Bortezomib treatment induces a higher mortality rate in lupus model mice with a higher disease activity

Background

Bortezomib (Bz) is a proteasome inhibitor that directly targets antibody-producing plasma cells. We recently reported the first randomized control trial that evaluated the effects of Bz in patients with systemic lupus erythematosus (SLE). In that study, we demonstrated that Bz treatment is associated with many adverse reactions in patients with refractory disease. In the present study, we examine the therapeutic and toxic effects of Bz on MRL/MpJ-lpr/lpr (MRL/lpr) mice with severe disease activity.

Methods

Female MRL/lpr mice at 10 and 14 weeks of age were treated with phosphate buffered saline (PBS) (n = 19), Bz (750 μg/kg twice weekly) (n = 27), or cyclophosphamide (Cyc) (1 mg/body, once in 2 weeks) (n = 20). Cellular subsets, serum immunoglobulin, anti-double-stranded DNA (anti-dsDNA) antibody titer, and a pathological index of glomerulonephritis were then analyzed at 22 weeks of age. Survival curves of the 10-week-old and 14-week-old Bz-treated groups were compared. Blood counts, creatinine, liver enzymes, and serum cytokine levels were measured 1 week after Bz treatment. Gene expression profiling of spleens from Bz and Cyc treatment mice were compared with those from control mice.

Results

The anti-dsDNA antibody levels were significantly higher in 14-week-old than in 10-week-old mice, indicating a higher disease activity at 14 weeks. A significant decrease in the number of splenic cells and glomerulonephritis index was observed in Bz-treated and Cyc-treated mice. Bz, but not Cyc, significantly decreased serum immunoglobulin and anti-dsDNA antibody titer levels. Survival curve analysis revealed a significantly higher mortality rate in 14-week-old than in 10-week-old Bz-treated and control groups. Following two injections of Bz, serum IL-6 and TNF-α levels were significantly more elevated in 14-week-old than in 10-week-old mice. Potentially immunogenic molecules, such as heat shock proteins, were characteristically upregulated in spleens of Bz-treated but not Cyc-treated mice.

Conclusions

In spite of its therapeutic effect, Bz treatment had more toxic effects associated with increased proinflammatory cytokine levels in mice with a higher disease activity. Understanding the mechanism of the toxicity and developing preventive strategies against it is important for the safe clinical application of Bz in human SLE.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1397-7) contains supplementary material, which is available to authorized users.

Crucial role of carbonic anhydrase IX in tumorigenicity of xenotransplanted adult T-cell leukemia-derived cells

Carbonic anhydrase IX (CA9) is a membrane‐associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T‐cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1‐N6 subline from the ATL‐derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1‐N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1‐CA9^high and ST1‐CA9^low sublines. ST1‐CA9^high cells, like ST1‐N6 cells, were more strongly tumorigenic than ST1‐CA9^low or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1‐CA9^high cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild‐type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9⁺CD25⁺ cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL‐derived cells and may be involved in malignant development of lymphoma‐type ATL.

High Prevalence of Acute Exacerbation of Interstitial Lung Disease in Japanese Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by extensive fibrosis and autoantibodies. Its clinical manifestations are diverse and include Raynaud's phenomenon, gastrointestinal dysmotility, interstitial lung disease (ILD), pulmonary hypertension, and renal crisis. Among these, ILD is the primary cause of SSc-related death. It has been considered that acute exacerbation of ILD (AE-ILD) is not common in patients with SSc; however, little is known about the prevalence of AE-ILD in Japanese patients with SSc. In this study, we aimed to clarify the prevalence, clinical characteristics, and prognosis of patients with SSc who developed AE-ILD and to identify predictive factors for AE-ILD in our Japanese cohorts. Clinical data of patients who visited our department from 1990 to 2014 and fulfilled the 2013 classification criteria for SSc were retrospectively reviewed. A total of 139 patients were enrolled. The mean age of onset was 49.1 years, and 113 (81.3%) patients were female; 116 (83.5%) had limited cutaneous involvement, and the overall 10-year survival rate was 92.0%. Among 66 (47.5%) patients with ILD, 13 (9.4%) developed AE-ILD. Patients with AE-ILD had a significantly higher incidence of overlap with polymyositis (PM) or dermatomyositis (DM) and lower prevalence of anticentromere antibodies with higher mortality rate compared with those without AE-ILD. Multivariate Cox regression analysis identified that an overlap with PM or DM was the most significant predictive factor for AE-ILD. Our study results suggest that Japanese patients with SSc, particularly patients overlapped with PM or DM, have a high risk of AE-ILD.

Forced FOG1 expression in erythroleukemia cells: Induction of erythroid genes and repression of myelo-lymphoid transcription factor PU.1

The transcription factor GATA-1-interacting protein Friend of GATA-1 (FOG1) is essential for proper transcriptional activation and repression of GATA-1 target genes; yet, the mechanisms by which FOG1 exerts its activating and repressing functions remain unknown. Forced FOG1 expression in human K562 erythroleukemia cells induced the expression of erythroid genes (SLC4A1, globins) but repressed that of GATA-2 and PU.1. A quantitative chromatin immunoprecipitation (ChIP) analysis demonstrated increased GATA-1 chromatin occupancy at both FOG1-activated as well as FOG1-repressed gene loci. However, while TAL1 chromatin occupancy was significantly increased at FOG1-activated gene loci, it was significantly decreased at FOG1-repressed gene loci. When FOG1 was overexpressed in TAL1-knocked down K562 cells, FOG1-mediated activation of HBA, HBG, and SLC4A1 was significantly compromised by TAL1 knockdown, suggesting that FOG1 may require TAL1 to activate GATA-1 target genes. Promoter analysis and quantitative ChIP analysis demonstrated that FOG1-mediated transcriptional repression of PU.1 would be mediated through a GATA-binding element located at its promoter, accompanied by significantly decreased H3 acetylation at lysine 4 and 9 (K4 and K9) as well as H3K4 trimethylation. Our results provide important mechanistic insight into the role of FOG1 in the regulation of GATA-1-regulated genes and suggest that FOG1 has an important role in inducing cells to differentiate toward the erythroid lineage rather than the myelo-lymphoid one by repressing the expression of PU.1.

Evaluation of the safety and efficacy of recombinant soluble thrombomodulin for patients with disseminated intravascular coagulation associated with acute leukemia: multicenter prospective study by the Tohoku Hematology Forum

It has been suggested that use of recombinant soluble thrombomodulin (rTM) is superior to conventional drugs in treatment of disseminated intravascular coagulation (DIC) complicating acute leukemia. However, its safety and efficacy have not been fully examined in prospective studies. Here, we performed a multicenter prospective study to examine outcomes of rTM treatment for DIC in patients with acute leukemia. Of 33 patients registered in this study, 13 had acute myeloid leukemia (AML), three had acute lymphoblastic leukemia (ALL), and 17 had acute promyelocytic leukemia (APL). The cumulative rates of DIC resolution at day 7 and day 35 were 56 and 81% in AML/ALL and 53 and 77% in APL, respectively. The median time from the initiation of rTM to DIC resolution was 4 days in AML/ALL and 6 days in APL patients. Adverse events related to hemorrhage occurred in two AML/ALL patients (13%) and three APL patients (18%). Of these, one AML/ALL patient died with intracranial hemorrhage, and two APL patients died with intracranial hemorrhage and pulmonary hemorrhage. These results suggest that rTM may improve the survival of acute leukemia patients with DIC by inhibiting early death related to hemorrhagic events, as reported previously.

Impact of TET2 deficiency on iron metabolism in erythroblasts

Sideroblastic anemia is characterized by the presence of ring sideroblasts (RSs), which are caused by iron accumulation in the mitochondria of erythroblasts and are present in both the acquired and congenital forms of the disease. However, the mechanism leading to RS formation remains elusive. Acquired sideroblastic anemia is usually observed in myelodysplastic syndrome (MDS). Because a subset of MDS harbors a somatic mutation of TET2, it may be involved in iron metabolism and/or heme biosynthesis in erythroblasts. Tet2 knockdown (Tet2^trap) induced exhibited mild normocytic anemia and elevated serum ferritin levels in 4-month-old mice. Although typical RSs were not observed, increased mitochondrial ferritin (FTMT) amounts were observed in the erythroblasts of Tet2-knockdown mice. Quantitative real-time polymerase chain reaction demonstrated significant dysregulation of genes involved in iron and heme metabolism, including Hmox1, Fech, Abcb7, and Sf3b1 downregulation. After the identification of a cytosine-guanine island in the promoters of Fech, Abcb7, and Sf3b1, we evaluated DNA methylation status and found significantly higher methylation levels at the CpG sites in the erythroblasts of Tet2-knockdown mice. Furthermore, Tet2 knockdown in erythroblasts resulted in decreased heme concentration and accumulation of FTMT. Therefore, TET2 plays a role in the iron and heme metabolism in erythroblasts.

Clinical utility of next-generation sequencing for inherited bone marrow failure syndromes

PURPOSE

Precise genetic diagnosis of inherited bone marrow failure syndromes (IBMFS), a heterogeneous group of genetic disorders, is challenging but essential for precise clinical decision making.

METHODS

We analyzed 121 IBMFS patients using a targeted sequencing covering 184 associated genes and 250 IBMFS patients using whole-exome sequencing (WES).

RESULTS

We achieved successful genetic diagnoses for 53 of 121 patients (44%) using targeted sequencing and for 68 of 250 patients (27%) using WES. In the majority of cases (targeted sequencing: 45/53, 85%; WES: 63/68, 93%), the detected variants were concordant with, and therefore supported, the clinical diagnoses. However, in the remaining 13 cases (8 patients by target sequencing and 5 patients by WES), the clinical diagnoses were incompatible with the detected variants.

CONCLUSION

Our approach utilizing targeted sequencing and WES achieved satisfactory diagnostic rates and supported the efficacy of massive parallel sequencing as a diagnostic tool for IBMFS.Genet Med advance online publication 19 January 2017.

Iron-heme-Bach1 axis is involved in erythroblast adaptation to iron deficiency

Iron plays the central role in oxygen transport by erythrocytes as a constituent of heme and hemoglobin. The importance of iron and heme is also to be found in their regulatory roles during erythroblast maturation. The transcription factor Bach1 may be involved in their regulatory roles since it is deactivated by direct binding of heme. To address whether Bach1 is involved in the responses of erythroblasts to iron status, low iron conditions that induced severe iron deficiency in mice were established. Under iron deficiency, extensive gene expression changes and mitophagy disorder were induced during maturation of erythroblasts. Bach1^−/− mice showed more severe iron deficiency anemia in the developmental phase of mice and a retarded recovery once iron was replenished when compared with wild-type mice. In the absence of Bach1, the expression of globin genes and Hmox1 (encoding heme oxygenase-1) was de-repressed in erythroblasts under iron deficiency, suggesting that Bach1 represses these genes in erythroblasts under iron deficiency to balance the levels of heme and globin. Moreover, an increase in genome-wide DNA methylation was observed in erythroblasts of Bach1^−/− mice under iron deficiency. These findings reveal the principle role of iron as a regulator of gene expression in erythroblast maturation and suggest that the iron-heme-Bach1 axis is important for a proper adaptation of erythroblast to iron deficiency to avoid toxic aggregates of non-heme globin.

Dentin hypersensitivity-like tooth pain seen in patients receiving steroid therapy: An exploratory study

To ascertain whether steroid therapy evokes dentin hypersensitivity (DH)-like tooth pain, we performed a study based on compelling evidence from patients receiving steroid therapy. An exploratory study was conducted using a questionnaire for 220 patients prescribed steroids who attended the Department of Hematology and Rheumatology of Tohoku University Hospital. Group comparisons between patients with and without steroid pulse therapy were analysed by statistical means. In this study, any DH-like tooth pain that commenced subsequent to steroid treatment was defined as steroid-derived (SD) tooth pain. The prevalence of SD tooth pain was 17.7% (39/220 patients). SD tooth pain was triggered in many vital teeth by cold and/or hot water (84.2% and 23.7%, respectively) with the pain characterised as continuous, in contrast to typical DH tooth pain. SD tooth pain was significantly more frequent in pulse therapy patients than in non-pulse therapy patients (p < 0.05). Logistic regression analysis adjusted for age and sex showed similar results (odds ratio = 3.74, p = 0.013). Moreover, a positive correlation was observed between the steroid dose and pain score (ρ = 0.642). Dose reduction or discontinuation of steroid therapy relieved SD tooth pain in all cases. Thus, steroid therapy can evoke DH-like tooth pain during treatment.

An Lysophosphatidic Acid Receptors 1 and 3 Axis Governs Cellular Senescence of Mesenchymal Stromal Cells and Promotes Growth and Vascularization of Multiple Myeloma

Mesenchymal stromal cells (MSCs) are multipotent progenitor cells and there is much interest in how MSCs contribute to the regulation of the tumor microenvironment. Whether MSCs exert a supportive or suppressive effect on tumor progression is still controversial, but is likely dependent on a variety of factors that are tumor-type dependent. Multiple myeloma (MM) is characterized by growth of malignant plasma cells in the bone marrow. It has been shown that the progression of MM is governed by MSCs, which act as a stroma of the myeloma cells. Although stroma is created via mutual communication between myeloma cells and MSCs, the mechanism is poorly understood. Here we explored the role of lysophosphatidic acid (LPA) signaling in cellular events where MSCs were converted into either MM-supportive or MM-suppressive stroma. We found that myeloma cells stimulate MSCs to produce autotaxin, an indispensable enzyme for the biosynthesis of LPA, and LPA receptor 1 (LPA1) and 3 (LPA3) transduce opposite signals to MSCs to determine the fate of MSCs. LPA3-silenced MSCs (siLPA3-MSCs) exhibited cellular senescence-related phenotypes in vitro, and significantly promoted progression of MM and tumor-related angiogenesis in vivo. In contrast, siLPA1-MSCs showed resistance to cellular senescence in vitro, and efficiently delayed progression of MM and tumor-related angiogenesis in vivo. Consistently, anti-MM effects obtained by LPA1-silencing in MSCs were completely reproduced by systemic administration of Ki6425, an LPA1 antagonist. Collectively, our results indicate that LPA signaling determines the fate of MSCs and has potential as a therapeutic target in MM. Stem Cells 2017;35:739-753.

Extracorporeal Shock Wave Therapy for Digital Ulcers of Systemic Sclerosis: A Phase 2 Pilot Study

Patients with systemic sclerosis (SSc) often display Raynaud's phenomenon and digital skin ulcers. As these ulcers are not associated with autoimmune factors or abnormal coagulation, conventional immunosuppressive therapies, vasodilators, and anticoagulants are often ineffective. Here, we used extracorporeal shock wave therapy (ESWT) to treat these ulcers. Nine SSc patients with new digital ulcers, previously treated with at least one currently available vasodilator or anticoagulant were enrolled. One ESWT session consisted of 100 pulses at 0.08-0.25 mJ/mm(2) in 20 areas on both hands and 15 areas on both feet, totaling 7,000 pulses. Treatment was performed once per week for 9 weeks with observations over 20 weeks. Outcomes were evaluated according to the number and diameter of ulcers, Rodnan skin score, Health Assessment Questionnaire (HAQ), EuroQol 5 dimensions (EQ-5D), visual analog scale for pain, and the PainVision system. The surface skin temperature of all the fingers was measured using thermography. Ulcers showed signs of healing after one session, and their mean number decreased from 5.4 to 1.1 at 9 weeks. In particular, of the 18 large ulcers (> 5 mm) observed in 7 patients before the treatment, 10 disappeared and the rest became smaller; namely, the mean size decreased from 10.9 mm to 2.5 mm at 20 weeks. The average scores on the HAQ, EQ-5D, and PainVision system also improved. Treatment was minimally invasive and could be repeated without any adverse effects. ESWT may be added to standard treatments for indolent digital ulcers of SSc, as an effective and safe method.

Causes of macrocytic anemia among 628 patients: mean corpuscular volumes of 114 and 130 fL as critical markers for categorization

There have been no studies on the distribution of causes of macrocytic anemia with respect to mean corpuscular volume (MCV) cutoff values. We retrospectively investigated the causes of macrocytic anemia (MCV ≥100 fL) among 628 patients who visited the outpatient hematology clinic in Tohoku University Hospital. To ensure data validity, we also analyzed data from 307 patients in eight other hospitals in the Tohoku district. The leading causes of macrocytic anemia (number of patients, %) were myelodysplastic syndromes (121, 19.3 %), suspected bone marrow failure syndromes (BMF; 74, 11.8 %), aplastic anemia (51, 8.1 %), plasma cell dyscrasia (45, 7.2 %), and vitamin B12 deficiency (40, 6.4 %) in Tohoku University Hospital. We made three primary findings as follows. First, the most common cause of macrocytic anemia is BMF. Second, lymphoid and solid malignancies are also common causes of macrocytosis. Third, macrocytic anemia may be classified into three groups: Group 1 (megaloblastic anemia and medications), which can exceed MCV 130 fL; Group 2 (alcoholism/liver disease, BMF, myeloid malignancy, and hemolytic anemia), which can exceed MCV 114 fL; and Group 3 (lymphoid malignancy, chronic renal failure, hypothyroidism, and solid tumors), which does not exceed MCV 114 fL. These conclusions were supported by the results from eight other hospitals.

A Comparative Study of Ethylene Oxide Gas, Hydrogen Peroxide Gas Plasma, and Low-Temperature Steam Formaldehyde Sterilization

Objective:

To compare the efficacies of ethylene oxide gas (EOG), hydrogen peroxide gas plasma (PLASMA), and low-temperature steam formaldehyde (LTSF) sterilization methods.

Methods:

The efficacies of EOG, PLASMA, and LTSF sterilization were tested using metal and plastic plates, common medical instruments, and three process challenge devices with narrow lumens. All items were contaminated with Bacillus stearothermophilus spores or used a standard biological indicator.

Results:

EOG and LTSF demonstrated effective killing of B. stearothermophilus spores, with or without serum, on plates, on instruments, and in process challenge devices. PLASMA failed to adequately sterilize materials on multiple trials in several experiments, including two of three plates, two of three instruments, and all process challenge devices.

Conclusions:

Our results suggest that PLASMA sterilization may be unsuccessful under certain conditions, particularly when used for items with complex shapes and narrow lumens. Alternatively, LTSF sterilization demonstrates excellent efficacy and is comparable to EOG sterilization. LTSF could potentially act as a substitute if EOG becomes unavailable due to environmental concerns.

High prevalence of diffuse large B-cell lymphoma in occult hepatitis B virus-infected patients in the Tohoku district in Eastern Japan

Occult hepatitis B virus (HBV) infection is a clinical challenge, but its relationship to clinicopathologic features and the risk of progression to malignant lymphoma (ML) are poorly defined. We estimated the prevalence of HBV infection of 1,358 patients with newly diagnosed ML. HBV infection was more prevalent in ML than in control patients. The occult HBV infection group had a higher median onset age, no liver or spleen involvement, and higher prevalence of diffuse large B-cell lymphoma than the other groups, indicating that occult HBV infection is a distinct clinicopathologic entity. J. Med. Virol. 88:2206-2210, 2016. © 2016 Wiley Periodicals, Inc.

Non-biased and complete case registration of lymphoid leukemia and lymphoma for five years: a first representative index of Japan from an epidemiologically stable Miyagi Prefecture

Previous worldwide epidemiological studies on lymphoid leukemia and/or lymphoma (LL/L) had considerable bias because of difficulty in covering all clinical departments of hospitals in a restricted area (population base). These studies may not have reflected the actual number of newly diagnosed cases (incidence) strictly, or the true LL/L subtype frequencies. We searched all cases of newly diagnosed LL/L in Miyagi Prefecture over a 5-year period, including those that were discovered as LL/L sorely after autopsy. We registered the actual number of 2098 cases in the prefecture and calculated an accurate incidence rate (17.8 per 100,000 persons). Additionally, we identified more realistic and detailed frequencies of LL/L subtypes including the leukemic phase of some lymphomas. As Miyagi Prefecture is an area in which the population dynamics are relatively stable and representative of Japan, the result of our epidemiological study can be used as the first representative index of LL/L for Japan.

Pretreatment Screening for Hepatitis B Virus Infection in Patients with Systemic Lupus Erythematosus

Hepatitis B virus (HBV) infection is one of the most common diseases, and approximately two billion people are infected with HBV in the world. Until recently, hepatitis B surface antigen (HBsAg)-negative patients, carrying hepatitis B surface antibody (anti-HBs) and/or hepatitis B core antibody (anti-HBc), have been considered to have achieved the resolution of HBV infection; however, among those patients, the reactivation of HBV has been increasingly reported after chemotherapy, hematopoietic stem cell transplantation, or immunosuppressive therapy. The reactivation of HBV can cause lethal hepatitis called de novo hepatitis B. Therefore, serological examination for HBV infection before starting immunosuppressive therapy is now recommended for all patients with rheumatic diseases. Systemic lupus erythematosus (SLE) is one of the autoimmune diseases characterized by the production of autoantibodies and usually requires immunosuppressive therapy. However, to date, a few reports are available regarding the prevalence and time course of HBV infection in patients with SLE under immunosuppressive therapy. In this review, we update the prevalence and time course of HBV infection in lupus patients using our data and previous papers available, with a special emphasis on occult HBV infection and a decrease of HBV-related antibodies (anti-HBs and anti-HBc) under immunosuppressive therapy. This review also highlights the screening and management of HBV infection currently recommended and the potential role of HBV infection in the pathogenesis of SLE. Throughout the present review, we recommend the pretreatment screening for HBV infection in patients with SLE as well as patients with other rheumatic diseases.

Xenotransplantation elicits salient tumorigenicity of adult T-cell leukemia-derived cells via aberrant AKT activation

The transplantation of human cancer cells into immunodeficient NOD/SCID/IL‐2Rγc^null (NOG) mice often causes highly malignant cell populations like cancer stem cells to emerge. Here, by serial transplantation in NOG mice, we established two highly tumorigenic adult T‐cell leukemia‐derived cell lines, ST1‐N6 and TL‐Om1‐N8. When transplanted s.c., these cells formed tumors significantly earlier and from fewer initial cells than their parental lines ST1 and TL‐Om1. We found that protein kinase B (AKT) signaling was upregulated in ST1‐N6 and TL‐Om1‐N8 cells, and that this upregulation was due to the decreased expression of a negative regulator, INPP5D. Furthermore, the introduction of a constitutively active AKT mutant expression vector into ST1 cells augmented the tumorigenicity of the cells, whereas treatment with the AKT inhibitor MK‐2206 attenuated the progression of tumors induced by ST1‐N6 cells. Collectively, our results reveal that the AKT signaling pathway plays a critical role in the malignancy of adult T‐cell leukemia‐derived cells.