Acinar Cell Proliferation Research Articles

Cytarabine chemotherapy induces meibomian gland dysfunction

PurposeCytarabine (Ara-C) chemotherapy causes symptoms resembling meibomian gland dysfunction (MGD), suggesting potential associations between Ara-C and MGD. In this study, the pathological effects of Ara-C on MGD were investigated in a rodent model. MethodsMice received Ara-C with or without rosiglitazone (PPARγ agonist) for 7 consecutive days. Slit-lamp biomicroscope was used for ocular examinations. Immunofluorescence detected acinar cell proliferation, differentiation, and ductal keratinization in the meibomian gland (MG). Lipid accumulation was evaluated by Oil Red O and LipidTox staining. Lipogenic status, FoxO1/FoxO3a cellular localization, and oxidative stress were visualized via immunohistochemistry. Western blotting assessed relative protein expression and AKT/FoxO1/FoxO3a pathway phosphorylation. ResultsAra-C (50 mg/kg) did not affect mouse survival but induced damage to ocular surface microenvironment, including corneal epithelial defects, MG orifice plugging and acinar dropout, and lacrimal gland (LG) dysfunction. Ara-C intervention inhibited proliferation and caused progenitor loss in the MG, as evidenced by reduced PCNA + labeling and P63+/Lrig1+ basal cell numbers. The MG ducts of Ara-C-treated mice exhibited marked dilatation, lipid deposition, and hyperkeratinization (K1/K10 overexpression). Ara-C disrupted MG lipid metabolism by downregulating PPARγ and its downstream lipogenic targets AWAT2/SOAT1/ELOVL4 and upregulating HMGCR. Dephosphorylation of AKT and the subsequent nuclear translocation of FoxO1/FoxO3a contributed to Ara-C-induced PPARγ downregulation. Ara-C triggered oxidative stress with increases in 4-HNE and 8-OHdG and Keap1/Nrf2/HO-1/SOD1 axis dysregulation. Rosiglitazone treatment ameliorated MGD-associated pathological manifestations, LG function, MG lipid metabolism, and oxidative stress in Ara-C-exposed mice. ConclusionsSystemic Ara-C chemotherapy exerted topical cytotoxic effects on the ocular surface, and PPARγ restoration by rosiglitazone mitigated Ara-C-induced MGD alterations.

HDAC1/2 and HDAC3 play distinct roles in controlling adult Meibomian gland homeostasis

PurposeTo investigate the roles of HDAC1/2 and HDAC3 in adult Meibomian gland (MG) homeostasis. MethodsHDAC1/2 or HDAC3 were inducibly deleted in MG epithelial cells of adult mice. The morphology of MG was examined. Proliferation, apoptosis, and expression of MG acinus and duct marker genes, meibocyte differentiation genes, and HDAC target genes, were analyzed via immunofluorescence, TUNEL assay, and RNA in situ hybridization. ResultsCo-deletion of HDAC1/2 in MG epithelium caused gradual loss of acini and formation of cyst-like structures in the central duct. These phenotypes required homozygous deletion of both HDAC1 and HDAC2, indicating that they function redundantly in the adult MG. Short-term deletion of HDAC1/2 in MG epithelium had little effect on meibocyte maturation but caused decreased proliferation of acinar basal cells, excessive DNA damage, ectopic apoptosis, and increased p53 acetylation and p16 expression in the MG. By contrast, HDAC3 deletion in MG epithelium caused dilation of central duct, atrophy of acini, defective meibocyte maturation, increased acinar basal cell proliferation, and ectopic apoptosis and DNA damage. Levels of p53 acetylation and p21 expression were elevated in HDAC3-deficient MGs, while the expression of the differentiation regulator PPARγ and the differentiation markers PLIN2 and FASN was downregulated. ConclusionsHDAC1 and HDAC2 function redundantly in adult Meibomian gland epithelial progenitor cells and are essential for their proliferation and survival, but not for acinar differentiation, while HDAC3 is required to limit acinar progenitor cell proliferation and permit differentiation. HDAC1/2 and HDAC3 have partially overlapping roles in maintaining survival of MG cells.

TGFβ and Hippo Signaling Pathways Coordinate to Promote Acinar to Ductal Metaplasia in Human Pancreas.

Acinar-to-ductal metaplasia (ADM) serves as a precursor event in the development of pancreatic ductal adenocarcinoma (PDAC) upon constitutive environmental and genetical stress. While the role of ADM in PDAC progression has been established, the molecular mechanisms underlying human ADM remain elusive. We previously demonstrated the induction of ADM in human acinar cells through the transforming growth factor beta (TGFβ) signaling pathway. We aim to investigate the interaction between TGFβ and Hippo pathways in mediating ADM. RNA-sequencing was conducted on sorted normal primary human acinar, ductal, and AD (acinar cells that have undergone ADM) cells. ATAC-seq analysis was utilized to reveal the chromatin accessibility in these three cell types. ChIP-Seq of YAP1, SMAD4, and H3K27ac was performed to identify the gene targets of YAP1 and SMAD4. The role of YAP1/TAZ in ADM-driven cell proliferation, as well as in oncogenic KRAS driven proliferation, was assessed using sphere formation assay. AD cells have a unique transcription profile, with upregulated genes in open chromatin states in acinar cells. YAP1 and SMAD4 co-occupy the loci of ADM-related genes, including PROM1, HES1, and MMP7, co-regulating biological functions such as cell adhesion, cell migration, and inflammation. Overexpression of YAP1/TAZ promoted acinar cell proliferation but still required the TGFβ pathway. YAP1/TAZ were also crucial for TGFβ-induced sphere formation and were necessary for KRAS-induced proliferation. Our study reveals the intricate transition between acinar and AD states in human pancreatic tissues. It unveils the complex interaction between the Hippo and TGF-β pathways during ADM, highlighting the pivotal role of YAP1/TAZ and SMAD4 in PDAC initiation.

Extensive elimination of acinar cells during normal postnatal pancreas growth

While programmed cell death plays important roles during morphogenetic stages of development, post-differentiation organ growth is considered an efficient process whereby cell proliferation increases cell number. Here we demonstrate that early postnatal growth of the pancreas unexpectedly involves massive acinar cell elimination. Measurements of cell proliferation and death in the human pancreas in comparison to the actual increase in cell number predict daily elimination of 0.7% of cells, offsetting 88% of cell formation over the first year of life. Using mouse models, we show that death is associated with mitosis, through a failure of dividing cells to generate two viable daughters. In p53-deficient mice, acinar cell death and proliferation are reduced, while organ size is normal, suggesting that p53-dependent developmental apoptosis triggers compensatory proliferation. We propose that excess cell turnover during growth of the pancreas, and presumably other organs, facilitates robustness to perturbations and supports maintenance of tissue architecture.

Recent advances in age-related meibomian gland dysfunction (ARMGD)

Meibomian glands (MGs), located within the tarsal plate of the eyelid, secrete meibum which is the lipid-rich secretion necessary for stabilizing the tear film and preventing tear evaporation. Changes in the quality and quantity of meibum produced causes MG dysfunction (MGD), the leading cause of evaporative dry eye disease (EDED). MGD is an underdiagnosed disease and it is estimated that, in the US, approximately 70 % of the population over 60 have MGD. Three forms of MGD occur based on their meibum secretion: hyposecretory, obstructive, and hypersecretory MGD. The pathophysiology of MGD remains poorly understood, however aging is the primary risk factor. With age, MGs undergo various age-related changes, including decreased acinar basal cell proliferation, hyperkeratinization, MG atrophy, and eventual MG drop-out, leading to age-related MGD (ARMGD). Additionally, studies have suggested that MGs can suffer inflammatory cell infiltration and changes innervation patterns with aging, which could also contribute towards ARMGD. This review focuses on how the aging process affects the MG, and more importantly, how age-related changes to the MG can lead to MG atrophy and MG drop-out, ultimately leading to ARMGD. This review also highlights the most recent developments in potential therapeutic interventions for ARMGD.

Organotypic culture model of mouse meibomian gland as a screening platform for risk factors related to meibomian gland dysfunction

PurposeMeibomian glands (MGs) are crucial for maintaining tear film stability and ocular surface health. Here, we aim to establish a novel organotypic culture model of MGs and explore the risk factors of MG dysfunction (MGD). MethodsWe developed a novel organotypic culture model for MGs at the air-liquid interface. The viability and cell proliferation of MGs were assessed using CCK-8, immunofluorescence, and qPCR. Lipid accumulation was evaluated by Nile red staining and microscopic examination. Protein expression levels were evaluated by immunofluorescence and Western blot assay. EdU assay was employed to track the proliferation of acinar cells. The validity of the model was confirmed through culturing MGs from mice of different ages and incorporating certain drugs (Dex) into the culture system. ResultsUtilizing the novel culture model, the MG tissue exhibited sustained viability, cellular division, and continuous production of lipids for a duration of 7 days. Lipid droplets formed were directly visualized using light field microscopy. Through the cultivation of aged mice's MGs, it was discovered that aging resulted in diminished proliferation and lipid synthesis, along with an aberrant increase in Krt10 expression. Further application of this model showed that Dex treatment diminished MG's proliferation and lipid synthesis. Finally, an in vivo study was conducted to provide additional confirmation of the phenomenon of Dex-induced abnormalities. ConclusionsIn this study, a stable organotypic culture model of the MGs was established. The organotypic culture model offers a valuable tool to investigate the pathophysiological mechanisms and facilitate drug screening for MG-related diseases.

Traditional Chinese Medicine Danzhi qing'e decoction inhibits inflammation-associated prostatic hyperplasia via inactivation of ERK1/2 signal pathway.

Inflammation plays a critical role during benign prostatic hyperplasia (BPH) development. Danzhi qing'e (DZQE) decoction is a traditional Chinese medicine that has been widely used for estrogen and androgen-related diseases. However, its effect on inflammation-related BPH remains unclear. To investigate the effect of DZQE on inhibition of inflammation-related BPH, and further identify the possible mechanism involved. Experimental autoimmune prostatitis (EAP)-induced BPH was established and then 2.7g/kg of DZQE was administrated orally for 4 weeks. The prostate sizes, weights and prostate index (PI) values were recorded. Hematoxylin and eosin (H&E) was performed for pathological analyses. Macrophage infiltrate was evaluated by Immunohistochemical (IHC). The inflammatory cytokine levels were measured by Rt-PCR and ELISA methods. The phosphorylation of ERK1/2 was examined by Western blot. The expression differences of mRNA expressions between EAP-induced and oestrogen/testosterone (E2/T)-induced BPH was investigated by RNA sequencing analyses. In vitro, human prostatic epithelial BPH-1cells were stimulated with the conditioned medium from monocyte THP-1-derived M2 macrophages (M2CM), followed by treatment of Tanshinone IIA (Tan IIA), Bakuchiol (Ba), ERK1/2 antagonist PD98059 or ERK1/2 agonist C6-Ceramide. The ERK1/2 phosphorylation and cell proliferation were then detected by Western blotting and CCK8 assay. DZQE significantly inhibited the prostate enlargement and decreased PI value in EAP rats. Pathological analysis showed that DZQE alleviated prostate acinar epithelial cell proliferation by decreasing and reduction of CD68+ and CD206+ macrophage infiltration in the prostate. The levels of cytokines TNF-α, IL-1β, IL-17, MCP-1, TGF-β, and IgG in EAP rats' prostate or serum were significantly suppressed by DZQE as well. Moreover, mRNA sequencing data showed that the expressions of inflammation-related genes were elevated in EAP-induced BPH but not in E2/T-induced BPH. ERK1/2-related genes expression has been found in both E2/T and EAP-induced BPH. ERK1/2 is one of the core signal pathways involved in EAP-induced BPH, which was activated in EAP group but inactivated in DZQE group. In vitro, two active components of DZQE Tan IIA and Ba inhibited M2CM-induced BPH-1cell proliferation, similarly to ERK1/2 inhibitor PD98059 did. Meanwhile, Tan IIA and Ba inhibited M2CM-induced ERK1/2 signal activation in BPH-1cells. When re-activated the ERK1/2 by its activator C6-Ceramide, the inhibitory effects of Tan IIA and Ba on BPH-1cell proliferation were blocked. DZQE suppressed inflammation-associated BPH via regulation of ERK1/2 signal by Tan IIA and Ba.

Acinar Cell Proliferation Promoted by BMP2 in Injured Mouse Parotid Gland: BMP2 Promotes Cell Proliferation in Parotid Gland.

To identify factors that affect salivary gland recovery, we investigated the expression and function of bone morphogenetic protein 2 (BMP2) in mice. Using a micro clip, mice parotid glands were removed 7 days after the ligation of the unilateral parotid excretory duct. Thereafter, they were weighed and stained with hematoxylin and eosin, and BMP2 expression was examined via real-time reverse transcription-polymerase chain reaction. Primary cultures of parotid glands were prepared, and BMP2 protein was added to the culture medium for 48 hr to examine its effect on cell proliferation. E-cadherin and vimentin expression was examined using western blotting. Finally, immunohistochemical staining using an anti-Ki67 antibody was performed. Duct-ligated parotid glands weighed less than those that were collected after sham surgery and showed acinar cell atrophy. They also showed higher BMP2 expression than control glands. Primary-cultured parotid acinar cells supplemented with BMP2 showed higher proliferative potential than control cells. Furthermore, they showed E-cadherin, but not vimentin, expression, and their percentage of Ki67-positive cells were higher than that corresponding to the controls. Injury to salivary glands by excretory duct ligation increased BMP2 expression, which may be involved in maintaining salivary gland function by inducing acinar cell proliferation.

Involvement of aberrant acinar cell proliferation in scopolamine-induced dry eye mice

Dry eye is a multifactorial disease that causes dryness, inflammation and damage of ocular surface. Subcutaneous injection of the muscarinic cholinergic antagonist scopolamine under desiccating stress reduces tear production and induces dry eye symptoms in mice. However, the expression profile and pathogenic changes of the lacrimal gland remain incompletely understood. In the present study, we performed comparative transcriptomic analysis of lacrimal glands from the control and scopolamine-treated mice. Primary analysis identified 677 upregulated genes and 269 downregulated genes in the lacrimal gland of mice with scopolamine treatment. Unexpectedly, KEGG pathway and hierarchical clustering analysis showed the enrichment of “DNA replication” and “cell cycle” categories in the upregulated genes. Subsequently, we confirmed that the acinar cells were the major proliferating cells of lacrimal gland, which exhibited significant increasing of the proliferating cell nuclear antigen (PCNA) expression after scopolamine treatment, accompanied with the upregulation of DNA damage marker γ-H2AX. More importantly, both prophylactic and therapeutic administration of the cyclin-dependent kinase (CDK) inhibitor AT7519 rescued the tear reduction and alleviated dry eye severity in the scopolamine-treated mice, including corneal epithelial barrier function, lacrimal and corneal inflammation, and conjunctival goblet cell density. Therefore, we conclude that aberrant acinar cell proliferation is involved in the scopolamine-induced tear reduction and dry eye onset, which can be improved by AT7519 treatment.

Bone Marrow Mesenchymal Stem Cells Modified with microRNA-216a-5p Enhance Proliferation of Acinar Cells in Severe Acute Pancreatitis

This study assesses the effect of bone marrow mesenchymal stem cells (BMSC) modified with miR-216a-5p on acinar cell proliferation in SAP. 40 rats were equally assigned into miR-NC set, miR-216a-5p set, BMSC set and anti-miR-216a-5p set randomly. The SAP model was prepared using AR42J cells which were disposed with CAE. Cells were transfected with lipidosome method to meaure miR-216-5p by RT-PCR, cell proliferation by CCK-8 along with analysis of cell clone formation and apoptosis. miR-216a-5p in modified BMSC was significantly upregulated compared with BMSC, indicating that BMSC was modified with miR-216a-5p successfully. BMSC modified with miR-216a-5p significantly promoted cell proliferation and clone formation and decreased apoptosis. The luciferase activity in wild type of miR-216a-5p was reduced, indicating that miR-216-5p could target Pak2 gene. In conclusion, proliferation of acinar cells in SAP is prompted and apoptosis ise reduced by BMSC modified with miR-216a-5p, which is possibly through targeting PAK2 gene.

Downregulation of miR-146a-5p Promotes Acute Pancreatitis through Activating the TLR9/NLRP3 Signaling Pathway by Targeting TRAF6 In Vitro Rat Model.

Acute pancreatitis (AP) is mainly caused by acinar cells releasing various inflammatory factors, causing inflammatory storms and leading to severe pancreatitis. Detection methods and treatment targets for pancreatitis are lacking, raising the urgency of identifying diagnostic markers and therapeutic targets for AP. MicroRNAs (miRNAs) have recently been identified as molecular markers for various biological processes such as tumors, immunity, and metabolism, and the involvement of miRNAs in inflammatory responses has been increasingly studied. To explore the role of miRNAs in AP is the primary objective of this study. By using qPCR on our cerulein-induced pancreatitis cell model, it is worth noting that the change of miR-146a-5p expression in inflammation-related miRNAs in AP was predominant. Next, ELISA, CCK8, and flow cytometry were used to inspect the impact of miR-146a-5p on pancreatitis. BiBiServ bioinformatics anticipated binding ability of miR-146a-5p and 3′-untranslated region (3′UTR) of TNF receptor-associated factor 6 (TRAF6), and the dual-luciferase assay verified the combination of the two. TRAF6 knockdown verified the effect of TRAF6 on the progression of pancreatitis. Finally, rescue experiments verified the capability of miR-146a-5p and TRAF6 interaction on the Toll-like receptor 9 (TLR9)/NOD-like receptor protein 3 (NLRP3) signaling pathway and cell function. The expression of miR-146a-5p decreased in cerulein-induced AR42J pancreatic acinar cells. Functional experiments verified that miR-146a-5p facilitated the proliferation of AR42J pancreatic acinar cells and inhibited their apoptosis. Bioinformatic predictions and dual-luciferase experiments verified the actual binding efficiency between miR-146a-5p and 3′UTR of TRAF6. Our study confirmed that knockdown of TRAF6 restrained the progression of pancreatitis, and knockdown of TRAF6 rescued pancreatitis caused by miR-146a-5p downregulation by the TLR9/NLRP3 signaling pathway. Therefore, downregulation of miR-146a-5p in the induced pancreatitis cell model promotes the progression of pancreatitis via the TLR9/TRAF6/NLRP3 signaling pathway. There is potential for miR-146a-5p to serve as a diagnostic marker and therapeutic nucleic acid drug for AP.

Indirect Application of Intense Pulsed Light Induces Therapeutic Effects on Experimental Murine Meibomian Gland Dysfunction.

PurposeTo investigate the indirect effects of intense pulsed light (IPL) on morphological and pathological changes of the meibomian glands (MGs) in apolipoprotein E knockout (ApoE–/–) mice and explore the underlying mechanisms.MethodsApoE–/– mice were treated with or without IPL three times below the lower eyelids and MGs were not directly exposed to irradiation. The eyelids and ocular surface were observed under a stereoscope. The morphology of MGs was examined by photographing and hematoxylin and eosin staining. Lipid droplets in MGs were examined by Oil Red O staining. The ultrastructure of meibocytes and mitochondria was observed under transmission electron microscopy. The relative gene and protein expression in MGs of upper eyelids was determined by immunostaining, Western blot, and qRT–PCR.ResultsThree IPL treatments decreased the toothpaste-like plugging of orifices and thickening and irregularity of the upper and lower eyelid margins in ApoE–/– mice. The morphology of some MGs improved after IPL treatments, accompanied by increased proliferation of acinar basal cells and decreased ductal keratinization. Furthermore, the accumulation of hyperchromatic lipid droplets in the acini increased, and the lipid droplets distributed in the cells around the acini were round and small. Compared with untreated ApoE–/– mice, oxidative stress and apoptosis were downregulated by IPL treatment, accompanied by the improvements in mitochondrial structure. Further research showed that IPL treatments reduced the levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-17A, IL-6 in MGs and inactivated nuclear factor kappa B (NF-κ B).ConclusionCollectively, the results demonstrate that indirect effects of IPL can improve the structure and function of MGs and mitigate the progression of MGD, which may be related to the indirect effects of photobiomodulation.

Saliva biomarkers for Alzheimer’s disease risk in a rat model of low and high intrinsic exercise capacity

AbstractBackgroundIdentifying a natural‐occurring animal model for Alzheimer's Disease (AD) and a non‐invasive early AD diagnostic are significant AD research challenges. Previously, we developed rat models by selectively breeding for low and high intrinsic exercise capacity. We found that compared to High Capacity Runners (HCR), Low Capacity Runners (LCR) have a reduced lifespan and greater risk for cardiovascular disease, diabetes, and obesity.1 LCR exhibit neurodegeneration, impaired memory, and decreased hippocampal neurogenesis. Saliva is a relatively new AD‐associated research area, and as a bioanalytic,2 is an important extension of protein changes in the autonomic nervous system and immune response. Our goal is to determine whether salivary biomarkers link with exercise capacity and brain health in LCR and HCR rats.MethodWe studied three‐generations of female rats (6 months: 9 LCR, 10 HCR), (20 months: 8 LCR, and 8 HCR), and (26 months: 7 LCR, 6 HCR). We assessed exercise capacity using a treadmill running test and cognitive function using a Y‐maze. Salivary gland weight and salivary flow rate (SFR) of a submandibular gland (SMG) were measured and compared. The acinar cells proliferation of SMG was assessed by IHC using PCNA. Biomarkers for p‐tau ser610 and amyloid‐beta were investigated in hippocampus tissue, saliva, and plasma using ELISA.ResultThe LCR and HCR groups were significantly different for maximal treadmill running distance and time spent in novel arm of the Y‐Maze. The SFR and acinar cell proliferation were higher in HCR. The size and mass of SMG were bigger in LCR rats. Levels of p‐tau in saliva and plasma were markedly greater in LCR than HCR, but no differences in the hippocampus. There was no difference between the two groups in the hippocampus or saliva regarding amyloid‐beta levels. However, it was significantly increased in plasma in the LCR group compared with the HCR group.ConclusionTaken together, the findings of this study provide experimental evidence that saliva biomarkers are significantly increased in the LCR group compared with the HCR group. This is the first study using novel and unexplored preclinical rat models that combines exercise capacity with AD risk by utilizing saliva biomarkers.

MiR-489-3p modulates cell proliferation and apoptosis in cerulein-induced acute pancreatitis by targeting X-linked inhibitor of apoptosis protein

IntroductionThis study aims to explore the effect and mechanism of miR�489-3p on the proliferation and apoptosis of pancreatic acinar cells in acute pancreatitis (AP).Material and methodsX-linked inhibitor of apoptosis protein (XIAP) and miR-489-3p expression in serum of AP patients, pancreatic AR42J cells, and rat AP tissues were measured using quantitative reverse transcription poly�merase chain reaction and western blot. The effect of miR-489-3p on pro�liferation and apoptosis was determined by MTT assay and flow cytometry. The relationship between XIAP and miR-489-3p was verified using luciferase assay RNA immunoprecipitation assay. Histological changes in rat pancreatic tissues were observed via haematoxylin and eosin staining.ResultsMeasurement of miR-489-3p and XIAP expressions in AP patients revealed a negative correlation between miR-489-3p and XIAP. Increased miR-489-3p expression in AP patients indicated a poor prognosis. Cerulein was used to induce AP in AR42J cells and standard deviation rats. Exper�iments in cells and AP rat models showed that miR-489-3p can increase cell apoptosis and inhibit cell proliferation by regulating XIAP, as shown by elevated expressions of pro-apoptotic proteins (p53 and Bax) and decreased expression of proliferation indicator (Ki-67) after transfection of miR-489- 3p mimics. Meanwhile, knockdown of miR-489-3p abrogated the inhibitory effects of miR-489-3p on cell proliferation and the promotion on cell apop�tosis. Luciferase assay and RNA immunoprecipitation assay confirmed that XIAP can directly bind miR-489-3p.ConclusionsWe concluded that miR-489-3p modulates cell proliferation and apoptosis in AP by targeting XIAP. Given that high expression of miR�489-3p in AP indicated poor prognosis, it raises the possibility that miR�489-3p might be a novel and valuable therapeutic target and a prognosis indicator for AP.

ATF4-mediated histone deacetylase HDAC1 promotes the progression of acute pancreatitis

Acute pancreatitis (AP), an acute inflammatory process, can be difficult to diagnose. Activating transcription factor 4 (ATF4) has been reported to participate in the pathogenesis of AP. Additionally, histone deacetylases (HDACs) are shown to be closely related to the development of a variety of diseases, including inflammation disease. In our study, we tried to highlight the role of ATF4 in AP through regulation of HDAC1. Firstly, we validated the effect of ATF4 on pancreatic acinar cell proliferation, apoptosis, and inflammation through in vitro experiments on cellular models of caerulein-induced AP. Next, we examined the correlation between ATF4 and HDAC1, and between HDAC1 with neutral endopeptidase (NEP) and kruppel-like factor 4 (KLF4). Finally, the regulatory role of ATF4 in AP was further assessed by determination of pathological conditions, biochemical indicators and inflammation through in vivo experiments on caerulein-induced AP mouse models. After AP induction, highly expressed ATF4 was observed, and silencing ATF4 could promote pancreatic acinar cell proliferation and inhibit apoptosis. ATF4 could bind to the HDAC1 promoter and upregulate its expression in AP. Moreover, HDAC1 could increase KLF4 expression by inhibiting NEP expression. Functionally, silencing ATF4 could suppress AP through regulation of NEP-mediated KLF4 via downregulation of HDAC1. Above all, our study uncovered the promotive role of ATF4 in AP through upregulation of HDAC1.

Chronological study in microanatomy of human foetal pancreatic tissue

Introduction: The name of pancreas derives from the Greek’ word. The pancreas involves in diseases like diabetes mellitus and pancreatic cancer. It is contains Endocrine cells or Islets of Langerhans that secrete insulin, glucagon and somatostatin, which regulate blood glucose levels.1 The exocrine pancreatic acini secretes pancreatic enzymes and alpha fetoprotein which change the expression level during development and influences development and differentiation of pancreas.2 Endocrine disease causes diabetes which affects at least 200 million people worldwide, and this number is to be doubled by 2025.1 The exocrine part leads to pancreatic cancer causing about 65,000 deaths in European countries which is virtually incurable. Aims: The purpose of the current study was to investigate microanatomy (Histogenesis) of Pancreas in aborted fresh human foetuses without any congenital abnormality. So the present study was conducted to know the development of acini and islets and their clinical correlation. Materials and Methods: Foetuses aged between 12 to 40 weeks of gestational age and they were collected from Obstetrics and Gynaecology department of Kamineni Institute of Medical Sciences, Narkatpally, Nalgonda (Dt), Telangana, (India) and Kamineni Academy of Medical Sciences and Research centre, L.B. Nagar, Hyderabad. The histogenic procedures were employed at all gestational ages and were discussed with the available literature because various studies have proved that the islets of pancreas are necessary for the transplantation of pancreas, but very few studies showed the importance of pancreatic acini. Results and Conclusion: In the early weeks (12-18 weeks) the parenchyma forms primitive tubules with small lobes and lobules of acini and small spherical islets. As the age advances (18-24 weeks) the size and number of Islets are increased with encapsulation and proliferation of acinar cells. To conclude, at the age of 18-24 weeks the fetal pancreas is suitable for organ transplantation in patients with diabetes mellitus and pancreatic cancer. Keywords: Histogenesis, Gestational period, Pancreas, Serous acini, Islets of Langerhans, Microanatomy, Ducts, Alpha fetoprotein (AFP).

High-Fat Diet–Induced Functional and Pathologic Changes in Lacrimal Gland

The lacrimal gland is critical for maintaining the homeostasis of the ocular surface microenvironment through secreting aqueous tears in mammals. Many systemic diseases such as Sjögren syndrome, rheumatoid arthritis, and diabetes can alter the lacrimal gland function, eventually resulting in aqueous tear-deficient dry eye. Here, a high-fat diet (HFD) experimental mouse model was used to clarify how hyperlipidemia affects lacrimal gland function. Aqueous tear secretion fell about 50% after 1 month on a HFD. Lipid droplets accumulated in the matrix and acinar cells of the lacrimal gland after this period, along with changes in the lipid metabolism, changes in gene expression levels, and disruption of fatty acid oxidative activity. Immune cell infiltration and rises in the gene expression levels of the inflammation-related cytokines Il1β, Tnfα, Tsg6, Il10, Mmp2, and Mmp9 were found. HFD also induced mitochondrial hypermegasoma, increased apoptosis, and decreased lacrimal gland acinar cell proliferation. Replacement of the HFD with the standard diet partially reversed pathologic changes in the lacrimal gland. Similarly, supplementing the HFD with fenofibrate also partially reversed the inhibited tear secretion and reduced lipid accumulation, inflammation, and oxidative stress levels. The authors conclude that a HFD induces pathophysiological changes and functional decompensation of the lacrimal gland. Therefore, ingestion of a HFD may be a causative factor of dry eye disease.

1894-P: Interruption of Glucagon Signaling Increases Pancreas Mass

Interruption of glucagon signaling by glucagon receptor gene inactivation or treatment with a glucagon receptor blocking monoclonal antibody (GCGR-Ab) stimulates alpha cell proliferation and expansion. Surprisingly, pancreas weight is also increased in mice with GCG gene inactivation. To investigate mechanisms linking glucagon signaling and pancreas size, we treated C57BL/6J mice with GCGR-Ab or a control IgG. Eight weeks of treatment (N=4-15 mice/treatment) increased absolute pancreas weight (0.42±0.013 vs. 0.32±0.008; p<0.0001), pancreas weight normalized to body weight (1.39±0.03% vs. 1.11±0.02%; p<0.0001), and serum levels of 15 amino acids (AA), including glutamine (1.7-4.67 fold, p<0.0001). GCGR-Ab treatment promoted acinar cell proliferation (Ki67+, 0.65±0.14% vs. 0.20±0.03%; p=0.0058), increased acinar cell size (peri-islet region: 438.4±12.77 vs. 341.7±22.05μm2; p=0.0045; peripheral region: 431.1±9.34 vs. 334.2±25μm2, p=0.0055; central region: 437.0±10.45 vs. 338.7±13.6 μm2, p=0.0006), and increased pancreas protein content (248.3±9.84 vs. 194±8.67μg/mg tissue; p=0.0003). By electron microscopy, GCGR-Ab treatment increased acinar cell zymogen granule number (129±9 vs. 49±6; p<0.0001; n=28-37 cells/treatment) and led to acinar cell ER dilatation, but did not induce pancreatitis or alter acinar cell apoptosis or pancreatic macrophage number. Serum cholecystokinin and total glucagon-like peptide-1, trophic hormones linked to exocrine growth, were not changed by GCGR-Ab treatment. GCGR-Ab treatment upregulated mRNA and protein levels of the glutamine transporter, Slc38a3, and increased mTOR-related ribosomal protein S6 phosphorylation in acinar cells. Together, these data indicate that interruption of glucagon signaling increases pancreas mass by inducing acinar cell hyperplasia and hypertrophy and activates protein synthesis and mTOR signaling; whether this is mediated by elevated glutamine or AA levels is not known. Disclosure C. Dai: None. A. Bradley: None. K.C. Coate: None. G. Poffenberger: None. E. Spears: None. J.J. Wright: None. S. Shrestha: None. D. Dean: None. M. Brissova: None. A.C. Powers: None. Funding National Institutes of Health (DK117147)

Dysregulation of miR-192-5p in acute pancreatitis patients with nonalcoholic fatty liver and its functional role in acute pancreatitis progression.

Background: Nonalcoholic fatty liver disease (NAFLD) is a frequent metabolic disease and has been demonstrated to contribute to the severity of acute pancreatitis (AP). The present study aimed to investigate the aberrant expression of microRNA-192-5p (miR-192-5p) in AP patients with NAFLD, and further analyze the clinical significance and biological function of miR-192-5p in AP progression.Methods: Expression of miR-192-5p was estimated using quantitative real-time PCR (qRT-PCR). Diagnostic value of miR-192-5p was evaluated by the receiver operating characteristic curve (ROC). The effects of miR-192-5p on cell proliferation, apoptosis and inflammatory response of pancreatic acinar cells were further assessed by CCK-8 assay, flow cytometry and enzyme-linked immunosorbent assay (ELISA).Results: Circulating miR-192-5p was decreased in AP patients with NAFLD compared with those patients without NAFLD and healthy controls (P<0.05). The down-regulated expression of miR-192-5p had a relative high diagnostic accuracy to distinguish the AP patients with NAFLD from the cases without NAFLD. Furthermore, the overexpression of miR-192-5p in pancreatic acinar cells led to the decreased cell proliferation, increased cell apoptosis and suppressed inflammatory reaction (all P<0.05).Conclusion: Collectively, all data indicated that serum expression of miR-192-5p in AP patients with NAFLD is significantly decreased and serves as a candidate diagnostic biomarker. The up-regulation of miR-192-5p in pancreatic acinar cell leads to increased cell apoptosis and decreased inflammatory response, suggesting the potential of miR-192-5p as a therapeutic target of AP.

Potential role of two novel agonists of thyroid hormone receptor-β on liver regeneration.

ObjectivesAlthough the hepatomitogenic activity of triiodothyronine (T3) is well established, the wide range of harmful effects exerted by this hormone precludes its use in liver regenerative therapy. Selective agonists of the beta isoform of thyroid hormone receptor (TRβ) do not exhibit T3‐induced cardiotoxicity and show a good safety profile in patients with NASH. The aim of this study was to investigate whether two novel TRβ agonists, the prodrug TG68 and the active compound IS25 could stimulate hepatocyte proliferation without T3/TRα‐dependent side effects.MethodsRats were treated with three different doses (12.5, 25 and 50 μg/100 g body weight) for one week. Hepatocyte proliferation, liver injury and serum biochemical parameters were measured by immunohistochemistry, qRT‐PCR and Western blot.ResultsBoth drugs increased hepatocyte proliferation as assessed by bromodeoxyuridine incorporation (from 14% to 28% vs 5% of controls) and mitotic activity. Enhanced proliferation occurred in the absence of significant signs of liver injury as shown by lack of increased serum transaminase levels or of apoptosis. No cardiac or renal hypertrophy typically associated with treatment with T3 was observed. Importantly, no proliferation of pancreatic acinar cells, such as that seen after administration of T3 or the TRβ agonist GC1 was detected following either TG68 or IS25, demonstrating the hepato‐specificity of these novel TRβ agonists.ConclusionsThe present study shows that TG68 and IS25 induce massive hepatocyte proliferation without overt toxicity. Hence, these agents may have a significant clinical application for regenerative therapies in liver transplantation or other surgical settings.