# Assessing Aβ‐independent effects of Module 42 on immune function in vitro **Authors:** Ishita Ajith, Souvika Bakshi, Emma Mead, Opher Gileadi, Vittorio L. Katis, Paul E. Brennan, Katerina O. Gospodinova PMC · DOI: 10.1002/alz.71215 · Alzheimer's & Dementia · 2026-02-25 ## TL;DR This study explores how proteins in Module 42 affect immune functions in Alzheimer's disease, independent of amyloid beta. ## Contribution The study identifies Aβ-independent immune effects of Module 42 proteins in vitro. ## Key findings - MDK reduced phagocytosis while TMEFF2 ectodomain increased it. - Both MDK and TMEFF2 ectodomain promoted intracellular Ca2+ signaling. - TMEFF2 also suppressed Syk kinase activity without affecting cell viability. ## Abstract A deep multi‐omic analysis of post mortem human brains has identified a new co‐expression protein network – Module 42 (M42), strongly corelated with Alzheimer's disease (AD) pathology. M42 comprises 32 transmembrane and extracellular matrix (ECM)‐associated proteins, including the amyloid precursor protein (APP) and apolipoprotein E (apoE), and its members have been implicated in amyloid beta (Aβ) pathology. We systematically evaluated the Aβ‐independent effects of M42 on immune function in vitro. Recombinant M42 proteins were expressed and purified. Their effects on phagocytosis, intracellular signaling, and cell viability were assessed in human induced pluripotent stem cell‐derived macrophages. Treatment with Midkine (MDK) reduced phagocytosis, while treatment with the ectodomain of Transmembrane protein with EGF‐like and two follistatin‐like domains 2 (TMEFF2) had the opposite effect. Both proteins promoted intracellular Ca2+ signaling, and TMEFF2 also suppressed Syk kinase activity. No M42 proteins had an effect on viability. Our results suggest an additional role for M42 in AD via regulating immune functions. We tested M42 proteins for their effects on immune functions in vitro.Five proteins altered phagocytosis, and seven altered Ca2+ signaling.MDK and TMEFF2 ectodomain had an effect on both phagocytosis and Ca2+ signaling. We tested M42 proteins for their effects on immune functions in vitro. Five proteins altered phagocytosis, and seven altered Ca2+ signaling. MDK and TMEFF2 ectodomain had an effect on both phagocytosis and Ca2+ signaling. ## Linked entities - **Genes:** APP (amyloid beta precursor protein) [NCBI Gene 351], APOE (apolipoprotein E) [NCBI Gene 348], MDK (midkine) [NCBI Gene 4192], TMEFF2 (transmembrane protein with EGF like and two follistatin like domains 2) [NCBI Gene 23671] - **Proteins:** mdk.S (midkine S homeolog) - **Diseases:** Alzheimer's disease (MONDO:0004975) ## Full-text entities - **Genes:** Mdk (midkine) [NCBI Gene 17242] {aka MK, Mek}, BMP4 (bone morphogenetic protein 4) [NCBI Gene 652] {aka BMP2B, BMP2B1, MCOPS6, OFC11, ZYME}, SIRPA (signal regulatory protein alpha) [NCBI Gene 140885] {aka BIT, CD172A, MFR, MYD-1, MYD1, P84}, TREM2 (triggering receptor expressed on myeloid cells 2) [NCBI Gene 54209] {aka AD17, PLOSL2, TREM-2, Trem2a, Trem2b, Trem2c}, LRP1 (LDL receptor related protein 1) [NCBI Gene 4035] {aka A2MR, APOER, APR, CD91, DDH3, IGFBP-3R}, TMEFF2 (transmembrane protein with EGF like and two follistatin like domains 2) [NCBI Gene 23671] {aka CT120.2, HPP1, TENB2, TPEF, TR, TR-2}, CTHRC1 (collagen triple helix repeat containing 1) [NCBI Gene 115908], MAPT (microtubule associated protein tau) [NCBI Gene 4137] {aka DDPAC, FTD1, FTDP-17, MAPTL, MSTD, MTBT1}, FRZB (frizzled related protein) [NCBI Gene 2487] {aka FRE, FRITZ, FRP-3, FRZB-1, FRZB-PEN, FRZB1}, QPRT (quinolinate phosphoribosyltransferase) [NCBI Gene 23475] {aka HEL-S-90n, QPRTase}, EGF (epidermal growth factor) [NCBI Gene 1950] {aka HOMG4, URG}, Tmeff2 (transmembrane protein with EGF-like and two follistatin-like domains 2) [NCBI Gene 56363] {aka 4832418D20Rik, 7630402F16Rik, TR-2}, VEGFA (vascular endothelial growth factor A) [NCBI Gene 7422] {aka L-VEGF, MVCD1, VEGF, VPF}, NTN1 (netrin 1) [NCBI Gene 9423] {aka MRMV4, NET1, NTN1L}, Ntn1 (netrin 1) [NCBI Gene 18208] {aka Netrin-1}, Spon1 (spondin 1, (f-spondin) extracellular matrix protein) [NCBI Gene 233744] {aka D330035F22Rik, FSP}, KITLG (KIT ligand) [NCBI Gene 4254] {aka DCUA, DFNA69, FPH2, FPHH, KL-1, Kitl}, APOE (apolipoprotein E) [NCBI Gene 348] {aka AD2, APO-E, ApoE4, LDLCQ5, LPG}, SMOC1 (SPARC related modular calcium binding 1) [NCBI Gene 64093] {aka OAS}, OLFML3 (olfactomedin like 3) [NCBI Gene 56944] {aka HNOEL-iso, OLF44}, SFRP1 (secreted frizzled related protein 1) [NCBI Gene 6422] {aka FRP, FRP-1, FRP1, FrzA, SARP2}, DAG1 (dystroglycan 1) [NCBI Gene 1605] {aka 156DAG, A3a, AGRNR, DAG, LGMDR16, MDDGA9}, App (amyloid beta precursor protein) [NCBI Gene 11820] {aka Abeta, Abpp, Adap, Ag, Cvap, E030013M08Rik}, TREM2 [NCBI Gene 608965], SYK (spleen associated tyrosine kinase) [NCBI Gene 6850] {aka IMD82, p72-Syk}, Apoe (apolipoprotein E) [NCBI Gene 11816] {aka Apo-E}, SYK (spleen associated tyrosine kinase) [NCBI Gene 484196], GPC5 (glypican 5) [NCBI Gene 2262], RENBP (renin binding protein) [NCBI Gene 5973] {aka RBP, RNBP}, SPON1 (spondin 1) [NCBI Gene 10418] {aka VSGP/F-spondin, f-spondin}, PTN (pleiotrophin) [NCBI Gene 5764] {aka HARP, HB-GAM, HBBM, HBGF-8, HBGF8, HBNF}, MRC1 (mannose receptor C-type 1) [NCBI Gene 4360] {aka CD206, CLEC13D, CLEC13DL, MMR, MRC1L1, bA541I19.1}, NXPH1 (neurexophilin 1) [NCBI Gene 30010] {aka NPH1, Nbla00697}, CSF1 (colony stimulating factor 1) [NCBI Gene 1435] {aka CSF-1, MCSF, PG-M-CSF}, SDC4 (syndecan 4) [NCBI Gene 6385] {aka SYND4}, Nfkb1 (nuclear factor of kappa light polypeptide gene enhancer in B cells 1, p105) [NCBI Gene 18033] {aka NF-KB1, NF-kappaB, NF-kappaB1, p105, p50, p50/p105}, Ptn (pleiotrophin) [NCBI Gene 19242] {aka HARP, HB-GAM, HBBM, HBBN, HBGF-8, HBNF}, IL3 (interleukin 3) [NCBI Gene 3562] {aka IL-3, MCGF, MULTI-CSF}, Sfrp1 (secreted frizzled-related protein 1) [NCBI Gene 20377] {aka 2210415K03Rik, sFRP-1}, BDH2 (3-hydroxybutyrate dehydrogenase 2) [NCBI Gene 56898] {aka DHRS6, EFA6R, PRO20933, SDR15C1, UCPA-OR, UNQ6308}, MERTK (MER proto-oncogene, tyrosine kinase) [NCBI Gene 10461] {aka MER, RP38, Tyro12, c-Eyk, c-mer}, HTRA1 (HtrA serine peptidase 1) [NCBI Gene 5654] {aka ARMD7, CADASIL2, CARASIL, CARASIL2, HtrA, L56}, COL11A1 (collagen type XI alpha 1 chain) [NCBI Gene 1301] {aka CO11A1, COLL6, DFNA37, STL2}, MYB (MYB proto-oncogene, transcription factor) [NCBI Gene 4602] {aka Cmyb, c-myb, c-myb_CDS, efg}, APP (amyloid beta precursor protein) [NCBI Gene 351] {aka AAA, ABETA, ABPP, AD1, APPI, CTFgamma}, MDK (midkine) [NCBI Gene 4192] {aka ARAP, MK, NEGF2}, FLT1 (fms related receptor tyrosine kinase 1) [NCBI Gene 2321] {aka FLT, FLT-1, VEGFR-1, VEGFR1} - **Diseases:** memory loss (MESH:D008569), amyloid plaques (MESH:D058225), cognitive decline (MESH:D003072), depression (MESH:D003866), hypoxic (MESH:D002534), autoimmune diseases (MESH:D001327), amyloid (MESH:C000718787), Dementia (MESH:D003704), cancer (MESH:D009369), neurovascular dysfunction (MESH:D013901), infection (MESH:D007239), neurotoxicity (MESH:D020258), AD (MESH:D000544), neuropsychiatric symptoms (MESH:D001523), neuroinflammation (MESH:D000090862), anxiety (MESH:D001007), CNS disorders (MESH:D002493), hallucinations (MESH:D006212), inflammatory (MESH:D007249), RESEARCH (MESH:D014947), neurodegenerative disorder (MESH:D019636), delusions (MESH:D063726), sleep disturbances (MESH:D012893) - **Chemicals:** heparin (MESH:D006493), H (MESH:D006859), SDS (MESH:D012967), acetic acid (MESH:D019342), Calcium (MESH:D002118), GlutaMAX (MESH:C054122), sodium butyrate (MESH:D020148), CO2 (MESH:D002245), water (MESH:D014867), sepharose (MESH:D012685), paraformaldehyde (MESH:C003043), F12 (MESH:C007782), EDTA (MESH:D004492), polyethylenimine (MESH:D011094), His (MESH:D006639), Ni (MESH:D009532), DPBS (MESH:C012939), TALON (MESH:C013418), phosphatidylserine (MESH:D010718), streptomycin (MESH:D013307), 2-mercaptoethanol (MESH:D008623), lecanemab (MESH:C000612089), phenol red (MESH:D010637), Histamine (MESH:D006632), Cytochalasin D (MESH:D015638), heparan sulfate (MESH:D006497), metal (MESH:D008670), CytoD (-), HEPES (MESH:D006531), penicillin (MESH:D010406), glycosaminoglycan (MESH:D006025) - **Species:** Mus musculus (house mouse, species) [taxon 10090], Homo sapiens (human, species) [taxon 9606], Escherichia coli (E. coli, species) [taxon 562] - **Mutations:** (I) at 3, R47H - **Cell lines:** CRL-2266 — Homo sapiens (Human), Beta thalassemia, Transformed cell line (CVCL_BT13), S. frugiperda Sf9 — Spodoptera frugiperda (Fall armyworm), Spontaneously immortalized cell line (CVCL_Z459), Expi293F — Homo sapiens (Human), Transformed cell line (CVCL_D615), HiPSC — Homo sapiens (Human), Induced pluripotent stem cell (CVCL_C888), Sf9 — Spodoptera frugiperda (Fall armyworm), Spontaneously immortalized cell line (CVCL_0549), SH-SY5Y — Homo sapiens (Human), Neuroblastoma, Cancer cell line (CVCL_0019), hiPSC — Gallus gallus (Chicken), Induced pluripotent stem cell (CVCL_YE48), BIONi010-C — Homo sapiens (Human), Induced pluripotent stem cell (CVCL_1E68), HEK293 — Homo sapiens (Human), Transformed cell line (CVCL_0045) ## Full text _Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC12933249/full.md ## Figures 4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12933249/full.md ## References 32 references — full list in the complete paper: https://tomesphere.com/paper/PMC12933249/full.md --- Source: https://tomesphere.com/paper/PMC12933249