Gerónimo Maldonado-Martínez

Dr. Gerónimo Maldonado-Martínez

Comprehensive Cancer Center, San Juan, Puerto Rico, Puerto Rico
orcid
Viequense. Soliloquy expert. Impromptu advocate. Gummy candi...

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 December 2018 in Blood
Verified
Journal Article
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JMJessica Morales-Ortíz
Jessica Morales-Ortíz
VDVictoria Deal
Victoria Deal
FRFiorella Reyes
Fiorella Reyes
Gerónimo Maldonado-MartínezGerónimo Maldonado-Martínez
Gerónimo Maldonado-Martínez
NLNahomy Ledesma
Nahomy Ledesma
A. Valance WashingtonA. Valance Washington
A. Valance Washington
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) affect >200 000 individuals yearly with a 40% mortality rate. Although platelets are implicated in the progression of ALI/ARDS, their exact role remains undefined. Triggering receptor expressed in myeloid cells (TREM)–like transcript 1 (TLT-1) is found on platelets, binds fibrinogen, and mediates clot formation. We hypothesized that platelets use TLT-1 to manage the progression of ALI/ARDS. Here we retrospectively measure plasma levels of soluble TLT-1 (sTLT-1) from the ARDS Network clinical trial and show that patients whose sTLT-1 levels were >1200 pg/mL had nearly twice the mortality risk as those with <1200 pg/mL (P < .001). After correcting for confounding factors such as creatinine levels, Acute Physiology And Chronic Health Evaluation III scores, age, platelet counts, and ventilation volume, sTLT-1 remains significant, suggesting that sTLT-1 is an independent prognostic factor (P < .0001). These data point to a role for TLT-1 during the progression of ALI/ARDS. We use a murine lipopolysaccharide-induced ALI model and demonstrate increased alveolar bleeding, aberrant neutrophil transmigration and accumulation associated with decreased fibrinogen deposition, and increased pulmonary tissue damage in the absence of TLT-1. The loss of TLT-1 resulted in an increased proportion of platelet-neutrophil conjugates (43.73 ± 24.75% vs 8.92 ± 2.4% in wild-type mice), which correlated with increased neutrophil death. Infusion of sTLT-1 restores normal fibrinogen deposition and reduces pulmonary hemorrhage by 40% (P ≤ .001) and tissue damage by 25% (P ≤ .001) in vivo. Our findings suggest that TLT-1 uses fibrinogen to govern the transition between inflammation and hemostasis and facilitate controlled leukocyte transmigration during the progression of ARDS.

13 November 2018 in Oncotarget
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Journal Article
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TRTiffany J. Rios-Fuller
Tiffany J. Rios-Fuller
GOGabriela Ortiz-Soto
Gabriela Ortiz-Soto
MLMercedes Lacourt-Ventura
Mercedes Lacourt-Ventura
Gerónimo Maldonado-MartínezGerónimo Maldonado-Martínez
Gerónimo Maldonado-Martínez
LCLuis A. Cubano
Luis A. Cubano
Michelle M. Martinez-MontemayorMichelle M. Martinez-Montemayor
Michelle M. Martinez-Montemayor
Ganoderma lucidum extract (GLE) impairs breast cancer stem cells by targeting the STAT3 pathway Ganoderma lucidum extract (GLE) impairs breast cancer stem cells by targeting the STAT3 pathway

22 July 2015 in BMC Complementary and Alternative Medicine
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JGJannette Gavillán-Suárez
Jannette Gavillán-Suárez
AAAlexandra Aguilar-Perez
Alexandra Aguilar-Perez
NRNatalie Rivera-Ortiz
Natalie Rivera-Ortiz
KRKarla Rodríguez-Tirado
Karla Rodríguez-Tirado
WFWanda Figueroa-Cuilan
Wanda Figueroa-Cuilan
Michelle M. Martinez-MontemayorMichelle M. Martinez-Montemayor
Michelle M. Martinez-Montemayor
The increasing numbers of people who use plant-based remedies as alternative or complementary medicine call for the validation of less known herbal formulations used to treat their ailments. Since Puerto Rico has the highest rate of Type 2 diabetes within all the states and territories of the United States, and Puerto Ricans commonly use plants as diabetes adjuvants, it is important to study the plants’ physiological effects, and identify their bioactive compounds to understand their role in modulation of blood glucose levels. We present the phytochemical profiles and hypoglycemic effects of Tapeinochilus ananassae, Costus speciosus and Syzygium jambos. Phytochemicals in methanolic and aqueous extracts were analyzed by thin layer chromatography (TLC). Alkaloids (Bromocresol green, λ = 470 nm), flavonoids (AlCl3, λ = 415 nm), saponins (DNS, λ = 760 nm), tannins (FeCl3/K4Fe(CN)6, λ = 395 nm) and phenolics (Folin-Ciocalteau, λ = 765 nm) were quantified. Male C57BLKS/J (db/db) and C57BL/J (ob/ob) genetically obese mice were orally gavaged with aqueous extracts of lyophilized plant decoctions for 10wks. Our results show that T. ananassae had significantly greater amounts of flavonoids and tannins, while S. jambos showed the greatest concentration of phenolics and C. speciosus exhibited higher amounts of alkaloids. C57BLKS/J db/db treated with plant extracts show better glucose modulation when the extracts are administered in complement with an insulin injection. Finally, C57BL/J ob/ob mice on T. ananassae and S. jambos treatments show better blood glucose modulation over time. These results document for the first time the chemical profile of T. ananassae and provide evidence for a potential anti-diabetic efficacy of T. ananassae and S. jambos.

1 January 2016 in Journal of Cancer
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Journal Article
Open access
Ivette J Suarez-ArroyoIvette J Suarez-Arroyo
Ivette J Suarez-Arroyo
TRTiffany J. Rios-Fuller
Tiffany J. Rios-Fuller
YFYismeilin R. Feliz-Mosquea
Yismeilin R. Feliz-Mosquea
MLMercedes Lacourt-Ventura
Mercedes Lacourt-Ventura
DLDaniel J. Leal-Alviarez
Daniel J. Leal-Alviarez
Michelle M. Martinez-MontemayorMichelle M. Martinez-Montemayor
Michelle M. Martinez-Montemayor
The high incidence of resistance to Tyrosine Kinase Inhibitors (TKIs) targeted against EGFR and downstream pathways has increased the necessity to identify agents that may be combined with these therapies to provide a sustained response for breast cancer patients. Here, we investigate the therapeutic potential of Ganoderma lucidum extract (GLE) in breast cancer, focusing on the regulation of the EGFR signaling cascade when treated with the EGFR TKI, Erlotinib. SUM-149, or intrinsic Erlotinib resistant MDA-MB-231 cells, and a successfully developed Erlotinib resistant cell line, rSUM-149 were treated with increasing concentrations of Erlotinib, GLE, or their combination (Erlotinib/GLE) for 72h. Treatment effects were tested on cell viability, cell proliferation, cell migration and invasion. To determine tumor progression, severe combined immunodeficient mice were injected with SUM-149 cells and then treated with Erlotinib/GLE or Erlotinib for 13 weeks. We assessed the protein expression of ERK1/2 and AKT in in vitro and in vivo models. Our results show that GLE synergizes with Erlotinib to sensitize SUM-149 cells to drug treatment, and overcomes intrinsic and developed Erlotinib resistance. Also, Erlotinib/GLE decreases SUM-149 cell viability, proliferation, migration and invasion. GLE increases Erlotinib sensitivity by inactivating AKT and ERK signaling pathways in our models. We conclude that a combinatorial therapeutic approach may be the best way to increase prognosis in breast cancer patients with EGFR overexpressing tumors.

1 January 2016
Verified
Journal Article
Closed access
Ivette J Suarez-ArroyoIvette J Suarez-Arroyo
Ivette J Suarez-Arroyo
YFYismeilin R. Feliz-Mosquea
Yismeilin R. Feliz-Mosquea
JPJuliana Perez-Laspiur
Juliana Perez-Laspiur
RARezina Arju
Rezina Arju
SGShah Giashuddin
Shah Giashuddin
Michelle M. Martinez-MontemayorMichelle M. Martinez-Montemayor
Michelle M. Martinez-Montemayor

1 April 2016 in Journal of Biological Chemistry
Verified
Journal Article
Open access
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MMMiguel Méndez-González
Miguel Méndez-González
YKYuriy V. Kucheryavykh
Yuriy V. Kucheryavykh
AZAstrid Zayas-Santiago
Astrid Zayas-Santiago
WVWanda Vélez-Carrasco
Wanda Vélez-Carrasco
Gerónimo Maldonado-MartínezGerónimo Maldonado-Martínez
Gerónimo Maldonado-Martínez
MEMisty J. Eaton
Misty J. Eaton
The KCNJ10 gene encoding Kir4.1 contains numerous SNPs whose molecular effects remain unknown. We investigated the functional consequences of uncharacterized SNPs (Q212R, L166Q, and G83V) on homomeric (Kir4.1) and heteromeric (Kir4.1-Kir5.1) channel function. We compared these with previously characterized EAST/SeSAME mutants (G77R and A167V) in kidney-derived tsA201 cells and in glial cell-derived C6 glioma cells. The membrane potentials of tsA201 cells expressing G77R and G83V were significantly depolarized as compared with WTKir4.1, whereas cells expressing Q212R, L166Q, and A167V were less affected. Furthermore, macroscopic currents from cells expressing WTKir4.1 and Q212R channels did not differ, whereas currents from cells expressing L166Q, G83V, G77R, and A167V were reduced. Unexpectedly, L166Q current responses were rescued when co-expressed with Kir5.1. In addition, we observed notable differences in channel activity between C6 glioma cells and tsA201 cells expressing L166Q and A167V, suggesting that there are underlying differences between cell lines in terms of Kir4.1 protein synthesis, stability, or expression at the surface. Finally, we determined spermine (SPM) sensitivity of these uncharacterized SNPs and found that Q212R-containing channels displayed reduced block by 1 μm SPM. At 100 μm SPM, the block was equal to or greater than WT, suggesting that the greater driving force of SPM allowed achievement of steady state. In contrast, L166Q-Kir5.1 channels achieved a higher block than WT, suggesting a more stable interaction of SPM in the deep pore cavity. Overall, our data suggest that G83V, L166Q, and Q212R residues play a pivotal role in controlling Kir4.1 channel function.