scholarly journals Microglia-secreted TNF-α affects differentiation efficiency and viability of pluripotent stem cell-derived human dopaminergic precursors

2022 ◽  
Author(s):  
Shirley D Wenker ◽  
Victoria Gradaschi ◽  
Carina Ferrari ◽  
Maria Isabel Farias ◽  
Corina Garcia ◽  
...  

Parkinson's Disease is a neurodegenerative disorder characterized by the progressive loss of dopaminergic cells of the substantia nigra pars compacta . Even though successful transplantation of dopamine-producing cells into the striatum exhibits favourable effects in animal models and clinical trials; transplanted cell survival is low. Since every transplant elicits an inflammatory response which can affect cell survival and differentiation, we aimed to study in vivo and in vitro the impact of the pro-inflammatory environment on human dopaminergic precursors. We first observed that transplanted human dopaminergic precursors into the striatum of immunosuppressed rats elicited an early and sustained activation of astroglial and microglial cells after 15 days post-transplant. This long-lasting response was associated with Tumor necrosis factor alpha expression in microglial cells. In vitro conditioned media from activated BV2 microglial cells increased cell death, decreased Tyrosine hydroxylase -positive cells and induced morphological alterations on human neural stem cells-derived dopaminergic precursors at two differentiation stages: 19 days and 28 days. Those effects were ameliorated by inhibition of Tumor necrosis factor alpha, a cytokine which was previously detected in vivo and in conditioned media from activated BV-2 cells. Our results suggest that a pro-inflammatory environment is sustained after transplantation under immunosuppression, providing a window of opportunity to modify this response to increase transplant survival and differentiation. In addition, our data show that the microglia-derived pro-inflammatory microenvironment has a negative impact on survival and differentiation of dopaminergic precursors. Finally, Tumor necrosis factor alpha plays a key role in these effects, suggesting that this cytokine could be an interesting target to increase the efficacy of human dopaminergic precursors transplantation in Parkinson's Disease.

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1216-1225 ◽  
Author(s):  
F Rosselli ◽  
J Sanceau ◽  
E Gluckman ◽  
J Wietzerbin ◽  
E Moustacchi

Abstract We have previously shown an unbalanced cytokine production in Fanconi anemia (FA) cells, ie, an underproduction of interleukin 6 (IL-6) during growth. Among a number of cytokines analyzed, the only other anomalies detected concern tumor necrosis factor alpha (TNF alpha). In comparison to normal cells, this cytokine is overproduced by FA lymphoblasts from the four genetic complementation groups. Indeed, up to an eight-fold increase in TNF alpha is observed in the growth medium of FA cells. Moreover, addition of anti-TNF alpha antibodies partially corrects the FA hypersensitivity to treatment by mitomycin C (MMC). Treatment of FA cells with IL-6, which partially restored an almost normal sensitivity to MMC of FA cells also reduces the TNF alpha overproduction in FA lymphoblasts. No anomalies at the molecular level (Southern and Northern blot analyses) are detected for the TNF alpha gene and its mRNA. We have investigated the in vivo situation by assaying TNF alpha levels in the serum from FA homozygotes and obligate heterozygotes. In contrast to normal healthy donors or to aplastic anemia patients in whom serum TNF alpha is present only in trace amounts, all 36 FA patients and 21 FA parents monitored show a significantly (P < .001) higher level of serum TNF alpha activity. Consequently, abnormal TNF alpha production seems to be associated with the FA genetic background.


1992 ◽  
Vol 263 (3) ◽  
pp. R708-R715 ◽  
Author(s):  
L. Kapas ◽  
L. Hong ◽  
A. B. Cady ◽  
M. R. Opp ◽  
A. E. Postlethwaite ◽  
...  

Exogenously administered tumor necrosis factor-alpha (TNF-alpha) elicits several symptoms of generalized infections such as fever, increased sleep, and anorexia. The aim of the present work was to localize these effects of TNF-alpha to specific amino acid sequences of the parent molecule by characterizing the in vivo and in vitro activities of several synthetic TNF-alpha fragments. Intracerebroventricular injection of TNF-alpha elicited dose-dependent fevers and increases in non-rapid-eye-movement sleep (NREMS) in rabbits. Four fragments also promoted NREMS and five elicited monophasic fevers. All of the somnogenic fragments share the amino acid sequence 31-36. In rats, TNF-alpha and one of the fragments [TNF-alpha-(69-100)] suppressed 12-h food intake. Furthermore, TNF-alpha increased the expression of the intercellular adhesion molecule-1 and enhanced interferon-gamma-induced HLA-DR expression in human glioblastoma cell line. In contrast, none of the fragments possessed these in vitro activities. Our in vivo results support the concept that there are biologically active regions in the TNF-alpha molecule.


2002 ◽  
Vol 70 (12) ◽  
pp. 6628-6637 ◽  
Author(s):  
Christopher J. Papasian ◽  
Richard Silverstein ◽  
Jian Jun Gao ◽  
David M. Bamberger ◽  
David C. Morrison

ABSTRACT The murine d-galactosamine (d-gal) model of tumor necrosis factor alpha (TNF-α) hypersensitization was used as an initial tool to investigate the potential contribution of TNF-α to lethal intraperitoneal (i.p.) infection with Enterococcus faecalis. d-gal sensitized mice to lethal E. faecalis infection, whereas dexamethasone and neutralizing anti-TNF-α antibody protected d-gal-treated, E. faecalis-infected mice, implicating TNF-α in the lethal response to E. faecalis infection in d-gal-treated mice. Circulating TNF-α was undetectable for at least 8 h following i.p. E. faecalis infection, although low peritoneal levels of TNF-α were detected within 3 h, suggesting that localized TNF-α production contributed to the lethal response to E. faecalis infection in d-gal-treated mice. Although i.p. E. faecalis infection failed to induce a detectable systemic TNF-α response, circulating Interleukin-6 (IL-6) was detected within 3 h of infection. IL-6 was also detected in the peritoneum within an hour of infection, prior to the appearance of peritoneal TNF-α. In striking contrast to in vivo results, E. faecalis induced a potent and rapid TNF-α response from both mouse peritoneal macrophages and the RAW 264.7 cell line in vitro. This led us to hypothesize that TNF-α production in response to E. faecalis infection is suppressed by IL-6 in vivo. In vitro experiments demonstrated a statistically significant, but modest, inhibitory effect of IL-6 on TNF-α production by RAW cells stimulated with E. faecalis. Collectively, these data indicate that acute, lethal E. faecalis infection appears to induce an unusual cytokine response that differs in character from that previously described for most other gram-positive and gram-negative bacteria.


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