O007 Pancreas and islet transplantation in the United Kingdom during the COVID-19 era

Introduction

Methods

Results

Conclusion

Take-home message

BMP receptor blockade overcomes extrinsic inhibition of remyelination and restores neurovascular homeostasis

Extrinsic inhibitors at sites of blood–brain barrier disruption and neurovascular damage contribute to remyelination failure in neurological diseases. However, therapies to overcome the extrinsic inhibition of remyelination are not widely available and the dynamics of glial progenitor niche remodelling at sites of neurovascular dysfunction are largely unknown. By integrating in vivo two-photon imaging co-registered with electron microscopy and transcriptomics in chronic neuroinflammatory lesions, we found that oligodendrocyte precursor cells clustered perivascularly at sites of limited remyelination with deposition of fibrinogen, a blood coagulation factor abundantly deposited in multiple sclerosis lesions. By developing a screen (OPC-X-screen) to identify compounds that promote remyelination in the presence of extrinsic inhibitors, we showed that known promyelinating drugs did not rescue the extrinsic inhibition of remyelination by fibrinogen. In contrast, bone morphogenetic protein type I receptor blockade rescued the inhibitory fibrinogen effects and restored a promyelinating progenitor niche by promoting myelinating oligodendrocytes, while suppressing astrocyte cell fate, with potent therapeutic effects in chronic models of multiple sclerosis. Thus, abortive oligodendrocyte precursor cell differentiation by fibrinogen is refractory to known promyelinating compounds, suggesting that blockade of the bone morphogenetic protein signalling pathway may enhance remyelinating efficacy by overcoming extrinsic inhibition in neuroinflammatory lesions with vascular damage.

Transcriptomic analysis of pulmonary artery smooth muscle cells identifies new potential therapeutic targets for idiopathic pulmonary arterial hypertension

BACKGROUND AND PURPOSE

Pulmonary arterial hypertension (PAH, type 1 pulmonary hypertension) has a 3-year survival of ~50% and is in need of new, effective therapies. In PAH, remodelling of the pulmonary artery (PA) increases pulmonary vascular resistance and can result in right heart dysfunction and failure. Genetic mutations can cause PAH but it can also be idiopathic (IPAH). Enhanced contractility and proliferation of PA smooth muscle cells (PASMCs) are key contributors to the pathophysiology of PAH, but the underlying mechanisms are not well understood.

EXPERIMENTAL APPROACH

We utilized RNA-sequencing (RNA-seq) of IPAH and control patient-derived PASMCs as an unbiased approach to define differentially expressed (DE) genes that may identify new biology and potential therapeutic targets.

KEY RESULTS

Analysis of DE genes for shared gene pathways revealed increases in genes involved in cell proliferation and mitosis and decreases in a variety of gene sets, including response to cytokine signalling. ADGRG6/GPR126, an adhesion G protein-coupled receptor (GPCR), was increased in IPAH-PASMCs compared to control-PASMCs. Increased expression of this GPCR in control-PASMCs decreased their proliferation; siRNA knockdown of ADGRG6/GPR126 in IPAH-PASMCs tended to increase proliferation.

CONCLUSION AND IMPLICATIONS

These data provide insights regarding the expression of current and experimental PAH drug targets, GPCRs and GPCR-related genes as potentially new therapeutic targets in PAH-PASMCs. Overall, the findings identify genes and pathways that may contribute to IPAH-PASMC function and suggest that ADGRG6/GPR126 is a novel therapeutic target for IPAH.

Transcriptomic profiles reveal differences between the right and left ventricle in normoxia and hypoxia

Chronic hypoxia from diseases in the lung, such as pulmonary hypertension, pulmonary fibrosis, and chronic obstructive pulmonary disease, can increase pulmonary vascular resistance, resulting in hypertrophy and dysfunction of the right ventricle (RV). In order to obtain insight into RV biology and perhaps uncover potentially novel therapeutic approaches for RV dysfunction, we performed RNA-sequencing (RNA-seq) of RV and LV tissue from rats in normal ambient conditions or subjected to hypoxia (10% O2 ) for 2 weeks. Gene ontology and pathway analysis of the RV and LV revealed multiple transcriptomic differences, in particular increased expression in the RV of genes related to immune function in both normoxia and hypoxia. Immune cell profiling by flow cytometry of cardiac digests revealed that in both conditions, the RV had a larger percentage than the LV of double-positive CD45+ /CD11b/c+ cells (which are predominantly macrophages and dendritic cells). Analysis of gene expression changes under hypoxic conditions identified multiple pathways that may contribute to hypoxia-induced changes in the RV, including increased expression of genes related to cell mitosis/proliferation and decreased expression of genes related to metabolic processes. Together, the findings indicate that the RV differs from the LV with respect to content of immune cells and expression of certain genes, thus suggesting the two ventricles differ in aspects of pathophysiology and in potential therapeutic targets for RV dysfunction.

Establishment of an in vitro plantlet regeneration protocol for unique varieties of brinjal (Solanum melongena L.) var. Mattu Gulla and Perampalli Gulla

Brinjal (Solanum melongena L.) var. Mattu Gulla (MG) and var. Perampalli Gulla (PG) are unique varieties with distinct flavour cultivated in Udupi, Karnataka State, and are exposed to several biotic and abiotic stresses. An efficient and reproducible in vitro regeneration method is required to expedite the manipulation of these brinjal varieties to cope up with stress by tissue culture and gene transfer methods. The present study, reports a rapid and efficient in vitro regeneration protocol for these two varieties. The in vitro growth response was studied on Murashige and Skoog (MS) medium supplemented with 2, 4-D, BAP and IAA, and the plantlets were regenerated efficiently from callus cultures of leaf, cotyledon and hypocotyl explants. Among the three explants, the hypocotyl explants were found to have better callus induction and multiple shoot regeneration. High frequency of shoot initiation was achieved from hypocotyl derived calluses in MS media with 2.0 mg/L BAP and 0.5 mg/L IAA in MG and PG. Efficient and rapid shoot proliferation, and elongation were noted in MS medium with 1.0 mg/L BAP and 0.3 mg/L GA3. The in vitro regenerated shoots produced healthy roots when they were cultured on MS medium supplemented with 0.5 mg/L IBA. A significant difference was observed in percentage of callus induction, number of shoots per callus, shoot elongation and number of hardened plantlets of MG and PG. MG showed maximum response in all stages of culture than PG. Hardening of plantlets in tissue culture was achieved in three weeks. The hardened plantlets were grown in pots for further acclimatization in green house and finally transplanted to experimental garden where they developed into flowering plants and produced mature fruits with viable seeds.

Effect of factory effluents on physiological and biochemical contents of Gossypium hirsutum l

The effect of sago and sugar factory effluents was studied on Gossypium hirsutum L. var. MCU 5 and MCU 11. Plants were irrigated with 0, 25, 50, 75 and 100% of effluents of both factories. At lower concentration (25%) of sugar factory effluents had stimulatory effect on all biochemical contents observed. Moreover, all concentration of sago factory effluents were found to have inhibitory effect on all biochemical contents except proline content which increased with increasing concentration of both the effluents. Plants growing on adjacent to sago and sugar factories or they irrigated with such type of polluted water, may accumulate the heavy metals found in both the effluents, at higher levels in plant products and if consumed may have similar effect on living organisms.