Reversible Suppression Research Articles

Emergent Myxobacterial Behaviors Arise from Reversal Suppression Induced by Kin Contacts.

ABSTRACTA wide range of biological systems, from microbial swarms to bird flocks, display emergent behaviors driven by coordinated movement of individuals. To this end, individual organisms interact by recognizing their kin and adjusting their motility based on others around them. However, even in the best-studied systems, the mechanistic basis of the interplay between kin recognition and motility coordination is not understood. Here, using a combination of experiments and mathematical modeling, we uncover the mechanism of an emergent social behavior in Myxococcus xanthus. By overexpressing the cell surface adhesins TraA and TraB, which are involved in kin recognition, large numbers of cells adhere to one another and form organized macroscopic circular aggregates that spin clockwise or counterclockwise. Mechanistically, TraAB adhesion results in sustained cell-cell contacts that trigger cells to suppress cell reversals, and circular aggregates form as the result of cells’ ability to follow their own cellular slime trails. Furthermore, our in silico simulations demonstrate a remarkable ability to predict self-organization patterns when phenotypically distinct strains are mixed. For example, defying naive expectations, both models and experiments found that strains engineered to overexpress different and incompatible TraAB adhesins nevertheless form mixed circular aggregates. Therefore, this work provides key mechanistic insights into M. xanthus social interactions and demonstrates how local cell contacts induce emergent collective behaviors by millions of cells.IMPORTANCE In many species, large populations exhibit emergent behaviors whereby all related individuals move in unison. For example, fish in schools can all dart in one direction simultaneously to avoid a predator. Currently, it is impossible to explain how such animals recognize kin through brain cognition and elicit such behaviors at a molecular level. However, microbes also recognize kin and exhibit emergent collective behaviors that are experimentally tractable. Here, using a model social bacterium, we engineer dispersed individuals to organize into synchronized collectives that create emergent patterns. With experimental and mathematical approaches, we explain how this occurs at both molecular and population levels. The results demonstrate how the combination of local physical interactions triggers intracellular signaling, which in turn leads to emergent behaviors on a population scale.

Contextual reprogramming of CAR-T cells for treatment of HER2+ cancers

BackgroundAdoptive transfer of chimeric antigen receptor (CAR)-engineered T cells combined with checkpoint inhibition may prevent T cell exhaustion and improve clinical outcomes. However, the approach is limited by cumulative costs and toxicities.MethodsTo overcome this drawback, we created a CAR-T (RB-340-1) that unites in one product the two modalities: a CRISPR interference-(CRISPRi) circuit prevents programmed cell death protein 1 (PD-1) expression upon antigen-encounter. RB-340-1 is engineered to express an anti-human epidermal growth factor receptor 2 (HER2) CAR single chain variable fragment (scFv), with CD28 and CD3ζ co-stimulatory domains linked to the tobacco etch virus (TEV) protease and a single guide RNA (sgRNA) targeting the PD-1 transcription start site (TSS). A second constructs includes linker for activation of T cells (LAT) fused to nuclease-deactivated spCas9 (dCas9)-Kruppel-associated box (KRAB) via a TEV-cleavable sequence (TCS). Upon antigen encounter, the LAT-dCas9-KRAB (LdCK) complex is cleaved by TEV allowing targeting of dCas9-KRAB to the PD-1 gene TSS.ResultsHere, we show that RB-340-1 consistently demonstrated higher production of homeostatic cytokines, enhanced expansion of CAR-T cells in vitro, prolonged in vivo persistence and more efficient suppression of HER2+ FaDu oropharyngeal cancer growth compared to the respective conventional CAR-T cell product.ConclusionsAs the first application of CRISPRi toward a clinically relevant product, RB-340-1 with the conditional, non-gene editing and reversible suppression promotes CAR-T cells resilience to checkpoint inhibition, and their persistence and effectiveness against HER2-expressing cancer xenografts.

Opioids and obstructive sleep apnea.

Freire C, Sennes LU, Polotsky VY. Opioids and obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):647-652.

Double-Blind, Placebo-Controlled Trial of Cyproterone Acetate to Prevent Flare-Up Effect on Dogs Implanted With Deslorelin.

Deslorelin slow-released implants are registered in Europe for the reversible suppression of fertility in male dogs. After administration, a time-limited increase in sex hormones concentration and related behavioral problems may be observed. The aim of this work was to assess whether cyproterone acetate, a synthetic progestogen, can prevent this flare-up effect. Eighteen privately-owned entire male dogs were enrolled in this double-blind, placebo-controlled, randomized clinical trial. All subjects received a 4.7 mg deslorelin implant by SC route and 1–3 capsules containing either cyproterone acetate 2 mg/kg (N = 9) or a placebo (N = 9), by oral route BID for 14 days, depending on the dog's weight. The dogs were followed for 28 days. An increase in the blood testosterone concentration was observed in respectively 9/9 and 7/9 dogs of the control and cyproterone groups (p = 0.47). However, a worsening of the sex hormone related problems (i.e., urinary marking, mounting, aggressiveness toward other dogs and/or escape) was only observed in the placebo group, in 56 or 66% of the dogs as measured by respectively the veterinarian and the owners. Our study suggests that cyproterone acetate is effective and safe to supress the deslorelin induced behavioral flare-up effect, but not the rise in testosterone.

Impact of Fluoxetine on Behavioral Invigoration of Appetitive and Aversively Motivated Responses: Interaction With Dopamine Depletion.

Impaired behavioral activation and effort-related motivational dysfunctions like fatigue and anergia are debilitating treatment-resistant symptoms of depression. Depressed people show a bias towards the selection of low effort activities. To determine if the broadly used antidepressant fluoxetine can improve behavioral activation and reverse dopamine (DA) depletion-induced anergia, male CD1 mice were evaluated for vigorous escape behaviors in an aversive context (forced swim test, FST), and also with an exercise preference choice task [running wheel (RW)-T-maze choice task]. In the FST, fluoxetine increased active behaviors (swimming, climbing) while reducing passive ones (immobility). However, fluoxetine was not effective at reducing anergia induced by the DA-depleting agent tetrabenazine, further decreasing vigorous climbing and increasing immobility. In the T-maze, fluoxetine alone produced the same pattern of effects as tetrabenazine. Moreover, fluoxetine did not reverse tetrabenazine-induced suppression of RW time but it reduced sucrose intake duration. This pattern of effects produced by fluoxetine in DA-depleted mice was dissimilar from devaluing food reinforcement by pre-feeding or making the food bitter since in both cases sucrose intake time was reduced but animals compensated by increasing time in the RW. Thus, fluoxetine improved escape in an aversive context but decreased relative preference for active reinforcement. Moreover, fluoxetine did not reverse the anergic effects of DA depletion. These results have implications for the use of fluoxetine for treating motivational symptoms such as anergia in depressed patients.

Reversible Photothermal Modulation of Electrical Activity of Excitable Cells using Polydopamine Nanoparticles.

Advances in the design and synthesis of nanomaterials with desired biophysicochemical properties can be harnessed to develop non-invasive neuromodulation technologies. Here, the reversible modulation of the electrical activity of neurons and cardiomyocytes is demonstrated using polydopamine (PDA) nanoparticles as photothermal nanotransducers. In addition to their broad light absorption and excellent photothermal activity, PDA nanoparticles are highly biocompatible and biodegradable, making them excellent candidates for both in vitro and in vivo applications. The modulation of the activity (i.e., spike rate of the neurons and beating rate of cardiomyocytes) of excitable cells can be finely controlled by varying the excitation power density and irradiation duration. Under optimal conditions, reversible suppression (≈100%) of neural activity and reversible enhancement (two-fold) in the beating rate of cardiomyocytes is demonstrated. To improve the ease of interfacing of photothermal transducers with these excitable cells and enable spatial localization of the photothermal stimulus, a collagen/PDA nanoparticle foam is realized, which can be used as an "add-on patch" for photothermal stimulation. The non-genetic optical neuromodulation approach using biocompatible and biodegradable nanoparticles represents a minimally invasive method for controlling the activity of excitable cells with potential applications in nano-neuroscience and engineering.

Abstract LB175: APX601, a Potent TNFR2 Antagonist as a Novel and Promising Approach to Reverse Tumor Immune Suppression

Abstract A key barrier to effective immunotherapy for cancer is the immunosuppressive tumor microenvironment (TME) characterized by infiltrating regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC). While depletion of immune-suppressive cells is a promising cancer immunotherapy strategy, current approaches are ineffective due to lack of specificity and safety concerns. Tumor Necrosis Factor Receptor 2 (TNFR2) is emerging as a novel, selective target to overcome immunosuppression in the TME. Here we present APX601 as a potent Treg and myeloid suppressive cell inhibitor. APX601 is a humanized IgG1 antibody to TNFR2 generated using APXiMAB™, Apexigen's proprietary antibody platform. APX601 selectively binds human and monkey TNFR2, blocks the binding of TNFR2 to TNF-α and depletes TNFR2-expressing Treg and tumor cells in vitro. In addition to depleting suppressive cells, APX601 can also reverse MDSC and Tregs mediated immune suppression. In human TNFR2 knock-in syngeneic mouse tumor models CT26 and MC38, treatment with APX601 results in significant tumor growth inhibition both as a single agent and in combination with anti-PD-1. Thus, APX601 is a potent antagonist antibody against TNFR2 with the ability to reverse immune suppression in TME and inhibit tumor growth. APX601 was evaluated in a repeat dose range finding toxicology study in monkeys and demonstrated a good safety profile when administered up to 100mg/kg. These data strongly support the development of APX601 as a novel therapeutic approach for reversing tumor immune suppression and for the treatment solid tumors. Citation Format: Sushma Krishnan, Ryan Alvarado, George Huang, Xiaodong Yang, Erin L. Filbert. APX601, a Potent TNFR2 Antagonist as a Novel and Promising Approach to Reverse Tumor Immune Suppression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB175.

Abstract 2888: Reversible and dose-dependent suppression of motility of human breast cancer cells with ONC201 and/or TR57 in culture

Abstract The cytotoxicity and cytostatic effects of imipridone family drugs ONC201 and its analog TR57 (Madera, USA) in variety of cultured breast cancer cell line (estrogen dependent BT474) was manifested through induction of ISR (Integrated Stress Response), UPRER and UPRMT. The major consequences of drug treatment are inhibition of proliferation and mitochondrial structural and functional damage(s). Our preliminary data demonstrated that 24 h exposure of BT474 leads to dysregulation and suppression in mitochondrial Ca2+ uptake and Ca2+ capacity (Odinokova et al., 2021). In the present work, we extend our study to include the effect of these drugs on the rate of migration intact and treated cells in culture. Treatment of BT474 cells in culture for 24h resulted in decreased motility of cells from 17 ± 2 µm/h in the absence of the drugs to 5 ± 1 µm/h and to 3±1 µm/h in cells treated with 10µM of ONC201 or 50nM of TR57 (n=5). This suppression was fully reversible and removal of drugs for 120h resulted in time dependent restoration of the initial motility of BT474 cells, and TR57 caused larger inhibitory effect on motility as compared with ONC201. Buffering of extracellular Ca2+ with 5 mM EGTA or intracellular Ca2+ with 10 µM BAPTA, 30 min suppressed motility of cells (19 ± 2 µm/h vs 6 ± 1 µm/h). Gd3+, selective blocker of store operated Ca2+ entrance (SOCE) pathway at concentration of 10 µM suppressed the motility of BT474 cells, and rate of migration changed for from 16 ± 2 µm/h in control to 7± 2 µm/h, in Gd3+ treated cells. In line with our preliminary data, taken together these data indicate that ONC201 and/or TR57 induced dysfunction in mitochondrial Ca2+ homeostasis, which translates into the suppression of the migration of human breast cancer cells in culture. Support of Funding Information: Russian Science Foundation № 19-75-20145 Citation Format: Yana Evstratova, Margarita Kobyakova, Irina Odinokova, Alexander Stolyarov, Artyom Mishukov, Lee M. Graves, Ekhson Holmuhamedov. Reversible and dose-dependent suppression of motility of human breast cancer cells with ONC201 and/or TR57 in culture [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2888.

Abstract 1243: Effects of ITI-214, a potent and selective phosphodiesterase type 1 inhibitor, on tumor myeloid cellular composition, tumor volume and survival in mouse models of colorectal cancer when combined with an anti-PD-1 checkpoint inhibitor

Abstract We investigated the effect of ITI-214, a selective phosphodiesterase type 1 (PDE-1) inhibitor [Li et al., J Med Chem, 2016, 1149-64] on immune cell composition of the tumor microenvironment, tumor volume and survival in syngeneic mouse model of colorectal cancer. The studies are based on our previous preclinical work showing that PDE-1 inhibitors modulate the function of immune cells (microglia, macrophages) by reducing immune cell motility and down-regulating key cytokines (CCL2 and TNFa). We hypothesize that ITI-214 will inhibit macrophage infiltration into the tumor microenvironment and reverse macrophage suppression of immune responses in immunogenic cancers, thereby promoting antitumor immunity and tumor killing. The effects of ITI-214, alone or in combination with sub-effective doses of programmed cell death-1 (PD-1) immune checkpoint inhibitor, were assessed on the growth of CT26 tumor in BALB/c mice. Tumor responses in tumor-bearing mice treated with isotype antibodies (i.e. control group) were compared with groups of mice treated with ITI-214 monotherapy (50mg/kg, i.p. qd, from day 7), a sub-effective dose of anti-PD-1 antibody (150 µg anti-PD-1 RPMI-14, days 7, 11, 14, 17), and a combination of each dose of ITI-214 plus a sub-effective dose of the anti PD-1 antibody. Results showed that only mice receiving the combination of ITI-214 with a sub-effective dose of anti-PD-1 displayed significantly reduced tumor growth (p=0.001). Flow cytometry analysis of tumor-infiltrating immune cells revealed that tumors from ITI-214 monotherapy-treated mice showed significantly decreased numbers of tumor (infiltrating) macrophages which were further decreased in mice receiving the combination treatment. Further, the combination therapy of ITI-214 and anti-PD-1 enhanced anti-tumor immunity by eliciting increased numbers of Natural Killer (NK) cells and TNFa-producing CD4 T-cells. The results suggest that ITI-214 alone reduces numbers of tumor macrophages, an effect which we believe unmasks the anti-tumor immune response induced by anti-PD-1 antibodies. In separate experiments we assessed the effect of combined anti-PD-1 (5mg/kg anti-PD-1 RPMI-14, biwk x 2) and ITI-214 treatment (25 or 50mg/kg, oral, qd, from day 7) on survival; the effect of combined anti-PD-1 and ITI-214 treatment produced a complete response in about 50% of treated mice, translating into a statistically significant effect on survival as compared to control (p=0.001). Together, these studies demonstrate a synergistic ability of ITI-214 and anti-PD-1 to alter the tumor environment and control tumor growth. Translating these findings to humans suggests that ITI-214 may provide a means to expand the utility of immune checkpoint inhibitors in immunogenic tumors. Citation Format: Gretchen L. Snyder, Peter A. John, Marc V. Pulanco, Xingxing Zang, Allen A. Fienberg, Robert E. Davis. Effects of ITI-214, a potent and selective phosphodiesterase type 1 inhibitor, on tumor myeloid cellular composition, tumor volume and survival in mouse models of colorectal cancer when combined with an anti-PD-1 checkpoint inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1243.

Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications.

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

Downregulation of testicular function in the goat by altrenogest

BackgroundThe present study investigated whether the administration of the progestin altrenogest provides noninvasive, temporary, and reversible suppression of gonadal function in the goat as a potential alternative to chirurgical castration, which is related with irreversibility, risks of complications till death of the animal and welfare issues. Eight sexually mature Peacock goats were randomly divided into two groups. The experimental group was administered altrenogest (0.088 mg/kg) orally once daily for 7 weeks. The remaining four goats received an oral glucose solution and served as the control group. After completing the administration period, the reversibility of the medication was evaluated for another 7 weeks (observation phase). The treatment effects were assessed by clinical examination; ultrasound examination of the testes, including one-dimensional grayscale analysis, blood testosterone levels, analysis of semen parameters and libido. At the end of the observation period, the animals were castrated and the testicles were examined histologically.ResultsAltrenogest treatment had no significant effect on the physical development of the goats, the sonographic appearance of the testes, the gray values measured in the ultrasound images, or the blood testosterone levels. The effects of treatment on the testicular and semen parameters varied widely in the experimental animals; the testicle volume was significantly lower and the number of pathologically altered sperm in the ejaculate was significantly higher in treated animals.ConclusionThese findings indicate that daily altrenogest administration at a dose of 0.088 mg/kg does not reliably suppress gonadal function in the goat.

Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure.

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.

Role of the reuniens and rhomboid thalamic nuclei in anxiety-like avoidance behavior in the rat.

The nucleus reuniens (RE) and rhomboid (RH) nuclei of the ventral midline thalamus are reciprocally connected with the prefrontal cortex (PFC) and the hippocampus (HF) and serve as key intermediaries between these structures, regulating cognitive and emotional behaviors. Regarding affective behavior, several recent reports have described the involvement of RE/RH in the acquisition and retention of conditioned fear, but little is known regarding their role (RE/RH) in anxiety-like behaviors. We examined the role of RH/RE on avoidance and defensive behaviors in male Long Evans rats using the elevated plus maze (EPM). We found that the reversible suppression of RE/RH with muscimol increased avoidance behavior to the open arms of the plus maze as shown by: (a) significant reductions in open arm entries; (b) reductions in the mean duration of time spent in the open arms; and (c) significant increases in retreats during open arm exploration. This was coupled with decreases in the number of head dips in the maze. Consistent with these behavioral effects, a single exposure of naïve rats to the plus maze produced significant increases in c-fos expression selectively in RE and RH of midline thalamic nuclei. We posit that RE/RH normally acts to optimize adaptive responses to anxiety-eliciting situations, and disruptions of RE/RH produce severe deficits in coping behaviors-or as shown here increases in avoidance/defensive behaviors. In sum, the present results establish a novel role for RE/RH in anxiety-like avoidance behavior. In addition to its role in attention, working memory, and executive control, RE/RH also regulates adaptative responses to not only fear but also to anxiogenic stimuli. As such, dysfunction of RE/RH may contribute to the amalgamation of symptoms common to many mental health disorders including anxiety, depression, schizophrenia, and PTSD.

Parvovirus-Based Combinatorial Immunotherapy: A Reinforced Therapeutic Strategy against Poor-Prognosis Solid Cancers.

Simple SummaryOncolytic virotherapy using oncolytic viruses with natural or engineered cancer-destroying capacities has emerged as a promising treatment concept in modern oncology. Rodent protoparvoviruses, in particular the rat H-1 parvovirus (H-1PV), have demonstrated their broad-range tumor-suppressive properties in both preclinical models and clinical studies. In addition to inducing selective tumor cell death, these viruses are also able to exert immunostimulating effects and reverse tumor-driven immune suppression. Parvovirotherapy holds therefore a potential for enhancing the efficacy of other cancer immunotherapies. The aim of this review is to provide an overview of all H-1PV-based combinatorial immunotherapeutic approaches against poor-prognosis human solid cancers that have been tested so far. Current challenges and future prospects of parvoviro-immunotherapy, notably parvovirus inclusion into various immunotherapeutic protocols against glioblastoma, pancreatic cancer, among other standard therapy-refractory solid malignancies, are also discussed in the light of H-1PV further clinical development.Resistance to anticancer treatments poses continuing challenges to oncology researchers and clinicians. The underlying mechanisms are complex and multifactorial. However, the immunologically “cold” tumor microenvironment (TME) has recently emerged as one of the critical players in cancer progression and therapeutic resistance. Therefore, TME modulation through induction of an immunological switch towards inflammation (“warming up”) is among the leading approaches in modern oncology. Oncolytic viruses (OVs) are seen today not merely as tumor cell-killing (oncolytic) agents, but also as cancer therapeutics with multimodal antitumor action. Due to their intrinsic or engineered capacity for overcoming immune escape mechanisms, warming up the TME and promoting antitumor immune responses, OVs hold the potential for creating a proinflammatory background, which may in turn facilitate the action of other (immunomodulating) drugs. The latter provides the basis for the development of OV-based immunostimulatory anticancer combinations. This review deals with the smallest among all OVs, the H-1 parvovirus (H-1PV), and focuses on H-1PV-based combinatorial approaches, whose efficiency has been proven in preclinical and/or clinical settings. Special focus is given to cancer types with the most devastating impact on life expectancy that urgently call for novel therapies.

Reverse Force Suppression Method of Reluctance Coil Launcher Based on Consumption Resistor

When armature passes through the central plane of a driving coil in the process of reluctance coil launching, the magnetic force will reverse and slow down the armature speed. To overcome this problem, the principle of reluctance coil launcher is analyzed. Meanwhile, this paper establishes a finite element analysis model to calculate the electromagnetic force, velocity, displacement and other parameters of the armature while the reluctance coil launcher works. Based on the simulation results, dynamic characteristics of the reluctance coil launcher are summarized and two methods for reverse force suppression are discussed. Furthermore, an experiment system is established and some experiments are carried out. This research concludes that resistor consumption method can effectively restrain the generation of reverse force, with no obvious bad impact on other performance, which provides a practical approach to achieving higher speed and efficiency for reluctance electromagnetic launcher.

Micromechanism of ferroelectric fatigue and enhancement of fatigue resistance of lead zirconate titanate thin films

Ferroelectric random access memory (FeRAM) has been regarded as a promising technology for next-generation nonvolatile storage due to its excellent data storage performance and nonvolatile storage characteristics. However, fatigue degradation properties seriously impede the development and large-scale commercial use of FeRAM. In this paper, the interaction mechanism and enhancement of ferroelectric fatigue in lead zirconate titanate (PZT) thin film are investigated by the first-principles calculations (DFT). Theoretical calculations suggest that the coupling between oxygen vacancies and 180° domain walls in PZT is responsible for ferroelectric fatigue. Oxygen vacancies are more likely to be formed closer to domain wall, the “pinning” between oxygen vacancies and domain wall makes the migration of domain wall difficult, resulting in the suppression of polarization reversal and ultimately fatigue in ferroelectric thin film. The insertion of Ba(Mg<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub> (BMN) can absorb the oxygen vacancies in PZT and reduce the concentration of oxygen vacancies, and in doing so, the ferroelectric fatigue problem caused by the “pinning” effect of the oxygen vacancies can be eliminated. Moreover, the PZT thin films are deposited on Pt/Ti/SiO<sub>2</sub>/Si(100) by the sol-gel method with using BMN buffer layer. The remnant polarization (<i>P</i><sub>r</sub><italic/>) of PZT film decreases by 51% and the PZT/BMN film remains 85% after 10<sup>10</sup> cycles. Furthermore, it keeps stable even up to 10<sup>12</sup> cycles. This paper demonstrates that the PZT/BMN film with excellent ferroelectric and fatigue endurance possesses the promising applications in FeRAM.

GATA2 Mutation in Twins with Transient Aplastic Anemia after Chloramphenicol Exposure; A Follow up to Nagao and Mauer 1969

A case of identical twins who developed transient aplastic anemia after chloramphenicol exposure was reported by Nagao and Mauer in the New England Journal of Medicine in 1969. Bone marrow (BM) morphology and tritiated thymidine labeling indices were suggestive of a failure of delivery cells from the undifferentiated stem cell compartment. They concluded that an underlying genetic factor which predisposed to the development of drug induced aplastic anemia was highly likely. We now report long term follow up on the twins from that article and have identified that they both harbour a mutation in GATA2. Twin 1 presented with severe pancytopenia at age 8 months, 3 months after chloramphenicol exposure. His leukocytes and erythrocytes had normalized with supportive care, but platelet count (PC) remained low at 92,000/mm3. Later in life, he was diagnosed with transfusion acquired hepatitis C, treated with Sofosbuvir/Velpatasvir. He did not develop recurrent infections, warts, lymphedema, or pulmonary symptoms. At age 51, he was referred to Hematology for asymptomatic thrombocytopenia with a PC of 17,000/mm3. BM aspirate and biopsy showed a variably cellular marrow with relative erythroid hyperplasia and megaloblastoid features. Cytogenetics, FISH for myelodysplastic syndrome (MDS) related abnormalities and a 33 gene panel for MDS/chronic myelomonocytic leukemia related mutations by next generation sequencing were all normal. A next generation sequencing panel of 59 genes associated with hereditary BM failure syndromes was remarkable only for a previously unreported heterozygous mutation in GATA2 (c1040C>A, pThr347Asn). Twin 2 was also exposed to chloramphenicol at 5 months of age and was found to be pancytopenic when evaluated for BM donation for his brother. His pancytopenia spontaneously resolved at the end of observation. Subsequent medical problems included partial complex seizures, dysautonomia, vertigo, chronic pain syndrome and recurrent Clostridium difficile colitis. He had no history of other recurrent infections, warts, lymphedema, or pulmonary symptoms. He had mild asymptomatic cytopenias noted with a white blood cell count of 3600/mm3, a hemoglobin of 12.9 g/dl and a PC of 97,000/mm3 at the age of 50 years. At the age of 52, he was referred to hematology and was asymptomatic with a normal hemogram. DNA sequencing confirmed an identical GATA2 mutation. GATA2, a DNA binding transcription factor with two zinc finger domains, plays a significant role in gene regulation, cell fate decisions and maintenance of the hematopoietic stem cell pool. Excessive GATA2 activity is reported to prevent stem cells from leaving the pool, while insufficient GATA2 activity causes stem cells to differentiate at increased rates thereby depleting the pool. Homozygous GATA deletions/mutations are lethal. Reported mutations include deletions, frame shift mutations, nonsense mutations and point mutations. Many point mutations appear to act by causing haplo-insufficiency. The point mutation in these patients maps in proximity to the C-zinc finger domain and could potentially disrupt an exonic splicing enhancer causing an in-frame deletion of exon six. Clinical syndromes associated with GATA2 mutations include familial BM failure and cytopenia; familial myelodysplastic syndromes and acute myeloid leukemia; immunodeficiency with monocytopenia and recurrent viral, fungal and mycobacterial infections; immunodeficiency with decreased natural killer, dendritic, B cells, and monocytes; Emberger syndrome presenting with myelodysplastic syndrome, warts and lymphedema; and pulmonary alveolar proteinosis. Cytopenia has been the only clinically obvious manifestation in these twins. Chloramphenicol has been associated with two forms of hematological toxicity. The first is a dose related reversible bone marrow suppression presenting as anemia, and the second is idiosyncratic, often fatal, aplastic anemia. It was proposed that these may be opposite ends of a spectrum with an underlying genetic predisposition leading to the more severe forms. The finding of a GATA2 mutation in these patients supports Nagao and Maurer's speculation that an underlying genetic factor affecting stem cell regulation predisposed to the development of chloramphenicol induced aplastic anemia in these twins. Figure Disclosures No relevant conflicts of interest to declare.

Autoimmune Endocrinopathies: An Emerging Complication of Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (CPIs) reverse immune suppression that is thought to allow malignant growth. Despite remarkable efficacy in a subset of cancers, their use is accompanied by immune-related adverse events, including endocrinopathies such as hypophysitis, thyroid dysfunction, diabetes, and adrenalitis. These conditions are heterogenous, with differing incidence across CPI types, but are unified by the acuity and extremity of tissue-specific organ failure. Their occurrence may be associated with beneficial tumor control. Further understanding of the risk factors and mechanisms of these endocrine immunotoxicities can help optimize CPI use as well as improve understanding of spontaneous autoimmune diseases.

MicroRNA-623 Inhibits Epithelial-Mesenchymal Transition to Attenuate Glioma Proliferation by Targeting TRIM44.

ObjectiveGlioma has the highest incidence among the different tumor types within the nervous system, accounting for about 40% of them. Malignant glioma has a high invasion and metastasis rate, which leads to the poor prognosis of patients. By targeting specific genes, microRNAs serve as key regulators in the epithelial–mesenchymal transformation (EMT) process, which could provide new insights into the treatment of glioblastomas (GBM). The detailed molecular role that miR-623 plays in GBM still remains unclear.Materials and MethodsThe level of miR-623 in GBM cells was evaluated by RT-PCR. The function of miR-623 overexpression on GBM cell proliferation, migration, and invasion was assessed by MTS, Transwell analysis, and colony formation assay. In addition, a mouse subcutaneous xenograft model was used to study in vivo effects. The binding between miR-623 and TRIM44 was verified by a dual-luciferase reporter assay and the regulatory function of miR-623 on EMT markers was evaluated using Western blot.ResultsThe expression of miR-623 was repressed in the GBM cancer cell lines. MiR-623 overexpression or TRIM44 knockdown attenuated the proliferation, migration, and invasion of GBM cell lines. TRIM44 could facilitate the reverse suppression of EMT and miR-623 in GBM progression. MiR-623 was found to inhibit TRIM44 expression by directly binding to its 3ʹUTR. In addition, systemic delivery of miR-623 mimic reduced tumor growth and inhibited TRIM44 protein expression in tumor-bearing nude mice. Furthermore, our findings indicated that miR-623 overexpression or TRIM44 down-regulation impeded the proliferation and migratory ability of LN229 and U251MG glioma cells, and miR-623 attenuates TRIM44-induced EMT by directly targeting the 3ʹUTR of TRIM44, which could serve as preliminary research to identify potential therapeutic targets for future treatment of GBM.ConclusionOverall, microRNA-623 inhibits epithelial–mesenchymal transition to attenuate glioma proliferation by targeting TRIM44.

The introduction of immunosuppressor (TDO inhibitor) significantly improved the efficacy of irinotecan in treating hepatocellular carcinoma.

As TDO inhibitors can improve the efficacy of tumor chemotherapeutics, two TDO-targeted conjugates consisting of irinotecan (Ir) and a TDO inhibitor unit were designed and prepared to reverse tumor immune suppression, which could remarkably enhance antitumor activity of Ir by boosting cellular uptakes against TDO overexpressed HepG2 cancer cells. In vitro mechanistic studies demonstrated that compound PVIS-Ir and PVIG-Ir could arrest cell cycle at G2 phase and induce cell apoptosis by mitochondrial apoptotic pathway. Furthermore, compound PVIS-Ir could effectively inhibit TDO protein expression via releasing a TDO inhibitor derivative, which could also completely embed in TDO protein pocket. Further mechanism study indicated that PVIS-Ir could block kynurenine production and deactivate aryl hydrocarbon receptor (AHR), resulting in T-cell activation and proliferation. In vivo studies confirmed that PVIS-Ir could improve tumor immune microenvironment in a murine model. This combinational strategy of chemotherapy and immunotherapy can be a promising way in the treatment of hepatocellular carcinoma. Conjugates obtained by combining an immune checkpoint TDO inhibitor with irinotecan via different linkers could improve tumor immune microenvironment by inhibiting the TDO enzyme expression to block kynurenine production and induce HepG2 cancer cell apoptosis via DNA damage through releasing a TDO inhibitor and irinotecan in cancer cells.