👤 David H Spencer

Chronic neuroinflammation is associated with comorbidities in people with HIV (PWH) on antiretroviral therapy (ART). While cannabis use is associated with reduced neuroinflammation and neurocognitive impairment (NCI) in PWH, the underlying mechanisms are unknown. To address this gap in knowledge, we analyzed monocyte-derived macrophages (MDMs) from a cohort of 50 PWH and 33 people without HIV (mean age: 61.9 years), categorized by frequency of cannabis use (naïve/low, moderate, daily). We performed immunocytochemistry, RNA sequencing, and qPCR on MDMs and quantified related biomarkers in donor plasma. In this cohort study, daily cannabis use in PWH was associated with less global neurocognitive deficits, and with an anti-inflammatory immunometabolic-phenotype in MDMs characterized by (1) a metabolic shift from glycolysis to oxidative phosphorylation, (2) higher mitochondrial numbers, (3) altered cytokine profiles (pro-inflammatory downregulation, anti-inflammatory upregulation), and (4) higher brain-derived neurotrophic factor (BDNF) expression. These cellular changes were corroborated by a plasma biomarker profile in PWH including (1) lower levels of growth differentiation factor 15 and soluble triggering receptor expressed on myeloid cells 2, and (2) higher mature BDNF/precursor BDNF ratios that correlated with better cognition. Thus, cannabis use may mitigate NCI in PWH by immunometabolically reprogramming MDM function towards an anti-inflammatory and neuroprotective state. Show less

The number of people living with Alzheimer's disease (AD) is increasing worldwide as populations age. A hallmark of AD is the accumulation of amyloid-β (Aβ) in the brain, and pathways regulating amyloid-β precursor protein (AβPP) processing are of major interest for disease-modifying and preventive strategies such as exercise. Regular exercise is associated with a reduced risk of AD, potentially through limiting Aβ accumulation, yet the underlying cellular mechanisms remain unclear. Acute bouts of exercise induce the release of circulating signalling molecules that may influence AβPP metabolism. To investigate the effects of exercise on AβPP processing, human induced pluripotent stem cell (iPSC)-derived neurons and astrocytes were treated with serum collected before and immediately after high-intensity exercise. Both healthy control and familial AD (PSEN1 A246E) neurons and astrocytes were independently exposed to 10 % pre- or post-exercise serum for 30 min, after which markers of AβPP processing were quantified. Post-exercise serum contained increased amounts of Lacate, BDNF, IL-6, sAβPPα, and Aβ₁-₄₂, and reduced neprilysin activity (p < 0.05). Treatment with post-exercise serum acutely elevated ADAM10 activity in neurons, which was replicated by spiking lactate in pre-exercise serum. sAβPPα was also increased in PSEN1 neurons following post exercise serum treatment with increased Aβ₁-₄₂ secretion in both PSEN1 neurons and astrocytes (p < 0.05). These findings demonstrate that human post-exercise serum can modulate AβPP processing in iPSC-derived neural cells. This supports the concept that circulating exercise-induced factors can influence neuronal pathways relevant to AD pathology. Show less

Although familial hypercholesterolemia (FH) is a US Centers for Disease Control and Prevention tier 1 condition for genetic testing, the impact of testing on clinical outcomes is unclear. We aimed to assess whether genetic testing alters lipid management in HeartCare participants. For participants with pathogenic/likely pathogenic variants for FH observed at Baylor College of Medicine cardiology clinics, data on laboratory values, medication prescriptions, and diagnoses were collected and compared before and after genetic testing. In the 20 participants with APOB/LDLR variants and complete data, low-density lipoprotein cholesterol (LDL-C) was numerically lower but not significantly different before vs after genetic testing (103 vs 79.5 mg/dL). Sixteen (80%) participants were from the lipid clinic; the majority had a preexisting FH diagnosis. LDL-C levels were numerically lower, and more patients received proprotein convertase subtilisin/kexin type 9 inhibitor prescriptions after genetic testing; however, the difference was not statistically significant. The majority of patients with FH achieved LDL-C <100 mg/dL after genetic testing; however, most patients with APOB/LDLR variants were from the lipid clinic and had been diagnosed with FH by clinical criteria. Show less

Lymphoplasmacytic lymphoma / Waldenström macroglobulinemia (LPL/WM) is a rare and indolent low-grade B-cell lymphoproliferative neoplasm that often presents with vague symptoms or asymptomatically. While it most commonly involves the bone marrow, LPL/WM can sometimes involve the lymph nodes and spleen, and rarely the central nervous system, skin, and pleural cavities. We report a rare case of lymphoplasmacytic lymphoma/ Waldenström macroglobulinaemia presenting with predominant myometrial and cervical involvement. A 57-year-old G2P2 postmenopausal female with a history of HPV + HSIL presented following a single episode of abnormal uterine bleeding with associated urinary urgency and pelvic pressure. Transvaginal ultrasound examination was unremarkable and endometrial biopsy via hysteroscopy was unsuccessful due to stenotic cervical os. The patient subsequently underwent a total robotic hysterectomy with bilateral salpingo-oophorectomy. Examination of histologic sections showed atypical perivascular lymphoid aggregates consistent with involvement by a low-grade B-cell lymphoma with predominant myometrial and cervical involvement. Differential diagnosis at the time included marginal zone lymphoma (MZL) and lymphoplasmacytic lymphoma (LPL). Additional testing identified an IgM kappa paraproteinemia with MYD88 p.L265P mutation. Bone marrow biopsy and aspirate confirmed the diagnosis of lymphoplasmacytic lymphoma / Waldenström macroglobulinaemia (LPL/WM). To our knowledge, there have been only two cases previously described in the literature of LPL/WM involvement in the female genital tract; both of which had prominent involvement of the ovaries. Although exceedingly rare, LPL/WM involvement of the female genital tract should be considered on the differential diagnosis if atypical lymphoid cells or dense lymphoid aggregates are observed. Show less

The majority of pregnancy loss in ruminants occurs during the first two months of gestation, and a failure in placenta development is a major cause of pregnancy loss in cattle after day 20. Gaining a cell-type level understanding of normal placental development is essential for uncovering how this critical organ, responsible for nutrient exchange, gas transfer, and waste removal, fails during pregnancy loss. This study integrated single-cell RNA sequencing (scRNA-seq) from sheep and cattle during early placental development. Nineteen distinct cell populations were identified across species, with mesenchymal, epithelial, and trophoblast cells showing largely conserved expression profiles. Interestingly, two trophoblast clusters were unique to cattle, with one expressing IFNT2 (uninucleate) and another expressing CSH2 and PAG17 (binucleate). Genes associated with epithelial-to-mesenchymal transition (EMT), such as SNAI1, SNAI2, ZEB1, VIM, CDH1, and CLDN4, showed dynamic and prominent expression patterns in trophoblasts. Pseudotime and cell-cell signaling analyses supported the occurrence of EMT in uninucleate trophoblasts. Gene ontology comparisons revealed similarities between ruminant and human extravillous trophoblasts, suggesting conserved EMT across placental types. Collectively, these findings highlight EMT as a potentially critical process in early ruminant placentation. Show less

Familial chylomicronemia syndrome (FCS) is a rare disorder of triglyceride (TG) metabolism caused by loss of function variants in one of five known canonical genes involved in chylomicron lipolysis and clearance- Show less

Only rare cases of acute myeloid leukemia (AML) have been shown to harbor a t(8;11)(p11.2;p15.4). This translocation is believed to involve the fusion of NSD3 or FGFR1 with NUP98; however, apart from targeted mRNA quantitative PCR analysis, no molecular approaches have been utilized to define the chimeric fusions present in these rare cases. Here we present the case of a 51-year-old female with AML with myelodysplastic-related morphologic changes, 13q deletion and t(8;11), where initial fluorescence in situ hybridization (FISH) assays were consistent with the presence of NUP98 and FGFR1 rearrangements, and suggestive of NUP98/FGFR1 fusion. Using a streamlined clinical whole-genome sequencing approach, we resolved the breakpoints of this translocation to intron 4 of NSD3 and intron 12 of NUP98, indicating NUP98/NSD3 rearrangement as the likely underlying aberration. Furthermore, our approach identified small variants in WT1 and STAG2, as well as an interstitial deletion on the short arm of chromosome 12, which were cryptic in G-banded chromosomes. NUP98 fusions in acute leukemia are predictive of poor prognosis. The associated fusion partner and the presence of co-occurring mutations, such as WT1, further refine this prognosis with potential clinical implications. Using a clinical whole-genome sequencing analysis, we resolved t(8;11) breakpoints to NSD3 and NUP98, ruling out the involvement of FGFR1 suggested by FISH while also identifying multiple chromosomal and sequence level aberrations. Show less

Mutations or triplication of the alpha synuclein (ASYN) gene contribute to synucleinopathies including Parkinson's disease (PD), Dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Recent evidence suggests that ASYN also plays an important role in amyloid-induced neurotoxicity, although the mechanism(s) remains unknown. One hypothesis is that accumulation of ASYN alters endolysosomal pathways to impact axonal trafficking and processing of the amyloid precursor protein (APP). To define an axonal function for ASYN, we used a transgenic mouse model of synucleinopathy that expresses a GFP-human ASYN (GFP-hASYN) transgene and an ASYN knockout (ASYN Show less

Fibroblast growth factor receptors (FGFR) are emerging as an important therapeutic target for patients with advanced, refractory cancers. Most selective FGFR inhibitors under investigation show reversible binding, and their activity is limited by acquired drug resistance. This review summarizes the preclinical and clinical development of futibatinib, an irreversible FGFR1-4 inhibitor. Futibatinib stands out among FGFR inhibitors because of its covalent binding mechanism and low susceptibility to acquired resistance. Preclinical data indicated robust activity of futibatinib against acquired resistance mutations in the FGFR kinase domain. In early-phase studies, futibatinib showed activity in cholangiocarcinoma, and gastric, urothelial, breast, central nervous system, and head and neck cancers harboring various FGFR aberrations. Exploratory analyses indicated clinical benefit with futibatinib after prior FGFR inhibitor use. In a pivotal phase II trial, futibatinib demonstrated durable objective responses (42% objective response rate) and tolerability in previously treated patients with advanced intrahepatic cholangiocarcinoma harboring FGFR2 fusions or rearrangements. A manageable safety profile was observed across studies, and patient quality of life was maintained with futibatinib treatment in patients with cholangiocarcinoma. Hyperphosphatemia, the most common adverse event with futibatinib, was well managed and did not lead to treatment discontinuation. These data show clinically meaningful benefit with futibatinib in FGFR2-rearrangement-positive cholangiocarcinoma and provide support for further investigation of futibatinib across other indications. Future directions for this agent include elucidating mechanisms of resistance and exploration of combination therapy approaches. Show less

Mutations in CLN3 lead to photoreceptor cell loss in CLN3 disease, a lysosomal storage disorder characterized by childhood-onset vision loss, neurological impairment, and premature death. However, how CLN3 mutations cause photoreceptor cell death is not known. Here, we show that CLN3 is required for phagocytosis of photoreceptor outer segment (POS) by retinal pigment epithelium (RPE) cells, a cellular process essential for photoreceptor survival. Specifically, a proportion of CLN3 in human, mouse, and iPSC-RPE cells localized to RPE microvilli, the site of POS phagocytosis. Furthermore, patient-derived CLN3 disease iPSC-RPE cells showed decreased RPE microvilli density and reduced POS binding and ingestion. Notably, POS phagocytosis defect in CLN3 disease iPSC-RPE cells could be rescued by wild-type CLN3 gene supplementation. Altogether, these results illustrate a novel role of CLN3 in regulating POS phagocytosis and suggest a contribution of primary RPE dysfunction for photoreceptor cell loss in CLN3 disease that can be targeted by gene therapy. Show less

Studies support the idea that uterine epithelia and their secretions have important biological roles in conceptus survival, elongation, and implantation in sheep. The present study evaluated the transcriptome of the uterine luminal epithelium (LE) and glandular epithelium (GE) and the conceptus and proteome of uterine luminal fluid (ULF) during the peri-implantation period of pregnancy. Transcriptome (RNA-sequencing) analysis was conducted in LE and GE isolated from uteri of Day 10, 12, 14, 16, and 20 pregnant sheep by laser capture microdissection. In the LE, the total number of expressed genes increased between Days 10 and 20, whereas expressed genes in the GE increased from Days 10 to 14 and then decreased to Day 20. Most of the expressed genes in LE and GE from Days 10 to 14 are involved in cell survival and growth, whereas genes involved in cell organization and protein synthesis were most abundant on Days 16 and 20. Total expressed genes in the conceptus was greatest on Day 12, decreased to Day 16, and then increased to Day 20. Genes abundantly expressed in the elongating conceptus included IFNT, PTGS2, MGST1, FADS1, and FADS2, whereas SERPINA1, CSH1, and PLET1 were most abundant in the Day 20 conceptus. Proteins, identified by mass spectrometry, increased in the ULF from Days 10 to 16 and are involved in cellular reorganization or are proteases or chaperone proteins. These results support the idea that conceptus elongation and implantation is regulated by both extrinsic and intrinsic factors. This study provides critical information that serves as a foundation to discover new regulatory pathways governing uterine receptivity, conceptus elongation, trophectoderm differentiation, conceptus-endometrial interactions, and pregnancy establishment in ruminants. Show less