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Nivolumab Plus Ipilimumab Induce Hyper-Progression in Renal Medullary Carcinoma: Results of a Phase II Trial and Preclinical Evidence
No full textTherapeutic options for patients with renal medullary carcinoma (RMC) are limited. Here we report the results of a phase II clinical trial (NCT03274258) of anti-PD1 nivolumab plus anti-CTLA4 ipilimumab in patients with RMC, with objective response rate as primary outcome. Enrollment was halted for futility at a prespecified interim analysis as all 10 treated patients experienced rapid disease progression. 5/10 met radiological criteria for hyperprogression and median progression-free survival (secondary outcome) was 1.38 months (95% confidence interval: 1.28, 1.60). In a post-hoc single-cell RNA sequencing analysis, data from patients with RMC before and after nivolumab plus ipilimumab treatment indicated that immune checkpoint therapy (ICT) triggered an interferon-γ response that induced a myeloid mimicry program in tumor cells, regulated by the CEBPB / p300 axis and linked to proliferation and hyperprogression. In preclinical experiments using an immunocompetent somatic mosaic genetically engineered mouse model of RMC, combination ICT accelerated tumor growth while activating myeloid-affiliated transcriptional circuits. Selective pharmacologic inhibition of p300 suppressed this program and restored sensitivity to ICT. These findings reveal an adaptive mechanism of resistance to ICT in RMC and support targeting master myeloid regulators to enable therapeutic benefit
Phosphorylation of RYR1 at Ser2902 Decreases Ca2+ Leak in Skeletal Muscle and Susceptibility to Malignant Hyperthermia and Heat Stroke
No full textThe ryanodine receptor 1 (RYR1) is the sarcoplasmic reticulum (SR) Ca2+ release channel required for both skeletal muscle contraction and Ca2+ leak. Mutations in RYR1 cause malignant hyperthermia susceptibility (MHS) and enhanced sensitivity to heat stroke (ESHS), which can result in death due to excessive skeletal muscle thermogenesis upon exposure to volatile anesthetics or heat. Here, we investigated the molecular and physiological functions of phosphorylation of RYR1 at Ser2902 by the kinase SPEG (striated muscle preferentially expressed protein). Muscle from SPEG-deficient mice expressing RYR1 with a Ser2902 →Asp2902 (S2902D) point mutation to mimic phosphorylation by SPEG showed decreased SR Ca2+ sparks. Muscle from mice homozygous for the S2902D point mutation had reduced SR Ca2+ transients and small changes in force generation but overall mild phenotypic changes. YS mice, which are heterozygous for a Tyr524→Ser524 point mutation in RYR1, show increased Ca2+ leak and are a model of MHS and ESHS. Crossing YS mice with S2902D mice led to decreased SR Ca2+ leak and desensitization to both volatile anesthetics and heat. Thus, SPEG inhibits SR Ca2+ leak in skeletal muscle by phosphorylating Ser2902 on RYR1 and mutation of Ser2902 to Asp2902 to mimic this phosphorylation event rescues YS mice from heat-induced death
APOA1 Binding Protein Promotes Lymphatic Cell Fate and Lymphangiogenesis by Relieving Caveolae-Mediated Inhibition of VEGFR3 Signaling
No full textThe lymphatic system maintains tissue fluid balance, and its dysfunction can result in lymphedema. Although cholesterol is essential for cellular function, its role in lymphatic development has remained unknown. Here, we identify APOA1 binding protein (AIBP) as a key regulator that promotes lymphatic endothelial cell fate specification and lymphangiogenesis. Mechanistically, AIBP reduces plasma membrane cholesterol content, thereby enhancing VEGFR3 signaling by disrupting caveolae—small plasma membrane invaginations formed by the scaffolding protein caveolin-1 (CAV-1)—and relieving CAV-1–mediated inhibition. In zebrafish and mice, AIBP loss impairs VEGFR3 signaling and lymphatic development, defects that can be rescued by CAV-1 deletion or by a VEGFR3 mutant (VEGFR3AAA) lacking CAV-1 binding. Administration of recombinant AIBP augments VEGFC-induced lymphangiogenesis and accelerates the resolution of secondary lymphedema in adult mice. These findings define the AIBP–CAV-1 axis as a regulator of VEGFR3 signaling and lymphatic growth, offering potential therapeutic opportunities for treating lymphatic dysfunction
Genomic Balancing Act: Deciphering DNA Rearrangements in the Complex Chromosomal Aberration Involving 5p15.2, 2q31.1, and 18q21.32
No full textDespite extensive research into the genetic underpinnings of neurodevelopmental disorders (NDD), many clinical cases remain unresolved. We studied a female proband with a NDD, mildly dysmorphic facial features, and brain stem hypoplasia on neuroimaging. Comprehensive genomic analyses revealed a terminal 5p loss and a terminal 18q gain in the proband while a diploid copy number for chromosomes 5 and 18 in both parents. Genomic investigations in the proband identified an unbalanced translocation t(5;18) with additional genetic material from chromosome 2 (2q31.3) inserted at the breakpoint, pointing to a complex chromosomal rearrangement (CCR) involving 5p15.2, 2q31.3, and 18q21.32. Breakpoint junction analyses enabled by long-read genome sequencing unveiled the presence of four distinct junctions in the father, who is a carrier of a balanced CCR. The proband inherited from the father both the abnormal chromosome 5 resulting in segmental aneusomies of chr5 (loss) and chr18 (gain) and a der(2) homologue. Evidences suggest a chromoplexy mechanism for this CCR derivation, involving double-strand breaks (DSBs) repaired by non-homologous end joining (NHEJ) or alternative end joining (alt-EJ). The complexity of the CCR and the segregation of homologues elucidate the genetic model for this family. This study demonstrates the importance of combining multiple genomic technologies to uncover genetic causes of complex neurodevelopmental syndromes and to better understand genetic disease mechanisms
Variants in BSN, Encoding the Presynaptic Protein Bassoon, Result in a Distinct Neurodevelopmental Disorder With a Broad Phenotypic Range
No full textDisease-causing variants in synaptic function genes are a common cause of neurodevelopmental disorders (NDDs) and epilepsy. Here, we describe 14 individuals with de novo disruptive variants in BSN, which encodes the presynaptic protein Bassoon. To expand the phenotypic spectrum, we identified 15 additional individuals with protein-truncating variants (PTVs) from large biobanks. Clinical features were standardized using the Human Phenotype Ontology (HPO) across all 29 individuals, which revealed common clinical characteristics including epilepsy (13/29, 45%), febrile seizures (7/29, 25%), generalized tonic-clonic seizures (5/29, 17%), and focal-onset seizures (3/29, 10%). Behavioral phenotypes were present in almost half of all individuals (14/29, 48%), which included ADHD (7/29, 25%) and autistic behavior (5/29, 17%). Additional common features included developmental delay (11/29, 38%), obesity (10/29, 34%), and delayed speech (8/29, 28%). In adults with BSN PTVs, milder features were common, suggesting phenotypic variability, including a range of individuals without obvious neurodevelopmental features (7/29, 24%). To detect gene-specific signatures, we performed association analysis in a cohort of 14,895 individuals with NDDs. A total of 66 clinical features were associated with BSN, including febrile seizures (p = 1.26e-06) and behavioral disinhibition (p = 3.39e-17). Furthermore, individuals carrying BSN variants were phenotypically more similar than expected by chance (p = 0.00014), exceeding phenotypic relatedness in 179/256 NDD-related conditions. In summary, integrating information derived from community-based gene matching and large data repositories through computational phenotyping approaches, we identify BSN variants as the cause of a synaptic disorder with a broad phenotypic range across the age spectrum
A Hierarchy of Pdz Domain Scaffolding Proteins Clusters the Kv1 K+ Channel Protein Complex at the Axon Initial Segment
No full textAction potentials are initiated and modulated at the axon initial segment (AIS) by highly clustered ion channels. Voltage-gated Kv1 potassium channels underlie most outward AIS K+ current. AIS Kv1 channels exist in a large protein complex including ADAM22, Caspr2, and LGI1. However, their clustering mechanisms remain unknown. Because Kv1 channels have a highly conserved PDZ-binding motif, we used CRISPR-based genome editing to screen 18 PDZ domain-containing proteins identified in our previous AIS proximity proteome for their AIS localization. Among these, we found that the scaffolding proteins SCRIB and PSD93 are highly enriched at the AIS. Using CRISPR-mediated knockout, cell surface clustering assays, and coimmunoprecipitation, we show that SCRIB and PSD93 bind to and are required for AIS Kv1 channel clustering, whereas SCRIB links the AIS Kv1 channel protein complex to the master AIS scaffolding protein AnkyrinG. These results define a hierarchy of scaffolding proteins that combine to cluster AIS Kv1 channels
Intracranial Injury Following Nasogastric Tube Placement After Skull Base Surgery: A Case Report and Systematic Review
No full textInadvertent intracranial nasogastric tube placement is a recognized risk following skull base fracture, but prior skull base surgery also poses a significant and underrecognized risk for this potentially fatal complication. We report the case of a 75-year-old female admitted with Clostridioides difficile colitis, six months after endoscopic endonasal resection of a pituitary macroadenoma. A systematic review identified 10 prior cases of intracranial tube placement following skull base or sinonasal surgery, including nasotracheal and feeding tube insertions. Literature suggests that using small-bore flexible tubes and preserving anatomical barriers, such as the position of the middle turbinate and intact bony structures like the sphenoid sinus roof, may reduce risk. We aim to characterize the risk of iatrogenic intracranial tube placement through a systematic review and a representative case
Spinoplastic Surgery: A Review of Techniques, Indications, and Optimal Patient Selection
No full textBackground/Objectives: Spinoplastic surgery is an emerging multidisciplinary field developed to address and reduce the complication of pseudoarthrosis following complex spinal reconstructions. While the number of spinal fusion procedures continues to rise every year, fusion failure rates remain as high as 40%. Although pseudoarthrosis may not always manifest clinically, it remains a leading cause of persistent pain and need for subsequent revision surgeries. The multidisciplinary collaboration between spine and plastic surgeons in spinoplastic surgery has therefore emerged as a proactive strategy aimed at preventing complications, particularly in patients identified as high-risk for pseudoarthrosis. As the patient population expands and spinoplastic surgery continues to evolve, refining patient selection criteria becomes essential for achieving optimal surgical outcomes. This review aims to provide a comprehensive overview of recent advancements in spinoplastic surgery, highlighting current indications, surgical techniques, recent case reports, and strategies for identifying suitable candidates.
Methods: We performed a narrative review of English language literature through April 2025. Spinoplastic case reports and case series published within the last 20 years were included in the review.
Results: Indications for use of a spinoplastic approach clustered into prior fusion failure, extensive oncologic resection, severe spinal deformity, procedures requiring extensive spinal involvement, and/or patients at risk for impaired bone healing. Succesful radiographic union and improvement of symptoms were widely reported across all 9 case reports/series.
Conclusions: Although evidence is presently limited, spinoplastic surgery appears to achieve high bone graft fusion rates with acceptable morbidity and functional improvement in a carefully selected group of high-risk spinal reconstruction patients. Still, larger prospective studies are warranted to refine patient selection and validate functional benefit
Intracranial Neural Biomarkers of Psychiatric Symptoms and Their Utility for Guiding Neuromodulation Therapy: A Systematic Review
No full textThe quest to develop and improve neuromodulatory therapies for treatment-resistant psychiatric disorders has been fueled by the discovery of intracranial neural biomarkers of symptom dimensions. These neural correlates shed light on the underlying neurophysiology of the disorder and may even be useful in guiding therapy delivery. This systematic review summarizes recent efforts in this field relating neural activity to behavior and symptomatology. For years, the majority of these neurobehavioral relationships had been studied in the hospital or clinic environment. Recent technological advances in implanted neuromodulation devices that permit not only stimulation, but also intracranial neural recording have enabled this research to move into natural settings, recording for longer periods of time in the real world. We review this combined literature to identify neurobehavioral relationships that show commonalities across these different recording strategies and environments. We also discuss potential ways to use this information for guiding neuromodulation therapy. The success of closed loop stimulation strategies for movement disorders and epilepsy has led to interest in exploring similar approaches for psychiatric disorders. Such efforts, however, need to consider the disorder-specific time constant relating changes in a neural biomarker to changes in symptoms and behavior. This relationship likely differs between Parkinson\u27s disease and depression, OCD, or addiction. We interpret the results of our systematic review in this light to offer suggestions for future closed-loop or clinician in the loop implementations to inform the next generation of neuromodulatory therapies
Challenges and Opportunities of Acquiring Cortical Recordings for Chronic Adaptive Deep Brain Stimulation
No full textDeep brain stimulation (DBS), a proven treatment for movement disorders, also holds promise for the treatment of psychiatric and cognitive conditions. However, for DBS to be clinically effective, it may require DBS technology that can alter or trigger stimulation in response to changes in biomarkers sensed from the patient\u27s brain. A growing body of evidence suggests that such adaptive DBS is feasible, it might achieve clinical effects that are not possible with standard continuous DBS and that some of the best biomarkers are signals from the cerebral cortex. Yet capturing those markers requires the placement of cortex-optimized electrodes in addition to standard electrodes for DBS. In this Perspective we argue that the need for cortical biomarkers in adaptive DBS and the unfortunate convergence of regulatory and financial factors underpinning the unavailability of cortical electrodes for chronic uses threatens to slow down or stall research on adaptive DBS and propose public-private partnerships as a potential solution to such a critical technological gap