Activation of the α7nAChR by GTS-21 mitigates septic tubular cell injury and modulates macrophage infiltration.

The most common and serious complication among hospitalized and critically ill patients is sepsis-associated acute kidney damage (S-AKI), which raises the risk of comorbidities and is linked to a high mortality rate. Cholinergic anti-inflammatory pathway (CAP), an anti-inflammatory pathway mediated by the vagus nerve, acetylcholine, and α7 nicotinic acetylcholine receptors (α7nAChRs), offers new perspectives for the treatment of S-AKI. In this study, we investigated the role of CAP and α7nAChR in kidney injury by employing an LPS-induced septic kidney injury mouse model and GTS-21 intervention. C57BL/6 mice were injected with LPS, with or without GTS-21, in different subgroups. Kidney function was assessed by plasma creatinine, histology, and markers of kidney injury 24 h after intervention. The results demonstrated that GTS-21 could inhibit the systemic inflammatory response and directly protect the tubular cell injury from LPS. To explore the novel gene involved in this response, RNA sequencing of the renal proximal tubular epithelial cell (HK-2), pretreated with LPS and GTS-21, was conducted. The results indicate that GTS-21 administration reduces LPS-induced cytokines and chemokines secretion by HK-2, including CCL20, a potent chemokine attracting monocytes/macrophages. Furthermore, a macrophage transmigration assay revealed that GTS-21 inhibits macrophage transmigration by downregulating the expression of CCL20 in HK-2 cells. In conclusion, GTS-21, as an α7nAChR agonist, emerges as a noteworthy and versatile treatment for S-AKI. Its dual function of directly protecting renal tubular cells and regulating inflammatory responses represents a major advancement in the treatment of sepsis-induced AKI. This finding might pave the way for novel approaches to improving patient outcomes and reducing death rates in sepsis-related complications.

Renal macrophages induce hypertension and kidney fibrosis in Angiotensin II salt mice model.

The immune system is involved in hypertension development with different immune cells reported to have either pro or anti-hypertensive effects. In hypertension, immune cells have been thought to infiltrate blood pressure-regulating organs, resulting in either elevation or reduction of blood pressure. There is controversy over whether macrophages play a detrimental or beneficial role in the development of hypertension, and the few existing studies have yielded conflicting results. This study aimed to determine the effects of angiotensin II (Ang II) salt-induced hypertension on renal immune cells and to determine whether renal macrophages are involved in the induction of hypertension. Hypertension was induced by administration of Ang II and saline for two weeks. The effects of hypertension on kidney immune cells were assessed using flow cytometry. Macrophage infiltration in the kidney was assessed by immunohistochemistry and kidney fibrosis was assessed using trichrome stain and kidney real time-qPCR. Liposome encapsulated clodronate was used to deplete macrophages in C57BL/6J mice and investigate the direct role of macrophages in hypertension induction. Ang II saline mice group developed hypertension, had increased renal macrophages, and had increased expression of Acta2 and Col1a1 and kidney fibrotic areas. Macrophage depletion blunted hypertension development and reduced the expression of Acta2 and Col1a1 in the kidney and kidney fibrotic areas in Ang II saline group. The results of this study demonstrate that macrophages infiltrate the kidneys and increase kidney fibrosis in Ang II salt-induced hypertension, and depletion of macrophages suppresses the development of hypertension and decreases kidney fibrosis. This indicates that macrophages play a direct role in hypertension development. Hence macrophages have a potential to be considered as therapeutic target in hypertension management.

Swallowing-related muscle inflammation and fibrosis induced by a single dose of radiation exposure in mice.

BACKGROUND: Although radiotherapy is commonly used to treat head and neck cancer, it may lead to radiation-associated dysphagia (RAD). There are various causes of RAD, however, the mechanism has not yet been fully identified. Currently, the only effective treatment for RAD is rehabilitation. Additionally, there are few available animal models of RAD, necessitating the development of new models to establish and evaluate RAD treatments. We hypothesize that radiation-induced neck muscle fibrosis could be one of the causes of RAD due to impairment of laryngeal elevation. Therefore, in this study, we focused on the changes in inflammation and fibrosis of the strap muscles (Sternohyoid, Sternothyroid, and Thyrohyoid muscles) after a single-dose irradiation. This research aims to provide a reference animal model for future studies on RAD. RESULTS: Compared to control mice, those treated with 72-Gy, but not 24-Gy, irradiation had significantly increased tumor necrosis factor-α (TNF-α) (p < 0.01) and α-smooth muscle actin (αSMA) (p < 0.05) expression at 10 days and significantly increased expression levels of motif chemokine ligand-2 (CCL2), α-SMA, tumor growth factor-ß1 (TGF-ß1), type1 collagen, and interleukin-1ß (IL-1ß) (p < 0.05) in the muscles at 1 month by real-time PCR analysis. The results of immunohistochemistry showed that the deposition of type 1 collagen gradually increased in extracellular space after radiation exposure, and the positive area was significantly increased at 3 months compared to non-irradiated control. CONCLUSIONS: A single dose of 72-Gy irradiation induced significant inflammation and fibrosis in the strap muscles of mice at 1 month, with immunohistochemical changes becoming evident at 3 months. This cervical irradiation-induced fibrosis model holds potential for establishing an animal model for RAD in future studies. LEVEL OF EVIDENCE: N/A.

Bone marrow stromal cell antigen-1 deficiency protects from acute kidney injury.

This study aimed to investigate the role of bone marrow stromal cell antigen-1 (Bst1; also known as CD157) in acute kidney injury (AKI). Bst1 is a cell surface molecule with various enzymatic activities and downstream intracellular signaling pathways that modulate the immune response. Previous research has linked Bst1 to diseases such as ovarian cancer, Parkinson's disease, and rheumatoid arthritis. We used bilateral ischemia-reperfusion injury (IRI) as an AKI model and created bone marrow chimeric mice to evaluate the role of Bst1 in bone marrow-derived cells. We also used flow cytometry to identify Bst1/CD157 expression in hematopoietic cells and evaluate immune cell dynamics in the kidney. The findings showed that Bst1-deficient (Bst1-/-) mice were protected against renal bilateral IRI. Bone marrow chimera experiments revealed that Bst1 expression on hematopoietic cells, but not parenchymal cells, induced renal IRI. Bst1 was mainly found in B cells and neutrophils by flow cytometry of the spleen and bone marrow. In vitro, migration of neutrophils from Bst1-/- mice was suppressed, and adoptive transfer of neutrophils from wild-type Bst1+/+ mice abolished the renal protective effect in Bst1 knockout mice. In conclusion, the study demonstrated that Bst1-/- mice are protected against renal IRI and that Bst1 expression in neutrophils plays a crucial role in inducing renal IRI. These findings suggest that targeting Bst1 in neutrophils could be a potential therapeutic strategy for AKI.NEW & NOTEWORTHY Acute kidney injury (AKI), a serious disease for which there is no effective Federal Drug Administration-approved treatment, is associated with high mortality rates. Bone marrow stromal cell antigen-1 (Bst1) is a cell surface molecule that can cause kidney fibrosis, but its role in AKI is largely unknown. Our study showed that Bst1-/- mice revealed a protective effect against renal bilateral ischemia-reperfusion injury (IRI). Adoptive transfer studies confirmed that Bst1 expression in hematopoietic cells, especially neutrophils, contributed to renal bilateral IRI.

Alpha 7 nicotinic acetylcholine receptors signaling boosts cell-cell interactions in macrophages effecting anti-inflammatory and organ protection.

Activation of the cholinergic anti-inflammatory pathway (CAP) via vagus nerve stimulation has been shown to improve acute kidney injury in rodent models. While alpha 7 nicotinic acetylcholine receptor (α7nAChR) positive macrophages are thought to play a crucial role in this pathway, their in vivo significance has not been fully understood. In this study, we used macrophage-specific α7nAChR-deficient mice to confirm the direct activation of α7nAChRs in macrophages. Our findings indicate that the administration of GTS-21, an α7nAChR-specific agonist, protects injured kidneys in wild-type mice but not in macrophage-specific α7nAChR-deficient mice. To investigate the signal changes or cell reconstructions induced by α7nAChR activation in splenocytes, we conducted single-cell RNA-sequencing of the spleen. Ligand-receptor analysis revealed an increase in macrophage-macrophage interactions. Using macrophage-derived cell lines, we demonstrated that GTS-21 increases cell contact, and that the contact between macrophages receiving α7nAChR signals leads to a reduction in TNF-α. Our results suggest that α7nAChR signaling increases macrophage-macrophage interactions in the spleen and has a protective effect on the kidneys.

Induction of tetraspanin 13 contributes to the synergistic anti-inflammatory effects of parasympathetic and sympathetic stimulation in macrophages.

The autonomic nervous system plays an important role in the regulation of peripheral inflammation. Sympathetic nervous activation stimulates inflammatory gene expression and cytokines, whereas parasympathetic nervous activation suppresses the production of inflammatory cytokines by immune cells. However, most studies on the relationship between the autonomic nervous system and immune processes have analyzed a single branch of the autonomic nerves in isolation. Therefore, this study aimed to examine the effects of sympathetic and parasympathetic stimulation on macrophages, which are controlled by autonomic regulation. Macrophages were stimulated with lipopolysaccharide (LPS) to induce TNF-α. Then, the effects of ß2 adrenergic receptor and α7 nicotinic acetylcholine receptor activation on TNF-α production were assessed using concentration-dependent assays. RNA-seq data were also used to identify genes whose expression was enhanced by parasympathetic and sympathetic stimulation. The simultaneous activation of ß2 adrenergic receptors and α7 nicotinic acetylcholine receptors suppressed LPS-induced TNF-α production in a concentration-dependent manner. Moreover, simultaneous activation of these receptors had synergistic anti-inflammatory effects and induced Tspan13 expression, thereby contributing to anti-inflammatory mechanisms in macrophages. Our study revealed the synergistic anti-inflammatory effects of the parasympathetic and sympathetic stimulation of macrophages. Our results suggest that targeting both sympathetic and parasympathetic signaling is a promising therapeutic approach for inflammatory diseases.

Influenza Vaccination and Risk of Lung Cancer in Patients with Chronic Kidney Disease: A Nationwide, Population-Based Cohort Study.

Chronic kidney disease (CKD) is significantly associated with lung cancer incidence. The aim of this study was to elucidate whether influenza vaccination reduces the incidence of lung cancer in patients with CKD. This cohort study enrolled patients with a record of CKD diagnosis from 2000 to 2012 in Taiwan's National Health Insurance Research Database. Included patients were divided into vaccinated and unvaccinated groups. In total 12,985 patients with CKD were enrolled. Among these patients, 5495 were vaccinated and 7490 were unvaccinated. The risk of lung cancer was significantly lower in the influenza vaccination group after adjusting for age, sex, dialysis status, lung diseases, comorbidities, level of urbanization, and monthly income (adjusted hazard ratio (HR): 0.50, 95% confidence interval (CI; 0.38−0.65), p < 0.05). Lower risk of lung cancer was observed in both sexes, all age groups, dialysis status and co-existed lung diseases. The association between the risk of lung cancer and vaccination appeared to be dose-dependent (adjusted HRs: 0.91 (0.66−1.25), 0.49 (0.34−0.71), and 0.25 (0.17−0.38) for patients who received 1, 2 or 3, and ≥4 vaccinations during the follow-up period, respectively). In conclusion, Influenza vaccination decreased the risk of lung cancer in patients diagnosed with CKD. This potentially protective effect against lung cancer appeared to be dose dependent.

Direct-acting antiviral therapy of chronic hepatitis C improves liver fibrosis, assessed by histological examination and laboratory markers.

BACKGROUND/PURPOSE: Direct-acting antiviral agents achieve sustained virological response in most chronic hepatitis C patients. However, histological responses are not consistent among all patients. We conducted an observational study to analyze the histological changes after direct-acting antiviral agent therapy. METHODS: We recruited 220 patients who achieved sustained virological response after direct-acting antiviral agent. Histology was assessed by liver biopsy and laboratory indices including fibrosis-4 and aspartate aminotransferase to platelet ratio index. Primary outcomes were change in the dynamic laboratory results. Secondary outcomes were histological changes on liver biopsy. We analyzed the factors predictive of histological regression. RESULTS: The mean fibrosis-4 index decreased from 4.78 at baseline to 3.30, 3.31, 3.65, and 3.66 at week 4, 8, end of treatment, and 12 weeks after treatment, respectively (all p < 0.01). Mean aspartate aminotransferase to platelet ratio index decreased from 1.62 at baseline to 0.61, 0.66, 0.64, and 0.82 at week 4, 8, end of treatment, and 12 weeks after treatment, respectively (all p < 0.01). Mean Histological Activity Index at baseline and post-treatment was 6.9 ± 1.9 and 5.0 ± 2.3. The METAVIR fibrosis scores improved in 61.9% of the patients. We compared patients who achieved fibrosis-regression with the non-regression group. There was no significant difference in the baseline host/virological factors between the groups. CONCLUSION: Reversal of liver inflammation and fibrosis was achieved in a significant number of patients who received direct-acting antiviral agent. No baseline host or virological factor was predictive of histological regression after antiviral treatment.

Vagus nerve stimulation even after injury ameliorates cisplatin-induced nephropathy via reducing macrophage infiltration.

The efficacy of prior activation of an anti-inflammatory pathway called the cholinergic anti-inflammatory pathway (CAP) through vagus nerve stimulation (VNS) has been reported in renal ischemia-reperfusion injury models. However, there have been no reports that have demonstrated the effectiveness of VNS after injury. We investigated the renoprotective effect of VNS in a cisplatin-induced nephropathy model. C57BL/6 mice were injected with cisplatin, and VNS was conducted 24 hours later. Kidney function, histology, and a kidney injury marker (Kim-1) were evaluated 72 hours after cisplatin administration. To further explore the role of the spleen and splenic macrophages, key players in the CAP, splenectomy, and adoptive transfer of macrophages treated with the selective α7 nicotinic acetylcholine receptor agonist GTS-21 were conducted. VNS treatment significantly suppressed cisplatin-induced kidney injury. This effect was abolished by splenectomy, while adoptive transfer of GTS-21-treated macrophages improved renal outcomes. VNS also reduced the expression of cytokines and chemokines, including CCL2, which is a potent chemokine attracting monocytes/macrophages, accompanied by a decline in the number of infiltrating macrophages. Taken together, stimulation of the CAP protected the kidney even after injury in a cisplatin-induced nephropathy model. Considering the feasibility and anti-inflammatory effects of VNS, the findings suggest that VNS may be a promising therapeutic tool for acute kidney injury.

Subgroup analysis of the predictive ability of aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4) for assessing hepatic fibrosis among patients with chronic hepatitis C.

BACKGROUND: There are many laboratory indices to assess liver fibrosis. Aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4) index have been used as well-known serum markers of liver fibrosis. With the increasing use of non-invasive fibrosis assessment, it is important to recognize the limitations of these tests. The factors influencing the diagnostic accuracy to evaluate liver fibrosis are not well-established. This study aimed to perform a subgroup analysis of the predictive ability of laboratory indices. METHODS: Overall, 113 patients with chronic hepatitis C infection who underwent liver biopsy were retrospectively examined. The histological assessment of liver fibrosis was performed using the METAVIR scoring system, and the values of several laboratory tests were also evaluated on the same day. We categorized our study population by treatment status, body mass index (BMI), and age. RESULTS: The two laboratory indices APRI and FIB-4 index could predict advanced (F3-4) liver fibrosis and cirrhosis (F4), with the area under the receiver operating characteristic curve (AUROC) > 0.8 and accuracy >70%. The AUROCs and accuracies were higher among patients with sustained virological response (SVR) than among those without SVR. A higher predictive ability was also observed among patients with BMI <25 kg/m2. Age did not appear to affect liver fibrosis predictability. CONCLUSIONS: The laboratory indices APRI and FIB-4 index exhibit good diagnostic performance for determining advanced fibrosis and cirrhosis among patients with hepatitis C infection. The diagnostic accuracy appears better among patients with SVR and those with BMI <25 kg/m2.

Long-term histological change in chronic hepatitis C patients who had received peginterferon plus ribavirin therapy with sustained virological response.

BACKGROUND: The improvement in liver histology is an important aim in the management of hepatitis C virus (HCV) infection. Previous studies suggest that antiviral treatment could reduce the progression of hepatic fibrosis, especially in patients with sustained virological response (SVR). However, most studies were limited by short-term evaluations and the liver stiffness was assessed by non-invasive methods. In our study, we performed a paired liver biopsy study aimed at analyzing the long-term histological changes in patients with SVR. METHODS: We included 31 patients who had been previously treated with peginterferon plus ribavirin. All patients achieved SVR and had received pre- and post-treatment liver biopsies. The histological appearance of fibrosis and inflammation were assessed with METAVIR scoring system and Histological Activity Index (HAI) criteria. We analyzed several factors associated with the histological response. RESULTS: The median interval between two biopsies was 93.0 months. The percentage of patients with fibrosis regression, stable, and progression were 19%, 45%, and 36%. A total of 71% of patients achieved inflammation improvement, whereas 6% and 23% of patients had stable disease and disease-progression, respectively. We showed that the patients without baseline advanced fibrosis and those having a lower baseline HAI score had higher risk of fibrosis worsening. Baseline fibrosis and necroinflammation status did not influence HAI change significantly. CONCLUSION: The progression of hepatic fibrosis and inflammation can be reversed in some patients who had long-term virological suppression. Patients with advanced baseline fibrosis and higher inflammatory stages seemed to receive more histologic benefit from successful antiviral treatments.

Palmitate deranges erythropoietin production via transcription factor ATF4 activation of unfolded protein response.

Lipotoxicity plays an important role in the progression of chronic kidney damage via various mechanisms, such as endoplasmic reticulum stress. Several studies proposed renal lipotoxicity in glomerular and tubular cells but the effect of lipid on renal erythropoietin (EPO)-producing (REP) cells in the interstitium has not been elucidated. Since renal anemia is caused by derangement of EPO production in REP cells, we evaluated the effect of palmitate, a representative long-chain saturated fatty acid, on EPO production and the endoplasmic reticulum stress pathway. EPO production was suppressed by palmitate (palmitate-conjugated bovine serum albumin [BSA]) or a high palmitate diet, but not oleic acid-conjugated BSA or a high oleic acid diet, especially under cobalt-induced pseudo-hypoxia both in vitro and in vivo. Importantly, suppression of EPO production was not induced by a decrease in transcription factor HIF activity, while it was significantly associated with endoplasmic reticulum stress, particularly transcription factor ATF4 activation, which suppresses 3'-enhancer activity of the EPO gene. ATF4 knockdown by siRNA significantly attenuated the suppressive effect of palmitate on EPO production. Studies utilizing inherited super-anemic mice (ISAM) mated with EPO-Cre mice (ISAM-REC mice) for lineage-labeling of REP cells showed that ATF4 activation by palmitate suppressed EPO production in REP cells. Laser capture microdissection confirmed ATF4 activation in the interstitial area of ISAM-REC mice treated with palmitate-conjugated BSA. Thus, endoplasmic reticulum stress induced by palmitate suppressed EPO expression by REP cells in a manner independent of HIF activation. The link between endoplasmic reticulum stress, dyslipidemia, and hypoxia may contribute to development and progression of anemia in CKD.

Application of chronic liver failure-sequential organ failure assessment score for the predication of mortality after esophageal variceal hemorrhage post endoscopic ligation.

BACKGROUND: Esophageal variceal hemorrhage (EVH) is one of the high mortality complications in cirrhotic patients. Endoscopic variceal ligation (EVL) is currently the standard therapy for EVH. However, some patients have expired during hospitalization or survived shortly after management. AIM: To evaluate hospital and 6-week mortality by receiver operating characteristic (ROC) curve of chronic liver failure-sequential organ failure assessment (CLIF-SOFA) score compared to a model for end-stage liver disease (MELD) score and Child-Turcotte-Pugh (CTP) class. METHODS: We retrospectively collected 714 cirrhotic patients with EVH post EVL between July 2010 and June 2016 at Taitung MacKay Memorial Hospital, Taiwan. CLIF-SOFA score, MELD score, and CTP class were calculated for all patients admitted. RESULTS: Among the 714 patients, the overall hospital and 6-week mortality rates were 6.9% (49/715) and 13.1% (94/715) respectively. For predicting hospital death, area under receiver operating characteristic curve (AUROC) values of CLIF-SOFA score, MELD score, and CTP class were 0.964, 0.876, and 0.846. For predicting 6-week death, AUROC values of CLIF-SOFA score, MELD score, and CTP class were 0.943, 0.817, and 0.834. CLIF-SOFA score had higher AUROC value with statistical significance under pairwise comparison than did MELD score and CTP class in prediction of not only hospital but also 6-week mortality. The history of hepatocellular carcinoma was the risk factor for 6-week mortality. For patients with hepatocellular carcinoma the cut-point of CLIF-SOFA score was 5.5 for 6-week mortality and 6.5 for hospital mortality on admission. For patients without hepatocellular carcinoma, the cut-point of CLIF-SOFA score was 6.5 for both 6-week and hospital mortality. CONCLUSION: CLIF-SOFA score predicted post-EVL prognosis well. For patients without hepatocellular carcinoma, CLIF-SOFA score ≥6 suggests higher 6-week mortality and CLIF-SOFA score ≥7 suggests higher hospital mortality. For patients with hepatocellular carcinoma, CLIF-SOFA score ≥7 suggests higher 6-week and hospital mortality.

Pharmacological exploitation of the phenothiazine antipsychotics to develop novel antitumor agents-A drug repurposing strategy.

Phenothiazines (PTZs) have been used for the antipsychotic drugs for centuries. However, some of these PTZs have been reported to exhibit antitumor effects by targeting various signaling pathways in vitro and in vivo. Thus, this study was aimed at exploiting trifluoperazine, one of PTZs, to develop potent antitumor agents. This effort culminated in A4 [10-(3-(piperazin-1-yl)propyl)-2-(trifluoromethyl)-10H-phenothiazine] which exhibited multi-fold higher apoptosis-inducing activity than the parent compound in oral cancer cells. Compared to trifluoperazine, A4 demonstrated similar regulation on the phosphorylation or expression of multiple molecular targets including Akt, p38, and ERK. In addition, A4 induced autophagy, as evidenced by increased expression of the autophagy biomarkers LC3B-II and Atg5, and autophagosomes formation. The antitumor activity of A4 also related to production of reactive oxygen species and adenosine monophosphate-activated protein kinase. Importantly, the antitumor utility of A4 was extended in vivo as it, administrated at 10 and 20 mg/kg intraperitoneally, suppressed the growth of Ca922 xenograft tumors. In conclusion, the ability of A4 to target diverse aspects of cancer cell growth suggests its value in oral cancer therapy.

Refeeding syndrome in Southeastern Taiwan: our experience with 11 cases.

AIM: To present our experience with refeeding syndrome in southeastern Taiwan. METHODS: We conducted a retrospective study during a 2-year period at the Mackay Memorial Hospital, Taitung Branch. We enrolled patients with very little or no nutrition intake for more than 10 d, a high risk group of refeeding syndrome, including those suffering from alcohol abuse, cancerous cachexia, chronic malnutrition, and prolonged starvation. RESULTS: A total of 11 patients (7 males, 4 females) with nasogastric feeding were included as having refeeding syndrome. Most of them had the symptoms of diarrhea, lethargy, and leg edema. The initial nutritional supplement was found to be relatively high in calories (1355.1 ± 296.2 kcal/d), high in protein (47.3 ± 10.4 gm/d), low in vitamin B1 (2.0 ± 0.5 mg/d), low in potassium (1260.4 ± 297.7 mg/d), and low in phosphorus (660.1 ± 151.8 mg/d). Furthermore, hypophosphatemia (2.4 ± 0.9 mg/dL) was noted during follow-up. Based on the suggestions of a dietician and a gastroenterologist, the clinical disorders of diarrhea, malaise and leg edema were significantly improved. The level of phosphate was also increased (3.3 ± 0.6 mg/dL). CONCLUSION: Refeeding syndrome is an overlooked and risky disorder that has some potentially fatal complications. Nasogastric feeding in nursing homes is an important risk factor for patients and deserves greater attention based on the initial results of this study.

PKC-ß as a therapeutic target in CLL: PKC inhibitor AEB071 demonstrates preclinical activity in CLL.

Targeting B-cell receptor (BCR) signaling in chronic lymphocytic leukemia (CLL) has been successful with durable remissions observed with several targeted therapeutics. Protein kinase C-ß (PKC-ß) is immediately downstream of BCR and has been shown to be essential to CLL cell survival and proliferation in vivo. We therefore evaluated sotrastaurin (AEB071), an orally administered potent PKC inhibitor, on CLL cell survival both in vitro and in vivo. AEB071 shows selective cytotoxicity against B-CLL cells in a dose-dependent manner. Additionally, AEB071 attenuates BCR-mediated survival pathways, inhibits CpG-induced survival and proliferation of CLL cells in vitro, and effectively blocks microenvironment-mediated survival signaling pathways in primary CLL cells. Furthermore, AEB071 alters ß-catenin expression, resulting in decreased downstream transcriptional genes as c-Myc, Cyclin D1, and CD44. Lastly, our preliminary in vivo studies indicate beneficial antitumor properties of AEB071 in CLL. Taken together, our results indicate that targeting PKC-ß has the potential to disrupt signaling from the microenvironment contributing to CLL cell survival and potentially drug resistance. Future efforts targeting PKC with the PKC inhibitor AEB071 as monotherapy in clinical trials of relapsed and refractory CLL patients are warranted.

Sensitive liquid chromatography/mass spectrometry methods for quantification of pomalidomide in mouse plasma and brain tissue.

Pomalidomide was recently approved by the United States Food and Drug Administration for the treatment of patients with relapsed or refractory multiple myeloma who have received at least two prior therapies. As pomalidomide is increasingly evaluated in other diseases and animal disease models, this paper presents development and validation of a sensitive liquid chromatography tandem mass spectrometry assay for quantification of pomalidomide in mouse plasma and brain tissue to fill a gap in published preclinical pharmacokinetic and analytical data with this agent. After acetonitrile protein precipitation, pomalidomide and internal standard, hesperitin, were separated with reverse phase chromatography on a C-18 column with a gradient mobile phase of water and acetonitrile with 0.1% fomic acid. Positive atmospheric pressure chemical ionization mass spectrometry with selected reaction monitoring mode was applied to achieve 0.3-3000nM (0.082-819.73ng/mL) linear range in mouse plasma and 0.6-6000pmol/g in brain tissue. The within- and between-batch accuracy and precision were less than 15% for both plasma and brain tissue. The method was applied to measure pomalidomide concentrations in plasma and brain tissue in a pilot mouse pharmacokinetic study with an intravenous dose of 0.5mg/kg. This assay can be applied for thorough characterization of pomalidomide pharmacokinetics and tissue distribution in mice.