Background: The allogeneic islets transplantation is an ideal therapeutic strategy for patients with diabetes mellitus. However, it has been difficult to induce immunological tolerance against islets grafts. The CD4+CD25+ regulatory T-cells (Treg) play a role in suppressing T-cell activation. Thus, we evaluated whether Treg can regulate donor-specific T-cell tolerance that received allogeneic islets into the hepatic parenchyma (ITxHP) along with Treg.
Methods: C3H/He mice were used as donors; and streptozotocin-induced diabetic BALB/c mice were recipients. The protocol included three groups: Group A recipients received only 300 IE islets; Group B was given 300 IE islets and whole splenocytes; Group C was given 300 IE islets and Treg purified from peripheral lymph nodes.
Results: For all mice in Groups A and B, the fasting blood sugar exceeded 250mg/dl and graft rejection was observed. GVHD was observed earlier in Group B than in Group A. In contrast graft survival exceeded 30 days for two mice in Group C (50%, mean POD 28.5 +/- 24.0, P<0.05). Mixed lymphocyte reaction showed that T-cells from tolerant mice had very weak responses against spleen cells from C3H mice.
Conclusions: The simultaneous ITxHP with CD4+CD25+ T-cells administration prolonged islet graft survivals and induced donor-specific hyporesponsiveness.
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http://dx.doi.org/10.2152/jmi.51.178 | DOI Listing |
Biomedicines
December 2024
Department of Endocrinology, Second Affiliated Hospital of Air Force Military Medical University, Xi'an 710038, China.
: This study aims to investigate the effects of 4-methylumbelliferone (4-MU) on islet morphology, cell phenotype and function, and to explore possible mechanisms of β cell regeneration. : The Type 1 diabetes (T1D) model was induced by continuous dose injection of streptozotocin (STZ), and mice were treated with 4-MU for 3 weeks. Plasma insulin level, islet cell phenotype and immune infiltration were determined by IPGTT, ELISA, HE and immunofluorescence.
View Article and Find Full Text PDFInt J Endocrinol
December 2024
Department of Endocrinology and Metabolism, The First Affiliated Hospital of Shantou University Medical College, Shantou, China.
This study aimed to verify the effect of angiotensin (1-7) on improving islet function and further explore the signaling pathway that may be involved in this improvement. It also aimed to explore the effects of angiotensin (1-7) on blood glucose levels, islet function, and morphological changes in db/db mice and its potential signal pathway. Forty-five db/db mice were divided randomly into a model control group and different doses of angiotensin (1-7) intervention groups (0, 150, 300, and 600 g/kg/d), while seven db/m mice were assigned as the normal control group.
View Article and Find Full Text PDFBiol Trace Elem Res
December 2024
Endocrine and Metabolism Department, Lanzhou University Second Hospital, Chengguan District, No. 82, CuyingmenLanzhou, 730000, Gansu, China.
Nickel has an impact on human health, especially in the context of the new energy industries. Nickel's influence on glycemia remains controversial, and the effects and mechanisms of nickel on islet function still need further exploration. MIN6 cells were treated with different concentrations of nickel sulfate (NiSO) (0, 75, 150, and 300 µg/mL) for different durations (0, 12, 24, and 48 h).
View Article and Find Full Text PDFCardiovasc Hematol Disord Drug Targets
January 2025
Laboratory of Biology and Health, Neurosciences, Neuro-immunology and Behaviour Unit, Faculty of Science, Ibn Tofail University, Kenitra, Morocco.
Objective: This study aimed to assess the hypoglycemic effects of methanolic extract of in male Wistar rats that were diabetic due to streptozotocin.
Methods: Experimental diabetes was initially induced in male Wistar rats by intravenous injection of streptozotocin (55 mg/kg). Subsequently, the rats received daily oral administration of the methanolic extract of (250 mg/kg) and the standard drug metformin (300 mg/kg) for 28 days.
J Biol Chem
December 2024
Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee, USA. Electronic address:
MAFA and MAFB are related basic-leucine-zipper domain-containing transcription factors which have important overlapping and distinct regulatory roles in a variety of cellular contexts, including hormone production in pancreatic islet cells. Here, we first examined how mutating conserved MAF protein-DNA contact sites obtained from X-ray crystal structure analysis impacted their DNA-binding and Insulin enhancer-driven activity. While most of these interactions were essential and their disruption severely compromised activity, we identified that regions outside of these contact sites also contributed to transcriptional activity.
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