Hyperleptinemia is associated with impaired pulmonary host defense

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Abstract

We have previously reported that obesity attenuates pulmonary inflammation in both patients with acute respiratory distress syndrome (ARDS) and in mouse models of the disease. We hypothesized that obesity-associated hyperleptinemia, and not body mass per se, drives attenuation of the pulmonary inflammatory response and that this effect could also impair the host response to pneumonia. We examined the correlation between circulating leptin levels and risk, severity, and outcome of pneumonia in 2 patient cohorts (NHANES III and ARDSNet-ALVEOLI) and in mouse models of diet-induced obesity and lean hyperleptinemia. Plasma leptin levels in ambulatory subjects (NHANES) correlated positively with annual risk of respiratory infection independent of BMI. In patients with severe pneumonia resulting in ARDS (ARDSNet-ALVEOLI), plasma leptin levels were found to correlate positively with subsequent mortality. In obese mice with pneumonia, plasma leptin levels were associated with pneumonia severity, and in obese mice with sterile lung injury, leptin levels were inversely related to bronchoalveolar lavage neutrophilia, as well as to plasma IL-6 and G-CSF levels. These results were recapitulated in lean mice with experimentally induced hyperleptinemia. Our findings suggest that the association between obesity and elevated risk of pulmonary infection may be driven by hyperleptinemia.

Authors

Niki D.J. Ubags, Renee D. Stapleton, Juanita H.J. Vernooy, Elianne Burg, Jenna Bement, Catherine M. Hayes, Sebastian Ventrone, Lennart Zabeau, Jan Tavernier, Matthew E. Poynter, Polly E. Parsons, Anne E. Dixon, Matthew J. Wargo, Benjamin Littenberg, Emiel F.M. Wouters, Benjamin T. Suratt

Effects of cellular origin on differentiation of human induced pluripotent stem cell–derived endothelial cells

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Abstract

Human induced pluripotent stem cells (iPSCs) can be derived from various types of somatic cells by transient overexpression of 4 Yamanaka factors (OCT4, SOX2, C-MYC, and KLF4). Patient-specific iPSC derivatives (e.g., neuronal, cardiac, hepatic, muscular, and endothelial cells [ECs]) hold great promise in drug discovery and regenerative medicine. In this study, we aimed to evaluate whether the cellular origin can affect the differentiation, in vivo behavior, and single-cell gene expression signatures of human iPSC–derived ECs. We derived human iPSCs from 3 types of somatic cells of the same individuals: fibroblasts (FB-iPSCs), ECs (EC-iPSCs), and cardiac progenitor cells (CPC-iPSCs). We then differentiated them into ECs by sequential administration of Activin, BMP4, bFGF, and VEGF. EC-iPSCs at early passage (10 < P < 20) showed higher EC differentiation propensity and gene expression of EC-specific markers (PECAM1 and NOS3) than FB-iPSCs and CPC-iPSCs. In vivo transplanted EC-iPSC–ECs were recovered with a higher percentage of CD31⁺ population and expressed higher EC-specific gene expression markers (PECAM1, KDR, and ICAM) as revealed by microfluidic single-cell quantitative PCR (qPCR). In vitro EC-iPSC–ECs maintained a higher CD31⁺ population than FB-iPSC–ECs and CPC-iPSC–ECs with long-term culturing and passaging. These results indicate that cellular origin may influence lineage differentiation propensity of human iPSCs; hence, the somatic memory carried by early passage iPSCs should be carefully considered before clinical translation.

Authors

Shijun Hu, Ming-Tao Zhao, Fereshteh Jahanbani, Ning-Yi Shao, Won Hee Lee, Haodong Chen, Michael P. Snyder, Joseph C. Wu

Single-cell analysis of glandular T cell receptors in Sjögren’s syndrome

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Abstract

CD4⁺ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren’s syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4⁺CD45RA^– T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies.

Authors

Michelle L. Joachims, Kerry M. Leehan, Christina Lawrence, Richard C. Pelikan, Jacen S. Moore, Zijian Pan, Astrid Rasmussen, Lida Radfar, David M. Lewis, Kiely M. Grundahl, Jennifer A. Kelly, Graham B. Wiley, Mikhail Shugay, Dmitriy M. Chudakov, Christopher J. Lessard, Donald U. Stone, R. Hal Scofield, Courtney G. Montgomery, Kathy L. Sivils, Linda F. Thompson, A. Darise Farris

Attenuation of lung fibrosis in mice with a clinically relevant inhibitor of glutathione-S-transferase π

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Abstract

Idiopathic pulmonary fibrosis (IPF) is a debilitating lung disease characterized by excessive collagen production and fibrogenesis. Apoptosis in lung epithelial cells is critical in IPF pathogenesis, as heightened loss of these cells promotes fibroblast activation and remodeling. Changes in glutathione redox status have been reported in IPF patients. S-glutathionylation, the conjugation of glutathione to reactive cysteines, is catalyzed in part by glutathione-S-transferase π (GSTP). To date, no published information exists linking GSTP and IPF to our knowledge. We hypothesized that GSTP mediates lung fibrogenesis in part through FAS S-glutathionylation, a critical event in epithelial cell apoptosis. Our results demonstrate that GSTP immunoreactivity is increased in the lungs of IPF patients, notably within type II epithelial cells. The FAS-GSTP interaction was also increased in IPF lungs. Bleomycin- and AdTGFβ-induced increases in collagen content, α-SMA, FAS S-glutathionylation, and total protein S-glutathionylation were strongly attenuated in Gstp^–/– mice. Oropharyngeal administration of the GSTP inhibitor, TLK117, at a time when fibrosis was already apparent, attenuated bleomycin- and AdTGFβ-induced remodeling, α-SMA, caspase activation, FAS S-glutathionylation, and total protein S-glutathionylation. GSTP is an important driver of protein S-glutathionylation and lung fibrosis, and GSTP inhibition via the airways may be a novel therapeutic strategy for the treatment of IPF.

Authors

David H. McMillan, Jos L.J. van der Velden, Karolyn G. Lahue, Xi Qian, Robert W. Schneider, Martina S. Iberg, James D. Nolin, Sarah Abdalla, Dylan T. Casey, Kenneth D. Tew, Danyelle M. Townsend, Colin J. Henderson, C. Roland Wolf, Kelly J. Butnor, Douglas J. Taatjes, Ralph C. Budd, Charles G. Irvin, Albert van der Vliet, Stevenson Flemer, Vikas Anathy, Yvonne M.W. Janssen-Heininger

Renal rescue of dopamine D2 receptor function reverses renal injury and high blood pressure

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Abstract

Dopamine D2 receptor (DRD2) deficiency increases renal inflammation and blood pressure in mice. We show here that long-term renal-selective silencing of Drd2 using siRNA increases renal expression of proinflammatory and profibrotic factors and blood pressure in mice. To determine the effects of renal-selective rescue of Drd2 expression in mice, the renal expression of DRD2 was first silenced using siRNA and 14 days later rescued by retrograde renal infusion of adeno-associated virus (AAV) vector with DRD2. Renal Drd2 siRNA treatment decreased the renal expression of DRD2 protein by 55%, and DRD2 AAV treatment increased the renal expression of DRD2 protein by 7.5- to 10-fold. Renal-selective DRD2 rescue reduced the expression of proinflammatory factors and kidney injury, preserved renal function, and normalized systolic and diastolic blood pressure. These results demonstrate that the deleterious effects of renal-selective Drd2 silencing on renal function and blood pressure were rescued by renal-selective overexpression of DRD2. Moreover, the deleterious effects of 45-minute bilateral ischemia/reperfusion on renal function and blood pressure in mice were ameliorated by a renal-selective increase in DRD2 expression by the retrograde ureteral infusion of DRD2 AAV immediately after the induction of ischemia/reperfusion injury. Thus, 14 days after ischemia/reperfusion injury, the renal expression of profibrotic factors, serum creatinine, and blood pressure were lower in mice infused with DRD2 AAV than in those infused with control AAV. These results indicate an important role of renal DRD2 in limiting renal injury and preserving normal renal function and blood pressure.

Authors

Prasad R. Konkalmatt, Laureano D. Asico, Yanrong Zhang, Yu Yang, Cinthia Drachenberg, Xiaoxu Zheng, Fei Han, Pedro A. Jose, Ines Armando

Distinct activation thresholds of human conventional and innate-like memory T cells

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Abstract

Conventional memory CD8⁺ T cells and mucosal-associated invariant T cells (MAIT cells) are found in blood, liver, and mucosal tissues and have similar effector potential following activation, specifically expression of IFN-γ and granzyme B. To better understand each subset’s unique contributions to immunity and pathology, we interrogated inflammation- and TCR-driven activation requirements using human memory CD8⁺ T and MAIT cells isolated from blood and mucosal tissue biopsies in ex vivo functional assays and single cell gene expression experiments. We found that MAIT cells had a robust IFN-γ and granzyme B response to inflammatory signals but limited responsiveness when stimulated directly via their TCR. Importantly, this is not due to an overall hyporesponsiveness to TCR signals. When delivered together, TCR and inflammatory signals synergize to elicit potent effector function in MAIT cells. This unique control of effector function allows MAIT cells to respond to the same TCR signal in a dichotomous and situation-specific manner. We propose that this could serve to prevent responses to antigen in noninflamed healthy mucosal tissue, while maintaining responsiveness and great sensitivity to inflammation-eliciting infections. We discuss the implications of these findings in context of inflammation-inducing damage to tissues such as BM transplant conditioning or HIV infection.

Authors

Chloe K. Slichter, Andrew McDavid, Hannah W. Miller, Greg Finak, Brenda J. Seymour, John P. McNevin, Gabriela Diaz, Julie L. Czartoski, M. Juliana McElrath, Raphael Gottardo, Martin Prlic

A wearable artificial kidney for patients with end-stage renal disease

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Abstract

BACKGROUND. Stationary hemodialysis machines hinder mobility and limit activities of daily life during dialysis treatments. New hemodialysis technologies are needed to improve patient autonomy and enhance quality of life.

METHODS. We conducted a FDA-approved human trial of a wearable artificial kidney, a miniaturized, wearable hemodialysis machine, based on dialysate-regenerating sorbent technology. We aimed to determine the efficacy of the wearable artificial kidney in achieving solute, electrolyte, and volume homeostasis in up to 10 subjects over 24 hours.

RESULTS. During the study, all subjects remained hemodynamically stable, and there were no serious adverse events. Serum electrolytes and hemoglobin remained stable over the treatment period for all subjects. Fluid removal was consistent with prescribed ultrafiltration rates. Mean blood flow was 42 ± 24 ml/min, and mean dialysate flow was 43 ± 20 ml/min. Mean urea, creatinine, and phosphorus clearances over 24 hours were 17 ± 10, 16 ± 8, and 15 ± 9 ml/min, respectively. Mean β₂-microglobulin clearance was 5 ± 4 ml/min. Of 7 enrolled subjects, 5 completed the planned 24 hours of study treatment. The trial was stopped after the seventh subject due to device-related technical problems, including excessive carbon dioxide bubbles in the dialysate circuit and variable blood and dialysate flows.

CONCLUSION. Treatment with the wearable artificial kidney was well tolerated and resulted in effective uremic solute clearance and maintenance of electrolyte and fluid homeostasis. These results serve as proof of concept that, after redesign to overcome observed technical problems, a wearable artificial kidney can be developed as a viable novel alternative dialysis technology.

TRIAL REGISTRATION. ClinicalTrials.gov NCT02280005.

FUNDING. The Wearable Artificial Kidney Foundation and Blood Purification Technologies Inc.

Authors

Victor Gura, Matthew B. Rivara, Scott Bieber, Raj Munshi, Nancy Colobong Smith, Lori Linke, John Kundzins, Masoud Beizai, Carlos Ezon, Larry Kessler, Jonathan Himmelfarb

Cyclosporine A immunosuppression drives catastrophic squamous cell carcinoma through IL-22

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Abstract

Immune-suppressed organ transplant recipients (OTRs) can develop catastrophic squamous cell carcinoma (SCC), characterized by multiple primary tumors, extensive body surface area involvement, or metastases. There are currently no curative systemic therapies available. We previously showed that IL-22 enhances SCC proliferation. Herein, we examined links between cyclosporine (CSA), IL-22, and SCC in patients, cell lines, and mice with UV light–induced SCC. Eighteen of 114 OTRs developed catastrophic SCC, which was strongly associated with CSA treatment. We found that CSA drives T cell polarization toward IL-22–producing T22 cells, and CSA treatment increased IL-22 receptor in SCC cells. SCC tissue from OTRs showed increased expression of IL-22RA1. CSA potentiated rescue by IL-22 of serum-starved SCC cells; treatment of SCC cells with IL-22 and CSA increased both their migratory and invasive capacity. In a UV-induced model of SCC in SKH-1 immunocompetent mice, treatment with anti–IL-22 antibody reduced tumor number and tumor burden. We found that catastrophic SCC in OTRs is associated with CSA use, which may be acting by favoring T22 polarization. Since anti–IL-22 antibody administration decreased tumor number and tumor burden in vivo, blockade of the IL-22 axis may be developed as a viable therapeutic option for catastrophic SCC.

Authors

Melody Abikhair, Hiroshi Mitsui, Valerie Yanofsky, Nazanin Roudiani, Channa Ovits, Teddy Bryan, Tatiana M. Oberyszyn, Kathleen L. Tober, Juana Gonzalez, James G. Krueger, Diane Felsen, John A. Carucci

Quantitation of circulating satellite RNAs in pancreatic cancer patients

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Abstract

Pancreatic ductal adenocarcinoma (Pdac) is a malignancy with a poor prognosis due to difficulties in early detection. Although promising biomarkers are increasingly reported, such methods are not yet easy to apply clinically, mainly due to their low reproducibility or technical difficulties. In this study, we developed a convenient and sensitive method for quantifying aberrantly expressed satellite repeat RNAs in sera, which can be used to efficiently detect patients with Pdac. Here, we introduce a Tandem Repeat Amplification by nuclease Protection (TRAP) method combined with droplet digital PCR (ddPCR) to detect human satellite II (HSATII) RNAs, which are specifically expressed in human Pdacs at greater levels than normal tissues but are difficult to measure due to their repetitive sequences and irregularities. HSATII RNA core sequence levels in sera were significantly higher in Pdac patients compared with noncancer patients (median copy number: 14.75 and 3.17 per μl in the training set and 17.35 and 2.9 in the validation set, respectively). In addition, patients with intraductal papillary mucinous neoplasm (IPMN), a precancerous lesion of Pdac, could also be efficiently detected. This method can be routinely applied to screen patients with Pdac and high-risk patients, facilitating the development of preventive medicine for this disease.

Authors

Takahiro Kishikawa, Motoyuki Otsuka, Takeshi Yoshikawa, Motoko Ohno, Keisuke Yamamoto, Natsuyo Yamamoto, Ai Kotani, Kazuhiko Koike

Paneth cell defects in Crohn’s disease patients promote dysbiosis

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Abstract

BACKGROUND. Paneth cell dysfunction has been implicated in a subset of Crohn’s disease (CD) patients. We previously stratified clinical outcomes of CD patients by using Paneth cell phenotypes, which we defined by the intracellular distribution of antimicrobial proteins. Animal studies suggest that Paneth cells shape the intestinal microbiome. However, it is unclear whether Paneth cell phenotypes alter the microbiome complexity in CD subjects. Therefore, we analyzed the correlation of Paneth cell phenotypes with mucosal microbiome composition and ileal RNA expression in pediatric CD and noninflammatory bowel disease (non-IBD) patients.

METHODS. Pediatric CD (n = 44) and non-IBD (n = 62) patients aged 4 to 18 were recruited prior to routine endoscopic biopsy. Ileal mucosal samples were analyzed for Paneth cell phenotypes, mucosal microbiome composition, and RNA transcriptome.

RESULTS. The prevalence of abnormal Paneth cells was higher in pediatric versus adult CD cohorts. For pediatric CD patients, those with abnormal Paneth cells showed significant changes in their ileal mucosal microbiome, highlighted by reduced protective microbes and enriched proinflammatory microbes. Ileal transcriptome profiles showed reduced transcripts for genes that control oxidative phosphorylation in CD patients with abnormal Paneth cells. These transcriptional changes in turn were correlated with specific microbiome alterations. In non-IBD patients, a subset contained abnormal Paneth cells. However, this subset was not associated with alterations in the microbiome or host transcriptome.

CONCLUSION. Paneth cell abnormalities in human subjects are associated with mucosal dysbiosis in the context of CD, and these changes are associated with alterations in oxidative phosphorylation, potentially in a feedback loop.

FUNDING. The research was funded by Helmsley Charitable Trust (to T.S. Stappenbeck, R.J. Xavier, and D.P.B. McGovern), Crohn’s and Colitis Foundation of America (to N.H. Salzman, T.S. Stappenbeck, R.J. Xavier, and C. Huttenhower), and Doris Duke Charitable Foundation grant 2014103 (to T.C. Liu).

Authors

Ta-Chiang Liu, Bhaskar Gurram, Megan T. Baldridge, Richard Head, Vy Lam, Chengwei Luo, Yumei Cao, Pippa Simpson, Michael Hayward, Mary L. Holtz, Pavlos Bousounis, Joshua Noe, Diana Lerner, Jose Cabrera, Vincent Biank, Michael Stephens, Curtis Huttenhower, Dermot P.B. McGovern, Ramnik J. Xavier, Thaddeus S. Stappenbeck, Nita H. Salzman

CRIg-expressing peritoneal macrophages are associated with disease severity in patients with cirrhosis and ascites

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Abstract

Infections are an important cause of morbidity and mortality in patients with decompensated cirrhosis and ascites. Hypothesizing that innate immune dysfunction contributes to susceptibility to infection, we assessed ascitic fluid macrophage phenotype and function. The expression of complement receptor of the immunoglobulin superfamily (CRIg) and CCR2 defined two phenotypically and functionally distinct peritoneal macrophage subpopulations. The proportion of CRIg^hi macrophages differed between patients and in the same patient over time, and a high proportion of CRIg^hi macrophages was associated with reduced disease severity (model for end-stage liver disease) score. As compared with CRIg^lo macrophages, CRIg^hi macrophages were highly phagocytic and displayed enhanced antimicrobial effector activity. Transcriptional profiling by RNA sequencing and comparison with human macrophage and murine peritoneal macrophage expression signatures highlighted similarities among CRIg^hi cells, human macrophages, and mouse F4/80^hi resident peritoneal macrophages and among CRIg^lo macrophages, human monocytes, and mouse F4/80^lo monocyte-derived peritoneal macrophages. These data suggest that CRIg^hi and CRIg^lo macrophages may represent a tissue-resident population and a monocyte-derived population, respectively. In conclusion, ascites fluid macrophage subset distribution and phagocytic capacity is highly variable among patients with chronic liver disease. Regulating the numbers and/or functions of these macrophage populations could provide therapeutic opportunities in cirrhotic patients.

Authors

Katharine M. Irvine, Xuan Banh, Victoria L. Gadd, Kyle K. Wojcik, Juliana K. Ariffin, Sara Jose, Samuel Lukowski, Gregory J. Baillie, Matthew J. Sweet, Elizabeth E. Powell

Distal vessel stiffening is an early and pivotal mechanobiological regulator of vascular remodeling and pulmonary hypertension

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Abstract

Pulmonary arterial (PA) stiffness is associated with increased mortality in patients with pulmonary hypertension (PH); however, the role of PA stiffening in the pathogenesis of PH remains elusive. Here, we show that distal vascular matrix stiffening is an early mechanobiological regulator of experimental PH. We identify cyclooxygenase-2 (COX-2) suppression and corresponding reduction in prostaglandin production as pivotal regulators of stiffness-dependent vascular cell activation. Atomic force microscopy microindentation demonstrated early PA stiffening in experimental PH and human lung tissue. Pulmonary artery smooth muscle cells (PASMC) grown on substrates with the stiffness of remodeled PAs showed increased proliferation, decreased apoptosis, exaggerated contraction, enhanced matrix deposition, and reduced COX-2–derived prostanoid production compared with cells grown on substrates approximating normal PA stiffness. Treatment with a prostaglandin I₂ analog abrogated monocrotaline-induced PA stiffening and attenuated stiffness-dependent increases in proliferation, matrix deposition, and contraction in PASMC. Our results suggest a pivotal role for early PA stiffening in PH and demonstrate the therapeutic potential of interrupting mechanobiological feedback amplification of vascular remodeling in experimental PH.

Authors

Fei Liu, Christina Mallarino Haeger, Paul B. Dieffenbach, Delphine Sicard, Izabela Chrobak, Anna Maria F. Coronata, Margarita M. Suárez Velandia, Sally Vitali, Romain A. Colas, Paul C. Norris, Aleksandar Marinković, Xiaoli Liu, Jun Ma, Chase D. Rose, Seon-Jin Lee, Suzy A.A. Comhair, Serpil C. Erzurum, Jacob D. McDonald, Charles N. Serhan, Stephen R. Walsh, Daniel J. Tschumperlin, Laura E. Fredenburgh

Effect of tolerance versus chronic immunosuppression protocols on the quality of life of kidney transplant recipients

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Abstract

Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA.

BACKGROUND. Kidney transplant patients on tolerance protocols avoid the morbidity associated with the use of conventional chronic immunosuppressive regimens. However, the impact of tolerance versus conventional regimens on the quality of life (QOL) of kidney transplant patients is unknown.

METHODS. Five patients who achieved long-term immunosuppression-free renal allograft survival after combined kidney and bone marrow transplantation (tolerant group) were compared with thirty-two comparable kidney transplant recipients on conventional immunosuppression (conventional group). QOL was compared with 16 conventional recipients using the Kidney Disease Quality of Life Short Form 36 (KDQOL SF-36) and the Modified Transplant Symptom Occurrence and Symptom Distress Scale (MTSOSD-59R).

RESULTS. Patients in the tolerant group required significantly less treatment after transplant for hypertension and no medications for diabetes (P < 0.01). There was no incidence of diabetes, dyslipidemia, or malignancies in the tolerant group, while these were observed in 12.5%, 40.6%, and 11.8% of the conventional group, respectively. Tolerant patients experienced better overall health (P < 0.01) and scored higher on kidney transplant-targeted scales and healthy survey scales than patients in the conventional group according to the KDQOL SF-36 (P < 0.05). Tolerant patients were less likely to experience depression, dyspnea, excessive appetite/thirst, flatulence, hearing loss, itching, joint pain, lack of energy, muscle cramps, and lack of libido than conventional patients according to the MTSOSD-59R (P < 0.05).

CONCLUSION. Kidney transplant recipients who achieved tolerance experience significantly fewer incidences of complications, improved QOL, and fewer comorbid symptoms compared with patients on conventional immunosuppression. These results support the expanded use of tolerance protocols in kidney transplantation.

Authors

Maria Lucia L. Madariaga, Philip J. Spencer, Kumaran Shanmugarajah, Kerry A. Crisalli, David C. Chang, James F. Markmann, Nahel Elias, A. Benedict Cosimi, David H. Sachs, Tatsuo Kawai

Repurposing tromethamine as inhaled therapy to treat CF airway disease

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Abstract

In cystic fibrosis (CF), loss of CF transmembrane conductance regulator (CFTR) anion channel activity causes airway surface liquid (ASL) pH to become acidic, which impairs airway host defenses. One potential therapeutic approach is to correct the acidic pH in CF airways by aerosolizing HCO₃^– and/or nonbicarbonate pH buffers. Here, we show that raising ASL pH with inhaled HCO₃^– increased pH. However, the effect was transient, and pH returned to baseline values within 30 minutes. Tromethamine (Tham) is a buffer with a long serum half-life used as an i.v. formulation to treat metabolic acidosis. We found that Tham aerosols increased ASL pH in vivo for at least 2 hours and enhanced bacterial killing. Inhaled hypertonic saline (7% NaCl) is delivered to people with CF in an attempt to promote mucus clearance. Because an increased ionic strength inhibits ASL antimicrobial factors, we added Tham to hypertonic saline and applied it to CF sputum. We found that Tham alone and in combination with hypertonic saline increased pH and enhanced bacterial killing. These findings suggest that aerosolizing the HCO₃^–-independent buffer Tham, either alone or in combination with hypertonic saline, might be of therapeutic benefit in CF airway disease.

Authors

Mahmoud H. Abou Alaiwa, Janice L. Launspach, Kelsey A. Sheets, Jade A. Rivera, Nicholas D. Gansemer, Peter J. Taft, Peter S. Thorne, Michael J. Welsh, David A. Stoltz, Joseph Zabner

STAT3 accelerates uterine epithelial regeneration in a mouse model of decellularized uterine matrix transplantation

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Abstract

Although a close connection between uterine regeneration and successful pregnancy in both humans and mice has been consistently observed, its molecular basis remains unclear. We here established a mouse model of decellularized uterine matrix (DUM) transplantation. Resected mouse uteri were processed with SDS to make DUMs without any intact cells. DUMs were transplanted into the mouse uteri with artificially induced defects, and all the uterine layers were recovered at the DUM transplantation sites within a month. In the regenerated uteri, normal hormone responsiveness in early pregnancy was observed, suggesting the regeneration of functional uteri. Uterine epithelial cells rapidly migrated and formed a normal uterine epithelial layer within a week, indicating a robust epithelial-regenerating capacity. Stromal and myometrial regeneration occurred following epithelial regeneration. In ovariectomized mice, uterine regeneration of the DUM transplantation was similarly observed, suggesting that ovarian hormones are not essential for this regeneration process. Importantly, the regenerating epithelium around the DUM demonstrated heightened STAT3 phosphorylation and cell proliferation, which was suppressed in uteri of Stat3 conditional knockout mice. These data suggest a key role of STAT3 in the initial step of the uterine regeneration process. The DUM transplantation model is a powerful tool for uterine regeneration research.

Authors

Takehiro Hiraoka, Yasushi Hirota, Tomoko Saito-Fujita, Mitsunori Matsuo, Mahiro Egashira, Leona Matsumoto, Hirofumi Haraguchi, Sudhansu K. Dey, Katsuko S. Furukawa, Tomoyuki Fujii, Yutaka Osuga