Effects of Various Concentrations of Pronase on Flow Cytometric Crossmatching Patients Treated With Rituximab and Donor HLA-Specific Antibodies.

Background: Pronase pretreatment can reduce rituximab (RTX) interference by degrading CD20 in B-cell flow cytometry crossmatch (FCXM) testing. However, it may also reduce the assay sensitivity by degrading HLA molecules. We investigated the effects of various pronase concentrations on RTX interference and the analytical sensitivity of B-cell FCXM testing. Methods: Using 59 patient serum samples and 38 donor lymphocyte samples, we designed 97 recipient-donor pairs and divided them into three groups according to RTX use and the presence of weak-to-moderate donor HLA-specific antibody (DSA) reactions: RTX+/DSA-, RTX+/DSA+, and RTX-/DSA+. FCXM was performed after pretreating lymphocytes with six different pronase concentrations (0, 0.5, 1, 2, 3, and 4 mg/mL). Results: With B-FCXM testing, false-positive results due to RTX in the RTX+/DSA- group markedly decreased with increasing pronase concentrations. The median channel shift values in the RTX+/DSA+ and RTX-/DSA+ groups did not significantly decrease when the pronase concentration was increased from 1 mg/mL to 2 or 3 mg/mL. All eight RTX+/DSA+ cases that were positive at 1 mg/mL pronase but negative at 2 or 3 mg/mL had mean fluorescence intensity (MFI) DSA values of less than 3,000 except for DQ5 (MFI: 5,226). With T-cell FCXM, false-positive results were observed in 2.9% of 315 FCXM tests with pronase pretreatment. Conclusions: Higher concentrations (2 or 3 mg/mL) of pronase effectively eliminated RTX interference but still carried a risk for false negativity for weak DSA reactions in B-cell FCXM. Higher pronase concentrations can be used as an auxiliary method to detect moderate-to-strong DSA reactions in RTX-treated patients.

The iterative implementation of a comprehensive enhanced recovery after surgery protocol in all spinal surgery in Korea: a comparative analysis of clinical outcomes and medical costs between primary spinal tumors and degenerative spinal diseases.

OBJECTIVE: Most studies on the enhanced recovery after surgery (ERAS) protocol in spine surgery have focused on patients with degenerative spinal diseases (DSDs), resulting in a lack of evidence for a comprehensive ERAS protocol applicable to patients with primary spine tumors (PSTs) and other spinal diseases. The authors had developed and gradually adopted components of the comprehensive ERAS protocol for all spine surgical procedures from 2003 to 2011, and then the current ERAS protocol was fully implemented in 2012. This study aimed to evaluate the impact and the applicability of the comprehensive ERAS protocol across all spine surgical procedures and to compare outcomes between the PST and DSD groups. METHODS: Adult spine surgical procedures were conducted from 2003 to 2021 at the Seoul National University Hospital Spine Center and data were retrospectively reviewed. The author divided the study periods into the developing ERAS (2003-2011) and post-current ERAS (2012-2021) periods, and outcomes were compared between the two periods. Surgical procedures for metastatic cancer, infection, and trauma were excluded. Interrupted time series analysis (ITSA) was used to assess the impact of the ERAS protocol on medical costs and clinical outcomes, including length of stay (LOS) and rates of 30-day readmission, reoperation, and surgical site infection (SSI). Subgroup analyses were conducted on the PST and DSD groups in terms of LOS and medical costs. RESULTS: The study included 7143 surgical procedures, comprising 1494 for PSTs, 5340 for DSDs, and 309 for other spinal diseases. After ERAS protocol implementation, spine surgical procedures showed significant reductions in LOS and medical costs by 22% (p = 0.008) and 22% (p < 0.001), respectively. The DSD group demonstrated a 16% (p < 0.001) reduction in LOS, whereas the PST group achieved a 28% (p < 0.001) reduction, noting a more pronounced LOS reduction in PST surgical procedures (p = 0.003). Medical costs decreased by 23% (p < 0.001) in the DSD group and 12% (p = 0.054) in the PST group, with a larger cost reduction for DSD surgical procedures (p = 0.021). No statistically significant differences were found in the rates of 30-day readmission, reoperation, and SSI between the developing and post-current ERAS implementation periods (p = 0.65, p = 0.59, and p = 0.52, respectively). CONCLUSIONS: Comprehensive ERAS protocol implementation significantly reduced LOS and medical costs in all spine surgical procedures, while maintaining comparable 30-day readmission, reoperation, and SSI rates. These findings suggest that the ERAS protocol is equally applicable to all spine surgical procedures, with a more pronounced effect on reducing LOS in the PST group and on reducing medical costs in the DSD group.

Value of circulating neutrophil elastase for detecting recurrence of differentiated thyroid cancer.

Objective: The inflammatory microenvironment has been implicated in differentiated thyroid cancer (DTC). Inflammatory stimuli induce the release of components of neutrophils into extracellular space, leading to formation of neutrophil extracellular trap (NET), which can stimulate growth and progression of cancer. Generation of activated factor XII and thrombin is also involved in cancer progression. This study attempted to determine whether the level of circulating markers of NET, activated factor XII, and endogenous thrombin potential may be useful for detecting the recurrence of DTC. Methods: A total of 122 patients with DTC were recruited during the postoperative follow-up period. Measurement of the levels of circulating markers of NET (neutrophil elastase, histone-DNA complex, cell-free dsDNA), activated factor XII, and endogenous thrombin potential was performed. Results: A significantly elevated level of neutrophil elastase was detected in patients with recurrence (n = 12) compared to those without recurrence (n = 110), while significant elevation of the levels of other markers was not observed. The value for area under the curve (0.717, P = 0.018) of neutrophil elastase for detecting recurrence of DTC was superior to that (0.661, P = 0.051) of serum thyroglobulin. An elevated level of neutrophil elastase was significantly associated with recurrence of DTC independent of serum thyroglobulin. Conclusions: Because an elevated level of neutrophil elastase was detected in patients with recurrence of DTC and showed a significant association with recurrence of DTC, it can be proposed as a novel biomarker for use in detecting recurrence of DTC along with other tests.

Surgical treatment of spondylolisthesis by oblique lumbar interbody fusion and transpedicular screw fixation: Comparison between conventional double position versus navigation-assisted single lateral position.

BACKGROUND AND OBJECTIVES: Oblique lumbar interbody fusion (OLIF) procedures involve anterior insertion of interbody cage in lateral position. Following OLIF, insertion of pedicle screws and rod system is performed in a prone position (OLIF-con). The location of the cage is important for restoration of lumbar lordosis and indirect decompression. However, inserting the cage at the desired location is difficult without reduction of spondylolisthesis, and reduction after insertion of interbody cage may limit the amount of reduction. Recent introduction of spinal navigation enabled both surgical procedures in one lateral position (OLIF-one). Therefore, reduction of spondylolisthesis can be performed prior to insertion of interbody cage. The objective of this study was to compare the reduction of spondylolisthesis and the placement of cage between OLIF-one and OLIF-con. METHODS: We retrospectively reviewed 72 consecutive patients with spondylolisthesis for this study; 30 patients underwent OLIF-one and 42 underwent OLIF-con. Spinal navigation system was used for OLIF-one. In OLIF-one, the interbody cage was inserted after reducing spondylolisthesis, whereas in OLIF-con, the cage was inserted before reduction. The following parameters were measured on X-rays: pre- and postoperative spondylolisthesis slippage, reduction degree, and the location of the cage in the disc space. RESULTS: Both groups showed significant improvement in back and leg pains (p < .05). Transient motor or sensory changes occurred in three patients after OLIF-con and in two patients after OLIF-one. Pre- and postoperative slips were 26.3±7.7% and 6.6±6.2% in OLIF-one, and 23.1±7.0% and 7.4±5.8% in OLIF-con. The reduction of slippage was 74.4±6.3% after OLIF-one and 65.4±5.7% after OLIF-con, with a significant difference between the two groups (p = .04). The cage was located at 34.2±8.9% after OLIF-one and at 42.8±10.3% after OLIF-con, with a significant difference between the two groups (p = .004). CONCLUSION: Switching the sequence of surgical procedures with OLIF-one facilitated both the reduction of spondylolisthesis and the placement of the cage at the desired location.

Is laminectomy necessary for C1-C2 epidural schwannomas?

PURPOSE: Spinal schwannomas often require laminectomy for gross total resection. However, laminectomy may not be necessary due to the unique anatomy of epidural schwannomas at the C1-2 level, even with the intradural part. This study aimed to determine the need for laminectomy by comparing factors between patients who underwent laminectomy and those who did not and to identify the benefits of not performing laminectomy. METHODS: Fifty patients with spinal epidural schwannoma confined to C1-C2 level were retrospectively collected and divided into groups based on whether laminectomy was intended and performed. In all cases where laminectomy was conducted, patients underwent laminoplasty using microplate-and-screws, which deviates from the conventional laminectomy approach. Tumor characteristics were compared, and a cut-off value for laminectomy was determined. Outcomes were compared between groups, and factors influencing laminectomy were identified. Postoperative changes in cervical curves were measured. RESULTS: The diameter of the intradural part of the tumor was significantly longer in the laminectomy performed group, with a 14.86 mm cut-off diameter requiring laminectomy. Recurrence rates did not differ significantly between groups. Surgery time was substantially longer for the laminectomy performed group. No significant changes were observed in Cobb's angles of Oc-C2, C1-C2, and Oc-C1 before and after surgery. CONCLUSION: The study showed that the diameter of the intradural part of the tumor influenced the decision to perform laminectomy for removing epidural schwannomas at C1-C2. The cut-off value of the diameter of the intradural part of the tumor for the laminectomy was 14.86 mm. Not performing laminectomy can be a viable option with no significant differences in removal and complication rates.

IFN-γ Induces IL-15 Trans-Presentation by Epithelial Cells via IRF1.

IL-15 exhibits pleiotropic effects on NK and CD8+ T cells and contributes to host protection or immunopathology during infection. Although both type I IFNs and IFN-γ upregulate IL-15 expression, their effects on IL-15 upregulation and underlying mechanisms have not been compared comprehensively. In addition, little is known about trans-presentation of IL-15 by epithelial cells to lymphocytes. In this study, we analyzed the expression of IL-15 and IL-15Rα in the human hepatocyte-derived Huh-7 cell line after stimulation with IFN-α, IFN-ß, or IFN-γ using RT-PCR, flow cytometry, and confocal microscopy. We also performed knockdown experiments to investigate the signaling pathway involved in IL-15 upregulation. IFN-γ more potently upregulated IL-15 expression in Huh-7 cells than IFN-α and IFN-ß. Knockdown experiments revealed that IFN-γ- and IFN-ß-induced IL-15 expression relied on IFN regulatory factor 1 (IRF1), which is upregulated by STAT1 and IFN-stimulated gene factor 3, respectively. Inhibitor of κB kinase α/ß was also involved in IFN-γ-induced upregulation of IL-15. Furthermore, human NK cells were activated by coculture with IFN-γ-treated Huh-7 cells, which was abrogated by knocking down IL-15Rα in IFN-γ-treated Huh-7 cells, indicating that IFN-γ-induced IL-15 on Huh-7 cells activates NK cells via trans-presentation. In summary, our data demonstrate that IFN-γ potently elicits IL-15 trans-presentation by epithelial cells via IRF1. These data also suggest that the IFN-γ-IRF1-IL-15 axis may be a regulatory target for the treatment of diseases with IL-15 dysregulation.

Assessment of copy number in protooncogenes are predictive of poor survival in advanced gastric cancer.

The copy number (CN) gain of protooncogenes is a frequent finding in gastric carcinoma (GC), but its prognostic implication remains elusive. The study aimed to characterize the clinicopathological features, including prognosis, of GCs with copy number gains in multiple protooncogenes. Three hundred thirty-three patients with advanced GC were analyzed for their gene ratios in EGFR, GATA6, IGF2, and SETDB1 using droplet dPCR (ddPCR) for an accurate assessment of CN changes in target genes. The number of GC patients with 3 or more genes with CN gain was 16 (4.8%). Compared with the GCs with 2 or less genes with CN gain, the GCs with 3 or more CN gains displayed more frequent venous invasion, a lower density of tumor-infiltrating lymphocytes, and lower methylation levels of L1 or SAT-alpha. Microsatellite instability-high tumors or Epstein-Barr virus-positive tumors were not found in the GCs with 3 or more genes with CN gain. Patients of this groups also showed the worst clinical outcomes for both overall survival and recurrence-free survival, which was persistent in the multivariate survival analyses. Our findings suggest that the ddPCR-based detection of multiple CN gain of protooncogenes might help to identify a subset of patients with poor prognosis.

Combined hybrid structure of siRNA tailed IVT mRNA (ChriST mRNA) for enhancing DC maturation and subsequent anticancer T cell immunity.

RNA therapeutics have received much attention in the development of anti-cancer therapies. Among them, synthetic mRNA (IVT mRNA) was investigated for cancer immunotherapy due to its abilities to express tumor associated antigens with stimulation of immune responses in dendritic cells (DCs). Despite of its great potential, several hurdles were remained such as insufficient immune stimulation and DC maturation. In this study, we aimed to present a novel IVT mRNA that can simultaneously express tumor associated antigens while suppress STAT3 proteins. Combined functions of siRNA and IVT mRNA were investigated and the hybrid structure of siRNA tailed mRNA (ChriST mRNA) was developed. We prepared the ChriST mRNA by employing polyA tail structures with RNAi sequences at the 3' end of mRNA. Complementary strands were annealed to form duplex siRNA structure to induce STAT3 gene silencing. In addition, a hybrid structure of DNA/RNA was introduced into the ChriST mRNA between polyA tail and RNAi sequences. It was expected that DNA/RNA duplex would be readily cleaved by RNase H in the intracellular environment. After the cleavage, ChriST mRNA was fully functionalized in cells and exhibited enhanced tumor specific DC maturation.

Reactive Polymer Targeting dsRNA as Universal Virus Detection Platform with Enhanced Sensitivity.

Reactive poly(pentafluorophenyl acrylate) (PPFPA)-grafted surfaces offer a versatile platform to immobilize biomolecules. Here, we utilize PPFPA-grafted surface and double-stranded RNA (dsRNA) recognizing J2 antibody to construct a universal virus detection platform with enhanced sensitivity. PPFPA on silicon substrates is prepared, and surface hydrophilicity is modulated by partial substitution of the pentafluorophenyl units with poly(ethylene glycol). Following dsRNA antibody immobilization, the prepared surfaces can distinguish long dsRNAs from single-stranded RNAs of the same length and short dsRNAs. As long dsRNAs are common byproducts of viral transcription/replication, these surfaces can detect the presence of different kinds of viruses without prior knowledge of their genomic sequences. To increase dsRNA detection sensitivity, a two-step method is devised where the captured dsRNAs are visualized with multiple fluorophore-tagged J2 antibodies. We show that the developed platform can differentiate foreign long dsRNAs from cellular dsRNAs and other biomolecules present in the cell lysate. Moreover, when tested against cells infected with hepatitis A or C viruses, both viruses are successfully detected using a single platform. Our study shows that the developed PPFPA platform immobilized with J2 antibody can serve as a primary diagnostic tool to determine the infection status for a wide range of viruses.

Fibroblast Growth Factor Receptor 1 (FGFR1) Amplification Detected by Droplet Digital Polymerase Chain Reaction (ddPCR) Is a Prognostic Factor in Colorectal Cancers.

PURPOSE: The purpose of this study was to reveal the clinicopathological characteristics and prognostic implications associated with fibroblast growth factor receptor 1 (FGFR1) amplification in colorectal cancers (CRCs). MATERIALS AND METHODS: We measured the copy number of FGFR1 by droplet digital polymerase chain reaction (ddPCR), and analyzed the FGFR1 expression by immunohistochemistry, in 764 surgically resected CRCs (SNUH2007 dataset, 384 CRCs; SNUH Folfox dataset, 380 CRCs). RESULTS: CRCs with ≥ 3.3 copies of the FGFR1 gene were classified as FGFR1 amplified. FGFR1 amplification was found in 10 of the 384 CRCs (2.6%) in the SNUH2007 dataset, and in 28 of the 380 CRCs (7.4%) in the SNUH Folfox dataset. In the SNUH2007 dataset, there was no association between the FGFR1 copy number status and sex, gross appearance, stage, or differentiation. High FGFR1 expression was associated with female sex and KRAS mutation. At the molecular level, FGFR1 amplification was mutually exclusive with BRAF mutation, microsatellite instability, and MLH1 methylation, in both SNUH2007 and SNUH Folfox datasets. Survival analysis revealed that FGFR1 amplification was associated with significantly worse clinical outcome compared with no FGFR1 amplification, in both SNUH2007 and SNUH Folfox datasets. Within the SNUH2007 dataset, CRC patients with high FGFR1 expression had an inferior progression-free survival compared with those with low FGFR1 expression. The FGFR inhibitor, PD173074, repressed the proliferation of a CRC cell line overexpressing FGFR1, but not of cells with FGFR1 amplification. CONCLUSION: FGFR1 amplification measured by ddPCR can be a prognostic indicator of poor clinical outcome in patients with CRCs.

Structure-based glycoengineering of interferon lambda 4 enhances its productivity and anti-viral potency.

Interferon lambda 4 (IFNλ4) has been recently known and studied for its role in hepatitis C virus (HCV) infection, but its clinical potential is significantly hampered due to its poor expression in vitro. Our study reports the successful production of IFNλ4 from a mammalian cell line through a glycoengineering and structure-based approach. We introduced de novo N-glycosylation of IFNλ4, guided by structural analysis, and produced IFNλ4 variants in Expi293F that displayed improved expression and potency. To preserve the structure and functionality of IFNλ4, the model structure of the IFNλ4 signaling complex was analyzed and the N-glycosylation candidate sites were selected. The receptor binding activity of engineered IFNλ4 variants and their receptor-mediated signaling pathway were similar to the E. coli version of IFNλ4 (eIFNλ4), while the antiviral activity and induction levels of interferon-stimulated gene (ISG) were all more robust in our variants. Our engineered IFNλ4 variants may be further developed for clinical applications and utilized in basic research to decipher the immunological roles of IFNλ4.

The activation of bystander CD8+ T cells and their roles in viral infection.

During viral infections, significant numbers of T cells are activated in a T cell receptor-independent and cytokine-dependent manner, a phenomenon referred to as "bystander activation." Cytokines, including type I interferons, interleukin-18, and interleukin-15, are the most important factors that induce bystander activation of T cells, each of which plays a somewhat different role. Bystander T cells lack specificity for the pathogen, but can nevertheless impact the course of the immune response to the infection. For example, bystander-activated CD8+ T cells can participate in protective immunity by secreting cytokines, such as interferon-γ. They also mediate host injury by exerting cytotoxicity that is facilitated by natural killer cell-activating receptors, such as NKG2D, and cytolytic molecules, such as granzyme B. Interestingly, it has been recently reported that there is a strong association between the cytolytic function of bystander-activated CD8+ T cells and host tissue injury in patients with acute hepatitis A virus infection. The current review addresses the induction of bystander CD8+ T cells, their effector functions, and their potential roles in immunity to infection, immunopathology, and autoimmunity.

VEGF-A drives TOX-dependent T cell exhaustion in anti-PD-1-resistant microsatellite stable colorectal cancers.

Although immune checkpoint blockade therapies have demonstrated clinical efficacy in cancer treatment, harnessing this strategy is largely encumbered by resistance in multiple cancer settings. Here, we show that tumor-infiltrating T cells are severely exhausted in the microsatellite stable (MSS) colorectal cancer (CRC), a representative example of PD-1 blockade-resistant tumors. In MSS CRC, we found wound healing signature to be up-regulated and that T cell exhaustion is driven by vascular endothelial growth factor-A (VEGF-A). We report that VEGF-A induces the expression of transcription factor TOX in T cells to drive exhaustion-specific transcription program in T cells. Using a combination of in vitro, ex vivo, and in vivo mouse studies, we demonstrate that combined blockade of PD-1 and VEGF-A restores the antitumor functions of T cells, resulting in better control of MSS CRC tumors.

Development of a SFTSV DNA vaccine that confers complete protection against lethal infection in ferrets.

Although the incidence of severe fever with thrombocytopenia syndrome virus (SFTSV) infection has increased from its discovery with a mortality rate of 10-20%, no effective vaccines are currently available. Here we describe the development of a SFTSV DNA vaccine, its immunogenicity, and its protective efficacy. Vaccine candidates induce both a neutralizing antibody response and multifunctional SFTSV-specific T cell response in mice and ferrets. When the vaccine efficacy is investigated in aged-ferrets that recapitulate fatal clinical symptoms, vaccinated ferrets are completely protected from lethal SFTSV challenge without developing any clinical signs. A serum transfer study reveals that anti-envelope antibodies play an important role in protective immunity. Our results suggest that Gn/Gc may be the most effective antigens for inducing protective immunity and non-envelope-specific T cell responses also can contribute to protection against SFTSV infection. This study provides important insights into the development of an effective vaccine, as well as corresponding immune parameters, to control SFTSV infection.

Immune Checkpoint Inhibitor-induced Reinvigoration of Tumor-infiltrating CD8+ T Cells is Determined by Their Differentiation Status in Glioblastoma.

PURPOSE: Immune checkpoint inhibitors (ICI) are used for the treatment of various cancers, but clinical trials of anti-programmed cell death protein 1 (PD-1) with patients with recurrent glioblastoma (GBM) have failed to show clinical benefits. In this study, we examined the differentiation status of CD8+ tumor-infiltrating lymphocytes (TIL) from patients with primary GBM and their reinvigoration by ICIs to understand the nature of T-cell exhaustion in GBM. EXPERIMENTAL DESIGN: We isolated TILs from 98 patients with newly diagnosed GBM and examined the expression of immune checkpoint receptors and T-cell transcription factors using flow cytometry. TILs were ex vivo stimulated with anti-CD3 in the presence of anti-PD-1 and/or anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) and their proliferation assessed. RESULTS: CD8+ TILs had significantly increased expression of immune checkpoint receptors, including PD-1 and CTLA-4, compared with peripheral blood CD8+ T cells. Among CD8+ TILs, PD-1+ cells exhibited more terminally differentiated phenotypes (i.e., EomeshiT-betlo) than PD-1- cells. These data were confirmed by analyzing NY-ESO-1157-specific CD8+ TILs. Evaluating the proliferation of CD8+ TILs after ex vivo stimulation with anti-CD3 and anti-PD-1, we found that proliferation inversely correlated with the percentage of EomeshiT-betlo cells among PD-1+CD8+ TILs. When anti-CTLA-4 was used in combination with anti-PD-1, an additional increase in CD8+ TIL proliferation was observed in patients with low percentages of EomeshiT-betlo CD8+ TILs, who responded well to anti-PD-1 in ex vivo assays, but not in patients with high percentages of EomeshiT-betlo CD8+ TILs, who did not respond to anti-PD-1. CONCLUSIONS: In primary GBM, the differentiation status of CD8+ TILs determines their reinvigoration ability upon ICI treatment.

Extraocular Pressure Measurements to Avoid Orbital Compartment Syndrome in Aneurysm Surgery.

BACKGROUND: Orbital compartment syndrome (OCS) is a rare but devastating complication following pterional craniotomy. Although the causes of OCS are unclear, external compression of the orbit by a myocutaneous flap is commonly mentioned as a major factor. We evaluated the ocular influence of external compression using an extraocular pressure monitor. METHODS: We measured extraocular pressure in 86 patients who underwent surgery for cerebral aneurysm via a pterional approach. Clinical information and radiologic parameters, including the area of the medial rectus muscle (MRM) and the craniotomy height from the bottom of the anterior skull base, were collected. As a control group, 117 patients who underwent surgery without pressure monitoring were also evaluated. RESULTS: Extraocular pressure reached a maximum during craniotomy (mean, 22.0 mm Hg; range, 18.4-51.0 mm Hg) and decreased after myocutaneous flap adjustment (mean, 7.9 mm Hg; range, 5.4-17.5 mm Hg). Pressure before myocutaneous flap manipulation differed between patients with anterior communicating artery (Acomm) aneurysms and other patients (mean, 16.5 mm Hg vs. 9.4 mm Hg; P = 0.003). Among Acomm aneurysm cases, the monitored group showed a significantly lower MRM swelling ratio (postoperative MRM area/preoperative MRM area) compared with the control group (1.03 ± 0.10 vs. 1.17 ± 0.15; P = 0.036). CONCLUSIONS: Myocutaneous flaps can produce unnoticed overpressure on the orbit, resulting in OCS-related blindness during aneurysm clipping surgery, especially in cases involving mandatory lower craniotomy. The continuous extraocular compressive pressure monitoring technique is a simple and effective approach to prevent such a serious complication.

Mammalian sterile 20 kinase 1 and 2 are important regulators of hematopoietic stem cells in stress condition.

The mammalian Hippo signaling pathway has been implicated in the self-renewal and differentiation of stem and progenitor cells. MST1 and MST2 (MST1/2) are core serine-threonine kinases in the Hippo signaling pathway, one of which, MST1, has been extensively investigated for its role in T cell and myeloid cell function. These studies have identified MST1 as a promising therapeutic target in immunological disease. However, the roles of MST1/2 in hematopoietic stem cell (HSC) function in vivo are not fully understood. Here, we report that mice with a conditional deletion of Mst1/2 exhibit impaired hematopoietic stem and progenitor cell (HSPC) function under stress condition. Furthermore, Mst1/2 deletion markedly altered mature cell output. Therefore, MST1/2 are indispensable for maintenance as well as function of stem and progenitor cells under steady state conditions and with transplantation stress.

Metastatic Intracerebral Plasmacytoma Treated with Radiation and Thalidomide, Dexamethasone with Cyclophosphamide Chemotherapy.

Intracerebral plasmacytoma is an extremely rare disease for which no treatment protocol has been established. The authors present a case of metastatic intracerebral plasmacytoma that was partially resected and treated with radiation therapy. For tumor recurrence, a combination chemotherapy regimen was initiated. A 48-year-old male patient presented with dizziness and memory loss. Conventional magnetic resonance imaging (MRI) of the brain revealed a multilobulated mass with enhancing cystic and solid components measuring 7 × 7 × 6 cm in the left frontal lobe. The patient had undergone subtotal gastrectomy and transverse colectomy 8 years before admission and had been diagnosed with extraosseous plasmacytoma. At the time of the current presentation, the patient underwent craniotomy for the parenchymal lesion. Partial tumor resection was performed. Histologic and immunohistochemical examinations confirmed the diagnosis of plasmacytoma. Fractionated radiotherapy was administered, and no enhancing mass was observed on follow-up MRI. One year after radiotherapy, tumor recurrence was observed in a different area of the cerebral parenchyma. Combination thalidomide, dexamethasone, and cyclophosphamide chemotherapy was administered. After three cycles of chemotherapy, the tumor was well controlled on MRI. Hereafter, two more times of tumor recurrence occurred in the other sites of the cerebral parenchyma, but with chemoradiation therapy, the tumor was well suppressed. The findings of this case suggest that the cerebral parenchyma can be one of the metastatic sites for extraosseous plasmacytoma. In addition, combination chemotherapy with thalidomide, dexamethasone, and cyclophosphamide may be a useful treatment option for intracerebral plasmacytoma.

Peroxiredoxin 2 regulates PGF2α-induced corpus luteum regression in mice by inhibiting ROS-dependent JNK activation.

Luteal regression is a natural and necessary event to regulate the reproductive process in all mammals. Prostaglandin F2α (PGF2α) is the main factor that causes functional and structural regression of the corpus luteum (CL). It is well known that PGF2α-mediated ROS generation is closely involved in luteal regression. Peroxiredoxin 2 (Prx2) as an antioxidant enzyme plays a protective role against oxidative stress-induced cell death. However, the effect of Prx2 on PGF2α-induced luteal regression has not been reported. Here, we investigated the role of Prx2 in functional and structural CL regression induced by PGF2α-mediated ROS using Prx2-deficient (-/-) mice. We found that PGF2α-induced ROS generation was significantly higher in Prx2-/- MEF cells compared with that in wild-type (WT) cells, which induced apoptosis by activating JNK-mediated apoptotic signaling pathway. Also, PGF2α treatment in the CL derived from Prx2-/- mice promoted the reduction of steroidogenic enzyme expression and the activation of JNK and caspase3. Compared to WT mice, serum progesterone levels and luteal expression of steroidogenic enzymes decreased more rapidly whereas JNK and caspase3 activations were significantly increased in Prx2-/- mice injected with PGF2α. However, the impaired steroidogenesis and PGF2α-induced JNK-dependent apoptosis were rescued by the addition of the antioxidant N-acetyl-L-cysteine (NAC). This is the first study to demonstrate that Prx2 deficiency ultimately accelerated the PGF2α-induced luteal regression through activation of the ROS-dependent JNK pathway. These findings suggest that Prx2 plays a crucial role in preventing accelerated luteal regression via inhibition of the ROS/JNK pathway.

LATS-YAP/TAZ controls lineage specification by regulating TGFß signaling and Hnf4α expression during liver development.

The Hippo pathway regulates the self-renewal and differentiation of various adult stem cells, but its role in cell fate determination and differentiation during liver development remains unclear. Here we report that the Hippo pathway controls liver cell lineage specification and proliferation separately from Notch signalling, using mice and primary hepatoblasts with liver-specific knockout of Lats1 and Lats2 kinase, the direct upstream regulators of YAP and TAZ. During and after liver development, the activation of YAP/TAZ induced by loss of Lats1/2 forces hepatoblasts or hepatocytes to commit to the biliary epithelial cell (BEC) lineage. It increases BEC and fibroblast proliferation by up-regulating TGFß signalling, but suppresses hepatoblast to hepatocyte differentiation by repressing Hnf4α expression. Notably, oncogenic YAP/TAZ activation in hepatocytes induces massive p53-dependent cell senescence/death. Together, our results reveal that YAP/TAZ activity levels govern liver cell differentiation and proliferation in a context-dependent manner.