Intraportal Injection Research Articles

Survival impact of [225Ac]Ac-DOTATOC alpha-therapy in a preclinical model of pancreatic neuroendocrine tumor liver micrometastases.

A mouse model of liver metastases of pancreatic NETs was developed by intraportal injection of AR42J cells and explored using [68Ga]Ga-DOTATOC and [18F]F-FDG PET/MRI. Biodistribution study and radiation dosimetry of [225Ac]Ac-DOTATOC were determined in subcutaneous tumor-bearing NMRI-nude mice. Efficacy and toxicity were determined by intravenous injection of increasing activities of [225Ac]Ac-DOTATOC 10days after intraportal graft. Liver tumors showed a high uptake of [68Ga]Ga-DOTATOC and no uptake of [18F]F-FDG confirming the well-differentiated phenotype. All groups treated with [225Ac]Ac-DOTATOC showed a significant increase in overall survival compared with DOTATOC-treated mice, especially those treated with the highest activities: 53days with 240kBq (p = 0.0001), and 58days with 2 × 120kBq (p < 0.0001) vs 28days with non-radiolabeled DOTATOC. On blood tests, a transient and moderate decreased in white blood cells count after treatment and no severe hepatic or renal toxicity were observed after treatment which was consistent with pathological and radiation dosimetry findings. [225Ac]Ac-DOTATOC exhibit a favorable efficacy and toxicity profile in a mouse model of liver micrometastatic pancreatic NET.

Abstract 5373: Decoding the role of intrinsic pancreatic cellular signaling in shaping the immunosuppressive tumor microenvironment

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) has the highest mortality rate among major cancers, with over 50% of patients having liver metastases at diagnosis. Conventional T-cell-based immunotherapies are ineffective against PDAC liver metastases due to the intricate hepatic tumor microenvironment (TME) that hinders effective immune responses. Thus, it is vital to promote the influx of cytotoxic lymphocytes and prime antitumor immunity. PDAC cells exhibit plasticity and intrinsic cellular heterogeneity, leading to varying immune cell infiltrates and immune responses. Concurrently, early metastases to the liver create an immunosuppressive environment. Our study employs multiple PDAC models, originating from a congenic array of distinct PDAC cell clone tumors with varying degrees of T cell infiltration to delineate the signaling pathways that lead to immunosuppression in the pancreas and liver. Methods: The compendium of congenic PDAC murine cell clones mirrors immune heterogeneity observed in tumors, spanning from low to high T cell infiltration. To overcome a scarcity of tumor-specific neoepitopes in PDAC, we engineered PDAC cell clones expressing chicken ovalbumin (OVA) for antigen-specific T and B cell responses. By subcutaneous and intraportal vein injection of PDAC cell clones into mice, we induce primary pancreatic and metastatic liver tumors to explore immune phenotypes and assess anti-tumor adaptive immune responses, including myeloid and lymphoid cell subsets. Results: In vivo engraftment of PDAC clones showed varied CD4+/CD8+ T cells and polymorphonuclear myeloid-derived suppressor cells, accentuated with immunogenic OVA antigen expression. While all OVA+ PDAC lines elicited antigen-specific immune responses, only ‘TIL high’ tumors were eradicated, while ‘TIL low’ clones persisted in vivo. Additionally, ‘TIL low’ clones formed liver metastases upon intraportal injection, despite OVA expression. RNAseq unveiled differential expression in IL-1 family cytokines and receptors, chemokine-like factor gene superfamily, parathyroid hormone relevant function and metabolism. Current investigations include altering these pathways to re-program the tumor microenvironment and induce local immune suppression. Conclusion: Using diverse PDAC models, we created tumors with immune heterogeneity and altered transcriptional profiles. We identified validated differentially expressed immune altering cytokines, such as CXCL1 and CSF3, and potential novel IL-1 family genes and parathyroid signaling genes. The altered TME conferred protection against tumor antigen-specific immunity in certain clones, both in subcutaneous and liver metastasis models. Ongoing studies will assess the impact of these genes in the distinct environments, offering avenues for immunotherapeutic strategies targeting pancreatic cancer liver metastasis. Citation Format: Bushangqing Liu, Ethan Agritelley, Daniel Nussbaum, Junping Wei, Gangjun Lei, Melissa Gajda, Zachary Hartman. Decoding the role of intrinsic pancreatic cellular signaling in shaping the immunosuppressive tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5373.

Abstract 1385: Crosstalk between hepatocyte and myeloid-specific IL17 signaling in colorectal cancer metastasis

Abstract Advanced colorectal cancer (CRC) is resistant to current immunotherapies and prone to metastasis. Chronic inflammation mediated by cytokines such as interleukin (IL)17 activates the oncogenic pathways in cancer cells, promoting sporadic and inflammation-associated CRC. Increased levels of IL17A in early stages of CRC portends poor prognosis indicating its potential involvement into metastasis. We and others previously showed that IL17A signaling is required for early CRC tumorigenicity in a variety of models and that in early CRC, its ability to signal to epithelial cells is essential. What remains unknown is whether IL17 signaling to other cell types within the tumor microenvironment (TME) is essential to control tumor progression and metastasis. Using a model of colitis-associated cancer (CAC) we found that “late” IL17A neutralization decreases tumor burden, possibly acting through regulation of myeloid cells and chemokine network essential for the control of immunosuppressive TME. Next, using models of colorectal cancer liver metastasis (CRLM) including intraportal cell injection and cecum transplantation of organoids with distinct set of oncogenic mutation we found that IL17 neutralization reduces metastasis. FACS analysis revealed that IL17A promotes the recruitment of tumor-associated macrophages and other key myeloid subsets into the metastatic liver environment. Interestingly, ablation of IL17RC (receptor) in myeloid cells only (using Il17rcf/f -LysMCre mice) led to reduction in metastasis and reshaping of metastatic myeloid cell compartments. Meanwhile, IL17 signaling in hepatocytes was required for early metastasis and pre-metastatic niche formation, as the ablation of IL17RC in hepatocytes (using Il17rcf/f -AlbCre mice) led to a reduction of metastatic numbers but not growth. This coincided with reduced neutrophil recruitment and enhanced activation of cytotoxic innate lymphoid cells and CD8 T lymphocytes, indicating the role of hepatocyte specific IL17 signaling in blunting anti-tumor immunity. Our findings illuminate the role of inflammatory cytokine IL17 into CRC progression and metastasis and imply its distinct cell type specific role within the metastatic liver TME. Citation Format: Katarzyna Chojnacka, Dan Kamen, Katrina M. Reyes, Hana Tomizawa, Sergei I. Grivennikov. Crosstalk between hepatocyte and myeloid-specific IL17 signaling in colorectal cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1385.

Targeted mapping and utilization of the perihepatic surface for therapeutic beta cell replacement and retrieval in diabetic non-human primates.

Successful diabetes reversal using pancreatic islet transplantation by various groups illustrates the significant achievements made in cell-based diabetes therapy. While clinically, intraportal islet delivery is almost exclusively used, it is not without obstacles, including instant blood-mediated inflammatory reaction (IBMIR), relative hypoxia, and loss of function over time, therefore hindering long-term success. Here we demonstrate the perihepatic surface of non-human primates (NHPs) as a potential islet delivery site maximizing favorable characteristics, including proximity to a dense vascular network for adequate oxygenation while avoiding IBMIR exposure, maintenance of portal insulin delivery, and relative ease of accessibility through minimally invasive surgery or percutaneous means. In addition, we demonstrate a targeted mapping technique of the perihepatic surface, allowing for the testing of multiple experimental conditions, including a semi-synthetic hydrogel as a possible three-dimensional framework to improve islet viability. Perihepatic allo-islet cell transplants were performed in immunosuppressed cynomolgus macaques using a targeted mapping technique to test multiple conditions for biocompatibility. Transplant conditions included islets or carriers (including hydrogel, autologous plasma, and media) alone or in various combinations. Necropsy was performed at day 30, and histopathology was performed to assess biocompatibility, immune response, and islet viability. Subsequently, single-injection perihepatic allo-islet transplant was performed in immunosuppressed diabetic cynomolgus macaques. Metabolic assessments were measured frequently (i.e., blood glucose, insulin, C-peptide) until final graft retrieval for histopathology. Targeted mapping biocompatibility studies demonstrated mild inflammatory changes with islet-plasma constructs; however, significant inflammatory cell infiltration and fibrosis were seen surrounding sites with the hydrogel carrier affecting islet viability. In diabetic NHPs, perihepatic islet transplant using an autologous plasma carrier demonstrated prolonged function up to 6 months with improvements in blood glucose, exogenous insulin requirements, and HbA1c. Histopathology of these islets was associated with mild peri-islet mononuclear cell infiltration without evidence of rejection. The perihepatic surface serves as a viable site for islet cell transplantation demonstrating sustained islet function through 6 months. The targeted mapping approach allows for the testing of multiple conditions simultaneously to evaluate immune response to biomaterials at this site. Compared to traditional intraportal injection, the perihepatic site is a minimally invasive approach that allows the possibility for graft recovery and avoids IBMIR.

The liver microenvironment orchestrates FGL1-mediated immune escape and progression of metastatic colorectal cancer

Colorectal cancer (CRC) patients with liver metastases usually obtain less benefit from immunotherapy, and the underlying mechanisms remain understudied. Here, we identify that fibrinogen-like protein 1 (FGL1), secreted from cancer cells and hepatocytes, facilitates the progression of CRC in an intraportal injection model by reducing the infiltration of T cells. Mechanistically, tumor-associated macrophages (TAMs) activate NF-ĸB by secreting TNFα/IL-1β in the liver microenvironment and transcriptionally upregulate OTU deubiquitinase 1 (OTUD1) expression, which enhances FGL1 stability via deubiquitination. Disrupting the TAM-OTUD1-FGL1 axis inhibits metastatic tumor progression and synergizes with immune checkpoint blockade (ICB) therapy. Clinically, high plasma FGL1 levels predict poor outcomes and reduced ICB therapy benefits. Benzethonium chloride, an FDA-approved antiseptics, curbs FGL1 secretion, thereby inhibiting liver metastatic tumor growth. Overall, this study uncovers the critical roles and posttranslational regulatory mechanism of FGL1 in promoting metastatic tumor progression, highlighting the TAM-OTUD1-FGL1 axis as a potential target for cancer immunotherapy.

Endoscopic ultrasound-guided intraportal injection of autologous bone marrow in patients with decompensated liver cirrhosis: A case series

Endoscopic ultrasound-guided intraportal injection of autologous bone marrow in patients with decompensated liver cirrhosis: A case series

Surgery accelerates metastatic recurrence of PDAC: A novel, surgical, immune-competent mouse model

Background: Pancreatic ductal adenocarcinoma (PDAc) remains a resistant malignancy with dismal outcomes. Even with systemic treatment and surgical resection, 20-30% of patients will experience a metastatic recurrence within six months of surgery. This “rapid recurrence” (rrPDAc) is devastating and poorly understood and contributes to the nihilism surrounding pancreatic cancer. Etiologies of these metastatic lesions include occult synchronous metastases, as well as disseminated metachronous lesions, both of which we hypothesize may be affected by systemic and microenvironmental changes that occur due to surgical intervention. Unfortunately, identifying micrometastatic disease in humans before and after surgery is prohibitive, therefore we developed a preclinical system of PDAc metastasis accelerated by surgery. Metastatic models in PDAc are fraught with heavy utilization of intrasplenic or intraportal injections for seeding. They also frequently rely on immune-deficient murine hosts as well as tumor cell lines derived from metastatic lesions. Here, we describe accelerated induction of metastasis by surgery in an immune competent host.

Abstract 5633: Beta-Glucan treatment restricts liver metastasis in pancreatic cancer

Abstract Introduction: For most patients with pancreatic ductal adenocarcinoma (PDAC), metastatic disease is the main cause of mortality with the liver being the most common site of metastasis. In the liver, macrophages are the most abundant immune cell subset, yet their role in regulating liver metastasis remains poorly understood. Two distinct macrophage populations exist in the liver: liver-resident Clec4f+F4/80+ Kupffer cells (KCs) and Clec4fnegF4/80+ bone marrow derived macrophages (BMDMs). Here, we sought to understand the impact of these macrophage subsets on liver metastasis and the ability of a myeloid agonist, a β-glucan (BG), to skew macrophages towards an anti-metastatic phenotype. Methods: C57BL/6 mice were given an intraportal (iPo) injection of an LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre;LSL-Rosa26-Yfp (KPCY) cell line to model liver metastasis. Mice were necropsied 2 days later to measure metastatic seeding of cancer cells or 12-14 days later to assess metastatic lesion outgrowth. Liver metastatic burden and immune cell populations were analyzed by flow cytometry and immunohistochemistry. In macrophage depletion experiments, liver macrophages were depleted using clodronate encapsulated liposomes (CEL) delivered intraperitoneally. In studies involving BG treatment, weekly intravenous administration of BG began 2 days prior to iPo injection of cancer cells. Results: Liver macrophage depletion did not influence metastatic seeding in the liver; but, did inhibit the outgrowth of established metastatic colonies. Histological analysis showed that Clec4f+ KCs were excluded from metastatic lesions, whereas BMDMs actively infiltrated. BMDM infiltration into lesions was also largely unaffected by CEL treatment. To stimulate macrophages with anti-metastatic activity, BG was administered systemically and found to bind to &amp;gt;95% of KCs but only 30% of BMDMs and 20-35% of other immune cell populations. BG treatment attenuated liver metastasis when given during both the seeding and outgrowth phases of metastasis (mean metastatic burden as % live cells in liver: 1%, BG vs 6.5%, control, p&amp;lt;0.0001). Analysis of metastatic lesions in BG treated mice by histology showed smaller lesions (mean size: 0.9mm2, BG vs 1.5mm2, control, p=0.09), decreased proliferating cancer cells (mean # of proliferating cancer cells per unit metastatic area: 480, BG vs 810, control, p&amp;lt;0.0001), and increased numbers of CD3+ T cells at the periphery of lesions compared to lesions from control mice (mean # of T cells per mm2 metastatic area: 300, BG vs 135, control, p&amp;lt;0.0001). The efficacy of BG to restrict liver metastasis was dependent on liver macrophages. Conclusions: Taken together, these findings suggest that, while liver macrophages can be coopted to support metastatic outgrowth, treatment with a β-glucan, as a myeloid agonist is a novel strategy to engender liver macrophages with anti-metastatic activity. Citation Format: Stacy K. Thomas, Shaanti Choi-Bose, Heather Coho, Christopher Casella, Meredith L. Stone, Max M. Wattenberg, Gregory L. Beatty. Beta-Glucan treatment restricts liver metastasis in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5633.

Liver macrophage subsets differentially regulate metastasis in pancreatic cancer

Abstract Metastasis is the main cause of morbidity and mortality in patients with cancer. In pancreatic ductal adenocarcinoma (PDA), the liver is the most common site of metastasis. During PDA progression, the liver microenvironment becomes altered to support metastatic seeding and colonization by disseminated tumor cells (DTC). Macrophages (MΦ), including liver-resident Clec4f+ Kupffer cells (KCs) and bone marrow derived MΦ (BMDMs), are the dominant immunological components of this niche, yet their precise roles in regulating metastasis remain poorly defined. Here, we sought to understand the interaction of DTCs with liver MΦ as they seed and colonize the liver. To model liver metastasis, mice received intraportal (iPo) injection of murine PDA cells with analysis 2 or 14 days later to examine metastatic seeding and outgrowth, respectively. Liver metastatic burden and immune cell populations were quantified by flow cytometry and immunohistochemistry. Liver MΦ were depleted using clodronate encapsulated liposomes (CEL) and KCs were depleted using Clec4fDTR mice administered diphtheria toxin. DTCs were found to interact with BMDMs more often than KCs during the seeding phase of metastasis. During colonization, KCs became excluded from metastatic colonies whereas BMDMs actively infiltrated. Although depletion of liver MΦ and KCs specifically did not affect metastatic seeding, MΦ depletion during the colonization phase inhibited metastatic colony outgrowth. Interestingly, BMDM infiltration into lesions was largely unaffected by CEL treatment, whereas KCs were uniformly depleted. This finding suggests that MΦ residing outside of metastatic lesions may be critical to supporting metastatic outgrowth. Supported by grants from NIH (T32 HL0439, F30 CA257287, R01 CA245323)

Delivery of non-viral naked DNA vectors to liver in small weaned pigs by hydrodynamic retrograde intrabiliary injection

Hepatic gene therapy by delivering non-integrating therapeutic vectors in newborns remains challenging due to the risk of dilution and loss of efficacy in the growing liver. Previously we reported on hepatocyte transfection in piglets by intraportal injection of naked DNA vectors. Here, we established delivery of naked DNA vectors to target periportal hepatocytes in weaned pigs by hydrodynamic retrograde intrabiliary injection (HRII). The surgical procedure involved laparotomy and transient isolation of the liver. For vector delivery, a catheter was placed within the common bile duct by enterotomy. Under optimal conditions, no histological abnormalities were observed in liver tissue upon pressurized injections. The transfection of hepatocytes in all tested liver samples was observed with vectors expressing luciferase from a liver-specific promoter. However, vector copy number and luciferase expression were low compared to hydrodynamic intraportal injection. A 10-fold higher number of vector genomes and luciferase expression was observed in pigs using a non-integrating naked DNA vector with the potential for replication. In summary, the HRII application was less efficient (i.e., lower luciferase activity and vector copy numbers) than the intraportal delivery method but was significantly less distressful for the piglets and has the potential for injection (or re-injection) of vector DNA by endoscopic retrograde cholangiopancreatography.

A case report on intraportal injection of autologous bone marrow-derived mononuclear cells and liver transplantation in a patient with cirrhosis

To date, liver transplantation remains the only effective treatment for patients with cirrhosis. Due to lack of other effective, alternative therapeutic methods, the search and development of new treatment technologies is problem number one. The development of cellular technologies is promising for use in clinical practice. Using this observation as an example, the safety and efficacy of cell therapy technology for prolonged stay on the liver transplant waiting list by a patient with cirrhosis is shown. After intraportal injection of autologous bone marrow-derived mononuclear cells, liver cirrhosis stabilized on the CTP and MELD-Na scales for 22 months of observation, which allowed the patient to wait for an organ and successfully undergo liver transplantation.

Preferable Transplant Site for Hepatocyte Transplantation in a Rat Model

Intraportal injection is regarded as the current standard procedure of hepatocyte transplantation (HTx). In islet transplantation, which shares many aspects with HTx, recent studies have clarified that instant blood-mediated inflammatory reaction (IBMIR), characterized by strong innate immune responses, can cause poor engraftment, so other transplant sites to avoid such a reaction have been established. Although IBMIR was reported to occur in HTx, few reports have evaluated alternative transplant sites for HTx. In this study, we sought to determine the optimum transplant site for HTx. Rat hepatocytes (1.0 × 107) were transplanted at the 9 transplant sites (intraportal (IPO), intrasplenic (IS), liver parenchyma, subcutaneous, intraperitoneal, renal subcapsular, muscle, inguinal subcutaneous white adipose tissue, and omentum) of analbuminemic rats. The serum albumin levels, immunohistochemical staining (albumin, TUNEL, and BrdU), and in vivo imaging of the grafts were evaluated. The serum albumin levels of the IPO group were significantly higher than those of the other groups (p < .0001). The BrdU-positive hepatocyte ratio of liver in the IS group (0.9% ± 0.2%) was comparable to that of the IPO group (0.9% ± 0.3%) and tended to be higher than that of the spleen in the IS group (0.5% ± 0.1%, p = .16). Considering the in vivo imaging evaluation and the influence of splenectomy, the graft function in the IS group may be almost entirely achieved by hepatocytes that have migrated to the liver. The present study clearly showed that the intraportal injection procedure is more efficient than other procedures for performing HTx

Formation of amyloid in encapsulated human pancreatic and human stem cell-generated beta cell implants.

Detection of amyloid in intraportal islet implants of type 1 diabetes patients has been proposed as cause in their functional decline. The present study uses cultured adult human islets devoid of amyloid to examine conditions of its formation. After intraportal injection in patients, amyloid deposits <15µm diameter were identified in 5%-12% of beta cell containing aggregates, 3-76months posttransplant. Such deposits also formed in glucose-controlling islet implants in the kidney of diabetic mice but not in failing implants. Alginate-encapsulated islets formed amyloid during culture when functional, and in all intraperitoneal implants that corrected diabetes in mice, exhibiting larger sizes than in functioning nonencapsulated implants. After intraperitoneal injection in a patient, retrieved single capsules presented amyloid near living beta cells, whereas no amyloid occurred in clustered capsules with dead cells. Amyloid was also demonstrated in functional human stem cell-generated beta cell implants in subcutaneous devices of mice. Deposits up to 35µm diameter were localized in beta cell-enriched regions and related to an elevated IAPP over insulin ratio in the newly generated beta cells. Amyloid in device-encapsulated human stem cell-generated beta cell implants marks the formation of a functional beta cell mass but also an imbalance between its activated state and its microenvironment.

NPY stimulates cholesterol synthesis acutely by activating the SREBP2-HMGCR pathway through the Y1 and Y5 receptors in murine hepatocytes

AimsThe development of non-alcoholic fatty liver disease (NAFLD) is partially attributed to disturbance in cholesterol metabolism and sympathetic overactivity. Excessive levels of the sympathetic neurotransmitter neuropeptide Y (NPY) positively correlated with both NAFLD and cholesterol accumulation. We wanted to determine, for the first time, whether NPY promotes cholesterol accumulation directly in hepatocytes and elucidate the underlying mechanism. Main methodsIn vivo, NPY was injected through the hepatic portal vein into SD rats. One hour later, serum and liver tissues were collected. In vitro, BRL-3A hepatocytes were treated with NPY, and with Y1, Y2, Y5, receptor antagonists as well as with extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) antagonist, respectively. Cholesterol content was measured by coupled enzyme method. Precursor sterol-regulatory element binding protein 2 (pSREBP2), mature SREBP2 (mSREBP2), HMG-CoA reductase (HMGCR), ERK1/2, pERK1/2, cAMP-dependent protein kinase (PKA), and pPKA protein expression levels were examined by western blotting. Key findingsIn rats, intraportal vein injection of NPY activates pSREBP2, mSREBP2, and HMGCR protein expression, and induces hepatic cholesterol accumulation. In BRL-3A cells, we observed that NPY increases cholesterogenic protein expression and cholesterol synthesis through Y1 and Y5 receptors. This effect is mediated by the activation of the ERK1/2 signaling pathway. SignificanceWe demonstrated, for the first time, that NPY can activate the cholesterogenic pathway and elucidated the underlying mechanism. Thus, NPY and NPY receptors might be new targets for the treatment of NAFLD and dyslipidemia.

The Assessment of the Efficiency of Cell Therapy of Experimental Liver Cirrhosis by Means of Ultrasound Examination

Objective: to determine the relevance of ultrasound examination in diagnostics and assessment of the efficiency of cell therapy of experimental liver cirrhosis in rabbits.Material and methods. The experiment was performed on white Californian rabbits (n = 45). Liver cirrhosis was modelled by means of subcutaneous injections of 50 % solution of carbon tetrachloride according to the scheme. Cell therapy was performed by means of a single intraportal injection of autologous mesenchymal stem cells (MSCs) at an amount of 5 × 106 cells per kg. During the experiment all the animals were performed the ultrasound examination of the abdominal cavity, as well as the morphological analysis of liver tissue samples.Results. After 5 months of the liver cirrhosis modeling, the anteroposterior liver size and diameter of the portal vein in group 2 and group 3 were statistically larger than in group 1 (р &lt; 0.001, Mann-Whitney test). There was no statistical difference in the anteroposterior liver size (р = 0.38) and diameter of the portal vein (р = 0.36) between group 2 and group 3. 1 month after the injection of autologous MSCs, the rabbits of group 3 detected some improvement of the echimage of the damaged liver, which was also reflected in a statistically significant decrease of the liver size by 8.2 % (р &lt; 0.01, Wilcoxon test) and diameter of the portal vein by 23 % (р &lt; 0.001) in comparison with the indicators before the injection of MSCs.Conclusion. The ultrasound examination in the present study has proved itself to be a reliable method of intravital diagnostics of pathological changes in the conditions of a chronic experiment, and also has revealed a positive impact of cell therapy on liver cirrhosis in the rabbits. The obtained data were confirmed by the morphological methods of the analysis of the liver tissue samples of the animals during the experiment.

Butyrate, a metabolite of intestinal bacteria, enhances sleep

Emerging evidence suggests that the intestinal microbiota is a source of sleep-promoting signals. Bacterial metabolites and components of the bacterial cell wall are likely to provide important links between the intestinal commensal flora and sleep-generating mechanisms in the brain. Butyrate is a short-chain fatty acid produced by the intestinal bacteria by the fermentation of nondigestible polysaccharides. We tested the hypothesis that butyrate may serve as a bacterial-derived sleep-promoting signal. Oral gavage administration of tributyrin, a butyrate pro-drug, elicited an almost 50% increase in non-rapid-eye movement sleep (NREMS) in mice for 4 hours after the treatment. Similarly, intraportal injection of butyrate led to prompt and robust increases in NREMS in rats. In the first 6 hours after the butyrate injection, NREMS increased by 70%. Both the oral and intraportal administration of butyrate led to a significant drop in body temperature. Systemic subcutaneous or intraperitoneal injection of butyrate did not have any significant effect on sleep or body temperature. The results suggest that the sleep-inducing effects of butyrate are mediated by a sensory mechanism located in the liver and/or in the portal vein wall. Hepatoportal butyrate-sensitive mechanisms may play a role in sleep modulation by the intestinal microbiota.

Unsurpassed Intrahepatic Islet Engraftment - the Quest for New Sites for Beta Cell Replacement.

The liver is currently the site of choice for clinical islet transplantation, even though many alternative implantation sites have lately been proposed as more ideal for graft survival. The suggested sites, for example intramuscular space, omentum, bone marrow, and spleen, are sometimes difficult to compare due to differences in animal model, islet isolation procedure, and islet quality. In addition, the variation in transplanted islet mass is vast. The aim of this commentary is to review alternative implantation sites tested experimentally as well as in clinical islet transplantation. Although many sites have been investigated, none have convincingly proved better suited for clinical islet transplantation than intraportal injection to the liver, regardless of whether it is autologous or allogeneic transplantation. However, in order to fully evaluate upcoming bioengineering techniques, such as scaffolds containing insulin-producing cells derived from stem cells, the need of an alternative site has arisen to enable cellular monitoring, which currently cannot be achieved within the liver.

Intravascular and intraparenchymatous hepatic segmentary sclerosis.

To evaluate the morphological effects of injected sclerosing agents into the liver. This study was performed on twenty dogs, distributed into five groups: Group 1 (n = 5) - control, Group 2 (n = 5) - injection of 50% glucose solution inside hepatic parenchyma and animals followed during seven days, Group 3 (n = 10) - injection of ethanol inside hepatic parenchyma and animals distribution into two subgroups Subgroup 3A (n = 5) - followed during 24 hours and subgroup 3B (n = 5) - followed during seven days (group 3B), Group 4 (n = 5) - ethanol injection inside left portal vein branch and followed during 24 hours. Livers were macroscopically evaluated, submitted to hepatic arteriography and portography, then histology. All animals in Group 4 died within 23 hours due to diffuse hepatic necrosis. The animals of groups 2 and 3 had a satisfactory evolution. Fibrosis formed in the segment reached by the sclerosant solution and interruption of the contrast flow injected into the portal system. Intrahepatic parenchymal ethanol injection is well tolerated and causes sclerosis restricted to a specific segment; however, intraportal ethanol injection causes massive hepatic necrosis and can lead to death.

A Comparison of the Transplant Efficiency between Intraportal and Intrasplenic Procedures in Hepatocyte Transplantation

Background In hepatocyte transplantation, intraportal injection is regarded as the current standard procedure worldwide. However, there have been some reports that an intrasplenic approach is more efficient in terms of the engraftment and function of hepatocytes. Of particular interest, in pancreatic islet transplantation, which shares many aspects with hepatocyte transplantation, an intrasplenic method was recently proven to be superior to the intraportal method regarding islet engraftment. Therefore, in the present study, we compared the transplant efficiency between intraportal and intrasplenic approaches in hepatocyte transplantation. Methods Rat hepatocytes were isolated using a modified two-step collagenase perfusion technique and then purified by Percoll density gradient centrifugation. Hepatocytes (1.0 × 107) with a viability exceeding 90% were directly injected into the portal vein (n=8) or spleen pulp (n=8) of analbuminemic rats using a gastight syringe for 60 seconds. Blood samples were taken pre-transplantation and at weeks 2, 4, 6, 8, 10, 12, and 16 after transplantation. The serum albumin levels were quantified using a rat albumin enzyme-linked immunosorbent assay kit. Results The serum albumin levels of the intrasplenic group (pre-transplantation: 7.55±0.65 μg/ml, Week 2: 55.00±21.02 μg/ml, Week 4: 79.88±32.62 μg/ml, Week 6: 105.96±54.46 μg/ml, Week 8: 114.73±58.34 μg/ml, Week 10: 116.11±56.33 μg/ml, Week 12: 122.76±60.85 μg/ml, and Week 16: 133.96±66.03 μg/ml, respectively) were significantly lower than those of the intraportal group (pre-transplantation: 8.26±0.79 μg/ml, Week 2: 100.43±38.48 μg/ml, Week 4: 159.24±58.04 μg/ml, Week 6: 181.31±68.61 μg/ml, Week 8: 185.66±71.44 μg/ml, Week 10: 188.96±74.46 μg/ml, Week 12: 190.73±73.91 μg/ml and Week 16: 191.70±78.06 μg/ml, respectively, P<0.0001). Conclusions The present study clearly showed that the intraportal injection procedure is more efficient than the intrasplenic procedure for performing hepatocyte transplantation.

Sensitivity of pretargeted immunoPET using 68Ga-peptide to detect colonic carcinoma liver metastases in a murine xenograft model: Comparison with 18FDG PET-CT.

PurposeThe aim of this study was to compare the performances pretargeted immunoPET 68Ga-PETimaging (68Ga-pPET) with anti carcino-embryonic antigen (CEA) and anti-histamine-succinyl-glycine (HSG) recombinant humanized bispecific monoclonal antibody (TF2) and 68Ga-labeled HSG peptide (IMP288) to conventional 18FDG-PET in an orthotopic murine model of liver metastases of human colonic cancer.MethodsHepatic tumor burden following intra-portal injection of luciferase-transfected LS174T cells in nude mice was confirmed using bioluminescence. One group of animals was injected intravenously with TF2 and with 68Ga-IMP288 24 hours later (n=8). Another group received 18FDG (n=8), and a third had both imaging modalities (n=7). PET acquisitions started 1 hour after injection of the radioconjugate. Biodistributions in tumors and normal tissues were assessed one hour after imaging.ResultsTumor/organ ratios were significantly higher with 68Ga-pPET compared to 18FDG-PET (P<0.05) with both imaging and biodistribution data. 68Ga-pPET sensitivity for tumor detection was 67% vs. 31% with 18FDG PET (P=0.049). For tumors less than 200 mg, the sensitivity was 44% with 68Ga-pPET vs. 0% for 18FDG PET (P=0.031). A strong correlation was demonstrated between tumor uptakes measured on PET images and biodistribution analyses (r2=0.85).Conclusion68Ga-pPET was more sensitive than 18FDG-PET for the detection of human colonic liver metastases in an orthotopic murine xenograft model. Improved tumor/organ ratios support the use of pretargeting method for imaging and therapy of CEA-expressing tumors.