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"Opipari, Anthony"
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Role of Inflammasomes in Intestinal Inflammation and Crohn's Disease
2015
Inflammasomes are multiprotein complexes that process procytokines into mature forms of interleukin 1β and interleukin 18 and induce pyroptotic cell death. Evidence linking NLRP3, NLRC4, and NLRP6 inflammasomes to intestinal inflammation is reviewed to provide a basis to understand how the innate immune system discriminates pathogenic bacteria from commensal bacteria and shapes microbial ecology. Inflammasomes have a direct and important role limiting colitis by directing effective immune responses against pathogenic bacterial infections in the intestine. Chronic granulomatous disease is presented to reveal a contrasting proinflammatory effect of inflammasomes. This pathogenic effect is unmasked in a state of immunodeficiency where bacterial growth is poorly controlled increasing inflammasome activity. The role of inflammasomes in inflammation associated with Crohn's disease and ulcerative colitis is discussed. Finally, mechanistic studies linking genetic polymorphisms in ATG16L and NOD2 to inflammasome activation provide a basis for new hypotheses to explain how genetic polymorphism associated with Crohn's disease modulate intestinal inflammation. A deeper understanding of the role of inflammasomes in intestinal inflammation is expected to identify new ways of treating inflammatory bowel disease.
Journal Article
Ku70 Acetylation Mediates Neuroblastoma Cell Death Induced by Histone Deacetylase Inhibitors
2005
Histone deacetylase inhibitors (HDACIs) are therapeutic drugs that inhibit deacetylase activity, thereby increasing acetylation of many proteins, including histones. HDACIs have antineoplastic effects in preclinical and clinical trials and are being considered for cancers with unmet therapeutic need, including neuroblastoma (NB). Uncertainty of how HDACI-induced protein acetylation leads to cell death, however, makes it difficult to determine which tumors are likely to be responsive to these agents. Here, we show that NB cells are sensitive to HDACIs, and that the mechanism by which HDACIs induce apoptosis involves Bax. In these cells, Bax associates with cytoplasmic Ku70, a protein that typically increases chemotherapy resistance. Our data show that in NB cells Ku70 binds to Bax in an acetylation-sensitive manner. Upon HDACI treatment, acetylated Ku70 releases Bax, allowing it to translocate to mitochondria and trigger cytochrome c release, leading to caspase-dependent death. This study shows that Ku70 is an important Bax-binding protein, and that this interaction can be therapeutically regulated in NB cells. Whereas the Bax-binding ability of Ku70 allows it to block apoptosis in response to certain agents, it is also a molecular target for the action of HDACIs, and in this context, a mediator of NB cell death.
Journal Article
First‐in‐human safety, tolerability, and pharmacokinetic results of DFV890, an oral low‐molecular‐weight NLRP3 inhibitor
2024
This first‐in‐human study evaluated the safety, tolerability, single‐ and multiple‐dose pharmacokinetic profiles with dietary influence, and pharmacodynamics (PD) of DFV890, an oral NLRP3 inhibitor, in healthy participants. In total, 122 participants were enrolled into a three‐part trial including single and 2‐week multiple ascending oral doses (SAD and MAD, respectively) of DFV890, and were randomized (3:1) to DFV890 or placebo (SAD [3–600 mg] and MAD [fasted: 10–200 mg, once‐daily or fed: 25 and 50 mg, twice‐daily]). DFV890 was generally well‐tolerated. Neither deaths nor serious adverse events were reported. A less than dose‐proportional increase in exposure was observed with the initially used crystalline suspension (3–300 mg); however, an adjusted suspension formulation using spray‐dried dispersion (SDD; 100–600 mg) confirmed dose‐proportional increase in exposure. Relative bioavailability between crystalline suspension and tablets, and food effect were evaluated at 100 mg. Under fasting conditions, Cmax of the tablet yielded 78% compared with the crystalline suspension, and both formulations showed comparable AUC. The fed condition led to a 2.05‐ and 1.49‐fold increase in Cmax and AUC0–last compared with the fasting condition. The median IC50 and IC90 for ex‐vivo lipopolysaccharide‐stimulated interleukin IL‐1β release inhibition (PD) were 61 (90% CI: 50, 70) and 1340 ng/mL (90% CI: 1190, 1490). Crystalline tablets of 100 mg once‐daily or 25 mg twice‐daily were sufficient to maintain ~90% of the IL‐1β release inhibition over 24 h at steady state. Data support dose and formulation selection for further development in diseases, in which an overactivated NLRP3 represents the underlying pathophysiology.
Journal Article
Alternative NHEJ pathway proteins as components of MYCN oncogenic activity in human neural crest stem cell differentiation: implications for neuroblastoma initiation
by
Newman, Erika A.
,
Hoenerhoff, Mark J.
,
Van Noord, Raelene A.
in
Antibodies
,
Apoptosis
,
Biochemistry
2017
Neuroblastoma is a cancer of neural crest stem cell (NCSC) lineage. Signaling pathways that regulate NCSC differentiation have been implicated in neuroblastoma tumorigenesis. This is exemplified by
MYCN
oncogene targets that balance proliferation, differentiation, and cell death similarly in normal NCSC and in high-risk neuroblastoma. Our previous work discovered a survival mechanism by which
MYCN
-amplified neuroblastoma circumvents cell death by upregulating components of the error-prone non-canonical alternative nonhomologous end-joining (alt-NHEJ) DNA repair pathway. Similar to proliferating stem cells, high-risk neuroblastoma cells have enhanced DNA repair capacity, overcoming DNA damage with higher repair efficiency than somatic cells. Adequate DNA maintenance is required for lineage protection as stem cells proliferate and during tumor progression to overcome oncogene-induced replication stress. On this basis, we hypothesized that alt-NHEJ overexpression in neuroblastoma is a cancer cell survival mechanism that originates from DNA repair systems of NCSC, the presumed progenitor cell of origin. A human NCSC model was generated in which inducible
MYCN
triggered an immortalized phenotype capable of forming metastatic neuroectodermal tumors in mice, resembling human neuroblastoma. Critical alt-NHEJ components (DNA Ligase III, DNA Ligase I, and Poly [ADP-ribose polymerase 1]) were highly expressed in normal early NCSC, and decreased as cells became terminally differentiated. Constitutive
MYCN
expression maintained high alt-NHEJ protein expression, preserving the expression pattern of the immature neural phenotype. siRNA knockdown of alt-NHEJ components reversed
MYCN
effects on NCSC proliferation, invasion, and migration. DNA Ligase III, Ligase I, and PARP1 silencing significantly decreased neuroblastoma markers expression (TH, Phox2b, and TRKB). These results utilized the first human NCSC model of neuroblastoma to uncover an important link between
MYCN
and alt-NHEJ expression in developmental tumor initiation, setting precedence to investigate alt-NHEJ repair mechanics in neuroblastoma DNA maintenance.
Journal Article
Niclosamide Enema for Active Distal Ulcerative Colitis: A Phase 1, Open-Label Study
by
Lolli, Elisabetta
,
Glick, Gary
,
Calabrese, Emma
in
Adult
,
Aged
,
Anti-Inflammatory Agents, Non-Steroidal - administration & dosage
2024
Background
Oral and rectal formulations of 5-aminosalicylic acid are the first-line therapy for mild-to-moderate, distal ulcerative colitis (UC), but such a treatment is not effective in one-third of patients. Niclosamide is a small molecule, developed and approved as an orally administered drug to treat helminthic infections, with an excellent safety profile. Preclinical work showed that niclosamide is an anti-inflammatory agent, thereby providing the rationale to explore its safety and efficacy in patients with UC. This phase 1, open-label trial was aimed at assessing the safety of niclosamide formulated as an enema in patients with mild-to-moderate, distal UC, who relapsed on maintenance therapy with oral and/or rectal 5-aminosalicylic acid.
Methods
Seventeen patients with active UC received niclosamide enema (150 mg/60 mL) twice a day for 6 weeks. The primary endpoint was the safety of niclosamide treatment. Secondary endpoints included clinical remission and improvements in endoscopic Mayo/histologic scores. Endoscopic remission percentages exclude participants meeting criteria at baseline for endoscopic remission.
Results
Niclosamide was well tolerated by all 17 patients that were enrolled and treated. No serious adverse event was registered. Fifteen mild adverse events were registered in 6 patients and considered to be unrelated to the treatment. Clinical remission was achieved in 10 (59%) of 17 patients. Improvements of endoscopic Mayo score and histologic Geboes score were seen in 7 (58%) of 12 and 7 (41.2%) of 17 patients, respectively.
Conclusions
Niclosamide enema treatment is safe and well tolerated. Niclosamide improves clinical symptoms and endoscopic/histologic signs of UC; however, appropriately designed placebo-controlled clinical trials are required to confirm efficacy.
Journal Article
CLU blocks HDACI-mediated killing of neuroblastoma
by
Kuick, Rork
,
Opipari, Anthony W.
,
Subramanian, Chitra
in
Acetylation
,
Acetylation - drug effects
,
Antigens, Nuclear - metabolism
2011
Clusterin is a ubiquitously expressed glycoprotein with multiple binding partners including IL-6, Ku70, and Bax. Clusterin blocks apoptosis by binding to activated Bax and sequestering it in the cytoplasm, thereby preventing Bax from entering mitochondria, releasing cytochrome
c
, and triggering apoptosis. Because increased clusterin expression correlates with aggressive behavior in tumors, clusterin inhibition might be beneficial in cancer treatment. Our recent findings indicated that, in neuroblastoma cells, cytoplasmic Bax also binds to Ku70; when Ku70 is acetylated, Bax is released and can initiate cell death. Therefore, increasing Ku70 acetylation, such as by using histone deacetylase inhibitors, may be therapeutically useful in promoting cell death in neuroblastoma tumors. Since clusterin, Bax, and Ku70 form a complex, it seemed likely that clusterin would mediate its anti-apoptotic effects by inhibiting Ku70 acetylation and blocking Bax release. Our results, however, demonstrate that while clusterin level does indeed determine the sensitivity of neuroblastoma cells to histone deacetylase inhibitor-induced cell death, it does so without affecting histone deacetylase-inhibitor-induced Ku70 acetylation. Our results suggest that in neuroblastoma, clusterin exerts its anti-apoptotic effects downstream of Ku70 acetylation, likely by directly blocking Bax activation.
Journal Article
Actual Versus Perceived Risk of Cervical Cancer Among College Women Smokers
2007
Cervical cancer is a well-established smoking-related illness, but many at-risk women are unaware of this link. Objective: The authors designed this study to (1) investigate the relationship of smoking behavior with the history of abnormal Pap test results, sexual history, and perceived risk of cervical cancer and (2) determine whether self-classified smoking status (and hence perceived risk) corresponds with actual smoking behavior in a college student population. Participants and Method Summary: College women students (N = 135) completed a survey assessing smoking history, health history, sexual risk behavior, and risk awareness. Results: Relative to those who had not smoked in the past month, current smokers (n = 36, or 27% of the total sample) perceived themselves to be at higher risk for developing cervical cancer, but did not demonstrate increased awareness of specific cervical cancer risk factors, including smoking. Twenty-eight percent (10 of 36) of past-month smokers did not define themselves as current smokers.
Conclusion: The authors conclude that antismoking and health-related messages targeting smokers may misfire for individuals who do not define themselves as smokers but are nonetheless at risk for smoking-related consequences and escalating use.
Journal Article
Evaluating the ability of visual images to inform college women about the link between smoking and cervical intraepithelial neoplasia (CIN) and to motivate quitting: Critical dimensions
by
Kleinsmith, Lewis
,
Snedecor, Sandy M.
,
Saules, Karen K.
in
Adult
,
Attrition (Research Studies)
,
Audiovisual Aids
2007
Because cervical intraepithelial neoplasia (CIN, or dysplasia) is associated with behavioral factors, health education is an important part of the care of patients at risk for this disease. Smoking, which is strongly associated with CIN and cancers, is particularly important because smoking cessation, even after the onset of CIN, improves outcomes. This study is part of an effort to identify effective ways to convey information about the association between smoking and CIN to at-risk women.
We created 8 images to systematically incorporate a range of artistic approaches to inform viewers about the relationship between smoking and CIN. College women smokers were recruited to participate. Participants rated the images on the extent to which they attracted attention and motivated smoking cessation.
Significant differences were identified in the response of this population to visual images differing in content and style. Informative images were more compelling than those that were emotive.
Further exploration is warranted to improve our understanding of how visual forms of health education can impact smoking cessation by those at risk for cervical cancer.
Journal Article