Addition of synthetic polymer in the freezing solution of mesenchymal stem cells from equine adipose tissue as a future perspective for reducing of DMSO concentration.

The regenerative therapies with stem cells (SC) has been increased by the cryopreservation, permitting cell storage for extended periods. However, the permeating cryoprotectant agents (CPAs) such as dimethylsulfoxide (DMSO) can cause severe adverse effects. Therefore, this study evaluated equine mesenchymal stem cells derived from adipose tissue (eAT-MSCs) in fresh (Control) or after slow freezing (SF) in different freezing solutions (FS).

Polyol additives modulate the in vitro stability and activity of recombinant human phenylalanine hydroxylase.

Phenylketonuria (PKU; OMIM 261600), the most common disorder of amino acid metabolism, is caused by a deficient activity of human phenylalanine hydroxylase (hPAH). Although the dietetic treatment has proven to be effective in preventing the psycho-motor impairment, much effort has been made to develop new therapeutic approaches. Enzyme replacement therapy with hPAH could be regarded as a potential form of PKU treatment if the reported in vitro hPAH instability could be overcome.

Modulation of the activity of newly synthesized human phenylalanine hydroxylase mutant proteins by low-molecular-weight compounds.

Phenylketonuria, the most frequent disorder of amino acid metabolism, is caused by a deficient activity of human phenylalanine hydroxylase (hPAH). Rescue of the enzyme activity of several recombinant hPAH mutant forms (I65T, R261Q, R270K and V388M) by low molecular weight compounds namely glycerol, trimethylamine N-oxide (TMAO) and sodium 4-phenylbutyrate (4-PB) was investigated using a prokaryotic expression model. The studied compounds were added to the culture medium, in a concentration dependent manner, simultaneously to induction of protein expression.

Co-expression of different subunits of human phenylalanine hydroxylase: evidence of negative interallelic complementation.

To study the interaction between two different subunits of the heteromeric human phenylalanine hydroxylase (hPAH), present in hyperphenylalaninemic (HPA) compound heterozygous patients, heteroallelic hPAH enzymes were produced. A dual vector expression system was used (PRO Bacterial Expression System) in which each mutant subunit was expressed from a separate compatible vector, with different epitope tags, in a single bacterial host. Experimental conditions were selected in order that each plasmid produced equivalent levels of mutant subunits.