Theodoros Xenakis

Mr. Theodoros Xenakis

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
20 March 2026 in Nature Biotechnology
Verified
Journal Article
Open access
PDF file
NDNatalie Durkin
Natalie Durkin
GHGeorge T. Hall
George T. Hall
RLRoberto Lutman
Roberto Lutman
MSMarianna Scuglia
Marianna Scuglia
TXTheodoros Xenakis
Theodoros Xenakis
PCPaolo De Coppi
Paolo De Coppi
Tissue engineering of the esophagus has been limited by stent dependance and poor muscle regeneration. Here we report an integrated strategy to engineer a 2.5-cm esophageal segment by microinjecting autologous pericyte-like myogenic precursors and fibroblasts in a decellularized porcine scaffold to repair circumferential defects in 10-kg minipigs ( n = 8), modeling pediatric use. Bioreactor maturation induced a proangiogenic phenotype, with in vivo support from biodegradable intraluminal stents and a vascularizing pleural wrap. This coordinated approach yielded safe and effective esophageal conduits; oral feeding supported normal growth, morbidity resembled that of clinical esophageal replacement and was endoscopically manageable, and 63% (5/8) survived to the 6-month endpoint. Comprehensive multimodal analyses demonstrated progressive recapitulation of native architecture, with increasing neuromuscular regeneration and vascularization, correlating with functional recovery, absence of symptomatic stricture and the presence of secondary peristalsis by 6 months. These results demonstrate that the combination of complementary regenerative, conditioning and surgical strategies enables a functionally integrated, contractile esophageal graft with ongoing structural maturation without immunosuppression.

17 January 2023 in Cells
Verified
Journal Article
Open access
PDF file
VJVignesh Jayarajan
Vignesh Jayarajan
GHGeorge T. Hall
George T. Hall
TXTheodoros Xenakis
Theodoros Xenakis
NBNeil Bulstrode
Neil Bulstrode
DMDale Moulding
Dale Moulding
Weili DiWeili Di
Weili Di
Primary keratinocytes including keratinocyte stem cells (KSCs) can be cultured as epidermal sheets in vitro and are attractive for cell and gene therapies for genetic skin disorders. However, the initial slow growth of freshly isolated keratinocytes hinders clinical applications. Rho-associated kinase inhibitor (ROCKi) has been used to overcome this obstacle, but its influence on the characteristics of KSC and its safety for clinical application remains unknown. In this study, primary keratinocytes were treated with ROCKi Y-27632 for six days (short-term). Significant increases in colony formation and cell proliferation during the six-day ROCKi treatment were observed and confirmed by related protein markers and single-cell transcriptomic analysis. In addition, short-term ROCKi-treated cells maintained their differentiation ability as examined by 3D-organotypic culture. However, these changes could be reversed and became indistinguishable between treated and untreated cells once ROCKi treatment was withdrawn. Further, the short-term ROCKi treatment did not reduce the number of KSCs. In addition, AKT and ERK pathways were rapidly activated upon ROCKi treatment. In conclusion, short-term ROCKi treatment can transiently and reversibly accelerate initial primary keratinocyte expansion while preserving the holoclone-forming cell population (KSCs), providing a safe avenue for clinical applications.

3 February 2026 in Nature Communications
Verified
Journal Article
Open access
PDF file
DBDimitri Budinger
Dimitri Budinger
PPPau Puigdevall
Pau Puigdevall
GHGeorge T. Hall
George T. Hall
CRCharlotte Roth
Charlotte Roth
TXTheodoros Xenakis
Theodoros Xenakis
SBSerena Barral
Serena Barral
The dopaminergic system has key roles in human physiology and is implicated in a broad range of neurological and neuropsychiatric conditions that are increasingly investigated using induced pluripotent stem cell-derived midbrain models. To determine similarities of such models to human systems, here we undertake single-cell and spatial profiling of first and second trimester fetal midbrain and compare it to in vitro midbrain models. Histological examination reveals that, by the second trimester, fetal midbrain tissue exhibits structural complexity comparable to that of adults. At the molecular level, single-cell profiling uncovers differences in cellular composition across models, with brain organoids most closely resembling late first trimester tissue — an observation supported by meta-integration of existing midbrain datasets. By reconstructing developmental trajectories of neuronal and astrocytic lineages, we map gene expression dynamics associated with maturation. Importantly, integration of spatial transcriptomics provides critical context for aligning organoid models, revealing that their spatial organization and intercellular signaling resemble the architecture and microenvironment of the second trimester midbrain. Ultimately, we leverage our findings to study Dopamine Transporter Deficiency Syndrome progression in patient-derived midbrain organoids, validating their relevance. Understanding the extent of human tissue recapitulation in midbrain laboratory models is essential to justify their use as biological proxies.

4 March 2025 in bioRxiv
Verified
Preprint
Open access
PDF file
AFAine Fairbrother-Browne
Aine Fairbrother-Browne
MGMelissa Grant-Peters
Melissa Grant-Peters
JBJonathan W. Brenton
Jonathan W. Brenton
HNHemanth Ramesh Nelvagal
Hemanth Ramesh Nelvagal
RRRegina H. Reynolds
Regina H. Reynolds
MRMina Ryten
Mina Ryten
Parkinson’s disease (PD) affects millions of people worldwide, and up to 40% of these patients develop dementia, profoundly affecting their quality of life. Whether Parkinson’s disease dementia (PDD) simply represents a late stage of PD or constitutes a distinct neurodegenerative process remains unresolved. To clarify this, we generated the largest single nuclear transcriptomic atlas of PD and PDD to date—almost one million nuclei derived from the anterior cingulate cortex and inferior parietal lobule of 64 post-mortem donors. By integrating these data with long-read RNA-seq, we found that the cellular compositions, biological pathways, and molecular profiles diverge substantially between PD and PDD, with limited overlap in differentially expressed genes and pathways. While PD was characterised by widespread upregulation of gene expression programs and robust regional signatures, PDD showed extensive pathway downregulation, loss of cortical regional identity, and significant shifts in transcript usage, including alterations in APP isoforms that may influence pathological amyloid beta accumulation. These findings reveal that PD and PDD represent fundamentally distinct disease states, offering important insights for understanding their underlying mechanisms and will guide the development of targeted therapies and more effective clinical trials.

22 July 2025 in bioRxiv
Verified
Preprint
Open access
YSYara E Sanchez-Corrales
Yara E Sanchez-Corrales
TXTheodoros Xenakis
Theodoros Xenakis
JMJose J Moreno-Villena
Jose J Moreno-Villena
LFLeysa Forrest
Leysa Forrest
NSNeil J Sebire
Neil J Sebire
SHSara Louise Hillman
Sara Louise Hillman
Summary: The molecular and cellular pathophysiology of the fetal-maternal interface in preeclamsia remains poorly understood, but it is increasingly clear that both fetus and mother make independent contributions to it. Here, we spatially distinguish them from each other and from gestational age for the severe form of the disease, interrogating tissues and cell types beyond the placenta for the Early and Late presentation of the condition. In addition to concerted hypoxia, angiogenic imbalance, fibrosis and aberrant metabolism in the placenta, new maternal immune signatures, including changes in macrophages, mitochondrial dysfunction and interferon signalling in the placenta, myometrium or chorioamniotic membranes, offer an explanation to systemic inflammation and endothelial dysfunction in the mother. These tissue and cell-specific responses are potential targets for therapy, with their prompt consideration in Early gestational disease likely beneficial due to its severity. Thus, timely intervention during gestation could change the extremely poor prognosis of severe disease.

15 November 2025 in bioRxiv
Verified
Preprint
Open access
TXTheodoros Xenakis
Theodoros Xenakis
JMJose J Moreno-Villena
Jose J Moreno-Villena
GHGeorge Hall
George Hall
SHSara L Hillman
Sara L Hillman
YSYara E Sanchez-Corrales
Yara E Sanchez-Corrales
SCSergi Castellano
Sergi Castellano
Demand for the application of single cell transcriptomics on difficult tissues, processed and stored in disparate conditions, has led to the development of various single cell modalities. We focus on the placenta, a challenging tissue to transcriptomically interrogate due to senescence, intermittent hypoxia, high levels of RNase activity and tissue trauma at delivery. We performed single cell and nuclei transcriptomics on two samples with probe-based and native molecule transcript capture, droplet based and in situ plate based cell isolation. We explored sample and storage variations, including freshly dissociated tissues, fixed cells, snap frozen and FFPE processing. We find that variations in sample processing and storage have much larger effect on cell type proportions than differences in chemistry, impacting the biology that can be learned or the identification of disease markers. Further, the transcriptomic output of in situ combinatorial indexing consistently overlaps, with single nucleus transcriptomics, sharing little with other modalities. This may limit combinatorial indexing for sampling cytoplasmstic mRNAs. Our comprehensive analysis of the varying effect of single cell transcriptomic modalities, including their sample management strategies, provides novel and essential considerations for the experimental design and analysis of single cell transcriptomics applicable to challenging tissues, offering actionable guidance for future experiments. GRAPHICAL