Low CD38 Identifies Progenitor-like Inflammation-Associated Luminal Cells that Can Initiate Human Prostate Cancer and Predict Poor Outcome

Inflammation is a risk factor for prostate cancer, but the mechanisms by which inflammation increases that risk are poorly understood. Here, we demonstrate that low expression of CD38 identifies a progenitor-like subset of luminal cells in the human prostate. CD38^lo luminal cells are enriched in glands adjacent to inflammatory cells and exhibit epithelial nuclear factor κB (NF-κB) signaling. In response to oncogenic transformation, CD38^lo luminal cells can initiate human prostate cancer in an in vivo tissue-regeneration assay. Finally, the CD38^lo luminal phenotype and gene signature are associated with disease progression and poor outcome in prostate cancer. Our results suggest that prostate inflammation expands the pool of progenitor-like target cells susceptible to tumorigenesis.

Blockade of CD38 diminishes lipopolysaccharide-induced macrophage classical activation and acute kidney injury involving NF-κB signaling suppression

The CD38, possessing ADP-ribosyl cyclase (ADPR-cyclase) and cyclic ADP-ribose hydrolase (cADPR-hydrolase), is able to regulate a variety of cellular activities. However, the role and mechanisms for CD38 in macrophage activation and sepsis-induced acute kidney injury (AKI) remain to be determined. Here we report that in cultured macrophages, Lipopolysaccharide (LPS) could upregulate CD38 expression in time and dose dependent manner. Knocking down or blockade of CD38 in macrophages could inhibit LPS-induced macrophage M1 polarization accompanied by diminished NF-κB signaling activation. In mouse model with LPS-induced acute kidney injury, blocking CD38 with quercetin could significantly relieve kidney dysfunction, kidney pathological changes as well as inflammatory cell accumulation. Similar to those in the cultured cells, quercetin could inhibit macrophage M1 polarization and NF-κB signaling activation in macrophages from kidneys and spleens in mice after LPS injection. Together, these results demonstrate that CD38 mediates LPS-induced macrophage activation and AKI, which may be treated as a therapeutic target for sepsis-induced AKI in patients.

NAD and the aging process: Role in life, death and everything in between

Life as we know it cannot exist without the nucleotide nicotinamide adenine dinucleotide (NAD). From the simplest organism, such as bacteria, to the most complex multicellular organisms, NAD is a key cellular component. NAD is extremely abundant in most living cells and has traditionally been described to be a cofactor in electron transfer during oxidation-reduction reactions. In addition to participating in these reactions, NAD has also been shown to play a key role in cell signaling, regulating several pathways from intracellular calcium transients to the epigenetic status of chromatin. Thus, NAD is a molecule that provides an important link between signaling and metabolism, and serves as a key molecule in cellular metabolic sensoring pathways. Importantly, it has now been clearly demonstrated that cellular NAD levels decline during chronological aging. This decline appears to play a crucial role in the development of metabolic dysfunction and age-related diseases. In this review we will discuss the molecular mechanisms responsible for the decrease in NAD levels during aging. Since other reviews on this subject have been recently published, we will concentrate on presenting a critical appraisal of the current status of the literature and will highlight some controversial topics in the field. In particular, we will discuss the potential role of the NADase CD38 as a driver of age-related NAD decline.

A field study of the association between CD38 gene and altruistic behavior: Empathic response as a mediator

Inspired by the enhancement effects of oxytocin on empathic responses and altruistic behaviors, we conducted a field study with a real fundraising event and investigated to what extent oxytocin pathway genes (CD38 and OXTR) modulate individual differences in charitable donation. Participants were informed that a teacher in their university was diagnosed with uremia and could not afford the cost of medication. They were given the opportunity to donate any amount of money and report their empathic responses to the misfortune of the teacher. We found a significant association between CD38 rs3796863 and the amount of donation both before and after controlling for gender, age, subjective socioeconomic status, religious belief, and social desirability. Individuals with the genotypes (AA/AC) leading to higher oxytocin levels reported stronger empathic responses and donated more money than individuals with the CC genotype. Moreover, empathic response mediated the gene-altruism association. However, we observed no significant associations between the three polymorphisms of OXTR (rs53576, rs2254298, and rs1042778) and the amount of donation. This study demonstrates the importance of CD38 as a source of individual differences in altruistic behavior and highlights the role of empathic response in bridging the link between the oxytocin pathway gene and altruism.

Increased proportion of a CD38highIgD+ B cell subset in peripheral blood is associated with clinical and immunological features in patients with primary Sjögren's syndrome

We investigated the correlation between the increased proportion of peripheral B cell subsets and clinical and immunological features in primary Sjögren's syndrome (pSS). We found that the proportion of CD19⁺ B cells was significantly increased in pSS as compared with HC and was correlated with serum IgG levels. Moreover, in vitro IgG production by CD19⁺ B cells was significantly increased in pSS and was positively and significantly correlated with serum IgG levels. FACS analysis revealed that the proportions of peripherally CD38^highIgD⁺ B cells and CD38^highIgD^- B cells were significantly increased in pSS. In addition, the proportion of CD38^highIgD⁺ B cells positively correlated with ESSDAI scores and serum levels of IgG, anti-Ro/SSA and anti-La/SSB antibodies while that of CD38^highIgD^- B cells showed no correlation with these parameters. Our data suggest that increased proportion of CD38^highIgD⁺ B cells in pSS is involved in IgG overproduction including autoantibodies, and correlates with disease progression.

Double CD38-/CD138- negative multiple myeloma

The standard diagnosis of multiple myeloma by flow cytometry is based on selection of population of CD38⁺/CD138⁺ positives cells. As the result treatment with proteasome inhibitors, CD138 may be underexpressed on atypical plasma cells. Thus, in order to improve this strategy, recently new CD138-independent method, based on CD38 positivity of plasma cells was developed. We present an unusual case of CD138^- negative multiple myeloma which had become double CD138^-/CD38^- negative after treatment with daratumumab by which we would like to illustrate potential pitfalls of both strategies.

Effects of Three Lipidated Oxytocin Analogs on Behavioral Deficits in CD38 Knockout Mice

Oxytocin (OT) is a nonapeptide that plays an important role in social behavior. Nasal administration of OT has been shown to improve trust in healthy humans and social interaction in autistic subjects. As is consistent with the nature of a peptide, OT has some unfavorable characteristics: it has a short half-life in plasma and shows poor permeability across the blood-brain barrier. Analogs with long-lasting effects may overcome these drawbacks. To this end, we have synthesized three analogs: lipo-oxytocin-1 (LOT-1), in which two palmitoyl groups are conjugated to the cysteine and tyrosine residues, lipo-oxytocin-2 (LOT-2) and lipo-oxytocin-3 (LOT-3), which include one palmitoyl group conjugated at the cysteine or tyrosine residue, respectively. The following behavioral deficits were observed in CD38 knockout (CD38^−/−) mice: a lack of paternal nurturing in CD38^−/− sires, decreased ability for social recognition, and decreased sucrose consumption. OT demonstrated the ability to recover these disturbances to the level of wild-type mice for 30 min after injection. LOT-2 and LOT-3 partially recovered the behaviors for a short period. Conversely, LOT-1 restored the behavioral parameters, not for 30 min, but for 24 h. These data suggest that the lipidation of OT has some therapeutic benefits, and LOT-1 would be most useful because of its long-last activity.

BAFF augments IgA2 and IL-10 production by TLR7/8 stimulated total peripheral blood B cells

Class‐switching of B cells to IgA can be induced via both T‐cell‐dependent and T‐cell‐independent mechanisms. IgA is most predominantly produced mucosally and is important for combating infections and allergies. In contrast to mice, humans have two forms of IgA; IgA1 and IgA2 with diverse tissue distribution. In early life, IgA levels might be sub‐optimal especially during the fall season when bacterial and viral infections are more common. Therefore, we investigated using human B cells whether T‐cell‐independent factors ‐promoting cell survival, class switching and immunoglobulin secretion‐ BAFF, APRIL, IL‐10 and retinoic acid can boost IgA production in the context of viral or bacterial infection. To this end total and naive peripheral blood B cells were stimulated with these factors for 6 days in the presence or absence of TLR7/8 agonist R848 (mimicking viral infection) or TLR9 agonist CpG‐ODN (mimicking bacterial infection). We show that BAFF significantly augments IgA2 production in TLR7/8 stimulated mature, but not naïve B cells. In addition, BAFF augments IL‐10 production and viability in TLR7/8 and TLR9 stimulated mature B cells. These data warrant further investigation of its role in immune regulation both in the periphery and mucosal tissues in early life or during disease.

Inhibiting the CD38/cADPR pathway protected rats against sepsis associated brain injury

BACKGROUND

The CD38/cADPR pathway has been found to play roles in various inflammatory conditions. However, whether CD38 plays a protective or detrimental effect in the central nervous system (CNS) is controversial. The aim of this study was to determine the effect of CD38/cADPR pathway in sepsis associated brain injury.

MATERIALS AND METHODS

Male Sprague-Dawley rats were undergone cecal ligation and puncture (CLP) or sham laparotomies. NAD⁺, cADPR and CD38 were measured in the hippocampus of septic rats at 0, 6, 12, 24, and 48h after CLP surgery. Rats were divided into the sham, CLP group, CLP+ CD38 expression lentivirus (CLP+ CD38 LV), CLP+ CD38 interference lentivirus (CLP+ CD38 Ri), CLP+ negative control lentivirus (CLP+NC) and the CLP+8-Br-cADPR groups. The Western blots of Bcl-2, Bax and iNOS, TUNEL assays, malondialdehyde (MDA) and superoxide dismutase (SOD) assays, transmission electron microscope analysis were performed in the hippocampus of rats.

RESULTS

NAD⁺, cADPR and CD38 levels increased significantly in the hippocampus of septic rats as early as 12-24h after CLP surgery. CD38 knockdown or blocking cADPR with 8-Br-cADPR significantly reduced apoptosis, MDA and SOD activity, iNOS expression and ultrastructural morphology damages in the hippocampus of septic rats.

CONCLUSIONS

In this study, we found that the CD38/cADPR pathway was activated in sepsis associated brain injury. Blocking this pathway protected the hippocampus from apoptosis, oxidative stress and ultrastructural morphology damages in septic rats.

Blood Transfusion Management and Transfusion-Related Outcomes in Daratumumab-Treated Patients With Relapsed or Refractory Multiple Myeloma

INTRODUCTION

Daratumumab, a human CD38 monoclonal antibody approved for multiple myeloma (MM) treatment, binds red blood cells (RBCs), resulting in panagglutination in compatibility tests. Published mitigation methods avoid additional testing, ensuring timely release of blood products. Blood transfusion management and transfusion-related outcomes of daratumumab-treated patients in the SIRIUS study are reported, with emphasis on 2 clinical sites.

PATIENTS AND METHODS

Patients had MM treated with ≥ 3 prior lines of therapy, including a proteasome inhibitor and an immunomodulatory drug, or were refractory to a proteasome inhibitor and an immunomodulatory drug. RBC typing and alloantibody screening were performed in gel cards. Antibody identification using RBC panels was performed on patients with positive antibody screens. Hematology panels and serum chemistry were analyzed ≤ 2 days before each daratumumab infusion and the first daratumumab dose within each treatment cycle, respectively. Pre- and posttransfusion hemoglobin values were analyzed retrospectively.

RESULTS

At clinical cutoff, patients received 236 transfusions; 47 (37.9%) of 124 patients received 147 packed RBC transfusions, and 17 (13.7%) received 89 platelet transfusions. No hemolysis was reported, and 1 platelet transfusion reaction was observed. At Mount Sinai, no transfusion adverse events were observed, no new unexpected RBC alloantibodies were identified, and transfusions increased hemoglobin values (median, 1.2 g/dL). At Levine Cancer Institute, 6 of 7 patients responded to transfusions, with a median hemoglobin change of 1.7 g/dL.

CONCLUSION

In SIRIUS, no RBC transfusion reactions, including hemolysis, were observed. Observations from Mount Sinai and Levine Cancer Institute confirm that transfusions may be administered safely to daratumumab-treated patients.

Cryptochrome-1 Gene Expression is a Reliable Prognostic Indicator in Egyptian Patients with Chronic Lymphocytic Leukemia: A Prospective Cohort Study

Objective

Traditional prognostic factors have proved insufficient to account for heterogeneity in the clinical behavior of chronic lymphocytic leukemia (CLL). Cryptochrome-1 (CRY-1) is a circadian clock gene essential in maintaining the circadian rhythm and regulating cell proliferation. We evaluated CRY-1 gene expression in CLL and addressed its putative role as a prognostic indicator for the clinical course of CLL.

Materials and Methods

A total of 100 CLL patients at diagnosis were studied for CRY-1 gene expression by real-time reverse-transcription polymerase chain reaction and were followed for assessment of time to first treatment (TFT).

Results

CRY-1 was expressed in 94% of the CLL patients at diagnosis. The median CRY-1 relative gene expression level (0.006) stratified patients into high and low expression groups. Forty of 100 (40%) CLL patients showed high CRY-1, 54/100 (54%) showed low CRY-1, and 6/100 (6%) had undetectable CRY-1 gene expression. High CRY-1 gene expression was concordant with CD38⁺, Zap-70⁺, and double CD38⁺Zap-70⁺ expression; unfavorable/intermediate cytogenetics; unmutated immunoglobulin heavy-chain variable-region gene; and diffuse marrow infiltration. The high CRY-1 gene expression patient group exhibited shorter TFT than the patients with low CRY-1 gene expression. A Cox proportional hazard regression model identified CRY-1 gene expression to be independently predictive for TFT.

Conclusion

CRY-1 is differentially expressed among CLL patients, stratifying them into low-risk and high-risk groups. CRY-1 gene expression could constitute a reliable prognostic indicator for CLL progression, complementing the role of standard well-established prognostic factors. CRY-1 gene expression could be employed as a prognostic indicator for disease progression during the initial prognostic work-up and follow-up for CLL patients.

Targeting NAD+ degradation: The therapeutic potential of flavonoids for Alzheimer's disease and cognitive frailty

Flavonoids are efficacious candidates as pharmaceuticals or nutraceuticals in the treatment of Alzheimer's disease (AD), aging and other age-related chronic inflammatory diseases. Natural flavonoids reduce pathological hallmarks, extracellular amyloid deposits and neurofibrillary tangles by mediating amyloid precursor protein (APP) processing, Aβ accumulation and tau pathology. The antioxidant and anti-inflammatory actions as well as modulation of sirtuins and telomeres are also involved in the amelioration of aging, neurodegeneration and other age-related diseases. Recently, some flavonoids were shown to inhibit poly (ADP-ribose) polymerases (PARPs) and cyclic ADP-ribose (cADP) synthases (CD38 and CD157), elevate intracellular nicotinamide adenine dinucleotide⁺ (NAD⁺) levels and activate NAD⁺ dependent sirtuin -mediated signaling pathways. We summarized how flavonoids reduce the degradation of NAD⁺ with an emphasis on the mechanisms through which flavonoids affect the NAD⁺-sirtuin axis to protect against AD. Aging and age-related diseases as well as a decline in the physiological reserve are the risk factors for cognitive frailty. Flavonoids with multiple therapeutic targets may also be potential candidates for the prevention and treatment of cognitive frailty.

CD38 deficiency suppresses adipogenesis and lipogenesis in adipose tissues through activating Sirt1/PPARγ signaling pathway

It has been recently reported that CD38 was highly expressed in adipose tissues from obese people and CD38-deficient mice were resistant to high-fat diet (HFD)-induced obesity. However, the role of CD38 in the regulation of adipogenesis and lipogenesis is unknown. In this study, to explore the roles of CD38 in adipogenesis and lipogenesis in vivo and in vitro, obesity models were generated with male CD38^-/- and WT mice fed with HFD. The adipocyte differentiations were induced with MEFs from WT and CD38^-/- mice, 3T3-L1 and C3H10T1/2 cells in vitro. The lipid accumulations and the alternations of CD38 and the genes involved in adipogenesis and lipogenesis were determined with the adipose tissues from the HFD-fed mice or the MEFs, 3T3-L1 and C3H10T1/2 cells during induction of adipocyte differentiation. The results showed that CD38^-/- male mice were significantly resistant to HFD-induced obesity. CD38 expressions in adipocytes were significantly increased in WT mice fed with HFD, and the similar results were obtained from WT MEFs, 3T3-L1 and C3H10T1/2 during induction of adipocyte differentiation. The expressions of PPARγ, AP2 and C/EBPα were markedly attenuated in adipocytes from HFD-fed CD38^-/- mice and CD38^-/- MEFs at late stage of adipocyte differentiation. Moreover, the expressions of SREBP1 and FASN were also significantly decreased in CD38^-/- MEFs. Finally, the CD38 deficiency-mediated activations of Sirt1 signalling were up-regulated or down-regulated by resveratrol and nicotinamide, respectively. These results suggest that CD38 deficiency impairs adipogenesis and lipogenesis through activating Sirt1/PPARγ-FASN signalling pathway during the development of obesity.

Up-regulated expression of oxytocin mRNA in peripheral blood lymphocytes from first-episode schizophrenia patients

Schizophrenia (SZ) is a severe neuropsychiatric disorder with significant social cognition impairment. Increasing evidence has suggested that neuropeptides oxytocin (OXT) and arginine vasopressin (AVP) are important mediators of complex social cognition and behavior associates with SZ. In the present study, forty-three first-episode schizophrenia (FES) patients and forty-seven healthy controls (HC) were included. The peripheral mRNA expression of OXT, OXT receptor (OXTR), AVP, AVP 1a receptor (AVPR1a) and CD38 was determined by real-time quantitative polymerase chain reaction (RT-qPCR). The FES patients have a relatively higher mRNA level of OXT and OXTR genes and lower expression of AVP and CD38 genes than HC. No difference was found for AVPR1a between FES patients and HC. As for the sex difference, the mRNA expression of OXT and OXTR showed no difference in both male and female FES patients compared to HC group. The AVP and CD38 genes in female FES patients showed decreased mRNA expression than female HC. Our findings support disrupted OXT and AVP systems in the FES patients.

Blocking the CD38/cADPR pathway plays a double-edged role in LPS stimulated microglia

Whether the CD38/cyclic ADP-ribose (cADPR) pathway plays a protective or detrimental role in neuroinflammation remains controversial. This study aimed to determine the role of CD38 in neuroinflammation using lipopolysaccharide (LPS)-stimulated BV2 microglial cells and co-cultured Neuro-2a (N2a) cells. In monoculture experiments, BV2 cells were divided into control, CD38 interference (CD38Ri), negative control (NC), LPS, CD38Ri+LPS, NC+LPS and 8-Br-cADPR+LPS groups. In co-culture experiments, N2a cells were co-cultured with BV2 cells for 48h. Nicotinamide adenine dinucleotide (NAD⁺), cADPR and intracellular Ca²⁺ levels and CD38 expression increased significantly in LPS-stimulated BV2 cells. CD38 knockdown or 8-Br-cADPR treatment significantly reduced NAD⁺, cADPR and intracellular Ca²⁺ levels. CD38 knockdown increased iNOS and NO levels in BV2 cells without LPS treatment; however, CD38 knockdown or 8-Br-cADPR treatment reduced iNOS and NO levels in BV2 cells with LPS treatment. CD38 knockdown increased the ratio of TUNEL-positive cells and cleaved Caspase 3/Caspase 3 ratio, and decreased the Bcl-2/Bax ratio in BV2 cells without LPS treatment; however, CD38 knockdown reduced the TUNEL positivity in BV2 cells with LPS treatment. CD38 knockdown or 8-Br-cADPR inhibited TNF-α, IL-6 (interleukin-6) and IL-1β levels in LPS-stimulated BV2 cells. Co-culture with CD38 knockdown or 8-Br-cADPR-treated BV2 cells did not influence apoptosis or iNOS expression in N2a cells. In conclusion, our results indicate that blocking the CD38/cADPR pathway reduces intracellular Ca²⁺, NO and the secretion of proinflammatory cytokines. CD38 knockdown exerted a detrimental effect in apoptosis and NO production in normal microglia, but played a protective role in apoptosis and NO production in LPS-stimulated microglia.

Expression and Regulatory Network Analysis of miR-140-3p, a New Potential Serum Biomarker for Autism Spectrum Disorder

Given its prevalence and social impact, Autism Spectrum Disorder (ASD) is drawing much interest. Molecular basis of ASD is heterogeneous and only partially known. Many factors, including disorders comorbid with ASD, like TS (Tourette Syndrome), complicate ASD behavior-based diagnosis and make it vulnerable to bias. To further investigate ASD etiology and to identify potential biomarkers to support its precise diagnosis, we used TaqMan Low Density Array technology to profile serum miRNAs from ASD, TS, and TS+ASD patients, and unaffected controls (NCs). Through validation assays in 30 ASD, 24 TS, and 25 TS+ASD patients and 25 NCs, we demonstrated that miR-140-3p is upregulated in ASD vs.: NC, TS, and TS+ASD (Tukey's test, p-values = 0.03, = 0.01, < 0.0001, respectively). ΔCt values for miR-140-3p and YGTSS (Yale Global Tic Severity Scale) scores are positively correlated (Spearman r = 0.33; Benjamini-Hochberg p = 0.008) and show a linear relationship (p = 0.002). Network functional analysis showed that nodes controlled by miR-140-3p, especially CD38 and NRIP1 which are its validated targets, are involved in processes convergingly dysregulated in ASD, such as synaptic plasticity, immune response, and chromatin binding. Biomarker analysis proved that serum miR-140-3p can discriminate among: (1) ASD and NC (Area under the ROC curve, AUC: 0.70; sensitivity: 63.33%; specificity: 68%); (2) ASD and TS (AUC: 0.72; sensitivity: 66.66%; specificity: 70.83%); (3) ASD and TS+ASD (AUC: 0.78; sensitivity: 73.33%; specificity: 76%). Characterization of miR-140-3p network would contribute to further clarify ASD etiology. Serum miR-140-3p could represent a potential non-invasive biomarker for ASD, easy to test through liquid biopsy.

Novel Immunotherapies for Multiple Myeloma

PURPOSE OF REVIEW

The treatment landscape of multiple myeloma is rapidly changing; however, despite improvement in patients' survival, it still remains a largely incurable disease. One hallmark of myeloma is substantial immune dysfunction leading to an increased infection rate and the inability of immune surveillance to detect neoplastic cells. Here, we critically analyze clinical approaches to harness the immune system to overcome this defect with a focus on antibody based and adoptive cellular therapies.

RECENT FINDINGS

Clinical trials exploring these immunotherapies to treat myeloma are now well underway and show promising results. In relapsed myeloma, monoclonal antibodies directed against plasma cell antigens and immune checkpoints have already shown substantial efficacy. In parallel, trials of adoptive cellular therapy have exciting promise in myeloma, having induced dramatic responses in a handful of early study participants. Taken together, immunotherapeutic approaches hold enormous potential in the field of multiple myeloma and in the near future can be combined with or even replace the current standard of care.

Immune signature profiling identified predictive and prognostic factors for esophageal squamous cell carcinoma

Understanding interactions between tumor and the host immune system holds great promise to uncover biomarkers for targeted therapies and clinical outcomes. However, systematical analysis of immune signatures in esophageal squamous cell carcinoma (ESCC) remains largely unstudied. In this study, immune signatures containing 708 immune related genes were curated from mRNA microarray data with tumor and paired normal tissues from 119 ESCC patients. Differential expression and survival analysis were performed with validations from Human Protein Atlas and an independent cohort of 110 ESCC patients by immunohistochemistry staining. We identified a total of 186 significantly dysregulated genes in ESCC, including downregulated genes SPINK5, IL1RN and upregulated genes SPP1 and PLAU, which were further confirmed in Human Protein Atlas data. Moreover, nine immune related genes (ABL1, ATF2, ATG5, C6, CD38, HMGB1, ICOSLG, IL12RB2 and PLAU) were significantly associated with patients' overall survival, among which, prognostic model was built including three independent factors ABL1, CD38 and ICOSLG. Validation by immunohistochemistry staining suggested that combination with tumor infiltrated CD4+ and CD8+ T lymphocytes would yield higher performance in distinguishing cases as high or low risk of unfavorable prognosis. In summary, we profiled the immune status in ESCC and established predictive and prognostic factors for ESCC, which could reflect immune disorders within tumor microenvironments and independently distinguish patients with a high risk of reduced survival, providing novel predictive and therapeutic targets for ESCC patients in the future.

Cytosolic interaction of type III human CD38 with CIB1 modulates cellular cyclic ADP-ribose levels

CD38 catalyzes the synthesis of the Ca²⁺ messenger, cyclic ADP-ribose (cADPR). It is generally considered to be a type II protein with the catalytic domain facing outside. How it can catalyze the synthesis of intracellular cADPR that targets the endoplasmic Ca²⁺ stores has not been resolved. We have proposed that CD38 can also exist in an opposite type III orientation with its catalytic domain facing the cytosol. Here, we developed a method using specific nanobodies to immunotarget two different epitopes simultaneously on the catalytic domain of the type III CD38 and firmly established that it is naturally occurring in human multiple myeloma cells. Because type III CD38 is topologically amenable to cytosolic regulation, we used yeast-two-hybrid screening to identify cytosolic Ca²⁺ and integrin-binding protein 1 (CIB1), as its interacting partner. The results from immunoprecipitation, ELISA, and bimolecular fluorescence complementation confirmed that CIB1 binds specifically to the catalytic domain of CD38, in vivo and in vitro. Mutational studies established that the N terminus of CIB1 is the interacting domain. Using shRNA to knock down and Cas9/guide RNA to knock out CIB1, a direct correlation between the cellular cADPR and CIB1 levels was demonstrated. The results indicate that the type III CD38 is functionally active in producing cellular cADPR and that the activity is specifically modulated through interaction with cytosolic CIB1.

Interferon-alpha-based immunotherapies in the treatment of B cell-derived hematologic neoplasms in today's treat-to-target era

B cell lymphoma and multiple myeloma (MM) are the most common hematological malignancies which benefit from therapeutic monoclonal antibodies (mAbs)-based immunotherapies. Despite significant improvement on patient outcome following the use of novel therapies for the past decades, curative treatment is unavailable for the majority of patients. For example, the 5-year survival of MM is currently less than 50%. In the 1980s, interferon-α was used as monotherapy in newly diagnosed or previously treated MM with an overall response rate of 15–20%. Noticeably, a small subset of patients who responded to long-term interferon-α further achieved sustained complete remission. Since 1990, interferon-α-containing regimens have been used as a central maintenance strategy for patients with MM. However, the systemic administration of interferon-α was ultimately limited by its pronounced toxicity. To address this, the selective mAb-mediated delivery of interferon-α has been developed to enhance specific killing of MM and B-cell malignant cells. As such, targeted interferon-α therapy may improve therapeutic window and sustain responses, while further overcoming suppressive microenvironment. This review aims to reinforce the role of interferon-α by consolidating our current understanding of targeting interferon-α with tumor-specific mAbs for B cell lymphoma and myeloma.

CD38 enhances the proliferation and inhibits the apoptosis of cervical cancer cells by affecting the mitochondria functions

Cervical cancer is one of the most common malignant tumors in women all over the world. The exact mechanism of occurrence and development of cervical cancer has not been fully elucidated. CD38 is a type II transmembrane glycoprotein, which was found to mediate diverse activities, including signal transduction, cell adhesion, and cyclic ADP-ribose synthesis. Here, we reported that CD38 promoted cell proliferation and inhibited cell apoptosis in cervical cancer cells by affecting the mitochondria functions. We established stable cervical cancer cell lines with CD38 over-expressed. CCK8 assay and colony formation assay indicated that CD38 promoted cervical cancer cell proliferation. Nude mouse tumorigenicity assay showed that CD38 significantly promotes tumor growth in vivo. CD38 also induced S phase accumulation in cell cycle analysis and suppressed cell apoptosis in cervical cancer cells. Meanwhile, flow cytometry analysis of mitochondria functions suggested that CD38 decreased intracellular Ca²⁺ levels in cervical cancer cells and CD38 was involved in down-regulation of ROS levels and prevented mitochondrial apoptosis in cervical cancer cells. The percentage of cells with loss of mitochondrial membrane potential (Δψm) in CD38-overexpressed cervical cancer cells was less than control groups. Furthermore, we found an up-regulation of MDM2, cyclinA1, CDK4, cyclinD1, NF-kB P65, c-rel, and a downregulation of P53, P21, and P38 by Western blot analysis. These results indicated that CD38 enhanced the proliferation and inhibited the apoptosis of cervical cancer cells by affecting the mitochondria functions.

Novel approaches to targeting MYD88 in Waldenström macroglobulinemia

INTRODUCTION

Waldenström macroglobulinemia (WM) is an incurable lymphoma characterized by the accumulation of IgM-producing lymphoplasmacytic cells in the bone marrow and other organs. Although WM patients can experience prolonged remissions, the disease invariably recurs advocating for the need of novel treatments in order to achieve higher response and survival rates. The discovery of a recurrent mutation in the MYD88 gene and an increased understanding behind the biology of MYD88 signaling have provided the opportunity to developing novel agents targeting the MYD88 pathway. Areas covered: The present review focuses on potential therapies that could change the landscape of treatment of patients with WM, specifically focusing on inhibitors of the Bruton tyrosine kinase (BTK), phosphatidylinositol-3 kinase, hematopoietic cell kinase, interleukin-1 receptor associated kinase and MYD88 assembly. Expert commentary: Novel agents such as the BTK inhibitor ibrutinib has shown to be safe and highly effective in the treatment of WM. Ibrutinib has been approved in Europe and the United States for its use in patients with symptomatic WM. Prospective studies are ongoing and/or planned to study many other novel agents alone and in combination with aims at improving response, survival and quality of life in patients with WM.

Monoclonal Antibodies in Multiple Myeloma: A New Wave of the Future

In 2015, 2 monoclonal antibodies were approved for the treatment of relapsed or refractory multiple myeloma (RRMM), elotuzumab and daratumumab. Elotuzumab is a monoclonal IgG-κ antibody directed against SLAMF7 (signaling lymphocytic activation molecule F7), a cell surface receptor involved in natural killer cell activation. Daratumumab is a monoclonal IgG-κ antibody that binds to CD38, a transmembrane protein found on the surface of myeloma cells and responsible for cellular adhesion and ectoenzymatic activity. Both elotuzumab and daratumumab act through recruitment of the immune system to enhance cellular cytotoxicity directed against myeloma cells. Elotuzumab requires lenalidomide and dexamethasone combined to enhance progression-free survival in patients with RRMM, and daratumumab has both single-agent and combination activity with either lenalidomide or the proteasome inhibitor bortezomib in RRMM. The adverse effect profile of both agents mainly consists of allergic-type infusion reactions. Other considerations for monoclonal antibody use in the treatment of MM include the potential for interference in serum protein electrophoresis testing and cross-reactivity of daratumumab with CD38 present on red blood cells. In the present report, we discussed the clinical development of daratumumab and elotuzumab and newer immunologic approaches to the treatment of MM.

CD38 as a PET Imaging Target in Lung Cancer

Daratumumab (Darzalex, Janssen Biotech) is a clinically approved antibody targeting CD38 for the treatment of multiple myeloma. However, CD38 is also expressed by other cancer cell types, including lung cancer, where its expression or absence may offer prognostic value. We therefore developed a PET tracer based upon daratumumab for tracking CD38 expression, utilizing murine models of non-small cell lung cancer to verify its specificity. Daratumumab was prepared for radiolabeling with ⁸⁹Zr (t_1/2 = 78.4 h) through conjugation with desferrioxamine (Df). Western blot, flow cytometry, and saturation binding assays were utilized to characterize CD38 expression and binding of daratumumab to three non-small cell lung cancer cell lines: A549, H460, and H358. Murine xenograft models of the cell lines were also generated for further in vivo studies. Longitudinal PET imaging was performed following injection of ⁸⁹Zr-Df-daratumumab out to 120 h postinjection, and nonspecific uptake was also evaluated through the injection of a radiolabeled control IgG antibody in A549 mice, ⁸⁹Zr-Df-IgG. Ex vivo biodistribution and histological analyses were also performed after the terminal imaging time point at 120 h postinjection. Through cellular studies, A549 cells were found to express higher levels of CD38 than the H460 or H358 cell lines. PET imaging and ex vivo biodistribution studies verified in vitro trends, with A549 tumor uptake peaking at 8.1 ± 1.2%ID/g at 120 h postinjection according to PET analysis, and H460 and H358 at lower levels at the same time point (6.7 ± 0.7%ID/g and 5.1 ± 0.4%ID/g, respectively; n = 3 or 4). Injection of a nonspecific radiolabeled IgG into A549 tumor-bearing mice also demonstrated lower tracer uptake of 4.4 ± 1.3%ID/g at 120 h. Immunofluorescent staining of tumor tissues showed higher staining levels present in A549 tissues over H460 and H358. Thus, ⁸⁹Zr-Df-daratumumab is able to image CD38-expressing tissues in vivo using PET, as verified through the exploration of non-small cell lung cancer models in this study. This agent therefore holds potential to image CD38 in other malignancies and aid in patient stratification and elucidation of the biodistribution of CD38.

Synthesis of the Ca2+-mobilizing messengers NAADP and cADPR by intracellular CD38 enzyme in the mouse heart: Role in β-adrenoceptor signaling

Nicotinic acid adenine dinucleotide phosphate (NAADP) and cyclic ADP-ribose (cADPR) are Ca²⁺-mobilizing messengers important for modulating cardiac excitation–contraction coupling and pathophysiology. CD38, which belongs to the ADP-ribosyl cyclase family, catalyzes synthesis of both NAADP and cADPR in vitro. However, it remains unclear whether this is the main enzyme for their production under physiological conditions. Here we show that membrane fractions from WT but not CD38^−/− mouse hearts supported NAADP and cADPR synthesis. Membrane permeabilization of cardiac myocytes with saponin and/or Triton X-100 increased NAADP synthesis, indicating that intracellular CD38 contributes to NAADP production. The permeabilization also permitted immunostaining of CD38, with a striated pattern in WT myocytes, whereas CD38^−/− myocytes and nonpermeabilized WT myocytes showed little or no staining, without striation. A component of β-adrenoreceptor signaling in the heart involves NAADP and lysosomes. Accordingly, in the presence of isoproterenol, Ca²⁺ transients and contraction amplitudes were smaller in CD38^−/− myocytes than in the WT. In addition, suppressing lysosomal function with bafilomycin A1 reduced the isoproterenol-induced increase in Ca²⁺ transients in cardiac myocytes from WT but not CD38^−/− mice. Whole hearts isolated from CD38^−/− mice and exposed to isoproterenol showed reduced arrhythmias. SAN4825, an ADP-ribosyl cyclase inhibitor that reduces cADPR and NAADP synthesis in mouse membrane fractions, was shown to bind to CD38 in docking simulations and reduced the isoproterenol-induced arrhythmias in WT hearts. These observations support generation of NAADP and cADPR by intracellular CD38, which contributes to effects of β-adrenoreceptor stimulation to increase both Ca²⁺ transients and the tendency to disturb heart rhythm.

Expression of CD38 in myeloma bone niche: A rational basis for the use of anti-CD38 immunotherapy to inhibit osteoclast formation

It is known that multiple myeloma (MM) cells express CD38 and that a recently developed human anti-CD38 monoclonal antibody Daratumumab mediates myeloma killing. However, the expression of CD38 and other functionally related ectoenzymes within the MM bone niche and the potential effects of Daratumumab on bone cells are still unknown. This study firstly defines by flow cytometry and immunohistochemistry the expression of CD38 by bone marrow cells in a cohort of patients with MM and indolent monoclonal gammopathies. Results indicate that only plasma cells expressed CD38 at high level within the bone niche. In addition, the flow cytometry analysis shows that CD38 was also expressed by monocytes and early osteoclast progenitors but not by osteoblasts and mature osteoclasts. Indeed, CD38 was lost during in vitro osteoclastogenesis. Consistently, we found that Daratumumab reacted with CD38 expressed on monocytes and its binding inhibited in vitro osteoclastogenesis and bone resorption activity from bone marrow total mononuclear cells of MM patients, targeting early osteoclast progenitors. The inhibitory effect was not observed from purified CD14⁺ cells, suggesting an indirect inhibitory effect of Daratumumab. Interestingly, all-trans retinoic acid treatment increased the inhibitory effect of Daratumumab on osteoclast formation.

These observations provide a rationale for the use of an anti-CD38 antibody-based approach as treatment for multiple myeloma-induced osteoclastogenesis.

A Rational Strategy for Reducing On-Target Off-Tumor Effects of CD38-Chimeric Antigen Receptors by Affinity Optimization

Chimeric antigen receptors (CARs) can effectively redirect cytotoxic T cells toward highly expressed surface antigens on tumor cells. The low expression of several tumor-associated antigens (TAAs) on normal tissues, however, hinders their safe targeting by CAR T cells due to on-target/off-tumor effects. Using the multiple myeloma (MM)-associated CD38 antigen as a model system, here, we present a rational approach for effective and tumor-selective targeting of such TAAs. Using "light-chain exchange" technology, we combined the heavy chains of two high-affinity CD38 antibodies with 176 germline light chains and generated ∼124 new antibodies with 10- to >1,000-fold lower affinities to CD38. After categorizing them into three distinct affinity classes, we incorporated the single-chain variable fragments of eight antibodies from each class into new CARs. T cells carrying these CD38-CARs were extensively evaluated for their on-tumor/off-tumor cytotoxicity as well as CD38-dependent proliferation and cytokine production. We identified CD38-CAR T cells of ∼1,000- fold reduced affinity, which optimally proliferated, produced Th1-like cytokines, and effectively lysed CD38²⁺ MM cells, but spared CD38⁺ healthy hematopoietic cells in vitro and in vivo. Thus, this systematic approach is highly suitable for the generation of optimal CARs for effective and selective targeting of TAAs.

Daratumumab for the treatment of multiple myeloma

INTRODUCTION

Proteasome inhibitors and immunomodulatory drugs have contributed to the dramatic improvement in survival for patients with myeloma over the past decades. However, the disease typically relapses and new classes of drugs are needed. In 2015, two monoclonal antibodies were approved for the treatment of patients with relapsed multiple myeloma, and immunotherapy has rapidly become indispensable in the management of myeloma patients. Areas covered: Here, the authors discuss the published data regarding the mechanism of action, safety and clinical efficacy of the CD38-targeted monoclonal antibody daratumumab for the treatment of patients with multiple myeloma. Expert opinion: Daratumumab is indicated for myeloma patients who have received at least 3 prior therapies, including bortezomib, lenalidomide and pomalidomide. In 2016, daratumumab in combination with lenalidomide and dexamethasone, or bortezomib and dexamethasone was approved for the treatment of patients with multiple myeloma who have received at least one prior therapy. Daratumumab displays an excellent safety profile. Moderate-grade infusion-related reactions occurring mostly during the first infusion are the main treatment-emergent adverse event. In the context of daratumumab therapy, attention should be paid to interference with blood compatibility testing and response assessment. Daratumumab-based combination therapies are currently under evaluation in relapsed and newly diagnosed patients.

New developments in the treatment of multiple myeloma - clinical utility of daratumumab

Multiple myeloma is a clonal disorder of plasma cells that is currently considered incurable. CD38 is a 46 kDa type II transmembrane glycoprotein that is highly expressed on myeloma cells. Daratumumab is a first in-class human IgG1 monoclonal antibody that targets CD38, and has antimyeloma effects through several mechanisms. Single-agent trials show surprising activity in heavily pretreated myeloma patients. Trials in the relapsed setting, where daratumumab is added to lenalidomide and dexamethasone or bortezomib and dexamethasone, have demonstrated significantly improved progression-free survival with acceptable toxicity. In this review, we discuss the mechanism of action, pharmacology and pharmacokinetics of daratumumab and review the available clinical data in detail. We examine how daratumumab interferes with transfusion testing due to the expression of CD38 on the red blood cells, leading to potential difficulties releasing blood products. Daratumumab also affects disease assessments in multiple myeloma, including serum protein electrophoresis, immunofixation and flow cytometry. Strategies to mitigate these effects are discussed. The optimal use of daratumumab has yet to be decided, and several trials are ongoing in the relapsed and upfront setting. We discuss the potential upfront role of this exciting therapy, which has significant potential for increased minimal residual disease negativity and improved progression-free survival even in high-risk groups.

NAADP-mediated Ca2+ signaling promotes autophagy and protects against LPS-induced liver injury

LPS has been shown to induce hepatocyte autophagy, but little is known about how LPS is able to do this during acute toxic liver injury. Our aim was to determine the existence of any selective Ca²⁺ signaling coupling to hepatocyte autophagy in response to LPS. LPS increased the autophagic process in hepatocytes, and CD38 knockdown prevented this response. Ned19, a specific inhibitor for nicotinic acid adenine dinucleotide phosphate (NAADP), prevented LPS-mediated Ca²⁺ signaling and autophagosome formation in hepatocytes. CD38 overexpression protected the liver from LPS/d-galactosamine (GalN)-induced injury, and NAADP administration promoted autophagosome formation and protected hepatocytes from injury induced by LPS/GalN. Autophagy was promoted by the up-regulation of autophagy-related gene expression via NAADP-mediated Ca²⁺ signaling in response to LPS. However, CD38-knockout mice displayed down-regulation in hepatocyte gene expression. Ned19 also inhibited the NAADP-stimulated induction of gene expression by inhibiting the LPS-induced nuclear translocation of transcription factor EB (TFEB). Hepatocyte autophagy protects against LPS-induced liver injury via the CD38/NAADP/Ca²⁺/TFEB pathway. The role of NAADP-mediated Ca²⁺ signaling in the autophagic process will help elucidate the complexities of autophagy regulation, which is essential toward the discovery of new therapeutic tools against acute liver injury.-Rah, S.-Y., Lee, Y.-H., Kim, U.-H. NAADP-mediated Ca²⁺ signaling promotes autophagy and protects against LPS-induced liver injury.

Roles and Modalities of Ectonucleotidases in Remodeling the Multiple Myeloma Niche

Ectoenzymes are cell surface molecules, which represent functional bridges between the environment and the cytoplasm. One set of ectoenzymes—CD39, CD38, CD203a, and CD73—leads to the generation of adenosine (ADO) by metabolizing ATP and NAD⁺. While ADO is known to control inflammation and suppress immune responses, other aspects of ADO function are still obscure, mainly due to its short half-life in biological fluids. Human multiple myeloma (MM) grows in the closed system of the bone marrow (BM) niche representing an ideal setting for studying ectoenzymes and their products. Another source of information on ectoenzyme function may derive from in vivo results of anti-CD38 antibody therapy in MM. Current results, obtained from in vitro models and from preliminary in vivo findings, indicate that ectoenzymes produce ADO locally in the BM niche. Furthermore, MM cells release microvesicles (MV), which thanks to their molecular cargo and surface ectoenzymes may function as particulate communicators outside of the niche. During anti-CD38 antibody therapy, the MV carry therapeutic IgG, determining that the prevalent orientation of MV will be toward cells and tissues expressing receptors for the IgG Fc domain. The resulting picture is one where MM adopts an immune escape strategy based on reshaping the environmental niche. This adaptation is followed by actions of MV that are exerted in biological fluids and circulating immune cells. By coating FcRs⁺ cells, MV modify pericellular spaces, reproducing the metabolic halo generated by ectoenzymes within closed systems.

CD38 promotes angiotensin II-induced cardiac hypertrophy

Cardiac hypertrophy is an early hallmark during the clinical course of heart failure and regulated by various signalling pathways. Recently, we observed that mouse embryonic fibroblasts from CD38 knockout mice were significantly resistant to oxidative stress such as H₂O₂‐induced injury and hypoxia/reoxygenation‐induced injury. In addition, we also found that CD38 knockout mice protected heart from ischaemia reperfusion injury through activating SIRT1/FOXOs‐mediated antioxidative stress pathway. However, the role of CD38 in cardiac hypertrophy is not explored. Here, we investigated the roles and mechanisms of CD38 in angiotensin II (Ang‐II)‐induced cardiac hypertrophy. Following 14 days of Ang‐II infusion with osmotic mini‐pumps, a comparable hypertension was generated in both of CD38 knockout and wild‐type mice. However, the cardiac hypertrophy and fibrosis were much more severe in wild‐type mice compared with CD38 knockout mice. Consistently, RNAi‐induced knockdown of CD38 decreased the gene expressions of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) and reactive oxygen species generation in Ang‐II‐stimulated H9c2 cells. In addition, the expression of SIRT3 was elevated in CD38 knockdown H9c2 cells, in which SIRT3 may further activate the FOXO3 antioxidant pathway. The intracellular Ca²⁺ release induced by Ang‐II markedly decreased in CD38 knockdown H9c2 cells, which might be associated with the decrease of nuclear translocation of NFATc4 and inhibition of ERK/AKT phosphorylation. We concluded that CD38 plays an essential role in cardiac hypertrophy probably via inhibition of SIRT3 expression and activation of Ca²⁺‐NFAT signalling pathway. Thus, CD38 may be a novel target for treating cardiac hypertrophy.

5-Hydroxytyrosol inhibits HIV-1 replication in primary cells of the lower and upper female reproductive tract

We investigated the potential anti-HIV-1 activity of the candidate microbicide 5-hydroxytyrosol (5-HT) both in primary human cervical tissue explants (CTE), established from tissues of women undergoing histerectomy, and in endometrium-associated leukocytes (EAL). CTE were exposed to either the laboratory-adapted HIV-1_BaL or to primary viral isolates in the presence or absence of 5-HT or 3TC/lamivudine as control and were then monitored for 12 days in terms of HIV-1 p24 Gag antigen production in culture supernatants. HIV-1_BaL replication was also evaluated in EAL by reverse transcriptase (RT) activity. The highest nontoxic concentrations of 5-HT (200 and 100 μM for CTE and EAL, respectively) exerted a significant inhibitory effect on virus replication in both primary cell systems. 5-HT did not cause significant alterations of the activation profile of CD4⁺ and CD8⁺ T cells, in terms of CD4, CCR5, CD25, CD69 and HLA-DR expression, although it decreased the percentage of CD38⁺CD8⁺ T cells. Thus, 5-HT deserves consideration as a potential candidate microbicide for preventing HIV-1 transmission or curtailing its replication in the female reproductive tract.

Synthesis and Evaluation of Thiazoloquinolinones with Linkers To Enable Targeting of CD38

Several monoclonal antibodies and inhibitors targeting CD38, an ectoenzyme overexpressed on malignant plasma cells, have previously been discovered. Herein, we expand structure-activity relationships of reported small-molecule thiazoloquinolinones and show that several 4-cyclohexylamino analogues have potent binding affinity for CD38 using surface plasmon resonance. Moreover, active amine analogues could be acylated and functionalized with alkyne and fluorescein groups. Fluorescein analogue 21 bound selectively to CD38 overexpressing cells, demonstrating the potential utility of thiazoloquinolinones as small-molecule conjugates for the delivery of therapeutic and imaging agents.

Contribution of p62 to Phenotype Transition of Coronary Arterial Myocytes with Defective Autophagy

Background:

Autophagy disorder contributes to dedifferentiation of arterial smooth muscle cells, but the mechanisms are poorly understood. Here, we sought to investigate the role of scaffolding adaptor p62/SQSTM1 (p62) in phenotype switching of mouse coronary arterial myocytes (CAMs) induced by CD38 gene deficiency or lysosomal dysfunction which blocks autophagic flux in the cells.

Methods:

Protein expression was measured by western blot analysis and immunofluorescent staining. Cell cycle and proliferation rate were analyzed by flow cytometry and MTS assay respectively. mRNA abundance was tested by qRT-PCR.

Results:

CD38 gene deficiency or bafilomycin A1 (baf), a selective lysosomal inhibitor treatment increased proliferation rate and vimentin expression in CAMs which was prevented by p62 gene silencing. Cell percentage in G₂/M and G₀/G₁ phase was decreased and increased by CD38 deficiency or baf treatment, respectively which was accompanied by accrual of cyclin-dependent kinase 1 (CDK1) protein. Although free ubiquitin content was increased, the colocalization of it to CDK1 was markedly decreased in CD38^−/− or baf treated CAMs. Furthermore, the changes in both cell cycle and CDK1 ubiquitinylation could be restored by p62 gene silencing.

Conclusion:

The results suggest in CD38^−/− or baf treated CAMs, p62 accumulation promotes phenotype transition and proliferation by accelerating cell cycle progress through G₂/M which might relate to the compromised ubiquitinylation and degradation of CDK1.

Structure-specific effects of lipidated oxytocin analogs on intracellular calcium levels, parental behavior, and oxytocin concentrations in the plasma and cerebrospinal fluid in mice

Oxytocin (OT) is a neuroendocrine nonapeptide that plays an important role in social memory and behavior. Nasal administration of OT has been shown to improve trust in healthy humans and social interaction in autistic subjects in some clinical trials. As a central nervous system (CNS) drug, however, OT has two unfavorable characteristics: OT is short‐acting and shows poor permeability across the blood–brain barrier, because it exists in charged form in the plasma and has short half‐life. To overcome these drawbacks, an analog with long‐lasting effects is required. We previously synthesized the analog, lipo‐oxytocin‐1 (LOT‐1), in which two palmitoyl groups are conjugated to the cysteine and tyrosine residues. In this study, we synthesized and evaluated the analogs lipo‐oxytocin‐2 (LOT‐2) and lipo‐oxytocin‐3 (LOT‐3), which feature the conjugation of one palmitoyl group at the cysteine and tyrosine residues, respectively. In human embryonic kidney‐293 cells overexpressing human OT receptors, these three LOTs demonstrated comparably weak effects on the elevation of intracellular free calcium concentrations after OT receptor activation, compared to the effects of OT. The three LOTs and OT exhibited different time‐dependent effects on recovery from impaired pup retrieval behavior in sires of CD38‐knockout mice. Sires treated with LOT‐1 showed the strongest effect, whereas others had no or little effects at 24 h after injection. These results indicated that LOTs have structure‐specific agonistic effects, and suggest that lipidation of OT might have therapeutic benefits for social impairment.

Functional evidence that progenitor cells near sites of inflammation are precursors for aggressive prostate cancer

While chronic inflammation has been causally associated with several epithelial malignancies, whether it causally contributes to the development of prostate cancer has remained unclear. We recently reported that progenitor-like inflammation-associated luminal cells marked by low expression of Cluster of Differentiation 38 (CD38) can initiate human prostate cancer and predict poor outcome.

Unsupportive social interactions and affective states: examining associations of two oxytocin-related polymorphisms

Two single-nucleotide polymorphisms (SNPs) on oxytocin-related genes, specifically the oxytocin receptor (OXTR) rs53576 and the CD38 rs3796863 variants, have been associated with alterations in prosocial behaviors. A cross-sectional study was conducted among undergraduate students (N = 476) to examine associations between the OXTR and CD38 polymorphisms and unsupportive social interactions and mood states. Results revealed no association between perceived levels of unsupportive social interactions and the OXTR polymorphism. However, A carriers of the CD38 polymorphism, a variant previously associated with elevated oxytocin, reported greater perceived peer unsupportive interactions compared to CC carriers. As expected, perceived unsupportive interactions from peers was associated with greater negative affect, which was moderated by the CD38 polymorphism. Specifically, this relation was stronger among CC carriers of the CD38 polymorphism (a variant thought to be linked to lower oxytocin). When examining whether the OXTR polymorphism moderated the relation between unsupportive social interactions from peers and negative affect there was a trend toward significance, however, this did not withstand multiple testing corrections. These findings are consistent with the perspective that a variant on an oxytocin polymorphism that may be tied to lower oxytocin is related to poor mood outcomes in association with negative social interactions. At the same time, having a genetic constitution presumed to be associated with higher oxytocin was related to increased perceptions of unsupportive social interactions. These seemingly paradoxical findings could be related to previous reports in which variants associated with prosocial behaviors were also tied to relatively more effective coping styles to deal with challenges.

Cyclic ADP-ribose as an endogenous inhibitor of the mTOR pathway downstream of dopamine receptors in the mouse striatum

The role of cyclic ADP-ribose (cADPR) as a second messenger and modulator of the mTOR pathway downstream of dopamine (DA) receptors and/or CD38 was re-examined in the mouse. ADP-ribosyl activity was low in the membranes of neonates, but DA stimulated it via both D1- and D2-like receptors. ADP-ribosyl cyclase activity increased significantly during development in association with increased expression of CD38. The cADPR binding proteins, FKBP12 and FKBP12.6, were expressed in the adult mouse striatum. The ratio of phosphorylated to non-phosphorylated S6 kinase (S6K) in whole mouse striatum homogenates decreased after incubation of adult mouse striatum with extracellular cADPR for 5 min. This effect of cADPR was much weaker in MPTP-treated Parkinson's disease model mice. The inhibitory effects of cADPR and rapamycin were identical. These data suggest that cADPR is an endogenous inhibitor of the mTOR signaling pathway downstream of DA receptors in the mouse striatum and that cADPR plays a certain role in the brain in psychiatric and neurodegenerative diseases.

CD38 in the pathogenesis of allergic airway disease: Potential therapeutic targets

CD38 is an ectoenzyme that catalyzes the conversion of β-nicotinamide adenine dinucleotide (β-NAD) to cyclic adenosine diphosphoribose (cADPR) and adenosine diphosphoribose (ADPR) and NADP to nicotinic acid adenine dinucleotide phosphate (NAADP) and adenosine diphosphoribose-2'-phosphate (ADPR-P). The metabolites of NAD and NADP have roles in calcium signaling in different cell types including airway smooth muscle (ASM) cells. In ASM cells, inflammatory cytokines augment CD38 expression and to a greater magnitude in cells from asthmatics, indicating a greater capacity for the generation of cADPR and ADPR in ASM from asthmatics. CD38 deficient mice develop attenuated airway responsiveness to inhaled methacholine following allergen sensitization and challenge compared to wild-type mice indicating its potential role in asthma. Regulation of CD38 expression in ASM cells is achieved by mitogen activated protein kinases, specific isoforms of PI3 kinases, the transcription factors NF-κB and AP-1, and post-transcriptionally by microRNAs. This review will focus on the role of CD38 in intracellular calcium regulation in ASM, contribution to airway inflammation and airway hyperresponsiveness in mouse models of allergic airway inflammation, the transcriptional and post-transcriptional mechanisms of regulation of expression, and outline approaches to inhibit its expression and activity.

Spleen atrophy related immune system changes attributed to infection of Angiostrongylus cantonensis in mouse model

The spleen is one of the most important peripheral immune organs, which is frequently affected in infectious diseases. Infectious diseases can induce splenic alterations including splenic atrophy and functional alteration, while splenic atrophy may in turn interferes with recovery of infectious diseases. Angiostrongyliasis is an infectious disease by Angiostrongylus cantonensis (A. cantonensis), which invade non-permissive hosts, such as humans and mice, to cause severe damage to the central nervous system (CNS) and acute inflammatory response. A. cantonensis infection-induced CNS injury has been confirmed to be due to profound immunopathology derived from peripheral immune components. However, the mechanism of immunopathology remains largely unknown. Here, we found that A. cantonensis invaded non-permissive hosts such as mice in the brain, but not in the other peripheral organs. However, this infection induced severe spleen atrophy. We further recognized that this atrophy is associated with a decrease of total splenocyte number and disruption of splenic structure due to reduced proliferation and increased apoptotosis. These also resulted in deterioration of T cell profile in the periphery with a low CD4/CD8 ratio and B/T cell ratio, and increased ratio of CD4⁺CD25⁺Foxp3⁺ Treg, CD8⁺CD28^- T, and CD38⁺T lymphocyte of spleen. Albendazole treatment can alleviate spleen atrophy and set T cell immune reconstitution in some extend. Our data showed that A. cantonensis infection can cause splenic atrophy. These results are suggested to put more emphasis to improve the function of immune system. Meanwhile, infection and treatment model will be useful to evaluate new therapeutic approaches which can prevent or reverse immunosuppression and infectious complications.

Molecular docking and CoMFA studies of thiazoloquin(az)olin(on)es as CD38 inhibitors: determination of inhibitory mechanism, pharmacophore interactions, and design of new inhibitors

In this research, molecular docking and 3D-QSAR studies were carried out on a series of 79 thiazoloquin(az)olin(on)es as CD38 inhibitors. Based on docking results, four interactions including hydrogen bonding with main chain of GLU-226 (H-M-GLU-226), Van der Waals interactions with side chain of TRP-125 (V-S-TRP-125), TRP-189 (V-S-TRP-189), and THR-221 (V-S-THR-221) were considered as pharmacological interactions. Active conformation of each ligand was extracted from docking studies and was used for carrying out 3D-QSAR modeling. Comparative molecular field analysis (CoMFA) was performed on CD38 inhibitory activities of these compounds on human and mouse. We developed CoMFA models with five components as optimum models for both data-sets. For human data-set, a model with high predictive power was developed. R², RMSE, and F-test values for training set of this model were .94, .24, and 179.58, respectively, and R² and RMSE for its test set were .92 and .32, respectively. The q² and RMSE values for leave-one-out cross validation test on training set were .78 and .46, respectively, that demonstrate created model is robust. Based on extracted steric and electrostatic contour maps for this model, three inhibitors with pIC₅₀ larger than 8.85 were designed.

Future therapeutic options for patients with Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare lymphoma characterized by the accumulation of IgM-producing lymphoplasmacytic cells. Although WM patients can experience prolonged remissions, the disease invariably recurs. Therefore, novel treatments associated with higher success rates and lower toxicity profiles are needed. The discovery of recurrent mutations in the MYD88 and CXCR4 genes has unraveled potential therapeutic targets in WM patients. As a result of these findings and based on the design and execution of a prospective clinical trial, the FDA granted approval to ibrutinib, an oral Bruton tyrosine kinase (BTK) inhibitor, to treat patients with symptomatic WM. The present review focuses on potential therapies that could change the landscape of treatment of patients with WM, specifically focusing on inhibitors or antagonists or the proteasome, BTK, CD38, BCL2 and the CXCR4 and MYD88 genes themselves. Novel agents with novel mechanisms of action should be evaluated in the context of carefully designed clinical trials.

Immunotherapies targeting CD38 in Multiple Myeloma

Recently, the monoclonal antibody daratumumab was approved as a single agent for the treatment of patients with relapsed/refractory Multiple Myeloma (MM). Daratumumab is an antibody targeting surface molecule CD38 on myeloma cells and the agent is already widely being used based on its good tolerability and proven efficacy. We believe, however, that the efficacy of this drug and other anti-CD38 monoclonal antibodies can be further improved by combining it with other types of immunotherapies. Furthermore, surface molecule CD38 can be used as a target for immunotherapies other than just naked monoclonal antibodies. In this report, we review the expression pattern of CD38 among normal tissues and in different types of plasma cell dyscrasias including their progenitor cells, minimal residual disease, and circulating tumor cells. We summarize the physiological role of CD38 as well as its role in the pathophysiology of MM and we present the most recent clinical trials using CD38 as a target. In addition, we highlight possible combination immunotherapies incorporating anti-CD38 monoclonal antibodies and we demonstrate alternative immunotherapeutic approaches targeting the same antigen such as CD38-specific chimeric antigen receptor (CAR) T cells.

CD49d shows superior performance characteristics for flow cytometric prognostic testing in chronic lymphocytic leukemia/small lymphocytic lymphoma

BACKGROUND

CD49d is emerging as a powerful adverse prognostic marker in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). However, flow cytometric testing for CD49d has not yet been widely adopted in the United States, in part due to the lack of establishment of its performance characteristics in the clinical setting, especially in comparison with the more common CLL/SLL prognostic markers CD38 and ZAP-70.

METHODS

CD49d expression levels in 124 CLL/SLL cases were assessed among peripheral blood (PB), bone marrow (BM), and lymph node (LN) specimens and correlated with available CD38 and ZAP-70 expression and cytogenetic findings. For 10 PB/BM specimens, the stability of CD49d, CD38, and ZAP-70 expression was assessed at <24 hours, 48 hours, 72 hours, and 96 hours.

RESULTS

39% (28 of 71) PB, 56% (18 of 32) BM, and 71% (15 of 21) LN involved by CLL/SLL were CD49d+, using a ≥30% threshold. The mean for the CD49d+ cases was 2.8 standard deviations (SD) above the cutoff for positivity, compared with 1.7 SD for CD38 and 1.1 SD for ZAP-70. CD49d demonstrated the lowest mean SD (0.91) and coefficient of variation (CV) (8.0%) compared with CD38 (SD = 2.1, CV = 10.4%) and ZAP-70 (SD = 9.8, CV = 40.5%) in stability studies over a 96-hours time period. CD49d+ CLL/SLL correlated with trisomy 12 (P = 0.025) and lack of isolated deletion (13q) (P = 0.005). CD38+ CLL/SLL correlated with deletion (11q) (P = 0.025). ZAP-70 did not correlate with any underlying cytogenetic abnormality.

CONCLUSIONS

CD49d is a robust adverse prognostic marker in CLL/SLL with superior performance characteristics. © 2016 International Clinical Cytometry Society.

Effects of oxytocin administration on spirituality and emotional responses to meditation

The oxytocin (OT) system, critically involved in social bonding, may also impinge on spirituality, which is the belief in a meaningful life imbued with a sense of connection to a Higher Power and/or the world. Midlife male participants (N = 83) were randomly assigned to receive intranasal OT or placebo. In exploratory analyses, participants were also genotyped for polymorphisms in two genes critical for OT signaling, the oxytocin receptor gene (OXTR rs53576) and CD38 (rs6449182 and rs3796863). Results showed that intranasal OT increased self-reported spirituality on two separate measures and this effect remained significant a week later. It also boosted participants' experience of specific positive emotions during meditation, at both explicit and implicit levels. Furthermore, the effect of OT on spirituality was moderated by OT-related genotypes. These results provide the first experimental evidence that spirituality, endorsed by millions worldwide, appears to be supported by OT.

Effect of antiviral treatment of chronic hepatitis C on the frequency of regulatory T cells, T-cell activation, and serum levels of TGF-beta

The aim was to analyze T-regulatory cells (Tregs), activated CD8(+) T cells, and transforming growth factor-beta (TGF)-β in hepatitis C patients. We enrolled 31 patients with chronic genotype 1 hepatitis C virus (HCV) infection, 30 seropositive persons with spontaneous HCV elimination, and 23 healthy volunteers. The patients were examined at the beginning of the interferon-alpha (IFN-α)-based therapy (baseline) and at weeks 4 (W4) and 12 (W12) of the therapy. The percentage of Tregs and the expression of activation markers CD38 and HLA-DR on CD8(+) T cells were analyzed in the peripheral blood by flow cytometry. Serum levels of TGF-β were measured in a multiplex assay using flow cytometry. The percentage of Tregs in patients was higher than in controls and seropositive persons. Similarly, the percentage of CD8(+) T cells expressing CD38 and HLA-DR was higher in patients compared with controls and seropositive persons. Chronic HCV infection is associated with elevated circulating Tregs and activated CD8(+) T cells. During IFN-α-based therapy these cells gradually increase, whereas TGF-β serum levels decrease.

CD38 Dictates Age-Related NAD Decline and Mitochondrial Dysfunction through an SIRT3-Dependent Mechanism

Nicotinamide adenine dinucleotide (NAD) levels decrease during aging and are involved in age-related metabolic decline. To date, the mechanism responsible for the age-related reduction in NAD has not been elucidated. Here we demonstrate that expression and activity of the NADase CD38 increase with aging and that CD38 is required for the age-related NAD decline and mitochondrial dysfunction via a pathway mediated at least in part by regulation of SIRT3 activity. We also identified CD38 as the main enzyme involved in the degradation of the NAD precursor nicotinamide mononucleotide (NMN) in vivo, indicating that CD38 has a key role in the modulation of NAD-replacement therapy for aging and metabolic diseases.

SIDT2 is involved in the NAADP-mediated release of calcium from insulin secretory granules

The Sidt2 global knockout mouse (Sidt2(-/-)) has impaired insulin secretion. The aim of this study was to assess the role of SIDT2 protein in glucose-induced insulin secretion in primary cultured mouse β-cells. The major metabolic and electrophysiological steps of glucose-induced insulin secretion of primary cultured β-cells from Sidt2(-/-) mice were investigated. The β-cells from Sidt2(-/-) mice had normal NAD(P)H responses and KATP and KV currents. However, they exhibited a lower [Ca(2+)]i peak height when stimulated with 20mM glucose compared with those from WT mice. Furthermore, it took a longer time for the [Ca(2+)]i of β-cell from Sidt2(-/-) mice to reach the peak. Pretreatment with ryanodine or 2-aminoethoxydiphenyl borate (2-APB) did not change [Ca(2+)]i the response pattern to glucose in Sidt2(-/-) cells. Extraordinarily, pretreatment with bafilomycin A1(Baf-A1) led to a comparable [Ca(2+)]i increase pattern between these two groups, suggesting that calcium traffic from the intracellular acidic compartment is defective in Sidt2(-/-) β-cells. Bath-mediated application of 50nM nicotinic acid adenine dinucleotide phosphate (NAADP) normalized the [Ca(2+)]i response of Sidt2(-/-) β-cells. Finally, glucose-induced CD38 expression increased to a comparable level between Sidt2(-/-) and WT islets, suggesting that Sidt2(-/-) islets generated NAADP normally. We conclude that Sidt2 is involved in NAADP-mediated release of calcium from insulin secretory granules and thus regulates insulin secretion.