Adherence to Mediterranean diet in liver transplant recipients: a cross-sectional multicenter study

BACKGROUND

Seeing the importance of healthy diet after liver transplant (LT), our study aimed to evaluate the adherence to Mediterranean diet (MD) in a large population of LT recipients.

METHODS

The present multicenter study was developed in clinically stable, liver transplanted patients, from June to September 2021. Patients completed a survey about adherence to MD, Quality of Life (QoL), sport, and employment. To analyze the correlations, we computed Pearson's coefficients; while to compare subgroups, independent samples t-tests and ANOVAs. We used a multivariable logistic regression analysis to find the predictors of impaired adherence to MD.

RESULTS

The questionnaire was administered to 511 patients. They were males in 71% of cases with a mean age of 63.1 years (SD±10.8). LT recipients coming from central Italy displayed higher adherence to the MD (M=11.10±1.91) than patients from northern (M=9.94±2.28, P<0.001) or southern Italy (M=10.04±2.16, P<0.001). Patients from central Italy showed a significantly higher consumption of fruit, vegetables, legumes, cereals, olive oil, fish and a significantly lower intake of dairy products than patients resident in the other Italian areas. At multivariate analysis, recipients from central Italy were 3.8 times more likely to report adherence to the MD. Patients with a high physical health score were more adherent to MD, as well as patients transplanted at an earlier time.

CONCLUSIONS

We demonstrated that place of stay, time from transplant and physical dimension of QoL significantly influences the adherence to MD. Continuous information campaigns about a correct diet and lifestyle would be necessary.

Recurrent activating mutations of CD28 in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of mature T-cell neoplasms with a poor prognosis. Recently, mutations in TET2 and other epigenetic modifiers as well as RHOA have been identified in these diseases, particularly in angioimmunoblastic T-cell lymphoma (AITL). CD28 is the major co-stimulatory receptor in T cells which, upon binding ligand, induces sustained T-cell proliferation and cytokine production when combined with T-cell receptor stimulation. We have identified recurrent mutations in CD28 in PTCLs. Two residues-D124 and T195-were recurrently mutated in 11.3% of cases of AITL and in one case of PTCL, not otherwise specified (PTCL-NOS). Surface plasmon resonance analysis of mutations at these residues with predicted differential partner interactions showed increased affinity for ligand CD86 (residue D124) and increased affinity for intracellular adaptor proteins GRB2 and GADS/GRAP2 (residue T195). Molecular modeling studies on each of these mutations suggested how these mutants result in increased affinities. We found increased transcription of the CD28-responsive genes CD226 and TNFA in cells expressing the T195P mutant in response to CD3 and CD86 co-stimulation and increased downstream activation of NF-κB by both D124V and T195P mutants, suggesting a potential therapeutic target in CD28-mutated PTCLs.

Analysis of major histocompatibility complex class I folding: novel insights into intermediate forms

Folding around a peptide ligand is integral to the antigen presentation function of major histocompatibility complex (MHC) class I molecules. Several lines of evidence indicate that the broadly cross-reactive 34-1-2 antibody is sensitive to folding of the MHC class I peptide-binding groove. Here, we show that peptide-loading complex proteins associated with the murine MHC class I molecule K(d) are found primarily in association with the 34-1-2(+) form. This led us to hypothesize that the 34-1-2 antibody may recognize intermediately, as well as fully, folded MHC class I molecules. To further characterize the form(s) of MHC class I molecules recognized by 34-1-2, we took advantage of its cross-reactivity with L(d) . Recognition of the open and folded forms of L(d) by the 64-3-7 and 30-5-7 antibodies, respectively, has been extensively characterized, providing us with parameters against which to compare 34-1-2 reactivity. We found that the 34-1-2(+) L(d) molecules displayed characteristics indicative of incomplete folding, including increased tapasin association, endoplasmic reticulum retention, and instability at the cell surface. Moreover, we show that an L(d) -specific peptide induced folding of the 34-1-2(+) L(d) intermediate. Altogether, these results yield novel insights into the nature of MHC class I molecules recognized by the 34-1-2 antibody.

Noggin maintains pluripotency of human embryonic stem cells grown on Matrigel

OBJECTIVE

Spontaneous differentiation of human embryonic stem cell (hESC) cultures is a major concern in stem cell research. Physical removal of differentiated areas in a stem cell colony is the current approach used to keep the cultures in a pluripotent state for a prolonged period of time. All hESCs available for research require unidentified soluble factors secreted from feeder layers to maintain the undifferentiated state and pluripotency. Under experimental conditions, stem cells are grown on various matrices, the most commonly used being Matrigel.

MATERIALS AND METHODS

We propose an alternative method to prevent spontaneous differentiation of hESCs grown on Matrigel that uses low amounts of recombinant noggin. We make use of the porosity of Matrigel to serve as a matrix that traps noggin and gradually releases it into the culture to antagonize bone morphogenetic proteins (BMP). BMPs are known to initiate differentiation of hESCs and are either present in the conditioned medium or are secreted by hESCs themselves.

RESULTS

hESCs grown on Matrigel supplemented with noggin in conditioned medium from feeder layers (irradiated mouse embryonic fibroblasts) retained both normal karyotype and markers of hESC pluripotency for 14 days. In addition, these cultures were found to have increased cell proliferation of stem cells as compared to hESCs grown on Matrigel alone.

CONCLUSION

Noggin can be utilized for short term prevention of spontaneous differentiation of stem cells grown on Matrigel.