Introduction Liver fibrosis is a common response to liver injury and, in severe cases, leads to cirrhosis. The hepatic stellate cells (HSC) become activated after liver injury and play a significant role in fibrogenesis. The activated HSC is characterized by increased proliferation, overexpression of α-smooth muscle actin (α-SMA), and excessive production of extracellular matrix (ECM) proteins. Oridonin, a naturally occurring diterpenoid, has been shown to induce apoptosis in liver and gastric cancer cells. However, its effects on HSC are unknown. Methods We tested the effects of oridonin on the activated human and rat hepatic stellate cell lines LX-2 and HSC-T6 as well as the human hepatocyte cell line C3A. Transforming growth factor β1 (TGF-β1) was used to stimulate LX-2 cells. Results Oridonin significantly inhibited LX-2 and HSC-T6 proliferation. In contrast, Oridonin had no anti-proliferative effect on C3A cells at our tested range. Oridonin induced apoptosis and S phase arrest in LX-2 cells. These findings were associated with an increase in p53, p21, p16, and cleaved PARP, and with a decrease in Cdk4. Oridonin markedly decreased expression of α-SMA and ECM protein type I collagen and fibronectin, blocked TGF-β1-induced Smad2/3 phosphorylation and type I Collagen expression. Conclusions Oridonin induces apoptosis and cell cycle arrest involving the p53/p21 pathway in HSC, and appears to be non-toxic to hepatocytes. In addition, oridonin suppressed endogenous and TGF-β-induced ECM proteins. Thus, oridonin may act as a novel agent to prevent hepatic fibrosis.

Experimental evidence suggests that the protein phosphatase calcineurin mediates the action of amyloid-β (Aβ) oligomers, the most toxic amyloid species thought to drive initial cognitive decline in Alzheimer’s disease (AD). However, there is currently no evidence that inhibition of calcineurin could prevent the onset of AD in humans. Here, we report for the first time that individuals chronically treated with calcineurin inhibitors to prevent solid organ transplant rejection have a significantly lower incidence of AD/dementia as compared to the general population. This result prompts further clinical development of calcineurin inhibition as a viable treatment for AD.

Pancreatitis is a necroinflammatory disease with acute and chronic manifestations. Accumulated damage incurred during repeated bouts of acute pancreatitis (AP) can lead to chronic pancreatitis (CP). Pancreatic parathyroid hormone-related protein (PTHrP) levels are elevated in a mouse model of cerulein-induced AP. Here, we show elevated PTHrP levels in mouse models of pancreatitis induced by chronic cerulein administration and pancreatic duct ligation. Because acinar cells play a major role in the pathophysiology of pancreatitis, mice with acinar cell-specific targeted disruption of the Pthrp gene (PTHrP(Δacinar)) were generated to assess the role of acinar cell-secreted PTHrP in pancreatitis. These mice were generated using Cre-LoxP technology and the acinar cell-specific elastase promoter. PTHrP(Δacinar) exerted protective effects in cerulein and pancreatic duct ligation models, evident as decreased edema, histological damage, amylase secretion, pancreatic stellate cell (PSC) activation, and extracellular matrix deposition. Treating acinar cells in vitro with cerulein increased IL-6 expression and NF-κB activity; these effects were attenuated in PTHrP(Δacinar) cells, as were the cerulein- and carbachol-induced elevations in amylase secretion. The cerulein-induced upregulation of procollagen I expression was lost in PSCs from PTHrP(Δacinar) mice. PTHrP immunostaining was elevated in human CP sections. The cerulein-induced upregulation of IL-6 and ICAM-1 (human acinar cells) and procollagen I (human PSCs) was suppressed by pretreatment with the PTH1R antagonist, PTHrP (7-34). These findings establish PTHrP as a novel mediator of inflammation and fibrosis associated with CP. Acinar cell-secreted PTHrP modulates acinar cell function via its effects on proinflammatory cytokine release and functions via a paracrine pathway to activate PSCs.

A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis. The session was held on July 23, 2014 and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, GI complications in this population, and unique features of children with chronic pancreatitis considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of chronic pancreatitis and total pancreatectomy outcomes and postsurgical diabetes outcomes was repeatedly emphasized.

The current study aims to identify the pro-fibrogenic role of Gremlin, an endogenous antagonist of bone morphogenetic proteins (BMPs) in chronic pancreatitis (CP). CP is a highly debilitating disease characterized by progressive pancreatic inflammation and fibrosis that ultimately leads to exocrine and endocrine dysfunction. While transforming growth factor (TGF)-β is a known key pro-fibrogenic factor in CP, the TGF-β superfamily members BMPs exert an anti-fibrogenic function in CP reported by our group recently. To investigate how BMP signaling is regulated in CP by BMP antagonists, the mouse CP model induced by cerulein was used. During CP induction, TGF-β1 mRNA increased 156-fold in two weeks, a BMP antagonist Gremlin 1 (Grem1) mRNA levels increased 145-fold at three weeks, and increases in Grem1 protein levels correlated with increases in collagen deposition. Increased Grem1 was also observed in human CP pancreata compared to normal. Grem1 knockout in Grem1+/− mice revealed a 33.2% reduction in pancreatic fibrosis in CP compared to wild-type littermates. In vitro in isolated pancreatic stellate cells, TGF-β induced Grem1 expression. Addition of the recombinant mouse Grem1 protein blocked BMP2-induced Smad1/5 phosphorylation and abolished BMP2's suppression effects on TGF-β-induced collagen expression. Evidences presented herein demonstrate that Grem1, induced by TGF-β, is pro-fibrogenic by antagonizing BMP activity in CP.

Improved techniques for pancreatic islet extraction can yield a reasonable number of transplantable cells. However, the isolation and purification process may damage the islets and impair their physiological functions. The aim of this study was to determine the effect of the isolation procedure on the structure of isolated islets and to correlate this with their functionality. Islets were isolated from rat pancreata and purified by Eurocollins-Ficoll discontinuous density gradient processing, and then processed for light microscopy, and scanning and transmission electron microscopy. Morphometric analysis was also performed. Islet functionality was determined by reversal of streptozotocin-induced diabetes and the intraperitoneal glucose tolerance test in a syngeneic rat model of pancreatic islet transplantation. Fragments of variable size and shape comprised a relatively large proportion (26%) of the isolated endocrine tissue. Isolated islets showed slight alterations of cell ultrastructure. Major damage (including breakage of the plasma membrane) and loss of cells were observed in the peripheral cells of the isolated islets. An equal mass of islet equivalent (IEq, islets with an average diameter of 150 µ m), but with a different islet equivalent /islet number ratio, was transplanted in diabetic animals. When larger and more complete islets were transplanted (higher ratio), better function of the graft was observed by reversal of hyperglycaemia and response to the glucose tolerance test as compared with the functionality and response of smaller (fragmented) islets transplanted (lower ratio). Digestion, trauma and hypoxia during isolation are responsible for qualitative and quantitative changes of isolated islets. Alterations in normal secretory function after the transplant were related to lower islet equivalent /islet number ratio. The incomplete integrity of the islets may explain the failure of the fine glycaemic metabolic regulation.

The revascularization and the structural changes resulting from interactions between the graft and the host were investigated in transplanted pancreatic islets under the kidney capsule. Islets were isolated from mice pancreata and transplanted in syngeneic diabetic animals. Graft-bearing kidneys were collected on different days posttransplant and processed for light microscopy, immunohistochemistry and transmission electron microscopy. A numerical analysis was performed in order to compare the percentage number of the different types of cells in native islets and at different time points after the transplant. Recipient animals reversed diabetes within 4 days.An intraperitoneal glucose tolerance test was performed to determine islet functionality under stressful conditions.During the initial few days post-transplant, the islets showed peculiar shapes and the graft tended to aggregate along the vessels. Starting at days 4 -7 post-transplant, islets were revascularized from vessels connected to both the cortical and the capsular vascular network of the kidney. From day 7-14 post-transplant, the vessels progressively appeared more similar in features and size to those of in situ pancreatic islets. Both the percentage number of the different cell types and the distribution of Alpha, Beta and Delta cells inside the graft were significantly different as compared with intact islets, demonstrating quantitative and structural changes after the engraftment. No concomitant proliferation of Beta cells was detected using a bromodeoxyuridin staining method. Despite the fact that quick revascularization preserved a large mass of tissue, the remodelling process of the graft and the newly formed vascularization led to a different organization of the endocrine tissue as compared with intact in situ islets. This constitutes the morphological basis for alterations of the normal intercellular interactions and may explain the altered secretory cell function often observed in transplant.

We have successfully used RNA interference to silence an endogenous tissue-specific gene (Ins2) in pancreatic islets when transfected in vitro or administered in vivo.