Barrier epithelia depend upon resident stem cells for homeostasis, defense, and repair. Epithelial stem cells of small and large intestines (ISCs) respond to their local microenvironments (niches) to ...fulfill a continuous demand for tissue turnover. The complexity of these niches and underlying communication pathways are not fully known. Here, we report a lymphatic network at the intestinal crypt base that intimately associates with ISCs. Employing in vivo loss of function and lymphatic:organoid cocultures, we show that crypt lymphatics maintain ISCs and inhibit their precocious differentiation. Pairing single-cell and spatial transcriptomics, we apply BayesPrism to deconvolve expression within spatial features and develop SpaceFold to robustly map the niche at high resolution, exposing lymphatics as a central signaling hub for the crypt in general and ISCs in particular. We identify WNT-signaling factors (WNT2, R-SPONDIN-3) and a hitherto unappreciated extracellular matrix protein, REELIN, as crypt lymphatic signals that directly govern the regenerative potential of ISCs.
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•Spatial transcriptomics and 3D imaging reveal lymphatics as key crypt niche residents•SpaceFold maps cells and cell-specific transcriptomes to the intestinal crypt-villus axis•Lymphatics serve as a critical signaling hub in the intestinal stem cell niche•Lymphatic factors maintain epithelial stemness and restrict differentiation
Niec et al. integrate spatial and single-cell transcriptomics data and develop computational approaches to finely map the cellular and transcriptional landscape of the intestinal crypt-villus axis. Combining these results with functional experiments, the authors expose lymphatics as a central signaling hub that promotes stem cell maintenance in the intestinal niche.
Through recurrent bouts synchronous with the hair cycle, quiescent melanocyte stem cells (McSCs) become activated to generate proliferative progeny that differentiate into pigment-producing ...melanocytes. The signaling factors orchestrating these events remain incompletely understood. Here, we use single-cell RNA sequencing with comparative gene expression analysis to elucidate the transcriptional dynamics of McSCs through quiescence, activation, and melanocyte maturation. Unearthing converging signs of increased WNT and BMP signaling along this progression, we endeavored to understand how these pathways are integrated. Employing conditional lineage-specific genetic ablation studies in mice, we found that loss of BMP signaling in the lineage leads to hair graying due to a block in melanocyte maturation. We show that interestingly, BMP signaling functions downstream from activated McSCs and maintains WNT effector, transcription factor LEF1. Employing pseudotime analysis, genetics, and chromatin landscaping, we show that following WNT-mediated activation of McSCs, BMP and WNT pathways collaborate to trigger the commitment of proliferative progeny by fueling LEF1- and MITF-dependent differentiation. Our findings shed light upon the signaling interplay and timing of cues that orchestrate melanocyte lineage progression in the hair follicle and underscore a key role for BMP signaling in driving complete differentiation.
Cervical cancer screening might contribute to the prevention of anal cancer in women. We aimed to investigate if routine cervical cancer screening results—namely high-risk human papillomavirus (HPV) ...infection and cytohistopathology—predict anal HPV16 infection, anal high-grade squamous intraepithelial lesions (HSIL) and, hence, anal cancer.
We did a systematic review of MEDLINE, Embase, and the Cochrane library for studies of cervical determinants of anal HPV and HSIL published up to Aug 31, 2018. We centrally reanalysed individual-level data from 13 427 women with paired cervical and anal samples from 36 studies. We compared anal high-risk HPV prevalence by HIV status, cervical high-risk HPV, cervical cytohistopathology, age, and their combinations, using prevalence ratios (PR) and 95% CIs. Among 3255 women with anal cytohistopathology results, PRs were similarly calculated for all anal HSIL and HPV16-positive anal HSIL.
Cervical and anal HPV infections were highly correlated. In HIV-negative women, anal HPV16 prevalence was 41% (447/1097) in cervical HPV16-positive versus 2% (214/8663) in cervical HPV16-negative women (PR 16·5, 95% CI 14·2–19·2, p<0·0001); these values were 46% (125/273) versus 11% (272/2588) in HIV-positive women (4·4, 3·7–5·3, p<0·0001). Anal HPV16 was also associated with cervical cytohistopathology, with a prevalence of 44% 101/228 for cervical cancer in HIV-negative women (PR vs normal cytology 14·1, 11·1–17·9, p<0·0001). Anal HSIL was associated with cervical high-risk HPV, both in HIV-negative women (from 2% 11/527 in cervical high-risk HPV-negative women up to 24% 33/138 in cervical HPV16-positive women; PR 12·9, 95% CI 6·7–24·8, p<0·0001) and HIV-positive women (from 8% 84/1094 to 17% 31/186; 2·3, 1·6–3·4, p<0·0001). Anal HSIL was also associated with cervical cytohistopathology, both in HIV-negative women (from 1% 5/498 in normal cytology up to 22% 59/273 in cervical HSIL; PR 23·1, 9·4–57·0, p<0·0001) and HIV-positive women (from 7% 105/1421 to 25% 25/101; 3·6, 2·5–5·3, p<0·0001). Prevalence of HPV16-positive anal HSIL was 23–25% in cervical HPV16-positive women older than 45 years (5/20 in HIV-negative women, 12/52 in HIV-positive women).
HPV-based cervical cancer screening programmes might help to stratify anal cancer risk, irrespective of HIV status. For targeted secondary anal cancer prevention in high-risk groups, HIV-negative women with cervical HPV16, especially those older than 45 years, have a similar anal cancer risk profile to that of HIV-positive women.
International Agency for Research on Cancer.
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5‐HT1A agonists attenuate antipsychotic‐induced catalepsy, a model of extrapyramidal symptoms (EPS). To explore the role of pre‐synaptic 5‐HT1A receptors, we examined these effects in ...mice expressing 50% fewer serotonin transporters (5‐HTT) in which pre‐synaptic 5‐HT1A receptors are down‐regulated, but post‐synaptic 5‐HT1A receptors are not.
Mice were pretreated with a 5‐HT1A agonist (ip), treated with haloperidol (cumulative dosing), and examined for catalepsy (bar test). In C57 mice, the 5‐HT1A partial agonist buspirone did not alter the ED50 of haloperidol (0.92 mg/kg). The 5‐HT1A agonist 8‐OH‐DPAT shifted the haloperidol dose‐effect curve to the right, with 10 mg/kg producing a maximum 2.7‐fold shift. Buspirone (32 mg/kg) blocked these effects of 8‐OH‐DPAT. In 5‐HTT(+/+) mice, 10 mg/kg 8‐OH‐DPAT shifted the haloperidol dose‐effect curve 3.5‐fold to the right. In contrast, 8‐OH‐DPAT did not alter haloperidol's ED50 in 5‐HTT(+/−) mice.
The finding that 8‐OH‐DPAT had anti‐cataleptic effects in C57 and in 5‐HTT(+/+) but not in 5‐HTT(+/−) mice suggests that pre‐synaptic 5‐HT1A receptors mediate these effects. In as much as 5‐HTT(+/−) mice are a model of chronic treatment with SSRI's, the lack of anti‐cataleptic effects of 8‐OH‐DPAT in these mice suggests that SSRI's may unmask and enhance EPS of antipsychotics with 5‐HT1A activity.
Supported by NARSAD (WK) and USPHS Grant MH64489 (LCD)
Responses to first-line programmed cell death protein 1 inhibition vary among patients with metastatic NSCLC and a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) greater than or equal ...to 50%. We previously reported improved clinical outcomes to first-line programmed cell death protein 1 inhibition in patients with metastatic NSCLC with a PD-L1 TPS of greater than or equal to 90% versus 50% to 89% in a pilot study. Here, we report the three-year survival with first-line pembrolizumab and cemiplimab in two large independent cohorts of patients with PD-L1 TPS greater than or equal to 90% versus 50% to 89% and characterize genomic and immunophenotypic differences between these PD-L1 expression groups, which were largely unknown.
We analyzed three-year outcomes of the following two independent cohorts: (1) a multicenter cohort of patients from four academic centers in the United States treated with pembrolizumab and (2) EMPOWER-Lung 1, randomized, phase III trial comparing first-line cemiplimab with chemotherapy. Tumor genomic profiling and multiplexed immunofluorescence were performed to evaluate genomic and immunophenotypic correlates of very high PD-L1 expression.
At three years of follow-up, progression-free survival (hazard ratio HR, 0.69; p < 0.001) and overall survival (HR, 0.70; p < 0.01) to first-line commercial pembrolizumab were significantly improved in patients with a PD-L1 TPS greater than or equal to 90% versus 50% to 89%. In the EMPOWER-Lung 1, patients assigned to the cemiplimab arm with a PD-L1 TPS greater than or equal to 90% also had significant improvements in progression-free survival (HR, 0.53; p < 0.0001) and overall survival (HR, 0.63; p = 0.007) compared with those with a PD-L1 of 50% to 89%. Tumor genomic profiling of 553 NSCLC samples revealed that mutations in STK11 and SMARCA4 were significantly more frequent in tumors with a PD-L1 TPS of 50% to 89% compared with those with a PD-L1 TPS greater than or equal to 90% (Q < 0.15), whereas BRCA2 was enriched in NSCLC samples with a PD-L1 TPS greater than or equal to 90% (Q < 0.15). Multiplexed immunofluorescence on 93 NSCLC samples identified higher intratumoral CD8+PD1+ T cells (p = 0.02) in tumors with PD-L1 TPS greater than or equal to 90% versus 50% to 89%.
Pembrolizumab and cemiplimab were found to have long-term survival benefit and favorable genomic and immunophenotypic profile in patients with advanced NSCLC with PD-L1 TPS greater than or equal to 90% compared with TPS 50% to 89%.
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