Interprofessional education (IPE) is an important step in advancing health professional education for many years and has been endorsed by the Institute of Medicine as a mechanism to improve the overall quality of health care. IPE has also become an area of focus for the American Association of Colleges of Pharmacy (AACP), with several groups, including these authors from the AACP Interprofessional Education Task Force, working on developing resources to promote and support IPE planning and development. This review provides background on the definition of IPE, evidence to support IPE, the need for IPE, student competencies and objectives for IPE, barriers to implementation of IPE, and elements critical for successfully implementing IPE.

This report describes the isolation, nucleotide sequencing, and functional expression of human cDNAs that restore reduced folate carrier activity in transport-defective cells. Based on homology to a partial murine cDNA probe, two functional cDNAs were isolated from a lambda gt11 library prepared from methotrexate transport upregulated K562 cells (K562.4CF). A 2.8-kilobase (kb) clone, KS43, contained a 1776-base pair open reading frame. The 2.5-kb clone, KS32, contained an internal deletion (626 base pairs) resulting a shortened open reading frame and 3'-untranslated region. KS43 and KS32 encoded proteins with multiple hydrophobic domains, one consensus N-glycosylation site, and predicted molecular masses of 65 and 58 kDa, respectively. The deduced amino acid sequence of KS43 is 79% and 80% homologous to the mouse and hamster sequences, respectively (Dixon, K. H., Lanpher, B. C., Chiu, J., Kelley, K., and Cowan, K. H. (1994) J. Biol. Chem. 269, 17-20; Williams, F. M. R., Murray R. C., Underhill, T. M., and Flintoff, W. F. (1994) J. Biol. Chem. 269, 5810-5816). Northern blots identified one primary transcript at 3.1 kb in parental K562, K562.4CF, and transport-impaired K500E cells; transcript levels varied by 7-fold. The expression of both KS43 and KS32 in methotrexate transport-defective Chinese hamster ovary cells restored methotrexate sensitivity and transport. Certain transport characteristics of the transfected cells resembled both the wild type human (K562) and hamster "classical" reduced folate carriers, suggesting the expression of a hybrid system. For instance, based on Ki values, up to a 4-fold increased affinity for 1843U89 over wild type hamster cells (typical of human cells), and a 19-fold increased affinity for methotrexate over K562 cells (typical of hamster cells) was observed. Further, a photoaffinity probe with high specificity for the reduced folate carrier labeled 94-kDa proteins in K562 cells and the transfectant containing the full-length KS43, and a 85-kDa protein in the transfectant containing the 3'-truncated KS32. No specifically labeled proteins were detected in wild type or mock-transfected hamster cells. Collectively, our results suggest that the KS43/KS32 cDNAs encode the human reduced folate carrier; however, additional modulatory/regulatory factors may be required to manifest the full spectrum of transport substrate activities typical of this system.

The basis for impaired reduced folate carrier (RFC) activity in methotrexate-resistant CCRF-CEM (CEM/ Mtx-1) cells was examined. Parental and CEM/Mtx-1 cells expressed identical levels of the 3.1-kilobase RFC transcript. A ϳ85-kDa RFC protein was detected in parental cells by photoaffinity labeling and on Western blots with RFC-specific antiserum. In CEM/Mtx-1 cells, RFC protein was undetectable. By reverse transcriptase-polymerase chain reaction and sequence analysis, G to A point mutations were identified in CEM/ Mtx-1 transcripts at positions 130 (P 1 ; changes glycine 44 3 arginine) and 380 (P 2 ; changes serine 127 3 asparagine Despite the availability of newer antifolates, methotrexate (Mtx) 1 continues to play an important role as an antineoplastic agent. To reach its intracellular target, dihydrofolate reductase, the preferred route of Mtx entry involves the reduced folate carrier (RFC; 1, 2). RFC transport of Mtx is critical to drug action because of its role in generating sufficient unbound intracellular antifolate to sustain maximal enzyme inhibition (1). Furthermore, high levels of Mtx are also necessary for the synthesis of Mtx polyglutamates (1).Defective membrane transport of Mtx by RFC has been identified as a major mechanism of Mtx resistance (1-11). Transport alterations can manifest as reduced rates of carrier translocation (reduced V max ), decreased affinities for transport substrates (increased K t ), or both, and may involve decreased levels of normal RFC (6) or the expression of structurally altered RFC proteins (7-11). For instance, in Mtx-resistant K562 (K500E) cells, impaired Mtx transport is accompanied by decreased RFC transcripts and protein (6). A G to A transition at position 890 of the murine RFC cDNA resulted in a substitution of serine 297 by asparagine and a selective decrease in Mtx binding affinity (ϳ4-fold) without effects on other antifolate analogs (aminopterin, Ref. 9). Likewise, replacement of serine 46 by asparagine (10) or glutamate 45 by lysine (11) in murine RFC resulted in greater impairment of uptake for Mtx than (6S)-5-formyl tetrahydrofolate. In severely transport defective L1210 cells (Mtx r A), loss of transport activity appeared to reflect a single (G to C) point mutation at nucleotide 429 of the murine RFC cDNA sequence which resulted in the substitution of proline 130 by alanine (7). However, these cells also contained a wild-type RFC allele that was not transcribed. A silent wild-type RFC allele was described for Mtx-resistant MOLT-3 cells (MOLT-3/Mtx 10,000 ; Ref. 8). Moreover, two mutations in the RFC coding region were detected which resulted in the creation of new stop codons and synthesis of truncated nonfunctional RFCs (8).In this report, the molecular mechanisms responsible for the transport-impaired phenotype (ϳ3% of wild-type) of Mtx-resistant (ϳ243-fold) CCRF-CEM (CEM/Mtx-1;12) cells were examined. We show that although the levels of RFC transcripts are essentially unchanged from wild-type cells, there is a complete loss of RFC protein due to ear...

Cellular senescence is a biological process by which cells lose their capacity to proliferate yet remain metabolically active. Although originally considered a protective mechanism to limit the formation of cancer, it is now appreciated that cellular senescence also contributes to the development of disease, including common respiratory ailments such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. While many factors have been linked to the development of cellular senescence, mitochondrial dysfunction has emerged as an important causative factor. In this study, we uncovered that the mitochondrial biogenesis pathway driven by the mammalian target of rapamycin/peroxisome proliferator-activated receptor-γ complex 1α/β (mTOR/PGC-1α/β) axis is markedly upregulated in senescent lung epithelial cells. Using two different models, we show that activation of this pathway is associated with other features characteristic of enhanced mitochondrial biogenesis, including elevated number of mitochondrion per cell, increased oxidative phosphorylation, and augmented mitochondrial reactive oxygen species (ROS) production. Furthermore, we found that pharmacological inhibition of the mTORC1 complex with rapamycin not only restored mitochondrial homeostasis but also reduced cellular senescence to bleomycin in lung epithelial cells. Likewise, mitochondrial-specific antioxidant therapy also effectively inhibited mTORC1 activation in these cells while concomitantly reducing mitochondrial biogenesis and cellular senescence. In summary, this study provides a mechanistic link between mitochondrial biogenesis and cellular senescence in lung epithelium and suggests that strategies aimed at blocking the mTORC1/PGC-1α/β axis or reducing ROS-induced molecular damage could be effective in the treatment of senescence-associated lung diseases.