Colitis-associated colorectal cancers are an etiologically distinct subgroup of colon cancers that occur in individuals suffering from inflammatory bowel disease and arise as a consequence of ...persistent exposure of hyperproliferative epithelial stem cells to an inflammatory microenvironment. An intrinsic defect in the intestinal epithelial barrier has been proposed to be one of several factors that contribute to the inappropriate immune response to the commensal microbiota that underlies inflammatory bowel disease. Matriptase is a membrane-anchored serine protease encoded by Suppression of Tumorigenicity-14 (ST14) that strengthens the intestinal epithelial barrier by promoting tight junction formation. Here, we show that intestinal epithelial-specific ablation of St14 in mice causes formation of colon adenocarcinoma with very early onset and high penetrance. Neoplastic progression is preceded by a chronic inflammation of the colon that resembles human inflammatory bowel disease and is promoted by the commensal microbiota. This study demonstrates that inflammation-associated colon carcinogenesis can be initiated and promoted solely by an intrinsic intestinal permeability barrier perturbation, establishes St14 as a critical tumor-suppressor gene in the mouse gastrointestinal tract and adds matriptase to the expanding list of pericellular proteases with tumor-suppressive functions.
Abstract
Background
Cryptococcal meningoencephalitis (CM) is a major cause of mortality in immunosuppressed patients and previously healthy individuals. In the latter, a post-infectious inflammatory ...response syndrome (PIIRS) is associated with poor clinical response despite antifungal therapy and negative cerebrospinal fluid (CSF) cultures. Data on effective treatment are limited.
Methods
Between March 2015 and March 2020, 15 consecutive previously healthy patients with CM and PIIRS were treated with adjunctive pulse corticosteroid taper therapy (PCT) consisting of intravenous methylprednisolone 1 gm daily for 1 week followed by oral prednisone 1 mg/kg/day, tapered based on clinical and radiological response plus oral fluconazole. Montreal cognitive assessments (MOCA), Karnofsky performance scores, magnetic resonance imaging (MRI) brain scanning, ophthalmic and audiologic exams, and CSF parameters including cellular and soluble immune responses were compared at PIIRS diagnosis and after methylprednisolone completion.
Results
The median time from antifungal treatment to steroid initiation was 6 weeks. The most common symptoms at PIIRS diagnosis were altered mental status and vision changes. All patients demonstrated significant improvements in MOCA and Karnofsky scores at 1 month (P < .0003), which was accompanied by improvements in CSF glucose, white blood cell (WBC) count, protein, cellular and soluble inflammatory markers 1 week after receiving corticosteroids (CS) (P < .003). All patients with papilledema and visual field deficits also exhibited improvement (P < .0005). Five out of 7 patients who underwent audiological testing demonstrated hearing improvement. Brain MRI showed significant improvement of radiological findings (P = .001). CSF cultures remained negative.
Conclusions
PCT in this small cohort of PIIRS was associated with improvements in CM-related complications with minimal toxicity in the acute setting.
This is a small case series describing functional outcomes in previously healthy cryptococcal meningitis patients treated with pulse corticosteroid taper therapy for postinfectious inflammatory syndrome (PIIRS).
Once multiple sclerosis (MS) reaches the progressive stage, immunomodulatory treatments have limited efficacy. This suggests that processes other than activation of innate immunity may at least ...partially underlie disability progression during late stages of MS. Pathology identified these alternative processes as aberrant activation of astrocytes and microglia, and subsequent degeneration of oligodendrocytes and neurons. However, we mostly lack biomarkers that could measure central nervous system (CNS) cell-specific intrathecal processes in living subjects. This prevents differentiating pathogenic processes from an epiphenomenon. Therefore, we sought to develop biomarkers of CNS cell-specific processes and link them to disability progression in MS.
In a blinded manner, we measured over 1000 proteins in the cerebrospinal fluid (CSF) of 431 patients with neuroimmunological diseases and healthy volunteers using modified DNA-aptamers (SOMAscan®). We defined CNS cell type-enriched clusters using variable cluster analysis, combined with in vitro modeling. Differences between diagnostic categories were identified in the training cohort (n = 217) and their correlation to disability measures were assessed; results were validated in an independent validation cohort (n = 214).
Astrocyte cluster 8 (MMP7, SERPINA3, GZMA and CLIC1) and microglial cluster 2 (DSG2 and TNFRSF25) were reproducibly elevated in MS and had a significant and reproducible correlation with MS severity suggesting their pathogenic role. In vitro studies demonstrated that proteins of astrocyte cluster 8 are noticeably released upon stimulation with proinflammatory stimuli and overlap with the phenotype of recently described neuro-toxic (A1) astrocytes.
Microglial activation and toxic astrogliosis are associated with MS disease process and may partake in CNS tissue destruction. This hypothesis should be tested in new clinical trials.
The progression and negative outcome of a variety of human carcinomas are intimately associated with aberrant activity of the c-Met oncogene. The underlying cause of this dysregulation, however, ...remains a subject of discussion, as the majority of cancer patients do not present with activating mutations in c-Met receptor itself. In this study, we show that the oncogenic protease matriptase is ubiquitously co-expressed with the c-Met in human squamous cell carcinomas and amplifies migratory and proliferative responses of primary epithelial cells to the cognate ligand for c-Met, pro-hepatocyte growth factor/scatter factor (proHGF/SF), through c-Met and Gab1 signaling. Furthermore, the selective genetic ablation of c-Met from matriptase-expressing keratinocytes completely negates the oncogenic potential of matriptase. In addition, matriptase-dependent carcinoma formation could be blocked by the pharmacological inhibition of the Akt-mammalian target of Rapamycin (mTor) pathway. Our data identify matriptase as an initiator of c-Met-Akt-mTor-dependent signaling axis in tumors and reveal mTor activation as an essential component of matriptase/c-Met-induced carcinogenesis. The study provides a specific example of how epithelial transformation can be promoted by epigenetic acquisition of the capacity to convert a widely available paracrine growth factor precursor to its signaling competent state.
Archaea possess a basal transcriptional apparatus that resembles that of eukaryotes. Here we report the 2.1-Å crystal structure of the archaeal transcription factor complex formed by the ...TATA-box-binding protein (TBP), the transcription factor IIB homolog, and a DNA target, all from the hyperthermophile Pyrococcus woesei . The overall fold of these two basal transcription factors is essentially the same as that of their eukaryotic counterparts. However, in comparison with the eukaryotic complexes, the archaeal TBP–DNA interface is more symmetrical, and in this structure the orientation of the preinitiation complex assembly on the promoter is inverted with respect to that seen in all crystal structures of comparable eukaryotic systems. This study of the structural details of an archaeal transcription factor complex presents the opportunity to examine the evolution of the basal eukaryotic transcriptional apparatus from a stereochemical viewpoint and to extend our understanding of the physical biochemistry of transcriptional initiation.
Objective
Inaccessibility of the inflammation compartmentalized to the central nervous system (CNS) may underlie the lack of efficacy of immunomodulatory treatments in progressive multiple sclerosis ...(MS). The double blind combination of Rituximab by IntraVenous and IntraThecAl injection versus placebo in patients with Low‐Inflammatory SEcondary progressive MS (RIVITALISE; NCT01212094) trial was designed to answer: (1) Whether an induction dose of intravenous and intrathecal rituximab efficiently depletes CNS B cells? and (2) If so, whether this leads to global inhibition of CNS inflammation and slowing of CNS tissue destruction?
Methods
Patients aged 18–65 years were randomly assigned to rituximab or placebo. Protocol‐stipulated interim analysis quantified the efficacy of B‐cell depletion.
Results
The efficacy on cerebrospinal fluid (CSF) biomarkers failed to reach criteria for continuation of the trial. B‐cell‐related CSF biomarkers (sCD21 and B‐cell activating factor) changed only in the active‐treatment arm. While CSF B cells were killed robustly (median −79.71%, P = 0.0176), B cells in CNS tissue were depleted inadequately (~−10–20%, P < 0.0001). Consequently, the T‐cell‐specific CSF biomarker sCD27 decreased slightly (−10.97%, P = 0.0005), while axonal damage marker, neurofilament light chain did not change. Insufficient saturation of CD20, lack of lytic complement, and paucity of cytotoxic CD56dim NK cells contribute to decreased efficacy of rituximab in the CNS.
Interpretation
Biomarker studies reliably quantified complementary pharmacodynamic effects of rituximab in the CNS, exposed causes for poor efficacy and determined that RIVITALISE trial would be underpowered to measure efficacy on clinical outcomes. Identified mechanisms for poor efficacy are applicable to all CNS‐inflammation targeting monoclonal antibodies.
•CSF SERPINA3 is a reliable pharmacodynamic marker of toxic astrogliosis in multiple sclerosis.•Inhibitors of pathways related to the ER stress (proteasome, HSP90 and mTOR) attenuated ...inflammation-induced conversion of astrocytes to a toxic phenotype.•In vitro drug library screening provided mechanistic insight into the generation of toxic astrocytes and identified potential candidates for immediate proof-of-principle clinical trials.
Multiple sclerosis (MS) is a chronic neuroinflammatory disorder, in which activated immune cells directly or indirectly induce demyelination and axonal degradation. Inflammatory stimuli also change the phenotype of astrocytes, making them neurotoxic. The resulting ‘toxic astrocyte’ phenotype has been observed in animal models of neuroinflammation and in MS lesions. Proteins secreted by toxic astrocytes are elevated in the cerebrospinal fluid (CSF) of MS patients and reproducibly correlate with the rates of accumulation of neurological disability and brain atrophy. This suggests a pathogenic role for neurotoxic astrocytes in MS.
Here, we applied a commercially available library of small molecules that are either Food and Drug Administration-approved or in clinical development to an in vitro model of toxic astrogliosis to identify drugs and signaling pathways that inhibit inflammatory transformation of astrocytes to a neurotoxic phenotype.
Inhibitors of three pathways related to the endoplasmic reticulum stress: (1) proteasome, (2) heat shock protein 90 and (3) mammalian target of rapamycin reproducibly decreased inflammation-induced conversion of astrocytes to toxic phenotype. Dantrolene, an anti-spasticity drug that inhibits calcium release through ryanodine receptors expressed in the endoplasmic reticulum of central nervous system cells, also exerted inhibitory effect at in vivo achievable concentrations. Finally, we established CSF SERPINA3 as a relevant pharmacodynamic marker for inhibiting toxic astrocytes in clinical trials.
Drug library screening provides mechanistic insight into the generation of toxic astrocytes and identifies candidates for immediate proof-of-principle clinical trial(s).
Background. Cryptococcus can cause meningoencephalitis (CM) among previously healthy non-HIV adults. Spinal arachnoiditis is under-recognized, since diagnosis is difficult with concomitant central ...nervous system (CNS) pathology. Methods. We describe 6 cases of spinal arachnoiditis among 26 consecutively recruited CM patients with normal CD4 counts who achieved microbiologic control. We performed detailed neurological exams, cerebrospinal fluid (CSF) immunophenotyping and biomarker analysis before and after adjunctive immunomodulatory intervention with high dose pulse corticosteroids affording causal inference into pathophysiology. Results. All 6 exhibited severe lower motor neuron involvement in addition to cognitive changes and gait disturbances from meningoencephalitis. Spinal involvement was associated with asymmetric weakness and urinary retention. Diagnostic specificity was improved by MRI imaging which demonstrated lumbar spinal nerve root enhancement and clumping or lesions. Despite negative fungal cultures, CSF inflammatory biomarkers, sCD27 and sCD21, as well as the neuronal damage biomarker, neurofilament light chain (NFL), were elevated compared to healthy donor (HD) controls. Elevations in these biomarkers were associated with clinical symptoms and showed improvement with adjunctive high dose pulse corticosteroids. Conclusions. These data suggest that a post-infectious spinal arachnoiditis is an important complication of CM in previously healthy individuals, requiring heightened clinician awareness. Despite microbiological control, this syndrome causes significant pathology likely due to increased inflammation and may be amenable to suppressive therapeutics.
•Idebenone is well-tolerated over two-year extended use.•Idebenone did not inhibit disability accumulation in a two-year baseline-versus treatment placebo-controlled trial.•GDF15 is a potential CSF ...biomarker of mitochondrial dysfunction in MS.
Multiple sclerosis (MS) is a chronic, immune-mediated neurodegenerative disorder of the central nervous system (CNS). While current MS therapies target the inflammatory processes, no treatment explicitly targets mitochondrial dysfunction and resulting axonal loss. Therefore, the aim of this study was to determine whether idebenone inhibits mitochondrial dysfunction and accumulation of disability in primary progressive MS (PPMS) and to enhance understanding of pathogenic mechanisms of PPMS progression using cerebrospinal fluid (CSF) biomarkers.
The double-blind, placebo-controlled Phase I/II clinical trial of Idebenone in patients with Primary Progressive MS (IPPoMS; NCT00950248) was an adaptively designed, baseline-versus-treatment, placebo-controlled, CSF-biomarker-supported trial. Based on interim analysis of the 1-year pre-treatment data, change in the area under the curve of Combinatorial Weight-Adjusted Disability Score (CombiWISE) became the primary outcome, with >80% power to detect ≥40% efficacy with 28 patients/arm treated for 2 years in baseline versus treatment paradigm. Changes in traditional disability scales and in brain ventricular volume were secondary outcomes. Exploratory outcomes included CSF biomarkers of mitochondrial dysfunction (Growth/differentiation factor 15 GDF15 and lactate), axonal damage (neurofilament light chain NFL), innate immunity (sCD14), blood brain barrier leakage (albumin quotient) and retinal nerve fiber layer thinning.
Idebenone was well tolerated but did not inhibit disability progression or CNS tissue destruction. Concentrations of GDF15, secreted predominantly by astrocytes and choroid plexus epithelium in vitro, increased after exposure to mitochondrial toxin rotenone, validating the ability of this biomarker to measure intrathecal mitochondrial damage. CSF GDF15 levels correlated strongly with age and MS patients had CSF levels of GDF15 significantly above age-adjusted healthy volunteers, with highest levels measured in PPMS. Idebenone did not change CSF GDF15 levels.
Mitochondrial dysfunction exceeding normal aging reflected by age-adjusted CSF GDF15 is present in the majority of PPMS patients, but it is not inhibited by idebenone.
Abstract
Background
Cryptococcal meningoencephalitis (CM) affects individuals with AIDS, transplants recipients and those previously healthy, with 30–50% mortality in most groups despite anti-fungal ...treatment. In the previously healthy, a post-infectious inflammatory response syndrome (PIIRS) analogous to cryptococcal IRIS in AIDS patients has recently been described. PIIRS is defined as a deterioration in mental status and/or audio-visual capacity despite optimal treatment for CM and negative CSF cultures. Pathophysiology is related to excessive T-cell responses to lysed fungal cells during therapy but data on effective treatment regimens are limited.
Methods
Between March 2015 and February 2019, 11 consecutive patients with PIIRS who evidenced clinical deterioration over a period of up to 10 weeks despite effective antifungals were referred to the NIH clinical center. Patients were prospectively treated with adjunctive pulse solumedrol 1 g daily for 1 week followed by prednisone 1 mg/kg/day, tapered based on clinical and radiological response plus oral fluconazole. Montreal cognitive assessments (MOCA) scores at baseline and 1 month were the primary endpoints and CSF parameters including WBC, glucose, HLA DR4+ CD4 and CD8 cells and cytokines were also determined at baseline and after 1 week of solumedrol. Paired nonparametric t-tests were conducted using GraphPad Prism 7.0.
Results
All patients demonstrated clinical improvement despite 7 being initiated at the point of stupor and 6 having received ventriculoperitoneal shunts without clinical response. MOCA scores at 1 month showed significant improvement (P = 0.002), accompanied by significant improvements in CSF: serum glucose ratios, CSF WBC, protein and HLADR4 positive T cells 1 week after receiving corticosteroids (P < 0.02). Patients with hearing or visual deficits exhibited clinical improvement. CSF cultures remained negative.
Conclusion
Our findings in this small observational cohort of refractory non-HIV CM with PIIRS demonstrated significant clinical benefit of high dose adjunctive pulse-taper corticosteroids. The study also demonstrates the utility of physiology-based immunophenotyping to guide therapy in neuroinflammation associated with infectious diseases.
Disclosures
All Authors: No reported Disclosures.
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