Am J Physiol Gastrointest Liver Physiol.
Soini T, Pihlajoki M, Andersson N, Lohi J, Huppert KA, Rudnick DA, Huppert SS, Wilson DB, Pakarinen MP, Heikinheimo M.
PMID: 29388792 | DOI: 10.1152/ajpgi.00362.2017
Biliary atresia (BA), a neonatal liver disease, is characterized by obstruction of extrahepatic bile ducts with subsequent cholestasis, inflammation, and progressive liver fibrosis. To gain insights into the pathophysiology of BA, we focused attention on GATA6, a transcription factor implicated in biliary development. Early in fetal development GATA6 expression is evident in cholangiocytes and hepatocytes, but by late gestation it is extinguished in hepatocytes. Utilizing a unique set of BA liver samples collected before and after successful portoenterostomy (PE), we found that GATA6 expression is markedly upregulated in hepatocytes of patients with BA compared to healthy and cholestatic disease controls. This upregulation is recapitulated in two murine models simulating bile duct obstruction and intrahepatic bile ductule expansion. GATA6 expression in BA livers correlates with two established negative prognostic indicators (age at PE, degree of intrahepatic bile ductule expansion) and decreases after normalization of serum bilirubin by PE. GATA6 expression in BA livers correlates with expression of known regulators of cholangiocyte differentiation ( JAGGED1, HNF1β, and HNF6). These same genes are upregulated after enforced expression of GATA6 in human hepatocyte cell models. In conclusion, GATA6 is a novel marker and a putative driver of hepatocyte-cholangiocyte metaplasia in BA and its expression in hepatocytes is downregulated after successful PE.
Amemiya K, Dankmeyer JL, Bearss JJ, Zeng X, Stonier SW, Soffler C, Cote CK, Welkos SL, Fetterer DP, Chance TB, Trevino SR, Worsham PL, Waag DM
PMID: 32013893 | DOI: 10.1186/s12865-020-0333-9
BACKGROUND:
Melioidosis is endemic in Southeast Asia and Northern Australia and is caused by the Gram-negative, facultative intracellular pathogen Burkholderia pseudomallei. Diagnosis of melioidosis is often difficult because of the protean clinical presentation of the disease, and it may mimic other diseases, such as tuberculosis. There are many different strains of B. pseudomallei that have been isolated from patients with melioidosis, but it was not clear if they could cause a similar disease in a chronic BALB/c murine model of melioidosis. Hence, we wanted to examine chronically infected mice exposed to different strains of B. pseudomallei to determine if there were differences in the host immune response to the pathogen.
RESULTS:
We identified common host immune responses exhibited in chronically infected BALB/c mice, although there was some heterogeneity in the host response in chronically infected mice after exposure to different strains of B. pseudomallei. They all displayed pyogranulomatous lesions in their spleens with a large influx of monocytes/macrophages, NK cells, and neutrophils identified by flow cytometry. Sera from chronically infected mice by ELISA exhibited elevated IgG titers to the pathogen, and we detected by Luminex micro-bead array technology a significant increase in the expression of inflammatory cytokines/chemokines, such as IFN-?, IL-1?, IL-1?, KC, and MIG. By immunohistochemical and in situ RNA hybridization analysis we found that the increased expression of proinflammatory cytokines (IL-1?, IL-1?, TNF-?, IFN-?) was confined primarily to the area with the pathogen within pyogranulomatous lesions. We also found that cultured splenocytes from chronically infected mice could express IFN-?, TNF-?, and MIP-1? ex vivo without the need for additional exogenous stimulation. In addition by flow cytometry, we detected significant amounts of intracellular expression of TNF-? and IFN-? without a protein transport blocker in monocytes/macrophages, NK cells, and neutrophils but not in CD4+ or CD8+ T cells in splenocytes from chronically infected mice.
CONCLUSION:
Taken together the common features we have identified in chronically infected mice when 10 different human clinical strains of B. pseudomallei were examined could serve as biomarkers when evaluating potential therapeutic agents in mice for the treatment of chronic melioidosis in humans
Journal of immunology (Baltimore, Md. : 1950)
Lai, CW;Bagadia, P;Barisas, DAG;Jarjour, NN;Wong, R;Ohara, T;Muegge, BD;Lu, Q;Xiong, S;Edelson, BT;Murphy, KM;Stappenbeck, TS;
PMID: 35868637 | DOI: 10.4049/jimmunol.2200278
The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln-/- and Muc16-/- mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell-produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.
BDNF produced by cerebral microglia promotes cortical plasticity and pain hypersensitivity after peripheral nerve injury
Huang, L;Jin, J;Chen, K;You, S;Zhang, H;Sideris, A;Norcini, M;Recio-Pinto, E;Wang, J;Gan, WB;Yang, G;
PMID: 34292944 | DOI: 10.1371/journal.pbio.3001337
Peripheral nerve injury-induced mechanical allodynia is often accompanied by abnormalities in the higher cortical regions, yet the mechanisms underlying such maladaptive cortical plasticity remain unclear. Here, we show that in male mice, structural and functional changes in the primary somatosensory cortex (S1) caused by peripheral nerve injury require neuron-microglial signaling within the local circuit. Following peripheral nerve injury, microglia in the S1 maintain ramified morphology and normal density but up-regulate the mRNA expression of brain-derived neurotrophic factor (BDNF). Using in vivo two-photon imaging and Cx3cr1CreER;Bdnfflox mice, we show that conditional knockout of BDNF from microglia prevents nerve injury-induced synaptic remodeling and pyramidal neuron hyperactivity in the S1, as well as pain hypersensitivity in mice. Importantly, S1-targeted removal of microglial BDNF largely recapitulates the beneficial effects of systemic BDNF depletion on cortical plasticity and allodynia. Together, these findings reveal a pivotal role of cerebral microglial BDNF in somatosensory cortical plasticity and pain hypersensitivity.
Kokumai, T;Omori, Y;Ishida, M;Ohtsuka, H;Mizuma, M;Nakagawa, K;Chiho, M;Ono, Y;Mizukami, Y;Miura, S;Kume, K;Masamune, A;Morikawa, T;Unno, M;Furukawa, T;
| DOI: 10.1016/j.modpat.2023.100102
Relevant protein expression of GATA6, CK5, vimentin, and mucins using immunohistochemistry was assessed for predicting the prognosis and chemotherapy efficacy in pancreatic cancer (PC). The protein expression was examined in 159 PCs resected after neoadjuvant chemotherapy (NAC-PCs) with 120 matched biopsy specimens taken before NAC. KRAS mutations were assessed by digital PCR. NAC-PCs were classified by GATA6 expression initially and CK5 expression subsequently into four types, i.e., classical type (n = 22) showing GATA6-high (≧ 50%)/CK5-low (< 10%), hybrid type (n = 45) showing GATA6-high/CK5-high (≧ 10%), basal-like type (n = 53) showing GATA6-low (< 50%)/CK5-high (≧ 30%), and null type (n = 39) showing GATA6-low/CK5-low (< 30%), which resulted in a well-stratification of the patients’ prognosis. The classical type showed the most favorable prognosis, while the null type showed the worst prognosis (multivariate hazard ratio 3.56, 95% confidence interval (CI) 1.63−7.77, p = 0.0015). The hybrid and basal-like types were in between. The risk for hepatic recurrence was lower in the classical type than null (multivariate odds ratio (mOR) 0.18, CI 0.04−0.96, p = 0.0449) and basal-like (mOR 0.24, CI 0.05−1.16, p = 0.0750) types. In contrast, the risk for loco-regional recurrence was higher in classical type than the basal-like type (mOR 5.03, CI 1.20−21.1, p = 0.0272). The hybrid type was subclassified into transition and co-expression patterns with different gastric mucin expression. Vimentin-high (≧ 10%, n = 30) in pre-NAC-PC tissues was associated with poor prognosis (p = 0.0256). Phenotypic transitions between pre- and post-NAC were common (73/120; 61%). PCs with NAC regression grades 2 and 3 showed a transition to poorer prognostic phenotypes (p = 0.0497). KRAS mutations were not associated with these phenotypes. In conclusion, GATA6 and CK5 immunohistochemical expression phenotypes may stratify the survival of NAC-PCs and reflect post-NAC phenotypic transitions associated with poor prognosis. Prompt evaluation of immunohistochemical phenotypes may contribute to designing a precision therapeutic strategy for PC patients.
Palmer MV, Wiarda J, Kanipe C and Thacker TC
PMID: 30895908 | DOI: 10.1177/0300985819833454
Mycobacterium bovis is a serious zoonotic pathogen and the cause of tuberculosis in many mammalian species, most notably, cattle. The hallmark lesion of tuberculosis is the granuloma. It is within the developing granuloma where host and pathogen interact; therefore, it is critical to understand host-pathogen interactions at the granuloma level. Cytokines and chemokines drive cell recruitment, activity, and function and ultimately determine the success or failure of the host to control infection. In calves, early lesions (ie, 15 and 30 days) after experimental aerosol infection were examined microscopically using in situ hybridization and immunohistochemistry to demonstrate early infiltrates of CD68+ macrophages within alveoli and alveolar interstitium, as well as the presence of CD4, CD8, and gammadelta T cells. Unlike lesions at 15 days, lesions at 30 days after infection contained small foci of necrosis among infiltrates of macrophages, lymphocytes, neutrophils, and multinucleated giant cells and extracellular acid-fast bacilli within necrotic areas. At both time points, there was abundant expression of the chemokines CXCL9, MCP-1/CCL2, and the cytokine transforming growth factor (TGF)-beta. The proinflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, as well as the anti-inflammatory cytokine IL-10, were expressed at moderate levels at both time points, while expression of IFN-gamma was limited. These findings document the early pulmonary lesions after M. bovis infection in calves and are in general agreement with the proposed pathogenesis of tuberculosis described in laboratory animal and nonhuman primate models of tuberculosis.
Aung KL, Fischer SE, Denroche RE, Jang GH, Dodd A, Creighton S, Southwood B, Liang SB, Chadwick D, Zhang A, O'Kane GM, Albaba H, Moura S, Grant RC, Miller JK, Mbabaali F, Pasternack D, Lungu IM, Bartlett JMS, Ghai S, Lemire M, Holter S, Connor AA, Moffitt
PMID: 29288237 | DOI: 10.1158/1078-0432.CCR-17-2994
Abstract
Purpose: To perform real-time whole genome sequencing (WGS) and RNA sequencing (RNASeq) of advanced pancreatic ductal adenocarcinoma (PDAC) to identify predictive mutational and transcriptional features for better treatment selection.Experimental Design:Patients with advanced PDAC were prospectively recruited prior to first-line combination chemotherapy. Fresh tumor tissue was acquired by image-guided percutaneous core biopsy for WGS and RNASeq. Laser capture microdissection was performed for all cases. Primary endpoint was feasibility to report WGS results prior to first disease assessment CT scan at 8 weeks. The main secondary endpoint was discovery of patient subsets with predictive mutational and transcriptional signatures.Results: Sixty-three patients underwent a tumor biopsy between December 2015 and June 2017. WGS and RNASeq were successful in 62 (98%) and 60 (95%), respectively. Genomic results were reported at a median of 35 days (range, 19-52 days) from biopsy, meeting the primary feasibility endpoint. Objective responses to first-line chemotherapy were significantly better in patients with the classical PDAC RNA subtype compared with those with the basal-like subtype (P = 0.004). The best progression-free survival was observed in those with classical subtype treated with m-FOLFIRINOX. GATA6 expression in tumor measured by RNA in situ hybridization was found to be a robust surrogate biomarker for differentiating classical and basal-like PDAC subtypes. Potentially actionable genetic alterations were found in 30% of patients.Conclusions: Prospective genomic profiling of advanced PDAC is feasible, and our early data indicate that chemotherapy response differs among patients with different genomic/transcriptomic subtypes.
Eroglu, E;Yen, CYT;Tsoi, YL;Witman, N;Elewa, A;Joven Araus, A;Wang, H;Szattler, T;Umeano, CH;Sohlmér, J;Goedel, A;Simon, A;Chien, KR;
PMID: 35550612 | DOI: 10.1038/s41556-022-00902-2
The contribution of the epicardium, the outermost layer of the heart, to cardiac regeneration has remained controversial due to a lack of suitable analytical tools. By combining genetic marker-independent lineage-tracing strategies with transcriptional profiling and loss-of-function methods, we report here that the epicardium of the highly regenerative salamander species Pleurodeles waltl has an intrinsic capacity to differentiate into cardiomyocytes. Following cryoinjury, CLDN6+ epicardium-derived cells appear at the lesion site, organize into honeycomb-like structures connected via focal tight junctions and undergo transcriptional reprogramming that results in concomitant differentiation into de novo cardiomyocytes. Ablation of CLDN6+ differentiation intermediates as well as disruption of their tight junctions impairs cardiac regeneration. Salamanders constitute the evolutionarily closest species to mammals with an extensive ability to regenerate heart muscle and our results highlight the epicardium and tight junctions as key targets in efforts to promote cardiac regeneration.