The mechanism by which cells undergo death determines whether dying cells trigger inflammatory responses or remain immunologically silent. Mitochondria play a central role in the induction of cell ...death, as well as in immune signaling pathways. Here, we identify a mechanism by which mitochondria and downstream proapoptotic caspases regulate the activation of antiviral immunity. In the absence of active caspases, mitochondrial outer membrane permeabilization by Bax and Bak results in the expression of type I interferons (IFNs). This induction is mediated by mitochondrial DNA-dependent activation of the cGAS/STING pathway and results in the establishment of a potent state of viral resistance. Our results show that mitochondria have the capacity to simultaneously expose a cell-intrinsic inducer of the IFN response and to inactivate this response in a caspase-dependent manner. This mechanism provides a dual control, which determines whether mitochondria initiate an immunologically silent or a proinflammatory type of cell death.
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•Deficiency in proapoptotic caspases induces viral resistance in vivo and in vitro•Mitochondrial permeabilization, combined with caspase inhibition, induces type I IFNs•The cGAS/STING pathway is required for caspase-regulated IFN expression•Mitochondrial DNA mediates the activation of the IFN response
During viral infections, mitochondrial events of apoptosis trigger the initiation of a cell intrinsic immune response, mediated by the expression of type I IFNs. Proapoptotic caspases, activated simultaneously by mitochondria, are required to inhibit that response and to maintain apoptosis immunologically silent.
The cJun NH 2 -terminal kinase (JNK) signaling pathway contributes to inflammation and plays a key role in the metabolic response to obesity, including insulin resistance. Macrophages are implicated ...in this process. To test the role of JNK, we established mice with selective JNK deficiency in macrophages. We report that feeding a high-fat diet to control and JNK-deficient mice caused similar obesity, but only mice with JNK-deficient macrophages remained insulin-sensitive. The protection of mice with macrophage-specific JNK deficiency against insulin resistance was associated with reduced tissue infiltration by macrophages. Immunophenotyping demonstrated that JNK was required for pro-inflammatory macrophage polarization. These studies demonstrate that JNK in macrophages is required for the establishment of obesity-induced insulin resistance and inflammation.
RNA interference is required for post-transcriptional silencing, but also has additional roles in transcriptional silencing of centromeres and genome stability. However, these roles have been ...controversial in mammals. Strikingly, we found that Dicer-deficient embryonic stem cells have strong proliferation and chromosome segregation defects as well as increased transcription of centromeric satellite repeats, which triggers the interferon response. We conducted a CRISPR-Cas9 genetic screen to restore viability and identified transcriptional activators, histone H3K9 methyltransferases, and chromosome segregation factors as suppressors, resembling Dicer suppressors identified in independent screens in fission yeast. The strongest suppressors were mutations in the transcriptional co-activator Brd4, which reversed the strand-specific transcription of major satellite repeats suppressing the interferon response, and in the histone acetyltransferase Elp3. We show that identical mutations in the second bromodomain of Brd4 rescue Dicer-dependent silencing and chromosome segregation defects in both mammalian cells and fission yeast. This remarkable conservation demonstrates that RNA interference has an ancient role in transcriptional silencing and in particular of satellite repeats, which is essential for cell cycle progression and proper chromosome segregation. Our results have pharmacological implications for cancer and autoimmune diseases characterized by unregulated transcription of satellite repeats.
The current model of apoptosis holds that upstream signals lead to activation of downstream effector caspases. We generated mice deficient in the two effectors, caspase 3 and caspase 7, which died ...immediately after birth with defects in cardiac development. Fibroblasts lacking both enzymes were highly resistant to both mitochondrial and death receptor-mediated apoptosis, displayed preservation of mitochondrial membrane potential, and had defective nuclear translocation of apoptosis-inducing factor (AIF). Furthermore, the early apoptotic events of Bax translocation and cytochrome c release were also delayed. We conclude that caspases 3 and 7 are critical mediators of mitochondrial events of apoptosis.
The 2021 edition of the World Health Organization (WHO) classification of central nervous system tumors introduces significant revisions across various tumor types. These updates, encompassing ...changes in diagnostic techniques, genomic integration, terminology, and grading, are crucial for radiologists, who play a critical role in interpreting brain tumor imaging. Such changes impact the diagnosis and management of nearly all central nervous system tumor categories, including the reclassification, addition, and removal of specific tumor entities. Given their pivotal role in patient care, radiologists must remain conversant with these revisions to effectively contribute to multidisciplinary tumor boards and collaborate with peers in neuro-oncology, neurosurgery, radiation oncology, and neuropathology. This knowledge is essential not only for accurate diagnosis and staging, but also for understanding the molecular and genetic underpinnings of tumors, which can influence treatment decisions and prognostication. This review, therefore, focuses on the most pertinent updates concerning the classification of adult diffuse gliomas, highlighting the aspects most relevant to radiological practice. Emphasis is placed on the implications of new genetic information on tumor behavior and imaging findings, providing necessary tools to stay abreast of advancements in the field. This comprehensive overview aims to enhance the radiologist’s ability to integrate new WHO classification criteria into everyday practice, ultimately improving patient outcomes through informed and precise imaging assessments.
Abstract Pediatric cardiomyopathies are mostly attributed to variants in sarcomere-related genes. Unfortunately, the genetic architecture of pediatric cardiomyopathies has never been previously ...studied in Jordan. We sought to uncover the genetic landscape of 14 patients from nine families with several subtypes of pediatric cardiomyopathies in Jordan using Exome sequencing (ES). Our investigation identified pathogenic and likely pathogenic variants in seven out of nine families (77.8%), clustering in sarcomere-related genes. Surprisingly, phenocopies of sarcomere-related hypertrophic cardiomyopathies were evident in probands with glycogen storage disorder and mitochondrial-related disease. Our study underscored the significance of streamlining ES or expanding cardiomyopathy-related gene panels to identify plausible phenocopies of sarcomere-related cardiomyopathies. Our findings also pointed out the need for genetic testing in patients with cardiomyopathy and their at-risk family members. This can potentially lead to better management strategies, enabling early interventions, and ultimately enhancing their prognosis. Finally, our findings provide an initial contribution to the currently absent knowledge about the molecular underpinnings of cardiomyopathies in Jordan.
Transcription factors specialized to limit the destructive potential of inflammatory immune cells remain ill-defined. We discovered loss-of-function variants in the X-linked ETS transcription factor ...gene ELF4 in multiple unrelated male patients with early onset mucosal autoinflammation and inflammatory bowel disease (IBD) characteristics, including fevers and ulcers that responded to interleukin-1 (IL-1), tumor necrosis factor or IL-12p40 blockade. Using cells from patients and newly generated mouse models, we uncovered ELF4-mutant macrophages having hyperinflammatory responses to a range of innate stimuli. In mouse macrophages, Elf4 both sustained the expression of anti-inflammatory genes, such as Il1rn, and limited the upregulation of inflammation amplifiers, including S100A8, Lcn2, Trem1 and neutrophil chemoattractants. Blockade of Trem1 reversed inflammation and intestine pathology after in vivo lipopolysaccharide challenge in mice carrying patient-derived variants in Elf4. Thus, ELF4 restrains inflammation and protects against mucosal disease, a discovery with broad translational relevance for human inflammatory disorders such as IBD.
Purpose
Breakthrough cancer pain (BtCP) is a prevalent health issue which is difficult to manage. A plethora of quantitative research in this area exists. There is a paucity of research on the ...perspectives of health professionals and patients surrounding domains impacting effective treatment, including definitions of BtCP, treatment, and education opportunities. This review aims to identify and synthesize the extent of qualitative research exploring health professional and patient perspectives of BtCP.
Methods
A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach was undertaken. The approach was registered with Prospero. MEDLINE, EMBASE, and Web of Science were searched for peer-reviewed literature published any date prior to May 19, 2022. Eligible sources must have considered health professional and/or patient perspectives of BtCP. A narrative synthesis approach was utilized.
Results
Three sources met the review criteria. One source explored nurse perspectives, while two sources explored patient perspectives. Study quality was moderate to high. Overlapping themes across the three studies included communication, defining BtCP, impact of BtCP, management of BtCP, perceptions of BtCP, analgesia and pain relief, and training and professional development.
Conclusion
Given limited research investigating clinician and patient perspectives of BtCP, a rich understanding informed by exploratory qualitative methods around identification, best management strategies, professional development, and factors promoting and inhibiting best practice remains unclear. Further qualitative inquiry is warranted, and it is expected such research will inform BtCP clinical guidelines.
Heterozygous variants in the DYNC1H1 gene have been associated chiefly with intellectual disability (ID), malformations in cortical development (MCD), spinal muscular atrophy (SMA), and ...Charcot–Marie‐Tooth axonal type 20 (CMT), with fewer reports describing other intersecting phenotypes. To better characterize the variable syndromes associated with DYNC1H1, we undertook a detailed analysis of reported patients in the medical literature through June 30, 2019. In sum we identified 200 patients from 143 families harboring 103 different DYNC1H1 variants, and added reports for four unrelated patients identified at our center, three with novel variants. The most common features associated with DYNC1H1 were neuromuscular (NM) disease (largely associated with variants in the stem domain), ID with MCD (largely associated with variants in the motor domain), or a combination of these phenotypes. Despite these trends, exceptions are noted throughout. Overall, DYNC1H1 is associated with variable neurodevelopmental and/or neuromuscular phenotypes that overlap. To avoid confusion DYNC1H1 disorders may be best categorized at this time by more general descriptions rather than phenotype‐specific nomenclature such as SMA or CMT. We therefore propose the terms: DYNC1H1‐related NM disorder, DYNC1H1‐related CNS disorder, and DYNC1H1‐related combined disorder. Our single center's experience may be evidence that disease‐causing variants in this gene are more prevalent than currently recognized.
Ecchordosis physaliphora is a rare congenital benign hamartomatous lesion originating from nodal cord remnants. This is histopathologically indistinguishable from chordoma, and hence imaging plays a ...key role in diagnosis. These lesions are hypointense on T1-weighted and hyperintense on T2-weighted images, and follow CSF signal. In contrast to chordoma, Ecchordosis Physaliphora does not demonstrate contrast enhancement. Here, we present a case of 32–year-old male with no prior medical history, who presented to an outside facility for chronic headache workup and incidentally detected indeterminate lytic defect in the bony clivus with a well demarcated smoothly corticated margin. Further assessment with MRI brain showed findings characteristic of Ecchordosis physaliphora, a benign congenital hamartomatous lesion originating from nodal cord remnants requiring no additional follow-up imaging or intervention.
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