kth.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Patterns of Life: Advancing Spatial Omics for a Better Understanding of Metabolic Tissues
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.ORCID iD: 0000-0002-6800-0432
2025 (English)Doctoral thesis, comprehensive summary (Other academic)
Sustainable development
SDG 3: Good Health and Well-Being
Abstract [en]

Life hinges on the precise interplay between gene regulation and metabolism, a dynamic balance that unfolds in specific tissues and underlies both normal physiology and disease. This thesis follows a unifying red thread, advancing spatial omics for tissue-specific metabolic insights and translational applications by combining cutting-edge spatial transcriptomics and spatial epigenomics to illuminate how local regulatory mechanisms shape metabolic function.

In the initial segment of the thesis, we establish the conceptual groundwork, exploring how chromatin accessibility and transcriptional programs orchestrate cellular metabolism. We then apply spatial transcriptomics to two distinct yet metabolically active tissues. Paper I maps subcutaneous white adipose tissue (WAT) and discovers multiple adipocyte subtypes with divergent insulin responses, underscoring the critical role of tissue architecture in metabolic homeostasis. Paper II extends these methods to the human placenta, revealing region-specific gene expression patterns that help explain the metabolic dysregulation observed in preeclampsia. Given the placenta’s pivotal role in maternal-foetal nutrient exchange, these findings offer novel insights into how morphological compartments become disrupted in disease.

Building on these insights, Paper III introduces spatial ATAC-seq, a novel technique for profiling open chromatin within intact tissues, linking regulatory elements to their spatial context. Paper IV refines this protocol for broader adoption, integrating it with commercial platforms and enabling seamless multi-omic workflows. Building on these technological advances, Paper V returns to adipose tissue in a clinically relevant setting, employing a multi-omic approach to chart the long-term remodelling of WAT after bariatric surgery. By capturing transcriptional shifts in adipocytes and immune–stromal interactions, we highlight the tissue-level transformations that underpin sustained metabolic improvements.

Collectively, these studies showcase how spatial omics can deepen our understanding of tissue-specific metabolism, bridging foundational biology and translational research. They also underscore the power of integrated multi-omic approaches in revealing how chromatin states, gene expression, and metabolic function intersect in situ. By decoding the spatial architecture of gene regulation, we not only unravel the cellular intricacies of adipose and placental tissues but also pave the way for targeted therapeutic interventions in metabolic diseases, offering a powerful lens through which to view, and ultimately shape human health.

Abstract [sv]

Livet vilar på det precisa samspelet mellan genreglering och metabolism, en dynamisk balans som utspelar sig i specifika vävnader och ligger till grund för både normal fysiologi och sjukdom. Denna avhandling beskriver utvecklingen av spatiala omik-metoder som ger insikter i vävnadsspecifik metabolism och möjliggör translationella tillämpningar. Genom att kombinera banbrytande spatiala transkriptomik och spatiala epigenomik belyser arbetet hur lokala regulatoriska mekanismer formar den metabola funktionen. I avhandlingens inledande del lägger vi den konceptuella grunden och utforskar hur kromatintillgänglighet och transkriptionsprogram styr cellens metabolism. Därefter tillämpar vi spatial transkriptomik på två metabolt aktiva vävnader. Paper I kartlägger subkutant vitt fett (WAT) och identifierar flera adipocyt-subtyper med olika insulinsvar, vilket understryker hur vävnadsarkitekturen är avgörande för metabol homeostas. Paper II överför dessa metoder till den mänskliga placentan och avslöjar region-specifika genuttrycksmönster som förklarar de metabola störningar som uppträder vid preeklampsi. Med tanke på placentans centrala roll i näringsutbytet mellan moder och foster ger dessa resultat nya insikter i hur morfologiska avgränsningar kan rubbas vid sjukdom. Utifrån dessa fynd presenterar Paper III spatial ATAC-seq, en ny teknik för att profilera öppet kromatin i intakta vävnader, vilket knyter samman regulatoriska element med deras spatiala kontext. Paper IV förfinar denna metod för bredare användning genom att integrera den med kommersiella plattformar och möjliggöra smidiga multi-omiska arbetsflöden. Slutligen återvänder Paper V till fettvävnaden i ett kliniskt relevant sammanhang och använder en multi-omisk strategi för att kartlägga långsiktig ombyggnad av WAT efter gastrisk bypass-operation. Genom att fånga upp transkriptionella förändringar i adipocyter och immunceller-stromaceller belyser vi de förändringar på vävnadsnivå som ligger bakom varaktiga metabola förbättringar. Sammantaget visar dessa studier hur spatiala omikmetoder kan fördjupa vår förståelse av vävnadsspecifik metabolism och överbrygga avståndet mellan grundläggande biologi och translationell forskning. De framhäver också styrkan i integrerade multi-omiska angreppssätt för att synliggöra hur kromatintillstånd, genuttryck och metabol funktion samverkar in situ. Genom att bevara den spatiala arkitekturen hos genreglering kan vi inte bara blottlägga de cellulära komplexiteterna i fettvävnad och placenta, utan även bana väg för riktade terapeutiska behandlingar vid metabola sjukdomar, och därigenom erbjuda ett kraftfullt verktyg för hur vi kan förstå och i förlängningen påverka människans hälsa

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2025.
Series
TRITA-CBH-FOU ; 2025:11
Keywords [en]
Spatial Transcriptomics, Spatial Omics, Epigenetics, Spatial Epigenetics, Adipose tissue, Placenta tissue
Keywords [sv]
Spatial transkriptomik, Spatial omik, Epigenetik, Spatial epigenetik, Fettvävnad, Placentavävnad
National Category
Medical Biotechnology
Research subject
Biotechnology
Identifiers
URN: urn:nbn:se:kth:diva-362817ISBN: 978-91-8106-273-1 (print)OAI: oai:DiVA.org:kth-362817DiVA, id: diva2:1954707
Public defence
2025-05-23, Air&Fire, Science for Life Laboratory, KISP (Karolinska Institutet Science Park), Tomtebodavägen 23A, Solna, via Zoom: https://kth-se.zoom.us/j/65783126092, Stockholm, 09:15 (English)
Opponent
Supervisors
Note

QC 2025-04-28

Available from: 2025-04-28 Created: 2025-04-25 Last updated: 2025-05-05Bibliographically approved
List of papers
1. Spatial mapping reveals human adipocyte subpopulations with distinct sensitivities to insulin
Open this publication in new window or tab >>Spatial mapping reveals human adipocyte subpopulations with distinct sensitivities to insulin
Show others...
2021 (English)In: Cell Metabolism, ISSN 1550-4131, E-ISSN 1932-7420, Vol. 33, no 9, p. 1869-+Article in journal (Refereed) Published
Abstract [en]

The contribution of cellular heterogeneity and architecture to white adipose tissue (WAT) function is poorly understood. Herein, we combined spatially resolved transcriptional profiling with single-cell RNA sequencing and image analyses to map human WAT composition and structure. This identified 18 cell classes with unique propensities to form spatially organized homo-and heterotypic clusters. Of these, three constituted mature adipocytes that were similar in size, but distinct in their spatial arrangements and transcriptional profiles. Based on marker genes, we termed these Adipo(LEP), Adipo(PLIN), and Adipo(SAA). We confirmed, in independent datasets, that their respective gene profiles associated differently with both adipocyte and whole-body insulin sensitivity. Corroborating our observations, insulin stimulation in vivo by hyperinsulinemic-euglycemic clamp showed that only Adipo(PLIN) displayed a transcriptional response to insulin. Altogether, by mining this multimodal resource we identify that human WAT is composed of three classes of mature adipocytes, only one of which is insulin responsive.

Place, publisher, year, edition, pages
Elsevier BV, 2021
National Category
Endocrinology and Diabetes Cell and Molecular Biology
Identifiers
urn:nbn:se:kth:diva-303062 (URN)10.1016/j.cmet.2021.07.018 (DOI)000696568500003 ()34380013 (PubMedID)2-s2.0-85114341893 (Scopus ID)
Note

QC 20211005

Available from: 2021-10-05 Created: 2021-10-05 Last updated: 2025-04-25Bibliographically approved
2. Spatial transcriptomics of human placentas reveal distinct RNA patterns associated with morphology and preeclampsia
Open this publication in new window or tab >>Spatial transcriptomics of human placentas reveal distinct RNA patterns associated with morphology and preeclampsia
Show others...
2023 (English)In: Placenta, ISSN 0143-4004, E-ISSN 1532-3102, Vol. 139, p. 213-216Article in journal (Refereed) Published
Abstract [en]

Spatial transcriptomics (ST) maps RNA level patterns within a tissue. This technology has not been previously applied to human placental tissue. We demonstrate analysis of human placental samples with ST. Unsupervised clustering revealed that distinct RNA patterns were found corresponding to different morphological structures. Additionally, when focusing upon terminal villi and hemoglobin associated structures, RNA levels differed between placentas from full term healthy pregnancies and those complicated by preeclampsia. The results from this study can provide a benchmark for future ST studies in placenta.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Differential gene expression, Hemoglobin, Morphology, Oxidoreductase pathway, Placenta, Preeclampsia, Pregnancy complications, Spatial transcriptomics, Villi
National Category
Gynaecology, Obstetrics and Reproductive Medicine
Identifiers
urn:nbn:se:kth:diva-335727 (URN)10.1016/j.placenta.2023.07.004 (DOI)001050255700001 ()37481829 (PubMedID)2-s2.0-85165700790 (Scopus ID)
Note

QC 20230911

Available from: 2023-09-11 Created: 2023-09-11 Last updated: 2025-04-25Bibliographically approved
3. Solid-phase capture and profiling of open chromatin by spatial ATAC
Open this publication in new window or tab >>Solid-phase capture and profiling of open chromatin by spatial ATAC
Show others...
2023 (English)In: Nature Biotechnology, ISSN 1087-0156, E-ISSN 1546-1696, Vol. 41, no 8, p. 1085-1088Article in journal (Refereed) Published
Abstract [en]

Current methods for epigenomic profiling are limited in their ability to obtain genome-wide information with spatial resolution. We introduce spatial ATAC, a method that integrates transposase-accessible chromatin profiling in tissue sections with barcoded solid-phase capture to perform spatially resolved epigenomics. We show that spatial ATAC enables the discovery of the regulatory programs underlying spatial gene expression during mouse organogenesis, lineage differentiation and in human pathology.

Place, publisher, year, edition, pages
Nature Research, 2023
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Identifiers
urn:nbn:se:kth:diva-338421 (URN)10.1038/s41587-022-01603-9 (DOI)000909592700002 ()36604544 (PubMedID)2-s2.0-85145698262 (Scopus ID)
Note

QC 20231023

Available from: 2023-10-23 Created: 2023-10-23 Last updated: 2025-04-25Bibliographically approved
4. Optimising Spatial ATAC-Seq for Enhanced Data Quality and Accessibility
Open this publication in new window or tab >>Optimising Spatial ATAC-Seq for Enhanced Data Quality and Accessibility
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Chromatin accessibility is fundamental to gene regulation, yet it remains challenging to study within intact tissues. We present an optimised spatial ATAC-seq protocol adapted for widely available polyA-capture slides, overcoming previous limitations in signal diffusion and accessibility. By refining tissue permeabilisation, fragment capture, and library construction, we substantially increased fragment yield while preserving high-resolution epigenomic mapping and multi-omic compatibility. Applied to embryonic day (E)15.5 mouse tissue, our approach yields robust chromatin accessibility maps with strong transcription start site enrichment and clear nucleosome periodicity, enabling fine-grained insight into region-specific regulatory programs. Moreover, co-embedding with single-nucleus ATAC-seq confirms high concordance between the two modalities and refines cell-type annotations. By matching the resolution of existing datasets and supporting a range of tissue types, this protocol broadens the accessibility of spatial epigenomics and provides a powerful platform for understanding how chromatin architecture shapes gene expression in situ.

National Category
Molecular Biology Genetics and Genomics
Research subject
Biotechnology
Identifiers
urn:nbn:se:kth:diva-362591 (URN)
Note

QC 20250422

Available from: 2025-04-21 Created: 2025-04-21 Last updated: 2025-04-25Bibliographically approved
5. Spatial Transcriptomic Insights into Adipose Tissue Remodelling During Weight Loss
Open this publication in new window or tab >>Spatial Transcriptomic Insights into Adipose Tissue Remodelling During Weight Loss
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Obesity is a major risk factor for insulin resistance and type 2 diabetes, yet the mechanisms through which weight loss ameliorates metabolic dysfunction remain incompletely understood. Here, we integrated bulk RNA sequencing, single-nucleus RNA sequencing, and spatial transcriptomics in individuals undergoing Roux-en-Y gastric bypass. Our data reveal profound remodelling of subcutaneous white adipose tissue (WAT) over a five-year period of sustained weight loss. Clinically, bariatric surgery led to marked reductions in body mass index, visceral fat, and systemic inflammation, accompanied by improved insulin sensitivity. At the tissue level, single-nucleus RNA-sequencing showed extensive transcriptional reprogramming of adipocytes, a decline in inflammatory myeloid cells, and shifts in fibroblast/adipogenic progenitors toward less fibrotic and more specialised subpopulations. Spatial transcriptomics identified three major adipocyte subtypes (LEP, PLIN, SAA) and demonstrated that the proinflammatory SAA population decreased significantly post-surgery. Notably, neighbourhood analyses revealed a more heterogeneous and intermingled cellular organisation at follow-up, suggesting enhanced cell-cell communication in a leaner, metabolically healthier microenvironment. Taken together, these findings underscore the pivotal role of adipose tissue adaptation in the metabolic benefits of bariatric surgery and provide a foundation for targeted therapies aimed at replicating or enhancing these tissue-level changes in obesity management.

National Category
Cell and Molecular Biology
Research subject
Biotechnology
Identifiers
urn:nbn:se:kth:diva-362592 (URN)
Note

QC 20250422

Available from: 2025-04-21 Created: 2025-04-21 Last updated: 2025-04-25Bibliographically approved

Open Access in DiVA

Kappa(8021 kB)63 downloads
File information
File name FULLTEXT01.pdfFile size 8021 kBChecksum SHA-512
67037e69a3d296ebe51ebbcbaba146a1ccdf6e2e8da3ba56f0c87efa226df12306a37a24945f84c3614508335ad58ef5ea8e1f5ac687b990e5d95a71deb85543
Type summaryMimetype application/pdf

Authority records

Bhalla, Nayanika

Search in DiVA

By author/editor
Bhalla, Nayanika
By organisation
Gene TechnologyScience for Life Laboratory, SciLifeLab
Medical Biotechnology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 383 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf