Alexandra Stolzing, PhD
Fraunhofer Institute for Cell Therapy and Immunology
04103 Leipzig, Germany
Group Leader: Stem Cell Biology and Regeneration
→ Group Webpage
Tel: +49 (0) 341- 355363405
Fax: +49 (0) 341- 355 36109
The study of cellular aging and the development of regenerative therapies.
◊◊ Cellular Reprogramming
My group is investigating ways to utilise cellular reprogramming technologies in order to re-instate regenerative capacity in aged tissue and in niches of aged stem cells. We study 4 main approaches:
Cellular Fusion: Cell fusion occurs spontaneously in humans after bone marrow transplantation or stem cell injections and is also part of the natural maintenance of several tissues. Silenced genes can become activated upon fusion and cells become infused with 'young' factors. An understanding of the intracellular regulatory network will enhance our ability to enlist this potential to direct changes and lead cells towards a specialized differentiation state or roll back the genetic age of a cell.
Induced Pluripotency: This group is applying a novel technique to de-differentiate aged and specialised cells towards a pluripotent state which has a similar differentiation potential to embryonic stem cells.
Partial Cloning: In partial cloning a nucleus is taken out of an adult cell, exposed temporarily to the cytoplasm of an enucleated oocyte, and then reinserted into the original or nearby cell. No reprogramming towards an embryonic status is required or intended. Partial reprogramming is potentially very valuable as the basis of autologous cellular rejuvenation therapies or for creating 'regeneration trigger cells' – impulses delivered by small quantities of particularly vigorous cells that can be used to initiate a 'regeneration cascade' in vivo or to initiate and modulate growth behaviour in the complex scaffolds used for tissue engineering.
Cell Conditioning: Insights from basic ageing studies have helped us to develop advanced protocolls for modulating cell fate and cell survival. By applying specially adapted cell culture techniques, a carefully monitored environment and by supplementation with certain cell culture factors, we are refining methods of maintaining and increasing the differentiation potential of adult stem cells.
◊◊ Aging interventions
Aging Stem Cells: The capacity of adult stem cell to assist with the regeneration of tissue and organs seems to decline during aging.
I am investigating which factors determine how progenitor cells change during aging. From this understanding, we can develop techniques to alter the differentiation behaviour of aged progenitor cells.
Such technologies will be particulary critical for the use of stem cell therapies in the elderly or in people with diseases, in which the autologus stem cell quality might be impaired. My group attempts to ‘prime’ stem cells via a novel combination of methods with the aim of increasing their capacity to regenerate in vivo.
Microglia Replacement Therapy: During aging, the role of microglia in the brain changes from ‘friend to foe’ –in young organisms microglia are actively participating in clearing protein debris from the brain and are renewed by adult stem cells. In aged and old organisms however, microglial replenishment is impaired. The brain is burdened with ‘old’ microglia that remain in chronic activation and thus cause inflammation and damage.
Our goal is to slow brain aging by supporting exciting cells and by reactivating endogenous stem cells. If you want to support us and help with our research please donate.
◊◊ Cryopreservation of cells
Cryopreservation is a process where whole tissues or cells are preserved by cooling to sub-zero temperatures. Such low temperatures assure that any biological activity is effectively stopped, including reactions that could lead to the deterioration of cells. Vitrification is a specialized form of cryopreservation converting a material into a glass-like form that is free from crystalline structures.
Cryopreservation exposes cells to significant stresse. Factors like fluctuation in temperature during freezing & thawing, and the use of inadequate cryoprotectant combinations can damage cells and tissues.
We aim to eliminate traditional cryoprotectants like DMSO in stem cell culture and to refine a cryopreservation method that improves the viability and differentiation potential of stem cells and stem-cell derived tissues.
I am always interessted in collaborating with colleagues in academia and the private sector alike.
Applications from research students with an interest in gerontology or cell therapy are also welcome.