Biology subjects

Valenzuela, L.

Publications and source records attributed to Valenzuela, L..

4 recordsLinked to original sources

bioRxiv2025

UC Irvine Brain Initiative Cell Atlas Network (BICAN) Brain Procurement Program for the Center for Multiomic Human Brain Cell Atlas Project

High-quality neurotypical postmortem human brain tissue is essential but difficult to obtain for constructing comprehensive human brain cell atlases. Here we describe the establishment of UC Irvines Brain Procurement Program, a coordinated initiative to collect and process neurotypical donor brains for multiomic mapping studies within the NIH BRAIN Initiative Cell Atlas Network (BICAN) consortium. Through partnerships with the Orange County Coroners Office, the UC Irvine Willed Body Program, UCI Medical Center, and the Childrens Hospital of Orange County, we have developed standardized workflows encompassing donor identification, postmortem brain recovery and processing, region-of-interest dissection, neurotypical donor selection, and data management. Our experience demonstrates the feasibility of a community-based, multi-institutional procurement framework while highlighting challenges in recruiting neurotypical donors and ensuring demographic representation reflective of Southern California. We further identify opportunities to strengthen outreach and donation pathways. This program provides a scalable model for advancing population-reflective, high-quality human brain cell atlas efforts. HighlightsO_LIEstablish a multi-site pipeline for procuring high-quality neurotypical human brains. C_LIO_LIDemonstrate feasibility of donor collection across childhood to adulthood. C_LIO_LIIdentify barriers and propose strategies to improve broad donor recruitment. C_LI

neuroscience↗

bioRxiv2025

The Winner Takes It All: a single genotype of Kalanchoe xhoughtonii is a global invader

Background and AimsInvasive alien plant species pose a global challenge, and their impact is amplified by globalisation and the accelerating pace of climate change. In mild-climate regions, drought-tolerant invasive plants showing broad environmental tolerance have a competitive advantage. One example is Kalanchoe xhoughtonii (Crassulaceae), popularly known as "mother of millions". It is a hybrid resulting from the interploid cross between K. daigremontiana and K. delagoensis, both native to Madagascar. Kalanchoe xhoughtonii, propagated as an ornamental plant, has emerged as a global invader in less than a century. Four morphotypes of this hybrid have been identified, with different ploidy levels and varying invasive capacities. Here we aim to investigate the genomic variability behind the invasion success of Kalanchoe xhoughtonii. MethodsWe sampled 57 accessions of Kalanchoe xhoughtonii, K. daigremontiana, K. delagoensis and closely related taxa, including old herbarium materials, from all over the world. We analysed genome size, chromosome numbers, sequenced the whole genome, analysed the complete plastome sequence of each accession, and studied the diversity of the ribosomal RNA genes. We also performed a detailed phylogenomic study using nuclear BUSCO genes. Key ResultsOur study reveals the genetic and cytogenetic variability between morphotypes, and shows that a single tetraploid genotype (morphotype A) dominates all populations, emerging as the first reported clonal hybrid capable of worldwide colonisation. Morphotype A shows a striking genetic uniformity, high phenotypic plasticity, and extremely high rates of vegetative reproduction, representing an example of a "general-purpose genotype". ConclusionsThe astonishing reproductive capacity, broad adaptability and the speed at which K. xhoughtonii is colonising new regions by clonal spread highlight the importance of understanding hybridisation and polyploidy in the invasion of ecosystems. Our findings call for the need for risk assessments before developing new hybrids for ornamental plant breeding that may exhibit invasive characteristics.

plant biology↗

bioRxiv2024

Extracellular vesicles from a novel chordoma cell line, ARF-8, promote tumorigenic microenvironmental changes when incubated with the parental cells and with human osteoblasts.

Chordomas are rare, generally slow-growing spinal tumors that nonetheless exhibit progressive characteristics over time, leading to malignant phenotypes and high recurrence rates, despite maximal therapeutic interventions. The tumors are notoriously resistant to therapies and are often in locations that make gross total resections difficult. Here, we describe a new chordoma cell line (ARF-8) derived from an extensive clival chordoma that extended back to the cervical spine. From the cultured cell line we characterized the ARF-8 cellular and extracellular vesicle (EV) proteomes, as well as the impacts of ARF-8 EVs on proteomes and secretomes of recipient cells (both ARF-8 and human osteoblasts) in autocrine and paracrine settings. All the characteristics associated with chordomas as cancers - migration and invasion, therapeutic resistance, metastatic potential - can be driven by tumor EVs. Our proteomic analyses suggested roles for transforming growth factor beta (TGFB) and cell-matrix interactions involving the epithelial-to-mesenchymal transition (EMT), and cell/extracellular matrix interactions in cell migration, consistent with a metastatic tumor phenotype. Our results demonstrated that ARF-8 tumor cell migration was dependent on general (arginine-glycine-aspartic acid [RGD]-based) integrin activity, and ARF-8 EVs could promote such migration. ARF-8 EVs also prompted proteomic/secretomic changes in human osteoblast cells, again with indications that cell-cell and cell-extracellular matrix interactions would be activated. Overall, the EVs promoted predicted tumorigenic phenotypes in recipient cells.

cancer biology↗

bioRxiv2019

Comparative of probiotics reveals cecal microbial component associated with performance parameters in broilers

Probiotics have become increasingly popular in poultry industry as a promising nutritional intervention to promote modulation of intestinal microbiota as a means of improving health and performance. This study aimed to determine the effects of different probiotic formulations on the cecal microbial communities and performance in 21 and 42 day-old-broilers, as well as to define associations between ceca microbial profile and growth parameters. Probiotics investigated included a synbiotic (SYNBIO), a yeast-based probiotic (YEAST), and three single-strain formulations of spore-forming Bacillus amyloliquefaciens (SINGLE1), B. subtilis (SINGLE2) and B. licheniformis (SINGLE3). Dietary inclusion of SYNBIO, YEAST, and SINGLE2 increased body weight (BW) by 7, 14, and 21d (p<0.05) compared to a basal diet without probiotics (CON). The treatments SYNBIO, and YEAST decreased mortality by 21d, while SYNBIO reduced the overall mortality rate by 42d (p<0.05). Bifidobacteriales had the highest (p<0.05) population in SINGLE2, whereas Clostridiales was reduced compared to CON, SINGLE1, and SINGLE3. The addition of SYNBIO into diet mainly stimulated (p<0.05) the cecal relative abundance of Lactobacillales by 21d. Besides, Spearmans correlation analyses revealed that population of Lactobacillales was associated with lower Enterobacteriales, higher BW, and lower mortality of growing broilers. These results suggest that the modulation of ceca microbiota and the greatest productive parameters were achieved by supplementation of specific probiotic mixture. The selection of probiotics by their ability to drive cecal microbiota towards lactic acid bacteria colonization may be a strategic approach to improve the indicators of performance in broilers.

microbiology↗