Pork and Chicken Meals Similarly Impact on Cognitive Function and Strength in Community-Living Older Adults: A Pilot Study.

A pilot quasi-experimental study investigated whether provision of pork, a rich source of thiamin, as the main protein source in meals four times/week for 12 weeks resulted in improved muscle mass, body strength, and cognitive function in community-living older adults compared to similar meals containing chicken. Retirement villages were randomized to receive pre-prepared frozen meals containing either pork or chicken. Dietary intake was assessed by three-day food records and cognitive domains assessed using validated tests. Hand grip strength was measured and lower extremity performance assessed by the sit-to-stand test, get-up-and-go test and six-minute walk test. Forty-eight volunteers participated (78.2 ± 6.2 y). In linear mixed models, controlling for baseline physical activity and dietary protein and energy intake, no differences were found between pork (n = 19) and chicken (n = 12) groups. The chicken group had improved Rey Auditory Verbal Learning test scores (verbal learning and memory) at six weeks (p < 0.001). Provision of four pork meals a week did not result in improvements in cognitive function, nor measures of strength or physical function, compared to those receiving chicken meals in healthy older adults. This suggests that merely changing the type of dietary protein provided by meat does not impact physical or cognitive function.

Lean Body Mass Associated with Upper Body Strength in Healthy Older Adults While Higher Body Fat Limits Lower Extremity Performance and Endurance.

Impaired strength adversely influences an older person's ability to perform activities of daily living. A cross-sectional study of 117 independently living men and women (age = 73.4 ± 9.4 year; body mass index (BMI) = 27.6 ± 4.8 kg/m²) aimed to assess the association between body composition and: (1) upper body strength (handgrip strength, HGS); (2) lower extremity performance (timed up and go (TUG) and sit to stand test (STS)); and (3) endurance (6-minute walk (SMWT). Body composition (% fat; lean body mass (LBM)) was assessed using bioelectrical impedance. Habitual physical activity was measured using the Minnesota Leisure Time Physical Activity Questionnaire (MLTPA) and dietary macronutrient intake, assessed using 24 h recalls and 3-day food records. Regression analyses included the covariates, protein intake (g/kg), MLTPA, age and sex. For natural logarithm (Ln) of right HGS, LBM (p < 0.001) and % body fat (p < 0.005) were significant (r² = 46.5%; p < 0.000). For left LnHGS, LBM (p < 0.000), age (p = 0.036), protein intake (p = 0.015) and LnMLTPA (p = 0.015) were significant (r² = 0.535; p < 0.000). For SMW, % body fat, age and LnMLTPA were significant (r² = 0.346; p < 0.000). For STS, % body fat and age were significant (r² = 0.251; p < 0.000). LBM is a strong predictor of upper body strength while higher % body fat and lower physical activity are associated with poorer outcomes on tests of lower extremity performance.

Placenta-derived MSCs are partially immunogenic and less immunomodulatory than bone marrow-derived MSCs.

Over the past few years, mesenchymal stem cells (MSCs) have become of increasing interest for use in the field of regenerative medicine. To date, bone marrow (BM) has been the main source of MSCs (BM-MSCs) for both experimental and clinical studies. However, the use of MSCs derived from BM can be problematic, due to the low number of MSCs found in bone marrow aspirates and the invasive procedure associated with obtaining them. We aimed to develop a method of obtaining high numbers of purified MSCs from placental tissue with minimal expansion and to characterize their phenotype and function relative to BM-MSCs. We show here that placenta-derived MSCs (PD-MSCs) can be isolated with high numbers from whole placental tissue. However, PD-MSCs isolated from whole tissue were often found to be a mixed population of both maternal and neonatal cells. The immunological properties of PD-MSCs and BM-MSCs were compared. PD-MSCs were found to express lower levels of HLA class I and higher levels of PDL-1 and CD1a, compared to BM-MSCs. HLA-DR became upregulated in PD-MSCs following treatment with IFNγ, whereas BM-MSCs expressed constitutively low levels of HLA-DR. Whilst untreated or IFNγ-treated BM-MSCs were incapable of stimulating T cells, we observed a small T cell proliferation in response to the highest concentration of PD-MSCs when treated with IFNγ. It was noted that BM-MSCs were more immunomodulatory than PD-MSCs in this study. We therefore suggest that BM-MSCs may be better candidates for use in commercial regenerative or transplantation medicine.

EB1 is required for spindle symmetry in mammalian mitosis.

Most information about the roles of the adenomatous polyposis coli protein (APC) and its binding partner EB1 in mitotic cells has come from siRNA studies. These suggest functions in chromosomal segregation and spindle positioning whose loss might contribute to tumourigenesis in cancers initiated by APC mutation. However, siRNA-based approaches have drawbacks associated with the time taken to achieve significant expression knockdown and the pleiotropic effects of EB1 and APC gene knockdown. Here we describe the effects of microinjecting APC- or EB1- specific monoclonal antibodies and a dominant-negative EB1 protein fragment into mammalian mitotic cells. The phenotypes observed were consistent with the roles proposed for EB1 and APC in chromosomal segregation in previous work. However, EB1 antibody injection also revealed two novel mitotic phenotypes, anaphase-specific cortical blebbing and asymmetric spindle pole movement. The daughters of microinjected cells displayed inequalities in microtubule content, with the greatest differences seen in the products of mitoses that showed the severest asymmetry in spindle pole movement. Daughters that inherited the least mobile pole contained the fewest microtubules, consistent with a role for EB1 in processes that promote equality of astral microtubule function at both poles in a spindle. We propose that these novel phenotypes represent APC-independent roles for EB1 in spindle pole function and the regulation of cortical contractility in the later stages of mitosis. Our work confirms that EB1 and APC have important mitotic roles, the loss of which could contribute to CIN in colorectal tumour cells.

CopA:GFP localizes to putative Golgi equivalents in Aspergillus nidulans.

The Golgi complex is a main component of the eukaryotic secretory system and functions to modify nascent proteins sent from the endoplasmic reticulum. Ultrastructural studies of filamentous fungi have shown Golgi to be individual smooth membrane cisternae that are referred to as Golgi equivalents or dictyosomes. The Aspergillus nidulans copA gene encodes a homolog of mammalian coat protein (alpha-COP), a constituent of the Golgi-localized COPI vesicle coat. Here, the localization of A. nidulansalpha-COP was examined in live cells using the reporter green fluorescent protein (GFP). CopA:GFP localized to putative Golgi equivalents that were concentrated at hyphal tips. The localization was disrupted by the fungal metabolite brefeldin A. To investigate the significance of the microtubule cytoskeleton in the localization of putative Golgi equivalents, the copA:gfp fusion was expressed in a temperature-sensitive dynein mutant. In addition, a wild-type strain expressing copA:gfp was treated with the microtubule-disrupting drug nocodazole. The results suggest that the microtubule cytoskeleton is not the primary mechanism of localizing putative Golgi equivalents in A. nidulans.

Examination of actin and microtubule dependent APC localisations in living mammalian cells.

BACKGROUND: The trafficking of the adenomatous polyposis coli (APC) tumour suppressor protein in mammalian cells is a perennially controversial topic. Immunostaining evidence for an actin-associated APC localisation at intercellular junctions has been previously presented, though live imaging of mammalian junctional APC has not been documented. RESULTS: Using live imaging of transfected COS-7 cells we observed intercellular junction-associated pools of GFP-APC in addition to previously documented microtubule-associated GFP-APC and a variety of minor localisations. Although both microtubule and junction-associated populations could co-exist within individual cells, they differed in their subcellular location, dynamic behaviour and sensitivity to cytoskeletal poisons. GFP-APC deletion mutant analysis indicated that a protein truncated immediately after the APC armadillo repeat domain retained the ability to localise to adhesive membranes in transfected cells. Supporting this, we also observed junctional APC immunostaining in cultures of human colorectal cancer cell line that express truncated forms of APC. CONCLUSION: Our data indicate that APC can be found in two spatially separate populations at the cell periphery and these populations can co-exist in the same cell. The first localisation is highly dynamic and associated with microtubules near free edges and in cell vertices, while the second is comparatively static and is closely associated with actin at sites of cell-cell contact. Our imaging confirms that human GFP-APC possesses many of the localisations and behaviours previously seen by live imaging of Xenopus GFP-APC. However, we report the novel finding that GFP-APC puncta can remain associated with the ends of shrinking microtubules. Deletion analysis indicated that the N-terminal region of the APC protein mediated its junctional localisation, consistent with our observation that truncated APC proteins in colon cancer cell lines are still capable of localising to the cell cortex. This may have implications for the development of colorectal cancer.