Biological heterogeneity in idiopathic pulmonary arterial hypertension identified through unsupervised transcriptomic profiling of whole blood

Idiopathic pulmonary arterial hypertension (IPAH) is a rare but fatal disease diagnosed by right heart catheterisation and the exclusion of other forms of pulmonary arterial hypertension, producing a heterogeneous population with varied treatment response. Here we show unsupervised machine learning identification of three major patient subgroups that account for 92% of the cohort, each with unique whole blood transcriptomic and clinical feature signatures. These subgroups are associated with poor, moderate, and good prognosis. The poor prognosis subgroup is associated with upregulation of the ALAS2 and downregulation of several immunoglobulin genes, while the good prognosis subgroup is defined by upregulation of the bone morphogenetic protein signalling regulator NOG, and the C/C variant of HLA-DPA1/DPB1 (independently associated with survival). These findings independently validated provide evidence for the existence of 3 major subgroups (endophenotypes) within the IPAH classification, could improve risk stratification and provide molecular insights into the pathogenesis of IPAH

Zn₇O₂(RCOO)₁₀ Clusters and Nitro Aromatic Linkers in a Porous Metal–Organic Framework

A new metal–organic framework, CALF-22 comprising Zn₇O₂(COO)₁₀ secondary building units and 2-nitro-1,4-benzenedicarboxylate, is reported. The porosity and gas adsorption of N₂, H₂, CO₂, and CH₄ are studied, and CALF-22 has a surface area in excess of 1000 m²/g. The stability of the larger zinc cluster and the effect of the nitro group on gas sorption are also studied

Enhancing Water Stability of Metal–Organic Frameworks via Phosphonate Monoester Linkers

A new porous metal–organic framework (MOF), barium tetraethyl-1,3,6,8-pyrenetetraphosphonate (CALF-25), which contains a new phosphonate monoester ligand, was synthesized through a hydrothermal method. The MOF is a three-dimensional structure containing 4.6 Å × 3.9 Å rectangular one-dimensional pores lined with the ethyl ester groups from the ligand. The presence of the ethyl ester groups makes the pores hydrophobic in nature, as determined by the low heats of adsorption of CH₄, CO₂, and H₂O (14.5, 23.9, and 45 kJ mol^–1, respectively) despite the polar and acidic barium phosphonate ester backbone. The ethyl ester groups within the pores also protect CALF-25 from decomposition by water vapor, with crystallinity and porosity being retained after exposure to harsh humid conditions (90% relative humidity at 353 K). The use of phosphonate esters as linkers for the construction of MOFs provides a method to protect hydrolytically susceptible coordination backbones through kinetic blocking

'Insecta exotica'

A new porous metal–organic framework (MOF), barium tetraethyl-1,3,6,8-pyrenetetraphosphonate (CALF-25), which contains a new phosphonate monoester ligand, was synthesized through a hydrothermal method. The MOF is a three-dimensional structure containing 4.6 Å × 3.9 Å rectangular one-dimensional pores lined with the ethyl ester groups from the ligand. The presence of the ethyl ester groups makes the pores hydrophobic in nature, as determined by the low heats of adsorption of CH₄, CO₂, and H₂O (14.5, 23.9, and 45 kJ mol^–1, respectively) despite the polar and acidic barium phosphonate ester backbone. The ethyl ester groups within the pores also protect CALF-25 from decomposition by water vapor, with crystallinity and porosity being retained after exposure to harsh humid conditions (90% relative humidity at 353 K). The use of phosphonate esters as linkers for the construction of MOFs provides a method to protect hydrolytically susceptible coordination backbones through kinetic blocking

Epigenetic control of female puberty

The timing of puberty is controlled by many genes. The elements coordinating this process have not, however, been identified. Here we show that an epigenetic mechanism of transcriptional repression times the initiation of female puberty in rats. We identify silencers of the Polycomb group (PcG) as major contributors to this mechanism, and show that PcG proteins repress Kiss1, a puberty-activating gene. Hypothalamic expression of two key PcG genes, Eed and Cbx7, decreases and methylation of their promoters increases preceding puberty. Inhibiting DNA methylation blocks both events and results in pubertal failure. The pubertal increase in Kiss1 is accompanied by EED loss from the Kiss1 promoter and enrichment of histone H3 modifications associated with gene activation. Preventing the eviction of EED from the Kiss1 promoter disrupts pulsatile GnRH release, delays puberty, and compromises fecundity. Our results identify epigenetic silencing as a novel mechanism underlying the neuroendocrine control of female puberty