flux in prostate epithelial cells was studied. Additionally, effect of autophagy on recombinant grafts consisting of prostate stromal and epithelial cells in nude mice was investigated.

Results

We demonstrated that IGF‐1 expression is down‐regulated in prostate fibroblasts after long‐term 5‐ARI application. A decrease in IGF‐1 levels was found to activate autophagic flux through the mTOR pathway in prostate epithelial cells, while the inhibition of IGF‐1 receptor function induced autophagy in prostate epithelial cells. In addition, we revealed that blocking autophagic flux initiation can reduce the volume of recombinant grafts in vivo. Finally, our findings suggest that long‐term 5‐ARI application reduces IGF‐1 secretion by prostatic stromal cells, thereby inducing autophagy of prostatic epithelial cells, which is one of the mechanisms underlying BPH pathogenesis and progression.

Conclusions

Focusing on the autophagy induced by low levels of IGF‐1 in prostatic epithelial cells, after elucidating AR signalling impairment of prostate stromal cells, might provide a novel strategy for the treatment and prevention of BPH development.

Estrogen Receptor Beta (ERβ) Mediated-CyclinD1 Degradation via Autophagy Plays an Anti-Proliferation Role in Colon Cells

Dysfunction of autophagic degradation machinery causes tumorigenesis, including colorectal cancer (CRC). Overexpression of CyclinD1 in CRC has been reported. Recent evidence also suggests that ERβ deficiency is related to the pathogenesis of CRC. Very little is known, however, about the detailed molecular mechanisms underlying the relationship among ERβ, autophagy, and CyclinD1 in CRC. Here, results showed that ERβ played an anti-proliferation role in HCT116 through impairing cell cycle but not apoptosis. Additionally, CyclinD1 accumulation was increased in response to chloroquine (CQ) or in MEF Atg7 knockout cells. Further, ERβ could inhibit the mammalian target of rapamycin (mTOR) or activate Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) to promote autophagy in HCT116. In summary, these results indicate that ERβ-mediated CyclinD1 degradation can inhibit colon cancer cell growth via autophagy.

Dacomitinib, a new pan-EGFR inhibitor, is effective in attenuating pulmonary vascular remodeling and pulmonary hypertension

Accumulating evidence suggests that epidermal growth factor receptor (EGFR) plays a role in the progression of pulmonary arterial hypertension (PAH). Clinically-approved epidermal growth factor inhibitors such as gefitinib, erlotinib, and lapatinib have been explored for PAH. However, None of them were able to attenuate PAH. So, we explored the role of dacomitinib, a new pan-EGFR inhibitor, in PAH. Adult male Sprague-Dawley rats were used to study hypoxia- or monocrotaline-induced right ventricular remodeling as well as systolic function and hemodynamics using echocardiography and a pressure-volume admittance catheter. Morphometric analyses of lung vasculature and pressure-volume vessels were performed. Immunohistochemical staining, flow cytometry, and viability, as well as scratch-wound, and Boyden chamber migration assays were used to identify the roles of dacomitinib in pulmonary artery smooth muscle cells (PASMCs). The results revealed that dacomitinib has a significant inhibitory effect on the thickening of the media, adventitial collagen increased. Dacomitinib also has a significant role in attenuating pulmonary artery pressure and right ventricular hypertrophy. Additionally, dacomitinib inhibits hypoxia-induced proliferation, migration, autophagy and cell cycle progression through PI3K-AKT-mTOR signaling in PASMCs. Our study indicates that dacomitinib inhibited hypoxia-induced cell cycle progression, proliferation, migration, and autophagy of PASMCs, thereby attenuating pulmonary vascular remodeling and development of PAH via the PI3K-AKT-mTOR signaling pathway. Overall, dacomitinib may serve as new potential therapeutic for the treatment of PAH.

Parenteral administration of l-arginine to twin-bearing Romney ewes during late pregnancy is associated with reduced milk somatic cell count during early lactation

Maternal milk is the primary source of nutrition for suckling mammals, and its yield and composition are important determinants of survival during the early neonatal period. The objective of this study was to examine whether parenteral administration of l-Arg to twin-bearing ewes, during mid to late pregnancy, influenced prepartum maternal mammary gland development and subsequent lactation performance in the early postpartum period (14 d). At 80 d of pregnancy, multiparous Romney ewes were housed indoors in group pens, split into 2 cohorts, and fed a lucerne-based pellet diet, formulated to meet 100% of National Research Council-recommended requirements for twin-bearing pregnant ewes, once a day. Cohort 1 was administered l-Arg (72.7 mg/kg of live weight via i.v, 3 times a day) from d 100 of pregnancy until d 140. At d 140, ewes were euthanized and maternal mammary tissues were collected for analysis of the biochemical indices total DNA, RNA, protein, protein synthetic efficiency (protein:RNA), cell size (protein:DNA), transcriptional efficiency (RNA:DNA), and the abundance of mammalian target of rapamycin (mTOR) and mTOR^Ser2448 protein. Cohort 2 was administered an identical l-Arg regimen as cohort 1, but from d 100 until parturition. Milk was collected over a 14-d period (d 1, 4, 7, 10, and 14) to assess milk yield and composition. In cohort 1, total mammary DNA (cell number) tended to be higher in l-Arg ewes, with no change in total mammary RNA or protein content, biochemical indices of protein synthetic efficiency, cell size or transcriptional efficiency, or mTOR protein abundance or phosphorylation. In cohort 2, milk composition analysis from l-Arg ewes showed lower (d 7-14) milk somatic cell counts, greater crude protein percentage from d 7 to 10 but lower at d 14, and altered absolute concentrations of some free AA (d 7 and 14) compared with controls. We propose that parenteral administration of l-Arg during late pregnancy is associated with increased mammary gland cellular content and decreased somatic cell counts during early lactation.

Chi-miR-3031 regulates beta-casein via the PI3K/AKT-mTOR signaling pathway in goat mammary epithelial cells (GMECs)

BACKGROUND

MicroRNAs can regulate gene expression at the posttranscriptional level through translational repression or target degradation. Our previous investigations examined the differential expression levels of chi-miR-3031 in caprine mammary gland tissues in colostrum and common milk stages.

RESULTS

The present study detected the role of chi-miR-3031 in the lactation mechanisms of GMECs. High-throughput sequencing was used to analyze transcriptomic landscapes of GMECs transfected with chi-miR-3031 mimics (MC) and a mimic negative control (NC). In the MC and NC groups, we acquired 39,793,503 and 36,531,517 uniquely mapped reads, respectively, accounting for 85.85 and 81.66% of total reads. In the MC group, 180 differentially expressed unigenes were downregulated, whereas 157 unigenes were upregulated. KEGG pathway analyses showed that the prolactin, TNF and ErbB signaling pathways, including TGFα, PIK3R3, IGF2, ELF5, IGFBP5 and LHβ genes, played important roles in mammary development and milk secretion. Results from transcriptome sequencing, real-time PCR and western blotting showed that chi-miR-3031 suppressed the expression of IGFBP5 mRNA and protein. The expression levels of β-casein significantly increased in the MC and siRNA-IGFBP5 groups. We observed that the down-regulation of IGFBP5 activated mTOR at the Ser2448 site in GMECs transfected with MC and siRNA-IGFBP5. Previous findings and our results showed that chi-miR-3031 activated the PI3K-AKT-mTOR pathway and increased β-casein expression by down-regulating IGFBP5.

CONCLUSIONS

These findings will afford valuable information for improving milk quality and contribute the development of potential methods for amending lactation performance.

Autophagy and unfolded protein response (UPR) regulate mammary gland involution by restraining apoptosis-driven irreversible changes

The postnatal mammary gland undergoes repeated cycles of proliferation and cell death, most notably when the fully differentiated (lactating) gland dedifferentiates to a prelactation state. Accumulation of milk proteins in the secretory epithelium creates the stress signal that triggers this process (involution). How this stress is perceived, and the cellular processes that are subsequently activated, remain unclear. We now report that Unfolded Protein Response (UPR), autophagy, and apoptosis related genes cluster separately during lactation and involution in the mouse mammary gland. Time-course experiments in rodents show that autophagy and UPR signaling are tightly co-regulated at the transition from reversible to irreversible involution. Inhibition of autophagy by chloroquine or genetic deletion of one ATG7 allele enhanced progression of mammary involution into the irreversible phase, as characterized by an early/precocious induction of apoptosis. These are the first preclinical in vivo data in support of a clinical trial testing an autophagy inhibitor for prevention of intraductal breast malignancy progression to invasive breast cancer. In marked contrast, stimulation of autophagy by low dose tunicamycin treatment reduced apoptosis and extended the reversible phase of involution by sustaining the secretory epithelium. Autophagy stimulators could be used short-term to promote lactation in women experiencing difficulties or irregularities in nursing. Taken together, these data indicate that UPR and autophagy play a key role in regulating the balance between cell survival and apoptosis during normal mammary gland regression.

Immunomodulatory Effects of 17β-Estradiol on Epithelial Cells during Bacterial Infections

The innate immune system can function under hormonal control. 17β-Estradiol (E2) is an important sexual hormone for the reproductive cycle of mammals, and it has immunomodulatory effects on epithelial cells, which are the first line of defense against incoming bacteria. E2 regulates various pathophysiological processes, including the response to infection in epithelial cells, and its effects involve the regulation of innate immune signaling pathways, which are mediated through estrogen receptors (ERs). E2 modulates the expression of inflammatory and antimicrobial elements such as cytokines and antimicrobial peptides. The E2 effects on epithelial cells during bacterial infections are characterized by an increase in the production of antimicrobial peptides and by the diminution of the inflammatory response to abrogate proinflammatory cytokine induction by bacteria. Here, we review several novel molecular mechanisms through which E2 regulates the innate immune response of epithelial cells against bacterial infections.

Transcriptome sequencing to detect the potential role of long non-coding RNAs in bovine mammary gland during the dry and lactation period

BACKGROUND

It is known that long non-coding RNAs (lncRNAs) play an important role in various biological processes, including cell proliferation, differentiation and apoptosis. However, their functions and profiles in lactation cycle of dairy cows are largely unknown. In this study, lncRNA-seq technique was employed to compare the expression profiles of lncRNAs and mRNAs from Chinese Holstein mammary gland in dry and lactation period.

RESULT

Totally 3746 differentially expressed lncRNAs (DELs) and 2890 differentially expressed genes (DEGs) were identified from the dry and lactation mammary glands of Holstein cows. Functional enrichment analysis on target genes of lncRNAs indicated that these genes were involved in lactation-related signaling pathways, including cell cycle, JAK-STAT, cell adhesion, and PI3K-Akt signaling pathways. Additionally, the interaction between lncRNAs and their potential miRNAs was predicted and partly verified. The result indicated that the lactation-associated miR-221 might interact with lncRNAs TCONS_00040268, TCONS_00137654, TCONS_00071659 and TCONS_00000352, which revealed that these lncRNAs might be important regulators for lactation cycle.

CONCLUSION

This study provides a resource for lncRNA research on lactation cycle of bovine mammary gland. Besides, the interaction between lncRNAs and the specific miRNA is revealed. It expands our knowledge about lncRNA and miRNA biology as well as contributes to clarify the regulation of lactation cycle of bovine mammary gland.

TRIENNIAL LACTATION SYMPOSIUM/BOLFA: Late gestation heat stress of dairy cattle programs dam and daughter milk production

Anticipated increases in the world population to 9 billion people will lead to increased demand for food. Dairy products represent one of the most sustainable animal sources of food protein because ruminants can utilize byproduct and forage feeds unsuitable for human consumption. Continued improvements in productivity will depend on deeper understanding of the biology of lactation, including developmental programming of tissues critical to that process. Although prenatal programming of postnatal phenotype is well documented for growth, behavior, and disease, there may also be instances of "programming" that last for a specific physiological stage (e.g., lactation). We distinguish between these 2 terms by the use of developmental programming to describe a permanent effect, whereas the more general term is used to describe nonpermanent impacts on the mammary gland. Despite this complexity, here we review the evidence that exposure to elevated temperature and humidity during late gestation can program reduced yields in the subsequent lactation, largely through effects at the mammary gland. Furthermore, we provide emerging evidence that adult capacity for milk synthesis can be programmed in the calf that dam is carrying by events during fetal life occurring 2 yr before. Specifically, calves born to dams that are heat stressed for the final 6 wk of gestation produce 19% less milk in lactation relative to calves from dams provided with evaporative cooling. Importantly, the increased milk yield in animals derived from dams under evaporative cooling occurred without a greater decline in BW that accompanies negative energy balance during early lactation. Therefore, the increase in milk production suggests an increase in the efficiency of conversion of feed to milk. These data indicate that a brief period of heat stress late in development reduces the physiological efficiency of the cow in a coordinated manner to result in a substantial decline in productivity. It is likely that this programming effect would be observed across genetic lines and result in poor sustainability of milk production. Milk will continue to be an important source of high-quality, human-edible food and technologies that improve the efficiency of production will be critical to enhance sustainability. These data provide compelling support for the concept that programming impacts on the dam and the developing fetus will play a role in optimizing the efficiency of production.

Hormone regulates endometrial function via cooperation of endoplasmic reticulum stress and mTOR-autophagy

In ruminant, the receptive endometrium and the elongation of the hatched blastocyst are required to complete the process of implantation. However, the mechanisms regulating goat endometrial function during the peri-implantation period of pregnancy are still unclear. In this study, EECs were treated with progesterone, estradiol, and interferon-tau (IFNT). We have found that endoplasmic reticulum (ER) stress was activated under hormones treatment. To identify the cellular mechanism of regulation of endometrial function, we investigated the effect of ER stress activator thapsigargin (TG) and inhibitor 4 phenyl butyric acid (4-PBA) on EECs. We found that TG, which activated the three branches of UPR, increased the expression of genes associated with promoting conceptus elongation and cellular attachment, significantly up-regulated the spheroid attachment rate and PGE₂ /PGF_2α ratio. 4-PBA pre-treatment inhibited UPR and inhibited promoting conceptus elongation and cellular attachment related genes, but the spheroid attachment rate and PGE₂ /PGF_2α ratio were not changed significantly. Moreover, knockdown of ATF6 via shATF6 promoted the conceptus elongation related genes, but increased the dissolution of the corpus luteum. Besides, blocking ATF6 attenuated autophagy by activating mammalian target of rapamycin (mTOR) pathway. Moreover, rapamycin (mTOR inhibitor) pre-treatment inhibited the expression of promoting conceptus elongation and increased PGE₂ /PGF_2α ratio. Taken together, our study indicated that physiological level of ER stress may contribute to early pregnancy success, and ATF6 signaling pathway cooperated with autophagy to regulate endometrial function by modulating mTOR pathway.

Insulin-like growth factor 1 inhibits autophagy of human colorectal carcinoma drug-resistant cells via the protein kinase B/mammalian target of rapamycin signaling pathway

Insulin-like growth factor 1 (IGF-1) is reported to inhibit autophagy of human colorectal carcinoma cells (HCT); however, little is known regarding the mechanisms underlying the inhibitory effect of IGF-1 on autophagy in HCT resistant strains. The present study aimed to analyze the inhibitory effect of IGF-1 on the autophagy of HCT resistant strains and its potential underlying mechanisms. The viability and apoptosis of HCT-8 colon cancer cells were analyzed, and expression levels of relevant genes and proteins were investigated using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Treatment of cells with IGF-1 induced apoptosis. IGF-1 treatment activated protein kinase B (AKT), which may inhibit autophagy via the AKT/mammalian target of rapamycin signaling pathway. Following inhibition of autophagy, drug resistant cells became sensitive to apoptosis induced by 5-fluorouracil.

Temperature-sensitive heparin-modified poloxamer hydrogel with affinity to KGF facilitate the morphologic and functional recovery of the injured rat uterus

Endometrial injury usually results in intrauterine adhesion (IUA), which is an important cause of infertility and recurrent miscarriage in reproductive women. There is still lack of an effective therapeutic strategy to prevent occurrence of IUA. Keratinocyte growth factor (KGF) is a potent repair factor for epithelial tissues. Here, a temperature-sensitive heparin-modified poloxamer (HP) hydrogel with affinity to KGF (KGF-HP) was used as a support matrix to prevent IUA and deliver KGF. The rheology of KGF-HP hydrogel was carefully characterized. The cold KGF-HP solution was rapidly transited to hydrogel with suitable storage modulus (G') and loss modulus (G″) for the applications of uterus cavity at temperature of 33 °C. In vitro release demonstrated that KGF was released from HP hydrogels in sustained release manner for a long time. In vivo bioluminescence imaging showed that KGF-HP hydrogel was able to prolong the retention of the encapsulated KGF in injured uterus of rat model. Moreover, the morphology and function of the injured uterus were significantly recovered after administration of KGF-HP hydrogel, which were evaluated by two-dimensional ultrasound imaging and receptive fertility. Not only proliferation of endometrial glandular epithelial cells and luminal epithelial cells but also angiogenesis of injured uterus were observed by Ki67 and CD31 staining after 7 d of treatment with KGF-HP hydrogel. Finally, a close relatively relationship between autophagy and proliferation of endometrial epithelial cells (EEC) and angiogenesis was firstly confirmed by detecting expression of LC3-II and P62 after KGF treatment. Overall, KGF-HP may be used as a promising candidate for IUA treatment.

Role of autophagy in oocytogenesis, embryogenesis, implantation, and pathophysiology of pre-eclampsia

Autophagy is a well-conserved mechanism in cells from yeast to mammals, and autophagy maintains homeostasis against stress. The role of autophagy was originally shown to be a mechanism of energy production under starvation. In fact, multiple lines of evidence reveal that autophagy has numerous functions, such as protection from stress, energy regulation, immune regulation, differentiation, proliferation, and cell death. In the field of reproduction, the role of autophagy in implantation, embryogenesis, placentation, and delivery has become clearer. In addition, recent study has elucidated that the placenta has the ability to protect extraplacental cells from virus infection by activating autophagy. During resent research into autophagy, several issues have occurred in the interpretation of the autophagy status. In this review, we discuss the relation between autophagy and reproductive events, and show the importance of autophagy for placentation and pre-eclampsia.